The Decline in Blood Glucose Levels Is Less With Intermittent High-Intensity Compared With Moderate Exercise in Individuals With Type 1 Diabetes
- Kym J. Guelfi, BSC(HONS)1,
- Timothy W. Jones, MD23 and
- Paul A. Fournier, PHD1
- 1School of Human Movement and Exercise Science, University of Western Australia, Crawley, Western Australia, Australia
- 2Department of Endocrinology and Diabetes, Princess Margaret Hospital, Subiaco, Western Australia, Australia
- 3Centre for Child Health Research, Telethon Institute of Child Health Research, University of Western Australia, Perth, Western Australia, Australia
- Address correspondence and reprint requests to Kym J. Guelfi, School of Human Movement and Exercise Science, University of Western Australia, 35 Stirling Hwy., Crawley, Western Australia, 6009, Australia. E-mail: kguelfi{at}cyllene.uwa.edu.au
Abstract
OBJECTIVE—To compare the response of blood glucose levels to intermittent high-intensity exercise (IHE) and moderate-intensity exercise (MOD) in individuals with type 1 diabetes.
RESEARCH DESIGN AND METHODS—Seven healthy individuals with type 1 diabetes were tested on two separate occasions, during which either a 30-min MOD or IHE protocol was performed. MOD consisted of continuous exercise at 40% Vo2peak, while the IHE protocol involved a combination of continuous exercise at 40% Vo2peak interspersed with 4-s sprints performed every 2 min to simulate the activity patterns of team sports.
RESULTS—Both exercise protocols resulted in a decline in blood glucose levels. However, the decline was greater with MOD (−4.4 ± 1.2 mmol/l) compared with IHE (−2.9 ± 0.8 mmol/l; P < 0.05), despite the performance of a greater amount of total work with IHE (P < 0.05). During 60 min of recovery from exercise, glucose levels remained higher in IHE compared with MOD (P < 0.05). Furthermore, glucose levels remained stable during recovery from IHE, while they continued to decrease after MOD (P < 0.05). The stabilization of blood glucose levels with IHE was associated with elevated levels of lactate, catecholamines, and growth hormone during early recovery from exercise (P < 0.05). There were no differences in free insulin, glucagon, cortisol, or free fatty acids between MOD and IHE.
CONCLUSIONS—The decline in blood glucose levels is less with IHE compared with MOD during both exercise and recovery in individuals with type 1 diabetes.
Footnotes
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A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
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- Accepted March 11, 2005.
- Received December 17, 2004.
- DIABETES CARE
