What Will Happen to the Blood Sugar Level During and After Exercise?

Exercise is good for losing weight, good for elevating mood, and good for blood sugar level and heart too. Though it is good for the blood sugar levels, it can be tricky at times. It is well known that exercise has multi-faceted benefits and its benefits are immense of blood sugar levels. Let us see how exercise affects the blood sugar level during and after exercise.

What Will Happen to the Blood Sugar Level During and After Exercise?

Blood Sugar Level During Exercise

The first benefit of exercise is that it reduces the blood sugar level. This happens because the muscles work harder and so they require more energy. The glucose found in our cells provides energy to our cells. Insulin is a hormone that helps in transferring the glucose from the blood to the cells.

The ways in which the blood sugar level reduces during exercise are as follows:

  • Increase in insulin sensitivity so that the muscle cells can utilize the insulin in a better way by taking up glucose both pre and post exercise.
  • As the muscles contract during exercise, the cells take up glucose for energy regardless of the availability of glucose or not.
  • The effect of physical exercise on the blood sugar level varies according to the time period you remain active and other factors too. Physical activity can reduce the blood sugar levels by 24 hours or even more after workout thus making the body sensitive to insulin.

As the body warms up during exercise, muscles need more nutrients for manufacturing energy. Using energy during physical exercise helps in balancing high blood sugar. With the increase in blood flow to the muscles, there is an increase in energy supply too. The muscle cells begin to burn glucose and this reduces the blood sugar levels. When your blood sugar level is high when you start the physical activity, it can rise higher. This happens because the body is not able to generate glucose in the blood and the liver breaks down glycogen. If the level of blood sugar is high pre-exercise, then wait till it reaches normal. In the case of diabetic patients, check the levels before you exercise and eat high fibers and complex carbohydrates as these promote a steady and slow rise in blood sugar that helps to sustain when you exercise.

Blood Sugar Level After Exercise

If your blood sugar level is within 250 prior to an exercise, the blood sugar level is usually seen to be at the same level or a little reduced after an exercise. Maintaining the same level of physical activity and exercise helps in reducing blood sugar levels after an exercise provided the insulin levels in the blood is adequate.

However, if the insulin level is inadequate in the blood, then an exercise session can result in further rise in blood sugar instead of an expected drop in it. Low insulin along with physical activity promotes secretion of many other hormones like norepinephrine, epinephrine, glucagon, cortisol, and growth hormone. These hormones collectively make the liver release more glucose into the blood, causing raise in blood sugar rather than reducing it. For preventing this, check the blood sugar levels prior to exercise and in case the level exceeds 250, delay the exercise till it goes below 250.

Another reason why the blood sugar levels rise after exercise is that of the vigorous exercise. When the exercise is more intense, the glucose secretion is greater. When the session is strenuous, stress hormones are secreted in huge quantities that stimulate the liver for releasing glucose. So, when the exercise is more vigorous, the release of glucose by the liver will cause the blood sugar level to rise rather than fall. Moreover, the stress hormones level in the blood get elevated after an intense workout for several hours and this result in quite raised sugar levels. Thus, blood sugar levels may stay high for many hours when exercise is done.

The athletes who do strenuous workouts regularly may not require eating large portions prior to the strenuous sessions. Additionally, the body adjusts to intense workouts causing a reduction in hormonal secretion when the workouts are done with the same intensity. As an effect, exercise at the beginning that cause a fall in blood sugar levels and lesser rise later on.


In short, monitor the blood sugar levels prior to exercise, during the exercise if the exercise session goes beyond an hour and post-exercise either one or two times. The non-athletes do not need high-intense workouts for improving the fitness and health in general or improving the blood sugar levels. It makes management of blood sugar difficult and can even increase the chance of injury, heart attack, sore muscles, etc.

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Team PainAssist
Team PainAssist
Written, Edited or Reviewed By: Team PainAssist, Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:August 3, 2018

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