oronary heart disease is the leading cause of death among people with diabetes. Exercise and an appropriate diet are the mainstay of treatment for diabetes, whether a person is on medication or not.
What does exercise do?
Exercise has what is known as an “insulin-like effect” and helps to lower the blood glucose levels.
Exercise helps to improve insulin sensitivity. This is most important for those with type 2 diabetes who are insulin resistant.
Exercise helps improve other risk factors for heart disease, such as improvements in blood pressure, cholesterol profile as well as weight loss.
Evaluation before exercise
It is important to consult your physician before beginning an exercise programme. A stress test is also recommended for those who smoke, have long-standing diabetes or additional risk factors for heart disease; high blood pressure, high cholesterol or family history of heart disease.
How much should you exercise?
It is important to warm up before exercise. It should consist of five to ten minutes of aerobic activity at low-intensity level.
Frequency of exercise: Four to six days a week, or daily at low to moderate intensity
Duration: 20-60 minutes per session
Intensity: 60-85 per cent of maximum heart rate. Maximum heart rate is calculated by the formula 220 minus age. However, if you do not want to measure your heart rate, you should exercise at an intensity which feels “fairly light to somewhat hard”.
Type of exercise: Any aerobic exercise which uses the large muscle groups in a continuous manner like walking, cycling or swimming, are good. In addition, strength training has also been shown to effectively control blood sugar. One set of eight to ten different exercises for the large muscle groups should be done two to three days a week. Following the activity, cool down for five to ten minutes to bring down the heart rate.
Points to remember:
Exercise reduces blood sugar levels, which is good, but sometimes the medicine and exercise combined may result in hypoglycaemia. So monitor blood glucose (with a glucometer) before and after exercise, at least the first few times.
Exercising late in the evening or night increases risk of hypoglycaemia while sleeping.
Insulin dose and site of injection may need to be adjusted when you start exercising. It is preferable to inject insulin in the stomach area rather than legs before exercise. Please do not adjust your dose without consulting your doctor.
Examine feet for any injuries on a daily basis. Some diabetics lose sensation in their feet and may not feel minor injuries, which then may lead to complications like ulcers.
Avoid high-impact exercises such as step aerobics if you have diabetic retinopathy.
Avoid starting exercise if your blood sugar is more than 300mg/dl or if you have a condition called ‘ketones’ in your urine. Always keep a sugary snack by your side while exercising. This can be consumed if you feel signs and symptoms of hypoglycaemia, such as light-headedness.
Make sure you wear a good pair of walking shoes with adequate cushioning to protect your feet. It is equally important to change your shoes on a regular basis, such as after every 500-700km of walking.
Dr Aashish Contractor is head, rehabilitation and sports medicine, H.N. Reliance Foundation Hospital, Mumbai.