For most with diabetes, physical activity has a blood glucose lowering effect (1). Hypoglycemia (i.e., blood glucose <65 mg/dL) resulting from exercise is a concern, particularly for insulin users (2). This study was undertaken to document the glycemic effects of engaging in 14 min of any physical activity done for the Big Blue Test (BBT; conducted by the Diabetes Hands Foundation), along with the incidence of hypoglycemia, in both insulin (78.9%) and noninsulin (21.1%) users. In 2011, all 3,916 BBT participants self-reported their diabetes status, physical activity performed, self-monitored blood glucose values before and after exercise, and use of supplemental insulin. Walking was the most common activity (40.0%), followed by running/jogging (13.3%), cycling (8.5%), dance (8.0%), and exercise conditioning machines (7.4%). Although 89.2% of all participants experienced a decrease in blood glucose levels, declines were significantly greater in insulin users (−35.2 ± 0.7 vs. −23.0 ± 1.0; P < 0.05) and more insulin users (3.9%) experienced postexercise hypoglycemia (121 vs. 4; P < 0.05), as expected (3). However, this small incidence of hypoglycemia suggests that a relatively short duration of exercise carries a fairly low risk. Only 0.8% of participants (23 insulin and 10 noninsulin users) recorded no change in blood glucose levels, whereas 10.0% of insulin users and 10.3% of noninsulin users had increased levels. Thus, the 2011 BBT has demonstrated that participation in 14 min of varying types of physical activity effectively lowers blood glucose levels in most individuals with diabetes. In type 1 diabetes, insulin administration, food intake, and exercise have to be carefully matched to avoid either hypoglycemia or hyperglycemia, whereas individuals with type 2 diabetes usually experience a glycemic reduction due to physical activity (4,5).
Acknowledgments
S.R.C. analyzed the data and wrote the manuscript. M.J.H. collected the data through the Diabetes Hands Foundation. Both contributed to the study design prior to data collection. S.R.C. is the guarantor of this work and, as such, had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
No potential conflicts of interest relevant to this article were reported.
Parts of this study were presented in abstract form at the 72nd Scientific Sessions of the American Diabetes Association, Philadelphia, Pennsylvania, 8–12 June 2012.
The authors would like to acknowledge Andreina Davila, Emily Coles, and Emily Walton for their assistance in formulating the data collection mechanisms for the Big Blue Test and in collecting and managing all the data.
References
- 1.Colberg SR, Sigal RJ, Fernhall B, et al. ; American College of Sports Medicine American Diabetes Association. Exercise and type 2 diabetes: the American College of Sports Medicine and the American Diabetes Association: joint position statement. Diabetes Care 2010;33:e147–e167 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Brazeau AS, Rabasa-Lhoret R, Strychar I, Mircescu H. Barriers to physical activity among patients with type 1 diabetes. Diabetes Care 2008;31:2108–2109 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Younk LM, Mikeladze M, Tate D, Davis SN. Exercise-related hypoglycemia in diabetes mellitus. Expert Rev Endocrinol Metab 2011;6:93–108 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Galbo H, Tobin L, van Loon LJ. Responses to acute exercise in type 2 diabetes, with an emphasis on metabolism and interaction with oral hypoglycemic agents and food intake. Appl Physiol Nutr Metab 2007;32:567–575 [DOI] [PubMed] [Google Scholar]
- 5.Szewieczek J, Dulawa J, Strzałkowska D, Hornik B, Kawecki G. Impact of the short-term, intense exercise on postprandial glycemia in type 2 diabetic patients treated with gliclazide. J Diabetes Complications 2007;21:101–107 [DOI] [PubMed] [Google Scholar]