Physical activity and sports are part of a healthy lifestyle: This is equally important for people with diabetes mellitus. Some type-1 diabetics even compete on high level in amateur or professionals sports. Others see it as an important element in daily life to improve glycaemia and preserve a good quality of life. People affected by type 2 diabetes particularly benefit from physical activity as a means of preventing or delaying further progression of the disease (Physical Activity Guidelines 2018).
Physical activity needs careful planning
Diabetics deal with elevated blood sugar levels, which result from insufficient insulin production, often combined with insufficient cellular response to insulin. Strict meal planning is required, in alignment with insulin supplementation, to normalize and stabilize blood sugar levels.
For a person with diabetes mellitus, sports and physical activity requires careful planning beforehand. Additional carbohydrate intake and insulin supplementation needs to be specifically targeted to the upcoming activity, its intensity and duration, in order to manage blood sugar levels and prevent exercise-induced hypoglycaemic episodes. For someone less experienced, this can be a challenge and often prevents people with diabetes to engage in regular physical activity.
Research-based guidance for diabetic management of physical activity
Research from the British Universities of Swansea and Newcastle (UK) aimed to find ways to improve blood glucose management during exercise, and create solutions on how to overcome barriers of those wishing to engage in physical activity.
They observed from a series of sport studies that people with type-1 diabetes were able to control blood sugar levels best during and after a 45 minutes high-intensity exercise, when they took
- isomaltulose instead of dextrose as carbohydrate load, in a dosage of 1 g per kg body weight and hour as 10% carb solution (West et al 2011).
- together with a 75% reduced dose of rapid acting insulin (West et al 2010).
- at 30 minutes before exercise (West and Stephens et al 2011).
Applying this as pre-exercise glucose management strategy helped to control glycemia rather stable. There appears to be merit for the inclusion of the slow release carbohydrate isomaltulose into such strategies. Isomaltulose improved glycemic control during and after exercise, protected against hypoglycaemia, and maintained running performance (Bracken et al 2012).
Figure 1: Proposed guidance for the diabetic management of physical activity.
… when evening exercise requires glycemic control overnight
Like with many people, a busy work schedule often pushes physical activity into evening hours. Since exercise can induce blood glucose fluctuations over several hours in diabetic conditions, evening exercise can pose a particular challenge for glycaemic control overnight. Two further studies were designed to address this with a sequence of the exercise bout described above, followed by an evening meal and a bedtime snack. Most stable blood glucose levels were achieved, when
- a low glycaemic evening meal with isomaltulose was consumed, together with a 50% reduction of rapid-acting insulin, about 1 hour after exercise, and
- a low glycaemic snack with isomaltulose was consumed, without insulin bolus, about 3 hours after the meal as bed time snack before sleeping. (Campbell et al 2014).
Reducing basal insulin by 20% in addition further contributed to the prevention of nocturnal hypoglycaemia. Campbell et al (2015) reported that virtually all participants who injected their usual amount of basal insulin showed a nocturnal hypoglycaemia, while the ones who reduced their basal insulin by 20% had stable blood glucose levels over the following 24 hours.
The combination of a low GI meal and a reduced insulin dose resulted in a reduction of inflammation, hyperglycemia, and the risk of developing hyperglycemia (Campbell et al 2014).
Figure 2: Enhanced guidance for diabetic management of evening exercise and subsequent glycaemic control overnight.
References
Physical Activity Guidelines Advisory Committee (2018) 2018 Physical Activity Guidelines Advisory Committee Scientific Report. Washington, DC: U.S: Department of Health and Human Services. Link: https://health.gov/paguidelines/second-edition/report/ (retrieved June 2019)
Bracken RM, Page R, Gray B, Kilduff LP, West DJ, Stephens JW, Bain SC (2012) Isomaltulose improves glycemia and maintains run performance in type 1 diabetes. Med Sci Sports Exerc 44(5):800–808. http://journals.lww.com/acsm-msse/fulltext/2012/05000/Isomaltulose_Improves_Glycemia_and_Maintains_Run.5.aspx.
Campbell MD, Walker M, Trenell MI, Stevenson EJ, Turner D, Bracken RM, Shaw JA, West DJ (2014) A low-glycemic index meal and bedtime snack prevents postprandial hyperglycemia and associated rises in inflammatory markers, providing protection from early but not late nocturnal hypoglycemia following evening exercise in type 1 diabetes. Diabetes Care 37:371–379. http://care.diabetesjournals.org/content/37/7/1845.full-text.pdf
Campbell MD, Walker M, Bracken RM, Turner D, Stevenson EJ, Gonzalez JT, Shaw JA, West DJ (2015) Insulin therapy and dietary adjustments to normalize glycemia and prevent nocturnal hypoglycemia after evening exercise in type 1 diabetes: a randomized controlled trial. BMJ Open Diabetes Res Care 3(1):e000085. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4442134/pdf/.
West DJ, Morton RD, Bain SC, Stephens JW, Bracken RM (2010) Blood glucose responses to reductions in pre-exercise rapid-acting insulin for 24 h after running in individuals with type 1 diabetes. J Sports Sci 28(7):781–788. https://www.ncbi.nlm.nih.gov/pubmed/20496226.
West DJ, Stephens JW, Bain SC, Kilduff LP, Luzio S, Still R, Bracken RM (2011) A combined insulin reduction and carbohydrate feeding strategy 30 min before running best preserves blood glucose concentration after exercise through improved fuel oxidation in type 1 diabetes mellitus. J Sports Sci 29(3):279–289. https://www.ncbi.nlm.nih.gov/pubmed/21154013.
West DJ, Morton RD, Stephens JW, Bain SC, Kilduff LP, Luzio S, Still R, Bracken RM (2011) Isomaltulose improves postexercise glycemia by reducing CHO oxidation in T1DM. Med Sci Sports Exerc 43(2):204–210. http://journals.lww.com/acsm-msse/fulltext/2011/02000/Isomaltulose_Improves_Postexercise_Glycemia_by.2.aspx.