There is an old adage that active people seek active lifestyles, and that Darwin’s theory of natural selection applies to exercise. It has always been hard to truly tell if exercise is associated with improved health, or whether healthy people are naturally drawn to more active tasks. For those who are still not convinced about the benefits of exercise as part of a healthier lifestyle, it has been a tough argument to refute.

Back in the mid 1980’s evidence started to mount that if people engaged in exercise over periods of time, they may reduce their chances of acquiring certain types of diseases, such as heart disease, and other cardiovascular disorders. Research also pointed out that regular exercise may reduce premature mortality, thus assisting persons in living longer through maintaining a healthy lifestyle. These results were independent of their gender, places where they lived, their body weight, and other types of medical conditions, such as blood pressure status, and family history of a particular disease.

The concept of exercise in the past ten years has moved into a new realm – that of looking at the the effects of exercise on special populations. Special populations groups are persons with diseases, and other metabolic conditions that are usually under the care of physicians or other health care personnel.

Exercise and Special Populations – Pregnancy

One of the first special population groups to be studied directly under exercise conditions were pregnant women. For many years previously, obstetricians felt that exercise may harm the developing baby and cause unnecessary problems during pregnancy and delivery. This was in the absence of any concrete scientific information.

Over the past 15 years there have been many research reports on the effects of exercise on pregnant women, from their response to different exercise programs, to their birth outcomes. The results have been impressive, in that most women seem to fair better physically when performing regular moderate exercise regimens than those who remain sedentary over the course of their pregnancies. Although there is still a lag between information presented in journals and articles, and what many physicians recommend, the consensus today is that an active lifestyle with this group may be better for both mom and baby.

Current reports highlight the need for pregnant women to perform low-impact aerobic exercise that will help with metabolism after the second trimester, and not injure joints that are being softened up in the third trimester for delivery. Walking 1-2 times per day after meals seems to help burn excess energy, and aerobic exercises such as the UBE (Upper Body Ergometer), and Aqua-Jogging^TM in a pool with a special buoyancy vest are two very good ways to stay in shape without excess stress to joints. They can be performed using basic fitness guidelines of 20-30 minutes, 3-4 days per week, keeping the heart rate in the training zone. Your physician should be kept abreast of your fitness program, and any unusual situations should be discussed with him/her.

Exercise and Seniors

Another special population group receiving attention in the medical literature and lay person press is the senior age group (55 years and over). For most of this century we were told that gaining weight, losing strength, developing disease, and losing energy were simply a part of the natural aging process. With the growing number of studies looking at exercise and life span, body fat loss, increasing strength, and reducing the incidence of certain diseases, through regular exercise over the years, it is becoming clear that inactivity – not aging per se, is the culprit in most, if not all, types of chronic diseases.

The senior population has had a boost for performing fitness routines with a report from Tufts University in Boston showing increases in strength in persons over 80 years old. Strength changes were demonstrated in subjects over a training program, with increases totaling over 170%. Even after a period of detraining, subjects still tested higher in strength scores than before they entered the program.

These results clearly show the need for incorporating moderate exercise programming at any age. The beneficial effects are being seen in groups once thought to have no business being in the workout environment.

Two areas of most concern to seniors are both bone and muscle weakness – the former with the concept of osteoporosis, and the latter with a decline in muscle strength and endurance over time. Again, walking has been shown to have an impact on cardiovascular fitness, and the use of aerobic machines may provide an improvement in workload over time without the impact on joints. Thera-Bandsª or rubber tubing are helpful with a beginning resistance exercise training program, and signing up with an exercise class, or having an instructor consult individually is helpful in getting a program started. Common sense, moderation, and proper exercise progression provide the intensity stimulus in the first month or so of exercise training.

Populations at risk for disease

For pregnant women and seniors, the benefits of regular exercise have been highlighted both in research and health periodicals. The question still remains if these particular populations are any more susceptible to disease because of their status. So, if we as our original question – does exercise help enhance health levels, or do they naturally select exercise to start out with?

The study of medical populations may give us a clue as to how exercise may be beneficial at improving health, independent of other variables that may contribute to health in the first place (such as genetics, dietary factors, where you live, etc.).

Diabetes affects over 20 million Americans, with over 5,000 new cases of diabetes being diagnosed every week. For over 70 years exercise has been touted as being part of the trilogy of treatment for persons with diabetes (along with a proper diet, and regular insulin routine). However, exercise has received little practical impetus from the health community, mainly because no one was sure what type of exercise, or how much was needed to actually impact diabetes care. Inactivity is seen as one of the major risk factors for development of diabetes over time, as is increased the likelihood of developing glucose intolerance, and insulin resistance. These factors are the reasons why many older adults develop diabetes later in life.

With the publication of three relevant research studies in 1991 and 1992, the question of exercise and its benefits for diabetes has been answered to a greater degree.

Two years ago, researchers from The University of California looked at alumni records from former university students to see who had been exercising regularly since their graduation from college (as far back at 1927). University records keep tabs on all students as to job occupation, health status, medical visits, leisure time activity, etc. Data was collected for many years, and when it was analyzed, it was found at alumni who exercised frequently (3 or more times per week), had less incidence for developing adult onset diabetes. Their risk for developing diabetes was almost half that of persons who did not exercise at all. This finding was independent of their family history of diabetes, and other physical factors, such as body weight and blood pressure status.

Within that same year another study was published in the British medical journal, the Lancet, with essentially the same results as the University of California study, only this time in an entirely different group of people, using the same type of research methods. This ongoing investigation is called the Nurse’s Health Study – which looks at health objectives in a sample of the nation’s nurses, was the data base. Information was collected from this group over years to assess health status in these women. After comparing those who exercised regularly versus their sedentary counterparts, the same type of results appeared. Those who exercised had almost a 33 percent less incidence of acquiring diabetes over time, independent of other factors.

Almost a year after the first publication, the Physician’s Health Study looked at exercising doctors and compared them with non-exercising counterparts. Again, those physicians who exercised at least 2 to 4 days per week had less incidence for diabetes development by about 30%, and those who exercised 5 or more days per week reduced their risk by 40%.

These series of investigations lend clear evidence to the concept of a protective effect of regular exercise in different population groups who may be at risk for developing disease over the course of their lifetimes. As scientists follow other groups of persons over years, we will learn more about the effects of exercise on mortality statistics, medical care, and enhanced quality of life for individuals.

Persons with diabetes should be concerned with keeping blood sugar levels at normal ranges throughout the day. They must avoid low blood sugar (hypoglycemia) due to prolonged exercise, as well. This balance is achieved through self blood sugar monitoring – using a small reflectance meter and sample of blood from a finger stick to keep track of sugar levels in the bloodstream. Self blood sugar monitoring is the cornerstone of good diabetes control, and may help avoid long term complications of the disease, such as blindness, gangrene, and heart disease.

Most exercises can be performed with diabetic persons, as long as self monitoring is part of their program. By knowing current sugar levels, they can safely plan the intensity and duration of their exercise. If they have had diabetes for longer than 10 years, lower impact exercises may be beneficial to guard against damaging feet, which may have some neuropathy (nerve damage). Consulting with personal physicians, and exercise specialists will produce individual exercises programs for improved health.

Medical populations

Exercise with medical patients started with cardiac rehabilitation. Patients were weaned into low intensity exercise programs using aerobic machines, later walking programs, and at the present, supervised exercise consisting of aerobics, weight training, and stretching programs. Their exercise options have grown as to what types of programs they can perform, and how it may effect their risk for cardiac abnormalities later in life. The goal for cardiac rehab programs to date is to reduce the incidence of recurrent heart problems in patients who have undergone bypass surgery, or had previous heart attacks.

For persons at risk, exercise may have an impact on reducing the occurrence, or severity of disease. What about persons who are already afflicted with a disease, such as high blood pressure?

One in four American has hypertension, and exercise has been studied as to its effects on blood pressure for over 25 years. Most persons who exercise regularly know that training raises blood pressure during the performance of the exercise itself. Many health professionals have been reluctant to tell their patients to exercise because of this fact.

However, exercise training over time reduces blood pressure levels. The key is finding the right type of exercise program that will not raise blood pressure much during exercise, and have beneficial long-term effects.

It has been found that moderate aerobic training (walking, aerobic machines, swimming, etc.) have little effect on blood pressure levels, if they are performed at a certain heart rate range. Regular exercise is best at keeping blood pressure levels in check. Sporadic training routines have little effect in the long run, and persons may not get into their exercising “groove” in terms of figuring out their heart rate, and their exercise intensity.

Dr. Deepak Chopra, the author of “Quantum Healing”, has added much information as to the effects of changing lifestyle and its effect on cancer patients. Those who perform meditation, regular exercise, and dietary interventions have had a better recovery from their cancer-related therapies. Exercise plays an important part of cancer recovery by strengthening weak muscles, adding more functional capacity in persons who have little energy for daily work activities, and boosting self-esteem though successful performance of tasks, and achieving goals. Moderate walking and water exercise programs have been successful with this group. The use of rubber tubing substitutes for dumb bells in terms of muscle strengthening. In the future exercise may be a part of every cancer patient’s recovery package.

One of the most interesting areas of exercise and medical populations is the effect exercise has on blood lipids. As heart disease is the worst chronic disease afflicting Americans, anything that can reduce cholesterol and other blood fats in the diet, and by other means is regarded highly.

It seems that aerobic exercise (and to some extent, strength training), has an effect on lowering total cholesterol with exercise. It raises the protective cholesterol (HDL), and reduces the atherosclerotic-producing cholesterol (LDL), along with cholesterol sub-fractions which may have an effect on health status. Judging by its effects on hyperlipidemia (high fat levels in the blood), patients with this disorder may use exercise as a type of medicine, and the right “prescription” may help reduce their blood fat levels, reducing their chance of suffering a cholesterol-related heart problem.

Arthritis patients have had to deal with pain their joints with every movement. So why should they exercise – as exercise makes joints move in lots of directions, and sometimes with a heavier load than just getting around? Exercise has been shown with this group to have beneficial effects of lessening the pain and inflammation of chronic rheumatoid arthritis. Programs such as PACE (People with Arthritis Can Exercise) have opened doors for persons and given them options as to what types of exercises they can perform, and the effects of exercise over prolonged periods of time.

Exercise has been shown to have beneficial effects in patients with Cystic Fibrosis, Post-Polio Syndrome, Raynaud’s Syndrome, End-Stage Renal Disease, Pulmonary Disease, and Peripheral Vascular Disease. Exercise is also being studied as to its beneficial effects on newer diseases such as HIV/AIDS, and Chronic Fatigue Syndrome. The American College of Sports Medicine has set guidelines for exercise professionals on dealing with these types of patients during exercise situations. With a joint effort by the health care community, patients who would have never thought of using exercise as part of their medical treatment may be working with their exercise specialist in addition to their doctor, nurse, dietitian, or physical therapist.

A Basic Medical Exercise Program

What constitutes a medical exercise program? Does an adult onset diabetic person have a different exercise program than an arthritic patient? As exercise programming is as individual as people, no two should have the exact type of program. Whether patients are working out in a supervised exercise setting, or participating in an aerobic exercise class, there are a few types of guidelines that are universal, and may help structure individual exercise.

1. Proper monitoring before exercise. Whether is is blood sugar monitoring, using a blood pressure cuff, taking a temperature reading, or stepping on the scale, performing a physical reading pre-exercise is important to see how hard and long you may be able to perform.
2. Proper warm-up. In a class full of students, or on your own, getting the muscles prepared for exercise is as easy as doing some light aerobic movements, and large-muscle stretching activities to get ready for the body of the exercise.
3. New goals and objectives. The goals for therapeutic exercises are – pain free movement, improved functional ability, learning new body movements, and perfecting technique on whatever type of exercise you are performing. If people thought about improving their technique in the weight room, or the aerobic dance floor, they would decrease their risks of ever having an injury – as the competitive nature of exercise takes a back seat to self-improvement and self-awareness. It has been said that Socrates learned to dance at 70 years of age because he felt that a part of himself needed improvement. Therapeutic exercise is half education, and half workout. Teaching patients new physical skills, and offering them instruction on how to deal with new movement is part of the objectives. It differs from mainstream exercise programs where individuals need much less guidance. The rewards are not just improvements in physical condition, but new tools to work with on their own (at home), and hopefully a new found sense of self acceptance and confidence to become healthier, and more self reliant.
4. Proper warm-down. In sports, warm down may mean a few stretches before going home. The importance of proper warm down in therapeutic situations cannot be overlooked. It is time for breathing (slow, proper belly breathing), it is a time for reflection and relaxation, and getting yourself “centered”, and it is a time to let the muscles flush out the extra work they have been asked to perform, and be able to function properly the next day without undue soreness. For patients who have been in stressful healing situations, the warm down serves as their focus to reduce pain, increase mental strength, and increase their own healing abilities.

There is no one type of exercise routine for medical situations, so no sample program is listed. A bit of reading and investigating by the individual will help them gain access to qualified professionals to help them start on their own program.

Tomorrow’s Exercise

Exercise in medicine, despite all of the research expounding its benefits, is still in its infancy. There are scattered programs around the country that provide exercise therapy for medical patients. Many health professionals are hesitant to refer patients to health clubs, as most employees are not well versed in medical aspects of disease. For those with extensive exercise physiology backgrounds, setting up private practice is also difficult, as the profession is not a licensed entity.

None the less, the future of exercise with medical populations seems to gaining momentum. More types of out-patient programs are cropping up, and some hospitals have adopted a rehabilitative format, performing therapy services in addition to acute patient care.

We would hope that it is part of a change in the system that now pays an enormous amount of money for medical procedures, to one which will help pay costs for “preventive health care”, which would include diet and exercise as the main components. Time will tell as to how the current political administration will handle today’s health care issues. If individuals are aware of the benefits of exercise therapy for special population needs, perhaps they will seek out exercise instruction in their community, and make a change in the system by themselves.

About the author:

Eric P. Durak received his Master’s degree in Exercise Physiology from the University of Michigan in 1986. His research and clinical interests include exercise applications for special populations groups, such as diabetes (IDDM, NIDDM, GDM), pregnancy, and metabolic disorders. He has published scientific articles in: The American Journal of Obstetrics and Gynecology, Diabetes Care, Sports Training, Medicine, Rehabilitation, and The Somatics Journal. He is the author of “Exercise and Diabetes – a Guidebook for Health Professionals, published through Medical Health and Fitness, based in Santa Barbara, CA.

Basic definitions of water therapy

Water fitness has grown largely as a result of one fundamental demographic trend – our aging population. Water is seen as a more gentle medium. Therefore, water programs were initially developed for special populations, such as seniors, who were considered too out of shape to participate in the more strenuous land-based exercise programs. Water conditioning was thought of only for the weak or injured, those to whom land workouts might potentially create more problems than they solve. Though it is now changing, this limited view of water exercise is still prevalent among fitness professionals and the fitness public. Understanding vertical water exercise and the tremendous potential it represents for the betterment of the human condition is what this manual is all about. Aqua training allows the instructor to expand their horizons for their own continuing education (learning about the water), and applying fitness principles to water training.

It will help students and instructors to understand that water is more than doing laps, or just having fun. It may become one of the most widely used forms of exercise by the end of this decade. Some important reasons are listed below:

Table 1: Water Exercise Components

1) Reduces impact forces while exercising

2) “Unweights” the body, buoyant medium

3) Provides three dimensional resistance

4) Provides mainly concentric muscular contractions

5) Allows the joints to move along a natural path

6) Helps control core body temperature

7) Provides accommodating resistance

8) Human cardiovascular system works more efficiently
in the water

9) Allows for a full range of motion

10) Provides a positive psychological environment

11) Time efficient

One thing should be understood concerning the relative buoyancy of water. It has nothing to do with how heavy a person is on land. It only has to do with how densely constructed that person is. Fat floats and muscle does not. Many aquatic professionals believe they must get a larger size water running belt or vest for an obese person than for a smaller, trimmer person. Usually just the opposite is true. Though an obese person may weight 250 pounds or more on land, in the water they are very buoyant and float quite easily. Thin persons, especially people who are muscular with little body fat are often negatively buoyant. In other words, they will sink in water. A 170 lb. athlete with 8% body fat needs a more buoyant flotation belt than a 300 lb. person with more than 30% body fat. One of the most attractive attributes of aquatic exercise is that its participants stay cooler than their land-based counterparts. Water facilities thermal exchange. A water temperature of 80 degrees Fahrenheit will cool the body several times faster than air at the same temperature. Because cool water dissipates heat so effectively, exercise can be done at a much more vigorous pace without the aquaciser becoming overheated.

When using water for a full line exercise program, the temperature of the water should be on the cool side of what the aquaciser thinks is comfortable. Normally, a pool temperature of 79o Fahrenheit (F) to 85o F is recommended. Though the pool may seem a little uncomfortable upon entering, within a few moments the aquacisers will appreciate the cooling effects of the water as they heat up.

Water temperature above 90o F will actually prevent the aquacisers from cooling off and cause an increase in their core body temperature. When submerged in water, sweat does not evaporate as it does in the air. It is this evaporation mechanism which cools the body as we sweat. Being submerged in water subverts this important cooling process. Therefore, water temperature should be maintained in a range that is several degrees cooler than skin surface temperature in order to cool the body. Skin temperature is around 93.5o F, which is why the cooling effects of water to the body ceases above 90o F, at least during exercise.

One of the properties of water is its effects on acceleration of the body. Since water is more dense than air, it has more resistance and it is harder for the body to accelerate through it. One of the factors modifying acceleration is drag – which is a force resisting the body’s movement in water. Components of drag include small waves (called eddys) that ripple along side the body as it moves through water. the faster the movement, the larger the eddy, and the more resistance occurs. The second component is friction of the water to the skin, which adheres to skin by virtue of it being in the water. Again, as movement increases, friction increases. The third component is tail suction, which describes the inability of water to not fill in behind body parts that are not aqua-dynamic enough, thus the body must “pull along” a certain amount of water as it moves – adding to the resistance. Water surrounds the body and resistance is provided equally in all directions. The 3-D freedom of movement afforded in the aquatic medium allows the joints to move in a manner which is most natural for them. This means that water is not only non-injurious to the joints but when used properly, water exercise can potentially be therapeutic to the joints.

As any weight lifter or strength coach knows, there are two types of resistance, positive and negative. Positive resistance is described when the muscle contracts and overcomes the weight, lifting it off the floor. A negative resistance is described when the weight overcomes the contractual force of the muscle and the weight is lowered back down.

Negative resistance has certain advantages and disadvantages from a training perspective. “Negatives” as they are often called, play a major role in increasing the size of the muscle and tendons. The major disadvantage negatives present is that they also cause minute tears in the connective tissue which often result in delayed onset muscle soreness (DOMS) and the possible development of adhesions over time. Soft tissue swelling and a restriction of blood flow to the affected area are also a result of negative resistance.

Positive resistance has none of these disadvantages. When using positive only resistance, the next day soreness is greatly reduced or eliminated. Swelling and adhesions are much less likely to occur. From a safety standpoint, positive only resistance is vastly superior since the danger of a falling weight or rubber band recoiling is non-existent. These factors or comfort and safety, along with the increase in blood flow resulting from positive only resistance exercise, make it the preferred form of resistance for most forms of physical therapy and as well as general population conditioning.

Water is a positive only resistance medium. When moving an object through water, once the muscle ceases to contract, the water does not apply force against the muscle to force it back. Water merely resists movement. This makes it a passive resistance medium. As such, it allows the exerciser to be maximally aggressive. This liberation from the need to protect against the injurious potential associated with negative resistance, can be a very dynamic training tool for elite and professional athletes.

Sample Exercises

Basic Water Movements- Warm-up

• Power Walk
• Deep Water Running

Basic Arm Movements

• Lateral Arms
• Lateral Raise/behind

Chest/Upper Back Exercises

• Pectoral Flys
• Horizontal Circles

Basic Leg Exercises

• Leg Extension/Flexion
• Leg Kicks

Water IS the training tool in the evolution of exercise. Its application to decondtioned and medical participants is almost universal. As more and more people become aware of water programs, and more of these programs become part of the health care contiuum of treatment, their use will expand even more.

References

1. Beasley, RL. Aquatic Exercise. Sports Medicine Digest. pp. 1-3, Jan. 1989.

2. Bishop, PA, Frazier, S. Smith, J. Physiologic responses to treadmill and water running. Physician and Sportsmedicine. 17:87-94, 1989.

3. Chappell, M. Therapy: The aquatic solution. Aquatics. pp. 24-29, Nov. 1989.

4. Cole, A.J. Moschetti, M., Eagleston, R.E. Getting backs into swim. Rehab Management. Aug./Sept. pg. 63-71, 1992.

5. Cole, A.J. Spine pain: aquatic rehabilitation strategies. Journal of Back and Musculoskeletal Rehabilitation. 4:4:273-86, Oct. 1994.

6. Koxzuta, LE, From sweats to swimsuits: Is water exercise the wave of the future? Physician and Sportsmedicine. 17;4:203-206, 1989.

7. Knopf, K., Fleck, L., Martin, MM. Water Workouts. 2nd edition. Hunter Books, San Jose, 1992.

8. McWaters, G. Deep water exercise during pregnancy. AKWA Letter. 1;2:3, 1987.

9. Mitchell, T. The use of props in water exercise for muscle conditioning. AKWA Letter. 3;1:6, 1989.

10. Sova, R. Heart rates in aquatic exercise. IDEA Today. pg. 9, 1990.

11. Sova, R. Aquatics Activities Handbook. Jones and Bartlett Publishers, Boston. 1993.

12. Triggs, M. Orthopedic aquatic therapy. Clinical Management. 11;30-31, 1991.

13. Vickery, S.R., Cureton, K.J., Langstaff, J.L. Heart rate and energy expenditure during aqua dynamics. Physician and Sports Medicine. 11;3:67-72, 1983.

A recent report described the use of melatonin to treat sleep disorders in hyperactive and neurologically compromised children: small nightly doses corrected the sleep problems, and investigators noticed improved mood and more stable and sociable dispositions tended to accompany the use of mleatonin with these children.

Melatonin also has exciting potential roles in ameliorating women’s health problems, such as osteoporosis, premenstrual syndrome, even birth control. As one of the body’s primary anti-stress hormones, it performs what are referred to as tonic and adaptogenic functions.

The Chemistry of Melatonin

Melatonin stabilizes the electrical actvity of the central nervous system and causes reapd synchronization of the elecytrical activity of te brin as well. In contrast, loss of the pineal gland predisposes animals to seizures. It has been proposed that the pineal, activn mostly but not exclusively through melatonin, is a “tranquilizing organ on behalf of homeostatic equilibrium”, and that it acts as a general synchronizing, stabilizing and moderating organ. This suggests that melatonin may have many applications for stabilizing and harmonizing aspects of brain function and chemical production.

Contraindications

If there is a weakness in our knowledge of the long terms effects of melatonin, it is in the area of this hormone’s indirect influences on the body. Individuals must find their own optimal dose. Starting doses are recommeded at 3 milligrams per day. Be sure to take melatonin in the evening. You might use it somewhat earlier than bedtime (5-8 pm). The optimal dose can vary widely in persons, apparently on account of drastic differences in the rate of which the liver metabolizes meltonin. The rate of metabolism is key to the increasing of doses over time.

Recent reports link the use of high levels of melatonin with sleep disorders, especially nightmares. These reports have been published mainly as case studies, but should be taken to heart with persons who are thinking of taking melatonin and are absolutely sure that there are no side effects. With any type of medication, there are always side effects if the dosage is not correct for individual needs.

Sports Performance

One of the most important aspects of proper performance (and one of the least practiced) is the concept of regular sleep patterns. Athletes are notorious for working their bodies extremely hard, and not getting the required sleep they need for proper performance. This is seen in a multitude of high school athletes who never make it through intercollegiate sports, and college athletes who do not continue after university sports. Dancers, and some professional athletes who have hectic travel schedules, who disregard the importance of sleep also limit their longevity in their sports.

Melatonin and General Health

People today have stressful lives. The importance of Melatonin cannot be understated if it can do what it proports to. It is estimated that one in four have trouble sleeping at some time. Most try to make up for it by sleeping in on weekends, but for many, to no avail.

Melatonin shows great promise for persons who are suffering from chronic diseases who may have psycholigical side effects of stress, worry, and trouble coping. Just getting a good night’s sleep for many helps in the recovery process.

Health and fitness professionals should be familiar with the benefical and side effects of the use of melatonin. Knowledge of beginning and graduating doses are also recomended. The chart below highlights a suggested progression as to the use of melatonin by condition and time.

Chart I
Experimental use of Melatonin
		Condition	Timing
Introductory dose	3 mg.	General	5-7 pm.
Moderate dose	200 mg.	IV use – research	evening
Large dose	300 mg.	women’s contraception study	evening
High dose	3,000 mg	toxicity study	evening

The optimal dose seems to be between 100-500 mg. per day given in the evening prior to bedtime. Taking melatonin in the daytime may exacerbate light damage to receptors in the eyes. For safety sake, all tablets should be taken in the dusk or evening hours.

Increasing Melatonin Production

The following list are some common sense facts about melatonin productions. Following these suggestions may help increase the natural production during the course of the day.

1. Get more early light time. Sleeping in can blur the distinction between night and day and reduce the amplitude of general sleep/wake cycles.

2. Be physically active in the day and limit naps to no more than 30 minutes. Activity turns off melatonin production during the day and reasies core temperature.

3. Try morning workouts as opposed to afternoon. The pineal gland is like a clock which needs to be reset every day. Combining light and activity is the most effective way to reset this clock.

4. Avoid caffeine and limit alcohol in the evening.

5. Eat larger high protein meals in the day, and smaller carbohydrate meals in the evening. Carbohydrates promote the production and delivery of tryptophan to the brain, which is the raw material from which melatonin and serotonin are made.
6. Eat dinner several hours before bedtime. Digestions raises core temperature which is undesireable for sleeping.

7. Avoid hard mental or physical work after about 6 pm. Stress hormones indeuced by work interferes with the production of serotonin and melatonin.




References

1. Barnett, ER. (pub). Physician’s Desk Reference for non-prescription drugs. Medical Economics Co. 1990.


2. Herbert, J. The age of dehyroepiandrosterone. Lancet. 345:1193-94, 1995.


3. Lewis, A.E., Cloutre, D. Melatonin and the biological clock. Keats Good Health Guide. Keats Publishing, New Canoon, CT. 1996.

What is interesting about DHEA is that the data collected thus far shows that low levels correlate with many aspects of the decline with aging – from vigorous good health into what we think of as old age. What is even more interesting is that low-dose, physiologic supplementation of DHEA appears to enhance one’s health and sense of well-being. Used as a medicine in higher doses, it appears to ameliorate many serious disease processes.

The Chemistry of DHEA

Until recently, scientists believed that DHEA only formed the pool from which other active hormones could be synthesized. It is clear that the chemical structure of DHEA is similar to that of testosterone. Both are derivatives of the cholesterol molecule. With the difference of one carbon-chain section of the molecule, cholesterol is strikingly similar to both DHEA and testosterone. Since it is similar to other steroid hormones (estrogen, progesterone, testosterone), it can convert of stimulate production of estrogens, testosterone, or cortisone, and many other steroid hormones when the body needs them.

Recent research indicates that, although DHEA is similar to other androgens, there are specific receptors on the cell surface that indicate a likelihood of individual function.

Potential Health Benefits of DHEA

The most important aspect of DHEA and health is that it has a barrage of claims for improving health in general, and reducing the effects of many chronic diseases. This may be the most powerful attribute to this over-the-counter hormone. To date, the following research has been performed with DHEA:

1. HEART DISEASE – Men with heart disease have lower naturally occuring levels of DHEA-sulphate than healthy men. They are three times more likely to die of heart disease. DHEA also lowers serum LDL cholesterol. The use of ingested DHEA may raise internal levels of the hormone and reduce the risk of aquiring heart disease. Research by Barret-Conner and colleagues confirms the risk reduction with the use of DHEA. It will be interesting to see if it is more-often prescribed (or taken supplimentally) in persons with one or more heart disease risk factors.

2. OBESITY – Obese mice do not become diseased if their diets are supplemented with DHEA. More research needs to be performed in persons with moderate and morbid (over 350 lbs.) obesity to see the benefits of taking DHEA would have, such as the reduction of peripheral vascular disease, diabetes, or hypertension.

3. CANCER – Mice bred for cancer do not develop cancer when their diets are supplemented. Also – there is an association with low levels of DHEA and breast cancer. If this concept can be applied to people, it would be one of the most significant attributes of taking DHEA. Mice bred for cancer have a much higer incidence rate for development of tumors than their non-experimental counterparts. If DHEA does completely reverse neoplastic development, it must be looked upon favorably. Remember that naturally occuring DHEA levels decrease with age, and all forms of cancer increase, so the relationship between low levels and tumor development is a sound one. We must also remember that much of the research in cardiovascular health in animals may not be directly applicable to humans. This research must be studied in humans with a strong family history of cancer development (in a primary prevention trial), or those who have had tumors removed, and followed for over a 5 year period to see what the remission status will be. None the less, it is a promising area of health improvement possibility.

4. AUTOIMMUNE RESPONSE – patients with lupus, rheumatoid arthritis, MS, and colitis have very low DHEA levels. When supplemented, they had increased stamina and improved sense of well-being. Lupus patients had significant improvement in their kidney disease. Because of the prevalence of autoimmune diseases (such as CFIDS, insulin dependent diabetes, etc.), the use of DHEA may again have tremendous possibilities in an area of research that has grown in stature over the past decade. DHEA may be part of the immuno-enhancing elements that are currently being tried to enhance the immune systems of many people.

5. OSTEOPOROSIS – DHEA can theoretically work like estrogen, androgen, and progesterone in preventing bone loss and stimulating bone formation. DHEA should be used in conjunction with a progressive resistance exercise program, as any supplement should.

DHEA and Athletic Performance

In sports the conversion of DHEA to testosterone is of great importance to athletes. If we can increase the body’s production of testosterone then we can not avoid an increase in strength, muscle mass, and reductions in body fat. The fact that DHEA may be considered an ergogenic aid (a substance that artificially boosts performance) will ultimately be engaged in debate. However, because DHEA is a “natural” hormone, it may not be banned as an illegal substance until a multitude of tests show it is both unsafe and provides too much enhancement of performance. Until those tests are made public and ratified as proven by a sports governing body, then DHEA usage may increase as an anabolic substance in the near future.

Conclusions

DHEA shows great promise both clinically and supplementally. The next few years will detail information as to whether we should be taking DHEA as an ergogenic aid, or as a basic component of our daily diet.

According to Steven Cherniske, MS – author of the new book entitiled: The DHEA Breakthrough, this hormone may have effects on different body systems and tissues depending on the dosage. Below is a table of the possible changes in body physiology based on different level doses of DHEA:

The next few years will decide the true benefits of taking DHEA as a supplement. However, in most medical conditions, and in general health, it seems as DHEA does have tremendous benefits for maintaining optimum health, especially for those over 40 years of age, or whose levels have started to decline.

1. Barnett, ER. (pub). Physician’s Desk Reference for non-prescription drugs. Medical Economics Co. 1990.

2. Cherniske, S. The DHEA Breakthrough. Balentine Books, New York, 1996.

2. Stempfer, MJ, Colditz, GA, Willett, WC, Manson, JE, et al. Postmenopausal estrogen therapy and cardiovascular disease. New England Journal of Medicine. 325:756-62, 1991.

3. Barrett-Conner, E., Khaw, K-T, Yen, SSC. A prospective study of dehydroepiandrosterone sulfate, mortality, and cardiovascular disease. New England Journal of Medicine. 315:1519-24, 1986.

4. Ebeling, P, Koivisto, VA. The physiological importance of dehyroepiandrosterone. Lancet. 343:1479-81, 1994.

5. Herbert, J. The age of dehyroepiandrosterone. Lancet. 345:1193-94, 1995.

The concept of exercise prescription is thought to be reserved for “health care professionals”. Exercise prescription is the application of fitness principles to persons with a medical condition. Although no exercise professional should diagnose a disease, or try to treat diseases in a medical fashion, if they have a working knowledge of the condition they are working with, and have read most of the medical/sports medical literature to see how other programs have been constructed, then they should be able to prescribe a program for patients with information from the referring physician, and in many instances recommendations from physical therapists on orthopedic limitations for each person, as well. The ability to work with other allied health professionals (physicians, physical therapists, occupational therapists, dietitians) will be important in prescribing exercise in these special population groups. This article highlights current scientific research concerning special populations, give specific medical concerns regarding each group, and when appropriate, detail sample programs that will benefit both the club member, as well as the instructor.

What Constitutes A Special Population?

A special population may be defined in terms of exercise as a group with a special medical condition who may require expertise and supervision to overcome that medical situation. Other special populations may just need to improve their skill levels and knowledge, or increase awareness and social interaction of conditioning by participating in a regular physical activity.

The need for applying exercise to these groups is becoming more important, as more scientific information becomes available as to the efficacy of therapeutic programs. Therefore, the medical conditions in this series will highlight general physiology of each condition, and give information regarding exercise. Keeping in contact with physicians and allied health workers will be an important aspect of working with these groups, and fitness professionals who work with special populations will themselves become a member of the health care team.

Diabetes Mellitus

One of the more prevalent special population groups are diabetic patients. Diabetes is is defined as impaired glucose metabolism, and is one of the most common medical problems in the United States today. It is the third leading cause of death in this country, because of the complications which are undetected by those afflicted manifest themselves into cardiovascular heart disease and stroke, eye disease and blindness, kidney failure, muscle disease, and damage to almost every internal organ. One of the keys to treating diabetes is to prevent its onset, or prevent complications from arising once the disease has been diagnosed.

The use of exercise in diabetes patients has shown improvement in glucose tolerance and overall metabolism, and improvement in overall blood glucose control, cholesterol and strength. Exercise in general (aerobic or strength training) has an insulin like effect on glucose uptake into cells.

Aerobic training programs in diabetes should consist of moderate to low impact (to guard against injury to feet and lower legs), and should be built up to regarding both intensity and time. Starting with walking is one of the most beneficial forms of exercise in diabetes, and for those with lower extremity problems, using arm crank exercises or other non-impact aerobic machines is also beneficial.

Progressive resistance programs for diabetic persons should consist of moderate weights to improve muscle tone and posture, and improve their blood sugar control. Because these patients may have had diabetes for a long time, it is important for them to have visited their doctor, and have had a medical exam before participating in any regular program. Physicians are responsible for administering the initial medical screen and stress test. They should also be involved in follow up routine exams to monitor patient progress in their diabetes management. If the patient has any questions about an exercise program, the doctor should be familiar with personnel who are trained in the area, and are willing and capable of working with their patient in prescribing exercise.

Recommendations

The following table highlights information for exercise and diabetes.

General recommendations

1. Carry a home glucose monitor and use it before and after each aerobics
   class. Record blood sugar values.
   

   
   

2. Carry some available short acting glucose solution and know when to use it. (apples, orange juice boxes, hard candy are excellent examples).
   

   
   

3. Have identification handy in case of an emergency. Instructors should know that if a member becomes dizzy, faint-like, or drunk-like, then some glucose feeding may be necessary. Life Savers, or a sugar drink (orange juice) should be administered without reservation within seconds of the beginning of these symptoms. Call for medical assistance. The best assurance against insulin shock (hypoglycemia), is to test blood sugar levels before EACH session.
   

1. Glucose <100 or >300 mg/dl means NO exercise until food or insulin is administered.

   
   

2. Diabetic complications usually mean that exercise is not medically advised. If a new member has a diagnosis of any complication, check with their physician before starting any program.
   

   
   

3. Outward signs of blisters on hands or feet, cardiac problems, high lipid levels.
   

   
   

4. Excessive amounts of weights lifted (>50% of estimated maximal voluntary contraction) for persons with overt complications, or physician recommendation.
   

   
   

5. Performing Valsalva Maneuver while training
   

2. Bray, GA, Gray, DS. Obesity II: Treatment. Western Journal of Medicine. 149:555-71, 1988.

3. Durak, EP, Jovanovic-Peterson, L, Peterson, CM: Randomized crossover study of the effect of resistance training on glycemic control, muscular strength, and cholesterol in type I diabetic men. Diabetes Care. 13:1039-43, 1990.

4. Graham, C. Lasko-McCarthey, P. Exercise options for persons with diabetic complications. Diabetes Educator. 16:212-20, 1990.

5. Horton, E.S. The role and management of exercise in diabetes mellitus. Diabetes Care. 11;2:201-11, 1988.

6. Manson, J.E., Nathan, D.M., Krolewski, A.S., Stamphfer, M.J., Willet, W.C. et al. A prospective study of exercise and incidence of diabetes among US male physicians. JAMA. 268;1:63-67, 1992.

7. Peterson, C.M., Dupuis, A., Levine, B.S., et al. Feasibility of improved blood glucose control in patients with IDDM. Diabetes Care. 2;4:329-35, 1979.

8. Pollack, ML, Wilmore, JH, Fox, SM. Exercise in Health and Disease. Saunders Publishing, 1986.

9. Schwartz, R.S., Exercise training in the treatment of diabetes mellitus in elderly subjects. Diabetes Care. 13;5:277-84, 1990.

Eric Durak is a clinical exercise physiologist and health educator. He is special populations advisor to the International Sports Sciences Association, and is the director of the Fitness Therapistª course.

Diabetes in Pregnancy

Gestational diabetes is a disorder that affects a small but significant percentage of women during their pregnancies. It is defined as abnormally high blood sugar levels after a meal, and is associated with changes in hormonal levels during the second trimester on of pregnancy. These physical changes, as well as a family history, body weight above 115 % of ideal, and poor dietary patterns may predispose women to GDM.

Approximately 3-5% of women will encounter GDM during their pregnancy. It rate is higher in low socioeconomic status women, and in Hispanics. The results of uncontrolled GDM throughout pregnancy may result in fetal macrosomia (baby birth weight above nine pounds), and increases the risk for neonatal morbidity, compensatory low blood sugar reactions in the neo-nate, and cesarean section. It is the major cause of still births in the United States.

GDM is associated with fetal macrosomia because of high levels of insulin secretion by the fetus in response to high levels of maternal sugar that cross the placenta. The mother’s own insulin is too large of a molecule to pass through the membrane, so the fetus must “overproduce” its own to compensate for the flood of sugar. Insulin is a growth hormone, and this is the cause of fetal macrosomia.

Screening for GDM

The usual diagnosis of GDM is by a 3 hour glucose tolerance test, whereby the mother drinks a 100 gram sugar solution, hoping to keep glucose levels from elevating too high over this time. The standard criteria is: Fasting levels < 105 mg/dl, 1 hour > 190, 2 hours > 165, 3 hours > 145 mg/dl. If a women is higher at any two time points, she is diagnosed with GDM.

Standard treatment of GDM is usually diet modification, staying with a meal plan higher in protein and fat to blunt the post-prandial (after meal) response. Women are encouraged to measure their own blood sugar levels at various times during the day with a home glucose monitor, which will record the results of a small drop of blood on a reflectance strip, and gives blood sugar results in a short time period.

If a standard diet is not successful in keeping blood sugar levels under control after meals, or during the fasting state, then insulin therapy is usually ordered by the doctor. It is done so because oral agents (used with many older adults with diabetes), is contraindicated in gestational diabetes, because of suspected risks to the fetus.

Insulin is administered around meal time on what is known as a “split routine”; or trying to match insulin amounts to types and amounts of foods eaten. If it is successful, then blood sugar levels will be in good control most of the time. Many women are not happy with the idea of taking insulin injections over the last two months of their pregnancy, and many are looking for other alternatives to this type of medical treatment.

Exercise and Diabetes

Exercise is one of the cornerstones of diabetic treatment. It has been used in type I (insulin-dependent), and type II (non insulin-dependent) diabetes for years. Exercise has an “insulin-like effect” on the muscle, causing blood sugar levels to drop, independently of insulin in most cases. It has been studied in many adults with diabetes, but until recently, not much in pregnant women.

The reason there was little research performed in GDM is that many physicians were not sure of the benefits of exercise in a normal pregnancy, let alone a high risk pregnancy such as a diabetic woman. After about 15 years of experiments, from the late 1970’s until the early 1990’s, the amount of scientific research in the area was increased, and the latest word in sports medicine is that many women are better off performing regular exercise as part of their pregnant routine, than being sedentary over their gestation. It mimics the evidence for people in general, in terms of basic health maintenance.

Exercise in GDM

One of the first studies performed in GDM used bicycles to look at blood sugar response to a controlled exercise situation. Results showed that indeed, these levels did lower in response to exercise. Other studies looked at diet and diet along with exercise and its effects on both short term, and long term blood sugar control. Again, those women who performed regular exercise showed improvement in their blood sugar control, even above that of diet alone. In fact, those exercisers used conditioning regimens in leu of insulin to keep themselves in control during the last half of their pregnancy.

The women in most research studies exercised on aerobic machines, keeping track of work load, and other criteria, such as fetal response to exercise (via heart rate monitoring), maternal heart rate and blood pressure, and of course, blood sugar response. The emphasis of the research also showed that some types of exercise machines, such as the upper body arm crank, and recumbent bike were better tolerated by exercising women, as they did not have any uterine contractions during exercise, compared with other forms of exercise which had a few contraction episodes, prompting an early ceasing of exercise (to be on the safe side).

The Benefits of Walking

Walking is coming into its own as a major health enhancement tool. One of the big questions as to the beneficial aspects of exercise in general is not so much if it is good for healthy people (does exercise make you healthier, or do healthy people naturally gravitate to exercise?), but what are its effects on those with disease.

Walking has been shown to reduce cholesterol levels, have a protective effect from coronary heart disease, reduce body weight, reduce blood pressure, and improve circulation in medical patients. The question to be asked is – what type of effect would it have in diabetes?

Many clinical exercise physiologists report that one of the only types of exercises that they can prescribe to their adult onset diabetic patients is daily walking – since many do not have exercise machines, or belong to a health club. They must therefore be creative in working with “home-based” exercise programs that their patients will adhere to, and benefit their diabetes control.

Walking about 30 minutes after eating has been beneficial in keeping post prandial blood sugars in control for many patients. They feel that they can accomplish a 20 to 30 minute walk 2 or 3 times per day, and over a couple of months, they feel better. Many have reduced their medication levels during their tenure in their walking program.

An application to GDM

How can the pregnant diabetic women accrue the benefits of exercise without an added financial expense, or jeopardizing her or her babies health? Barring any orthopedic limitations, walking 2 or 3 times a day may just be the ticket to enhancing her health, and keeping her blood sugars in check over the last half of her pregnancy. Many women feel that exercise programs become more fatiguing as the third trimester approaches, so even getting out for a walk and increasing circulation is a big help in keeping them feeling good.

A sample program would include a mid morning walk of 1 to 1.5 miles with a couple “up hill” challenges. An afternoon walk would include a pre-planned route that also included some small hills, but that is not too congested with traffic.

Walking at the local track will offer women a planned distance, as all tracks are a quarter mile in length. They also have soft surfaces for shock absorption, and usually are not crowded until track practice at 3-4 p.m.

Walking with a partner (perhaps one who is also pregnant) may help in keeping motivation levels high during pregnancy. With a diagnosis of GDM, and a growing belly, many women feel that they are to big to begin with, let alone trying to keep up with those who may not wish to keep their pace.

Good walking shoes are a must. Many women gain enough weight in the second trimester to warrant purchase of a new pair. This may help in case there are any minor swelling problems in the feet, and newer shoes are more stable. To date, there is not specific shoe for pregnancy, but there may be a market for them, with the advent of the new “baby boom”.

One aspect of good diabetes control is that of self-blood sugar monitoring, as highlighted above. Self monitoring lets any diabetic person know where their sugar levels are at any time of the day. In exercise, it sets the limits of conditioning, as higher levels may dictate more prolonged exercise programs to “burn off” more sugar, and lower levels may dictate the ingestion of a carbohydrate to prevent hypoglycemia (low blood sugar) reactions after exercise has finished. None the less, having a home monitor (usually reimbursed by insurance upon physician prescription) plays an important part of the diabetic exercise regimen, and should be used by any GDM women who wishes to perform walking programs (or any exercise) to keep in good metabolic control during her pregnancy.

It should always be remembered that any exercise program should be built up in terms of intensity and duration, including walking. There are many women who would not think of walking for 30 minutes two or three times a day, because of swelling, morning sickness, backache, or headaches. Consultation with your obstetrician should provide proper guidelines for any medical considerations needed to perform exercise safely, and within individual limits.

Then, working with an instructor, or on your own, exercise up to your perceived limits, and stay in those limits as you build endurance over a couple of weeks. It is possible to increase fitness levels during pregnancy, if they are done systematically. Walk for 5 minutes as a brisk pace, and gradually increase. If the goal is blood sugar control, compare walking times with post walking sugar checks. Over time there should be a consistent pattern.

Summary

Exercise not only has been touted as a good therapeutic treatment for diabetes, but recent epidemiology studies also shows a strong association between exercises levels, and the reduction of diabetes in general. This is known as primary prevention. Those persons who exercised the most had the least occurrence of the disease. This types of studies have given tremendous support to the advent of exercise in the diabetic population.

One case report highlighted a previously diagnosed GDM women in her first pregnancy who exercised throughout her second. The glucose tolerance test was normal – essentially preventing the occurrence of the disease in the second pregnancy. These are powerful reasons for pregnant women to inquire about exercise, and for doctors to prescribe it more often.

As more people in this country switch from heavy exercise routines, to health promoting activity programs, walking is emerging as a viable daily endeavor. Pregnant women who have been diagnosed with GDM may find that a simple walking program can keep their blood sugar levels under control, keep their body fat levels from increasing dramatically, and enhance their overall health. It all starts with the first step.

None the less, if most persons with diabetes (especially type 2 adult onset) would engage in a walking program every day for 15-30 minutes, they could significantly reduce their chances of having diabetes complications that are associated with the disease over time.

A recent report in a fitness publication revealed the average diabetic’s distane for exercise. A survey of 1,000 diabetics from the Joslin Clinic in Boston revealed that over 75% of them would rather take daily insulin injections for their control than perform regular exercise. That about sums it up in terms of their preference – but how did this scenario happen in the first place? Well, as it turns out, most diabetes physician caution their patients against exercise if their blood glucose levels are too high. It seems that if the sugar levels exceed a certain blood volume, then ketoacidosis could result if exercise proceds.

In my tenure as a diabetes and exercise researcher, I never could find the exact study that showed blood glucose levels actually increased if they were at a certain level (the ADA used the figure of 250 mg/dl). As a matter of fact, in my own studies, I found that as persons increased their fitness levels (say, after 2-3 weeks of exercise) their blood sugars would drop, even if they exceeded that 250 mg/dl amount pre-exercise. However, I never had any collaborating research to back up my work until last year.

One study in 1996 has come to my attention that deserves mention for all of theose health professionals who caution against exercise if blood glucose levels exceed that 250 mg/dl number. In a presentation at the 1996 American Association of Diabetes Educators national meeting in New Orleans, LA, Robert Hanisch and Ann Snyder presented information that will dramatically change the way exercise programs are applied to diabetics. In a study of over 1,000 consecutive exercise sessions, the authors attempted to identify if the classic information given to exercise instructors not to perform conditioning on a diabetic with blood glucose levels over 250 mg/dl was prudent advice. Over 300 exercise sessions were performed on patients with pre-exercise BGL’s over 240 mg/dl. However, only 4 sessions resulted in an increase in BG. The mean increase for these 4 sessions was 23.5 mg/dl. Conversely, the mean change in BG of the remaining 311 sessions was a decrease of 52.5 mg/dl. The mean decrease in type 1 subjects (n=133) was 61.3 mg/dl. The mean decrease in type 2 subjects was 46 mg/dl (n=178).

For 98.7% of this group, the advice to delay exercise due to a possible deterioration in the metabolic control post-exercise would have been incorrect. Therefore, the commonly provided advice regarding acceptable pre-exercise BG levels for a person with diabetes should be reconsidered.

My own experience with diabetes mirrors this advice. I tell trainers who may not be familiar with diabetes and exercise that conditioning sessions should be “blood glucose dependent” – meaning that higher levels constitute a more vigorous and longer training session (more glucose to burn). Lower levels (under 120 mg/dl) constitute a less vigorous session for less time. If these principles are followed, emergencies will be highly unlikely.

Exercise has been shown to be effective in preventing the occurance of diabetes in persons who are at high risk for contracting the disease. Studies also show that exercise may be performed with persons who have diabetes complications (although not at severe levels), and that persons can perform intense exercise and even sports competition with the disease without suffering undo problems.

With over 70 years worth of information on the benefits of exercise for diabetic persons, it should be part of EVERY diabetic persons’ medical plan to include daily moderate exercise for their diabetes control, weight management, muscle strength, aerobic fitness, and self esteem. In this instance, a little exercise goes a LONG way to improving health.

1. Barnard, RJ, Lattimore, L, Holly, G, Cherney, S, Pritikin, N. Response of NIDDM patients to an intensive program of diet and exercise. Diabetes Care. 1982, 5;4:370-74.

2. Barnard, RJ, Pritikin, N, et al. Effects of a high-complex carbohydrate diet and daily walking on blood pressure and medication status of hypertensive patients. Journal of Cardiac Rehab. 1983, 3:839.

3. Bernbaum, M, Albert, SG, Cohen, JD, Drimmen, A. Cardiovascular conditioning in individuals with diabetic retinopathy. Diabetes Care. 1989, 12;10, 740-42.

4. Cruickshanks, KJ, Moss, SE, Klein, R, Klein, BEK. Physical activity and proliferative retinopathy in people diagnosed with diabetes before age 30. Diabetes Care. 1992, 15;10:1267-72.

5. Durak, E.P., Jovanovic-Peterson, L, Peterson, C.M. Randomized crossover study of the effect of resistance training on glycemic control, muscular strength, and cholesterol in IDDM men. Diabetes Care. 13;10:1039-43, 1990.

19. Hanisch, R.J., Snyder, A.C. Exercise is safe with hyperglycemia. Diabetes Educator. 22:141, 1996. Presented at the 1996 AADE national meeting, New Orleans, LA

6. Helmrich, SP, Ragland, DR, Leung, RW, Paffenbarger, RS. Physical activity and the reduced occurrence of non-insulin dependent diabetes mellitus. New England Journal of Medicine. 325;3:147-52, 1991.

7. Horton, ES. The role and management of exercise in diabetes mellitus. Diabetes Care. 1988, 11;2:201-11.

8. Jackson, Blair, SR. The association between physical fitness and NIDDM in men and women. Medicine and Science in Sports and Exercise. 25:5:S-61, 1992.

9. Manson, JE, Rimm, EB, Stampfer, MJ, et al. Physical activity and the incidence of NIDDM in women. The Lancet. 338:774-77, 1991.

10. Manson, JE, Nathan, DM, Krolewski, AS, Stampfer, MJ, Willet, WC, Hennekens, CH. A prospective study of exercise and incidence of diabetes among US male physicians. JAMA. 268;1:63-67, 1992.

11. National Diabetes Information Clearinghouse. The Diabetes Dictionary. U.S Department of Health and Human Services. National Institutes of Health, 1989.

12. National Institutes of Health. Consensus conference on diet and exercise in NIDDM. Diabetes Care. 1987, 10;5:639-44.

13. Peterson, CM, Dupuis, A, Levine, BS, et al. Feasibility of improved blood glucose control in patients with IDDM. Diabetes Care. 1979, 2;4:329-35.

15. Shiffrin, A, Parikh, S. Accommodating planned exercise in type I patients on intensive insulin therapy. Diabetes Care. 8;4:337-42, 1985.

16. Shwartz, RS. Exercise training in the treatment of diabetes mellitus in elderly subjects. Diabetes Care. 13;5:277-84, 1990.

17. Graham, C, Lasko-McCarthey, P. Exercise options for persons with diabetic complications. Diabetes Educator. 1990, 16:212-20.

18. Kriska, AM, LaPorte, RE, Patrick, SL, Kueller, LH, Orchard, TJ. The association of physical activity and diabetic complication in individuals with insulin dependent diabetes mellitus: The epidemiology of diabetes complications study – VII. Journal of Clinical Epidemiology. 44;11:1207-14, 1991.

Types of Lipids

Of the many classes of lipids, it is well established that there are two classes that affect general health, and are affected in turn by exercise. The first group consists of cholesterols that may have adverse affects on the intima (inner lining) of the artery lining, thus creating increased risks for heart and vessel disease. These include: very-low density lipoproteins (VLDLs), low density lipoproteins (LDLs), and triglyderides. VLDL contains tryglyceride, and is a transport and storage form of fat tissue. LDL molecules are the end product of triglyceride metabolism.

High density lipoproteins (HDL), by contrast, has a protective effect against coronary artery disease10,11. HDL particles pick up free cholesterol from cells after esterification of the enzyme lecithin. HDL then transports cholesterol from liver tissue to cells requiring cholesterol or back to the liver for elimination.

The Risk Profile

The National Institutes of Health have produced a risk-statification table that would be of interest to Fitness Therapists, as it may help set guidelines for intensity-dependent workout schedules for persons depending on the severity of their lipid levels. A table is listed below:

Table 1.  Risk Profile for Specific Lipid Concentrations
	Total Cholesterol	LDL Cholesterol	HDL Cholesterol	Tryglycerides (all levels in mg/dl)
High Risk	245	190	35	1000
Moderate Risk	221-244	160-189	36-44	500-999
Mild Risk	201-220	130-159	45-54	250-499
Average Risk	182-200	<100-129	55-65	151-249
Low Risk	<182	<100	65	150

The N.C.E.P Guidelines

Whether or not the ingestion of cholesterol (via eggs, high-fat foods, etc.) is the cause of excessive blood levels of choesterol remains controversial. Some persons who eat very little cholesterol-laiden foods have genetically high levels of cholesterol naturally. None the less, the problem of high lipid levels is of enough concern that the US Department of Health and Human Services developed the National Cholesterol Education Program (NCEP) in 1989 to combat the problem in this country. The NCEP recommends a low-saturated fat, low cholestrol diet, with weight loss (when indicated) to control and correct elevated plasma cholestrol levels.

Weight loss is accomplished by a restricted diet, or increase physical activity. Performing more exercise usually increases the levels of HDL. Studies have been performed on athletes and general fitness advocates and most investigations have shown significant changes in the levels of HDL after exercise. It is evident that aerobic conditioning brings about the most significant changes in HDL. Studies are now underway to determine whether or not resistance exercise produces the same types of changes in cholesterol and its sub-components as aerobic training.

The model of exercise programming into a treatment regime for elevated lipid levels would follow a three phase program (such as the cardiac rehabilitation section above). This program should start with an initial phase where supervised training teaches clients the benefits of conditioning and their effects on lipid levels. They will then move to a phase whereby they assume more responsibility for a self-paced program, and the instructor changes in the routine and records outcomes information for medical professionals and payors.

PHASE	AEROBICS	STRENGTH	SETS/REPS	COMMENTS
Phase I	Walking: 10-15 min.	General range of motion: major muscles	2 sets of 15 reps: with light weights	Supervised: 1-0n-1 conditioning
	–or–
	Stationary cycling: 10-20 min.	Light dumb bells	2 sets of 15 reps	Work on improving: range of motion and technique each session
	Elastic/rubber tubing		1-2 sets, 5-10 reps
Phase II	Increase aerobic activity to 20 min. 3-4 days per week.	Light dumb bells	2-3 sets increase 8-10 reps each week	Increase 5 lbs. on the upper body, 10 lbs. on the lower body
				Supervised: 1-0n-1, moving to self-paced
Phase III	Any combination of aerobic machines, or low impact classes	Strength machines exercise, Free weights	2-4 sets of 10-8-6 reps	Exercise to a more progressive format Train with a partner Work on perfecting exercise form, strength, and range of motion

Conclusions

The key for making changes in lipid levels is adherence to a regular routine for the first phase of conditioning so that significant reductions in lipid levels may be achieved in a 2-3 month period, and these changes can be maintained over long periods of time (years). With a small weight loss, lipid recductions and hypertention will probably decrease, as well.

1. American College of Sports Medicine. Guidelines for Exercise Testing and Prescription. 4th edition. Lea and Febiger. 1991.


2. Kalkoff, RK, Kim, HJ, Cerletty, A, Ferrou, CA. Metabolic effects of weight loss in obese subjects: changes in plasma substrate levels, insulin, and growth hormone responses. Diabetes. 20; 83-91, 1971.


3. Katch, FI, McArdle, WD. Nutrition, Weight Control, and Exercise. (3rd ed.). Lea and Febiger Publishers, Philadelphia, PA, 1988.


4. Olefsky, J. Reaven, GM Farquahar, JW. Effects of weight reduction on obesity: Study of lipid and carbohydrate metabolism in normal and hyperproteinemic subjects. Journal of Clinical Investigation. 53;64-76, 1974.


5. Kokkinos, PF, Hurley, Strength training and lipoprotein-lipid profiles: A critical analysis and recommendations for further study. Sports Medicine. 9;5:26672, 1990.


6. Molitch, ME, Oill, P, O;Dell, WD. Massive hyperlipidemia during estrogen therapy. JAMA. 227:522, 1974.


7. Lipid Research Program. The lipid research clinic coronary primary prevention trail results. In: Reduction in incidence of coronary heart disease. JAMA. 251:351-64, 1984.


8. Lopez, SA, et al. Effect of exercise and physical fitness on serum lipids and lipoproteins. Athersclerosis. 20:1-9, 1974.


9. Summary of the Second Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. JAMA. 269:3015-3023, 1993.


10. Gordon, D.J., Rifkind, B.M. High density lipoprotein: The clinical implications or recent studies. New England Journal of Medicine. 321:1311-16, 1989.


11. Wood, P.D., Stefanick, M.L., Williams, P.T., Haskell, W.L. The effects on plasma lipoproteins of a prudent weight-reducing diet, with or without exercise, in overweight men and women. New England Journal of Medicine. 325:461-66, 1991.

In pregnancy, every task performed during the day may have some impact on gestation, such as work hours, laying in the sun, drinking alcohol, etc. So the concept of exercise should be taken out of the realm of performance or aesthetics, and should be part of the pregnant women’s health regime throughout pregnancy.

Since many types of equipment are not applicable to pregnancy, it has been historically difficult for pregnant women to perform machine exercises such as biking, rowing, and cross-country skiing without modifying the machines. Recently, there have been some advancements in the fitness community that may benefit pregnant women who wish to continue to perform exercise programs throughout their pregnancies.

The first area of enhancement is in aerobic machines. A few years ago a research study was performed on different types of aerobic machines to find out which ones may be safe to use throughout pregnancy, particularly ones that did not cause any unnecessary uterine contractions. Of all the machines tested, the upper body ergometer, or UBE performed the best. It is thought that the UBE, because it is used with the arms, tends not to disturb the fetus as much as exercise performed with the lower aspect of the body. Jarring, rhythmic movement of the legs, bouncing, etc. all cause some type of stress to the body overall. Movement of the arms in a seated position may be able to produce an aerobic effect without as much overall body stress. Since there was no discernable uterine contractions, and no effect on fetal heart rate, it is thought that the blood supply to the fetus was not disturbed much during the exercise itself.

Upper body aerobic exercise may play an important role in getting larger numbers of pregnant women to continue, or even begin an exercise program safely during their pregnancies.

The second area of interest is the buoyancy flotation devise known as the Aqua-Jogger^TM. The Aqua Jogger is a semi-floatation belt worn around the waist and used in the deep end of a pool. When using the belt, the exerciser is able to “jog” around the deep end at any given pace, or heart rate, while keeping the head and shoulders out of the water.

The beauty of the Aqua Jogger is that you do not have to be a swimmer to use the belt. Exercise has been touted as the perfect exercise for pregnant women, because it places virtually no stress on joints, it tones muscles though progressive resistance exercise, provides an aerobic component, and cools the body while performing exercise. The only drawback was that if the exerciser did not know how to swim, then they would not choose swimming as their main form of exercise. With the Aqua Jogger, that element has been eliminated.

The cost of the jogger is around $50, so it may be one of the smarter investments for a fitness program. If there is a community pool, or an exercise program that has a pool, it would be easy to use the jogger in the deep end of any facility. The jogger can be used long after pregnancy, as well.

The fourth area of exercise and pregnancy that would be beneficial for pregnant women is by using a heart rate monitor during classes, and general exercise. A heart rate monitor consists of an elastic strap around the ribs that has sensors picking up heart rate tones. The second part of the apparatus is the heart rate monitor, usually in the form of a wrist watch that has the actual reading of the heart rate. It is a very handy apparatus to have, if you are.

The third area of health enhancement is learning how to recognize a uterine contraction. When the uterus experiences excess stress, it usually starts to contract. Most of the time these contractions are not noticeable, except to the touch.

Fitness and health professionals who prescribe exercise during pregnancy should be aware that exercise itself may precipitate uterine contractions. In most cases, they are not harmful. but are an indicator that exercise may be too intense and should be halted. A uterine contraction, as in any other type of muscle contraction, feels hard to the touch. By placing the fingers just below the diaphragm, it is possible to palpate the top of the uterus to contraction. It is experienced simultaneously by the mother-to-be. Working with an obstetrician or nurse midwife could help you recognize what a contraction feels like.

Area number five is the most important. It is to use common sense. It comes from the cumulative experiences and perceptions that the health and fitness specialist understands the complexities of prescribing exercise during pregnancy. In most cases, it is simple. In others, it is more difficult. Nevertheless, each case is different and should be approached with professionalism and courtesy towards others who work with pregnant women.

Fitness professionals may be able to negotiate with medical groups to work with pregnant women in a preventive or therapeutic exercise format, but knowing the physiology of pregnancy, and how to construct a safe and effective program are paramount.

Enabling women to engage in exercise may improve their overall health, impact their birth process, and save medical costs. These are three compelling reasons to educate and instruct women in exercise routines prior to pregnancy, and during their entire gestation.

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