Diabetes & Exercise
Exercise is an important but a neglected aspect of the treatment of diabetes. Ayurveda stressed the importance of exercise in management of diabetes. Bouchardat, the famous French physician, advised his diabetic patients to earn their bread by the sweat of their brow.
Modern transport, the introduction of gadgets and the automation in industry have eliminated physical exertion in many jobs and in day-to-day life, in many societies. Diabetes is more common in those communities leading a sedentary life than in those who are physically active.
Benefits of exercise for Diabetes
Exercise enhances the efficiency of the heart and the lungs, improves the toning of the muscles and the blood vessels and encourages bowel movements. It reduces the level of blood lipids for example, cholesterol and triglycerides in blood and reduces blood viscosity. It improves the blood flow by opening new channels and lowers blood pressure. Regular exercise is beneficial in weight reduction. Since there is a close relation between diabetes, blood vessel disease and obesity exercise has special significance to a person with diabetes. Whether healthy or a diabetic, regular exercise gives a feeling of well-being.
Exercise increases insulin sensitivity. Diet and exercise are useful in prevention and management of type 2 diabetes.
During acute exercise, the muscles utilize glucose as its fuel. This glucose is produced by liver. The overall effect of exercise is to lower the blood glucose level. However, this beneficial effect of exercise occurs only if some insulin is available. When insulin is not available. strenuous exercise may produce hyperglycaemia and even ketoacidosis. This may happen in type 1 diabetes.
Grades of exercise
Exercise is graded according to the degree of energy expenditure.
| Light activity | - Standing, domestic work. |
| Mild activity | - Walking 4 km an hour, bicycling 8 km per hour and gardening. |
| Moderate activity | - Swimming, walking 5 to 6 km/hour, badminton and volley ball. |
| Vigorous activity | -Tennis, hill climbing, running 16 Km/hour, cycling 20 km/hour, wood chopping. |
Exercise programme for Diabetes
The exercise programme of a diabetic has to be individualized and incorporated into his/her daily schedule. The following points are considered while chalking out the exercise programme: age of the diabetic, duration of diabetes, physical fitness, condition of the heart, the blood vessels, the lungs and the eyes, time available and individual preference.
Coronary artery disease occurs very commonly in middle aged and elderly diabetics. Diabetics of this age group should undergo a stress test with an ECG monitoring, before undertaking a physical activity more strenuous than brisk walking. A young diabetic may run, bicycle and play tennis, badminton and Indian games. A middle-aged or an elderly diabetic should not undertake a new strenuous physical activity unless he/she is in regular physical training and unless judged fit by the doctor to do so. He/she should avoid vigorous competitive sports. Walking is the best exercise for middle-aged and elderly diabetics. Elderly individuals should not change the position of the head and neck suddenly.
Young women may participate in games. Physical exercise does not affect menstruation, A pregnant woman should avoid sports involving bumps and falls and avoid competitive sports.
The duration of exercise may be 30-20 minutes for those with a low physical fitness, 30-45 minutes for those with moderate fitness, and 60 minutes or more for those with a high degree of physical fitness. Strenuous physical exercise is not necessary.
Even moderate exercise is beneficial. Multiple short sessions of exercise of 10 min. each are as beneficial as a single long session of exercise. Exercise, more severe than moderate exercise, should be preceded and followed by warming and cooling period, of at least 5 min. each. In addition to daily moderate exercise, more vigorous exercise 3-4 times a week gives additional benefit.
Hazards of Exercise
Exercise is forbidden when blood glucose level is over 300 mg/dl in type 1 diabetes and over 400 mg/dl in type 2 diabetes, because with exercise, the blood glucose level would rise further. During exercise, the liver releases stored glucose. When circulating insulin is adequate, the muscles can use this glucose as fuel. A high blood glucose prior to exercise may mean that insulin circulating in the blood cannot match the blood glucose level. In such situations, glucose released from the liver during exercise increases the blood glucose level further.
Exercise is forbidden in the presence of ketosis. Exercise in such circumstances, will worsen ketosis, aggravate the blood glucose level and precipitate diabetic ketoacidosis.
Proper foot wear and other protective accessories should be used. Feet should be inspected before and after exercise. Activities which are likely to hurt the feet, such as vigorous walking, running and jogging are not advisable for those with thin and delicate skin of the feet or numbness of the feet or for those who have undergone an amputation of a part of the foot due to blood vessel disease. Swimming is an useful form of exercise when feet are numb. Walking should be avoided when there is an open wound, a cut, a painful corn or a callus of the foot.
A diabetic should report to the doctor when there is discomfort in the chest, jaws or arms, marked fatigue, severe breathlessness, dizziness or irregularity of heart beat during exercise. Exercise should not be started unless high blood pressure is controlled.
Strenuous physical activity or sudden straining should be avoided in the presence of advanced disease of the retina. Lifting weight more than 2% kg should be avoided after laser treatment of the retina. Abrupt changes in vision, blind spots, blurred vision could mean worsening of diabetic eye disease.
Exercise is not advisable in the presence of an illness or an infection or a serious injury. Alcohol should not be consumed immediately before or after an exercise.
Exercise may be hazardous at extremes of temperature. Chances of developing hypoglycaemia or dehydration increase in hot, humid weather. Frostbite and cracked skin can occur in extremely cold weather. It is preferable to exercise indoors in such situations.
Exercise and Hypoglycaemia
The exercising muscles use glucose when the release of insulin is adequate. Walking for one hour increases the requirement of carbohydrates by 20 g. More vigorous exercise can consume 40 g or more carbohydrates per hour of exercise. Exercise is an important cause of hypoglycaemia. A diabetic should plan his activities, including exercise and sports. A diabetic can judge by experience the amount of carbohydrates that has to be taken before an anticipated physical activity. A lean diabetic should take extra food 15-20 minutes before an anticipated exercise. Some diabetics may need food after the physical activity.
Instead of taking extra carbohydrates, persons taking insulin should reduce the dose of short acting insulin, usually by 30 to 50 per cent, before exercise, to avoid hypoglycaemia. Those taking combination of short and intermediate-acting insulin, should reduce the type of insulin which acts at the time of exercise. Till the pattern of blood glucose response to exercise is known, blood glucose monitoring before, during and after exercise is useful. The insulin dose need not be reduced, before a brief but an intense exercise. The insulin schedule can be readjusted according to post-exercise blood glucose level.
In type 2 diabetes extra carbohydrates are usually not necessary before exercise. Those on insulin or sulphonylureas, may have to reduce the doses of these drugs before exercise, to prevent hypoglycaemia.
Exercise should be avoided at the time of peak action of insulin. Insulin should not be injected over an exercising muscle.
A diabetic who is exercising should carry some sugar. A diabetic should take two to three teaspoons of sugar or glucose dissolved in water when he/she gets the warning signals of hypoglycaemia (see Ch. i 3).
A diabetic, taking insulin or the sulphonylurea group of drugs should not swim alone, and should carry some sugar in a waterproof pouch attached to a belt. His/her companions should be able to recognise and manage hypoglycaemia.
Sports
Diabetics participating in sports should have proper footwear, other protective accessories and should be aware of the hazards of the particular type of sport.
Many diabetics have distinguished themselves in various sports. William Talbert developed diabetes at the age of ten. His father encouraged him to take to tennis. Though a diabetic, Talbert won 38 national and 30 international tennis championships. He was the captain of the Davis Cup Team of the US for five consecutive years. He traveled more than 2,000,000 miles all over the world and gave himself insulin injections on trains, ships, planes and automobiles. Hamilton Richardson, the American tennis player, Ackerman, the South African Test cricketer, Wasim Akram. Pakistani test cricketeer and Bob Clarke, the American ice hockey champion have diabetes. Roger Mills and Dave Caterral, both diabetics taking insulin, played badminton for 30 hours to create a
Strenuous and hazardous sports like mountaineering and water polo are, in general, not suitable for diabetics. But there are many diabetics who have successfully participated in these and similar hazardous activities. A diabetic sportsman and his team mate should abb to recognise and treat hypoglycaemia. However diabetics who get hypoglycaemia without warning signals should not participate in hazardous activities.