What time of the day a diabetic should exercise ?

What is an “Exercise”? It is any form of bodily movements that increases the physical fitness and overall well-being of an individual. Everyone has a different reason to indulge in exercise. Few do it to reduce weight, to control their medical condition like hypertension  or diabetes mellitus, to prevent aging, to improve the strength of the muscles and the list goes on.

Benefits of exercising are that it helps to maintain a healthy weight, regulates digestive health, builds and maintains healthy bone density, muscle strength, and joint mobility, promotes physiological well-being, reduces surgical risks, and strengthens the immune system.

Today all over the globe,Diabetes Mellitus is on rise. Main reason for this is the change in lifestyle. Excessive stress, irregular working hours and eating patterns, less of physical activity are few of the causes to have diabetes at an early age. There are two types of diabetes – Type 1 and Type 2. Type 1 diabetes is insulin dependant diabetes wherein the body does not  produce insulin. Type 2 diabetes is insulin resistant diabetes wherein the insulin is normally produced by the body but the body is unable to utilize it.

What is the role of insulin in the body and what effect does exercise have in diabetes? When we ingest food, it is converted into glucose and it circulates in the blood. This stimulates the release of insulin from the beta cells of the pancreas. This insulin then helps the circulating glucose to enter our cells to produce energy. In diabetics, all this also happens but the only difference is that due to relative insulin deficiency not all glucose enters the cell and get converted to energy. When a diabetic person exercises, the sensitivity of tissue cells(skeletal muscle) to insulin increases and more glucose can then enter the cells and reduce the blood glucose levels.

Exercises can be performed during  any part of the day as per the individual’s choice. But when a diabetic performs any form of exercise, they need to be careful regarding excessive surge as well as drop in blood glucose levels as there are many factors which can affect his performance during the exercise session. He can have a hypoglycemic episode during the session (if exercise is prolonged) or later after 2 to 3 hours . In hypoglycemia, one can experience ,excessive sweating ,giddiness, blurred vision, palpitation or in worst case unconsciousness. Hence a diabetic must keep in mind about the food intake before the exercise, his dosage of medications which can be insulin or oral hypoglycemics,intensity of exercise , time of the day and site of insulin injection.

When the exercises are done during morning time, the levels of hormone cortisol are higher. (normal diurnal variation).These high levels of circulating cortisol lowers the action of insulin and keeps the blood glucose levels from dropping. Hence,in a diabetic patient performing exercise in the morning hours there are less chances of severe hypoglycemic attack. But in afternoon when the levels of cortisol drops in the blood there is less resistance to the insulin action which can lead to hypoglycemia. Hence  the morning doses of anti diabetic agents need to be reduced accordingly.

During the later part of the day when the cortisol levels are low,insulin resistance decreases and chances of hypoglycemia due to exercise increases.. Hence the need  to consume a snack prior to exercise containing carbohydrates as per duration and intensity of exercise

Exercising during the night time is no different than the day time. The only concern for night time exercising is that if for some reason the individual undergoes hypoglycemia in sleep, it can be difficult to manage. Although it is said that the light exercises done during night time would not be harmful.

After knowing the effects of exercise during all times of the day, it is recommended that it can be done at any time of the day. If it is decided to exercise during early part of the day before having breakfast and the medications, the individual will have to deal with the elevations in the blood glucose  that will result from the exercise. If it is decided to exercise later during the day, the individual will have to eat a snack before exercise or reduce the medications  to prevent late onset hypoglycemia.