The Effect of Exercise on Type 1 Diabetes: More than Meets the Eye

 

Pathology:

            Insulin is an important player for anabolic reactions in the body. In other words, when there are plenty of nutrients, like after a meal, insulin signaling makes the body use those and fill up the fatty acid and glycogen storages, and also signals for muscle build up (i.e., protein synthesis). Thus, insulin is a crucial endocrine hormone which without it many body functions are impaired. In type 1 diabetes, autoimmune destruction of beta cells takes place and due to loss of beta cell mass, the body cannot make enough insulin or even none at all. How is it bad?

Before we go any further, let’s do a simplified run of how insulin works. There is about 4 grams of glucose circulating in the blood of healthy individuals all the time. After a meal or snack, when blood glucose rises, insulin is secreted into the bloodstream. How? Beta cells of the pancreas make insulin which is later picked up by blood circulating in that area. Thereafter, insulin acts like a key that later on allows specific doors for glucose, called GLUT4, located on the cell surfaces of muscles or adipose tissues to open up. Upon interaction of insulin to its receptors on the cell surface, i.e. cell membrane, GLUT4 transporters will be translocated to the surface and allow entry of glucose. This process will continue until blood glucose level is back to normal.

So, in those with type 1 diabetes, there is a higher blood glucose to begin with and that amount goes even higher after a meal. Some of the symptoms of type 1 include: increased thirst and frequent urination, blurred vision, extreme hunger, weight loss, and fatigue. That is why those individuals take insulin injections to maintain the blood glucose level and prevent hyperglycemic (high blood glucose) situations. 

Research:

              The research investigating the effects of physical activity on type 1 diabetes is much less clear than what is available for type 2 diabetes (which we are going to be discussing next week). Although exercise is recommended for those with type 1 diabetes, the improvements in glycemic control with exercise has not been as clearly established as it has for type 2 (Peirce, 1999) (American Diabetes Association, 2002). However, although this is the case, it does not mean that exercise is not beneficial. Aerobic training has been seen to increase cardiorespiratory fitness, decrease insulin resistance, and improve fat levels in those with type 1 diabetes (Pivovarov et al. 2015). In addition, although the effect of resistance exercise on glycemic control for those with type 1 diabetes is unclear, resistance exercise can help decrease the risk of exercise-induced hypoglycemia in those with type 1 (Pivovarov et al. 2015).

              Therefore, although the effects of exercise on type 1 diabetes is unclear, those who suffer from this illness can still benefit from both aerobic and resistance activities.

Exercise:

              When dealing with exercise programs for those with type 1 diabetes, one needs to first question how intense, how long, and what kind of exercise will be conducted in order to properly prepare for it (Blackburn & Byron-Daniel, 2021). The best way to ensure that this is taken into account is to consult a medical professional. However, it is important to ensure that one’s glycemic levels are at an optimal range prior and during exercise. The American Diabetes Association in 2002, outlined several factors to consider when conduction or planning to conduct exercise:

1.    Avoid exercise if fasting glucose levels are 250 mg/dl and ketosis is present and use caution if glucose levels are 300 mg/dl and no ketosis is present.

a.       Ingest added carbohydrate if glucose levels are 100 mg/dl.

2.    Blood glucose monitoring before and after exercise

a.       Identify when changes in insulin or food intake are necessary.

b.       Learn the glycemic response to different exercise conditions.

3.    Food intake

a.       Consume added carbohydrate as needed to avoid hypoglycemia.

b.       Carbohydrate-based foods should be readily available during and after exercise.

**Don’t forget to check out this week's “Interesting Reading of the Week '' located in the sidebar.

**Please note that the exercise related programs from the studies are not the only effective training modality that produce benefits. If you believe that exercise will help you or someone you know, please contact a registered healthcare professional for more information.

**For more detail on this topic or to recommend future content, please email us.

 

Articles referenced:

American Diabetes Association. (2002). Diabetes mellitus and exercise. Diabetes care, 25(suppl 1), s64-s64

Blackburn, R., & Byron-Daniel, J. (2021). A qualitative exploration of attitudes towards physical activity, exercise and sport participation in people living with type one diabetes (T1D).

Peirce, N. S. (1999). Diabetes and exercise. British journal of sports medicine, 33(3), 161-172

Pivovarov, J. A., Taplin, C. E., & Riddell, M. C. (2015). Current perspectives on physical activity and exercise for youth with diabetes. Pediatric diabetes, 16(4), 242-255.