A 10-Second Sprint Acutely Prevents an Exercise-Mediated Decrease in Glycemia in Individuals with Type 1 Diabetes Mellitus
Abstract Number: 1062-P
Authors: VANESSA A. BUSSAU, LUIS D. FERREIRA, LEANNE M. YOUNGS, TIMOTHY W. JONES, PAUL A. FOURNIER
Institutions: Perth, WA, Australia
Results: Recently we have shown that a short 10-second maximal sprint can counter an insulin-mediated fall in blood glucose levels in individuals with type 1 diabetes mellitus (T1DM). What is not known is whether a short sprint can also prevent the fall in glycemia associated with moderate intensity exercise in individuals with T1DM. In order to address this issue, complication-free T1DM males (20 ± 0.7 years; mean ± S.E.) with HbA1c levels <9% were asked to inject their normal insulin dose and ingest their usual breakfast. Glycemia was determined every 15 minutes and allowed to fall to 10-12 mM, at which point the participants were asked to cycle at 40% of maximal intensity on an air-braked cycle ergometer for 20 minutes. They then performed a 10-second all-out sprint (sprint) or rested during recovery (control). This short sprint resulted in a one hour stabilization of glycemia at an average level of 7.3 ± 0.1 mM, whereas glycemia decreased by 2 mM but at a slower rate than during exercise in the control group. The stabilization in glycemia post-sprint was accompanied by an immediate significant (p<0.05) increase in epinephrine (0.28 ± 0.02 nM) and norephinephrine (7.02 ± 1.4 nM), which returned to pre-sprint levels within 10 and 15 minutes respectively. Growth hormone (GH) levels doubled to attain peak levels of 44.73 ± 10.6 mIU/L 15 minutes post-sprint. Cortisol levels also doubled to attain maximal levels of 565 ± 95.3 nM 30 minutes post-sprint. In contrast, free fatty acids, glucagon and insulin levels during exercise and post-sprint were not significantly different from resting levels (0.14 ± 0.1 mM; 71.98 ± 4.9 pg/ml; 36.4 ± 10.5 mU/L respectively). In the control group there was no significant increase in the levels of any counterregulatory hormones. In conclusion, a 10-second maximal sprint effort can acutely prevent an exercise-mediated fall in glycemia in individuals with T1DM possibly as a result of an increase in catecholamines, GH and cortisol levels.