Exercise Timing

The progression of diabetes mellitus can lead to increased complications, morbidity, and mortality. These complications can be delayed by a healthy lifestyle consisting of a balanced diet and physical activity.1There are a variety of exercises that you can engage in to benefit from improved glycemic control and insulin resistance as well as a decreased risk for cardiovascular disease.1However, exercise can result in altered blood glucose levels, so timing is an important factor to consider.2

Type 1 Diabetes

Individuals diagnosed with Type 1 Diabetes require a combined exercise routine of aerobic and resistance exercise training.3 To prevent exercise-induced hypoglycemia, resistance exercise followed by aerobic exercise in the same session is shown to aid in maintaining glycemic balance.1

Additionally, moderate-intensity aerobic exercise performed while fasting results in stable blood glucose levels.3 High-intensity activities are shown to either maintain or raise blood glucose, so shorter duration activities such as sprints are recommended.3 Due to the individual nature of blood glucose control, frequent blood glucose monitoring is essential to determine individual needs for carbohydrate intake and insulin dosing.3

Complications include nighttime hypoglycemia, up to 48 hours post-exercise. This can be prevented by bedtime snacks, lower insulin doses and continuous glucose monitoring if possible.3 Additionally, hyperglycemia following exercise can be prevented by adjusted insulin doses and moderate exercises with cooldown time.

Type 2 Diabetes

Recommendations for those diagnosed with Type 2 Diabetes are like those with Type 1 Diabetes. A combination of aerobic and resistance exercise training is recommended for benefits with blood glucose control; however, the order is not seen to matter with these individuals. Exercise timing throughout the day is up to personal preference.3 Improvements have been seen in hemoglobin A1c values from those individuals participating in exercise following mealtimes but prior to nutrient absorption (~6-8 hours following a meal).3

Prior to Beginning Exercise

When beginning exercise, individuals who are overweight or obese may find achieving aerobic recommendations difficult.1Therefore, sedentary individuals who want to begin physical activity may begin with everyday living activities and brisk walking.3 Beyond that, a doctor should be consulted before beginning vigorous exercise, especially with those with uncontrolled blood glucose levels and an elevated risk for cardiovascular disease.

References:

  1. Sampath Kumar, A., Maiya, A. G., Shastry, B. A., Vaishali, K., Ravishankar, N., Hazari, A., Gundmi, S., & Jadhav, R. (2019). Exercise and insulin resistance in type 2 diabetes mellitus: A systematic review and meta-analysis. Annals of Physical and Rehabilitation Medicine, 62(2), 98–103. https://doi.org/10.1016/j.rehab.2018.11.001
  2. Galassetti, P., & Riddell, M. C. (2013). Exercise and type 1 diabetes (T1DM). Comprehensive Physiology, 1309–1336. https://doi.org/10.1002/cphy.c110040
  3. Colberg, S. R. (2017). Key points from the updated guidelines on exercise and diabetes. Frontiers in Endocrinology, 8. https://doi.org/10.3389/fendo.2017.00033