Exercise for Diabetics

People with diabetes are encouraged to exercise regularly for better blood sugar control and to reduce the risk of cardiovascular diseases.

The reason for this is that muscles which are working use more glucose than those that are resting.

Muscle movement leads to greater sugar uptake by muscle cells and lower blood sugar levels. Additional benefits of exercise include a healthier heart, better weight control and stress management.

Exercise precautions

There are some exercise precautions which people with diabetes must take, however, when done safely, exercise is a valuable aid to optimal health.

Exercise precautions are designed to help people with diabetes avoid problems which can result from unwise exercise choices. Hypoglycemia can occur if a person who is taking blood sugar lowering medication has:

• Eaten too little carbohydrate (fruit, milk, starch) relative to the exercise.
• Taken too much medication relative to the exercise
• Combined effect of food and medication imbalances relative to the exercise

Those who do not take diabetes medication do not need to take these precautions. Drink plenty of water before, during and after exercise to stay well-hydrated.

Precautions for people on insulin or oral medication

Precautions to take if you take insulin or oral diabetes medication:

• If your blood sugar level is less than 5.5 mmols/l (100 mg/dl) prior to exercise, take a carbohydrate snack prior to beginning the exercise.
• If your blood sugar level is higher than 5.5 mmols/l (100 mg/dl) before exercise, it may not be necessary to take a carbohydrate snack before a light exercise session, but you may need extra carbohydrates during or following the exercise. Check your blood to see if your blood sugar dips below 4 mmols/l (70 mg/dl) following exercise.
• If you experience hypoglycemia, follow the Carbohydrate Treatment guidelines. Follow up with your doctor. You may be advised to lower your medication on days you exercise if your blood sugar levels are well-controlled and usually within target range. 
• For long duration and/or high intensity exercise sessions, plan extra carbohydrate snacks during the activity. Additional carbohydrates is suggested each 30 to 60 minutes of exercise (e.g. soccer game, hiking, biking, skating, etc).
• Always carry a fast-acting carbohydrate food such as glucose tablets when exercising in the event blood sugar drops too low and hypoglycemia symptoms develop during exercise.
• Wear a form of ID, which identifies you as having diabetes, particularly if you are exercising alone so that others may help you appropriately in the event something unexpected happens.

Severe Hyperglycemia (with or without Ketoacidosis)

This can occur when:

• Too little insulin is available to counteract the liver's production of sugar which is stimulated by exercise hormones.
• Too little insulin is available to assist glucose enter muscle cells quickly during exercise.
• Too much fat is utilized for exercise because sugar is unable. Ketones levels rise in the blood.

Precautions to take against hyperglycemia

Do not exercise if:

• Your blood sugar is above 13 mmol/s (240 mg/dl), especially with positive urine test for ketonuria, as exercising could result in higher blood sugars and lead to diabetic ketoacidosis. Follow your doctor's advice to lower blood sugar before recommencing exercise.
• You are sick with flu, infection or another illness that is worsening blood sugar control.
• If your blood sugar level is above 13 mmols/l (240 mg/dl) but less than 17 mmols/l (300 mg/dl), limit your activity to moderate intensity (walking, light biking), rather than a high intensity exercise (running, weight lifting, tennis).

Precautions for people with heart problems

People with heart conditions, in particular, should consult with their doctor before commencing an exercise regimen.

The British Heart Foundation advises people with existing heart conditions to avoid strenuous activity such as lifting weights, press ups or exercise which could result in chest pains or getting up from the floor quickly.

Worsening foot complications

Foot problems can occur when:

• Shoes fit poorly
• Socks are not worn or are not absorbent
• Friction or pressure points develop on feet

Precautions to take for feet

• Inspect feet daily for signs of friction or pressure sores.
• Speak with your physician, podiatrist or diabetes educator about proper foot care procedures.
• Buy shoes which are well-made for the type of exercise you do and which fit you.
• Consult a shoe retailer who specializes in exercise foot wear.
• Buy cotton, absorbent socks.