The 10-s Maximal Sprint

A novel approach to counter an exercise-mediated fall in glycemia in individuals with type 1 diabetes

  1. Vanessa A. Bussau, BSC (HONS)1,
  2. Luis D. Ferreira, PHD1,
  3. Timothy W. Jones, MD23 and
  4. Paul A. Fournier, PHD1
  1. 1School of Human Movement and Exercise Science, University of Western Australia, Crawley, Australia
  2. 2Department of Endocrinology, Princess Margaret Hospital, Subiaco, Australia
  3. 3Centre for Child Health Research, Telethon Institute of Child Health Research, University of Western Australia, Perth, Australia
  1. Address correspondence reprint requests to Vanessa A Bussau, BSc (Hons), School of Human MovementExercise Science, University of Western Australia, 35 Stirling Hwy., Crawley, Western Australia, Australia, 6009. E-mail: vbussau{at}cyllene.uwa.edu.au

Abstract

OBJECTIVE—To investigate whether a short maximal sprint can provide another means to counter the rapid fall in glycemia associated with moderate-intensity exercise in individuals with type 1 diabetes and therefore decrease the risk of early postexercise hypoglycemia.

RESEARCH DESIGN AND METHODS—In the study, seven male subjects with type 1 diabetes injected their normal insulin dose and ate their usual breakfast. When their postprandial glycemia fell to ∼11 mmol/l, they pedaled at 40% ˙Vo2peak for 20 min on a cycle ergometer then immediately engaged in a maximal 10-s cycling sprint (sprint trial) or rested (control trial); the sprint and rest trials were administered in a counterbalanced order.

RESULTS—Moderate-intensity exercise resulted in a significant fall (P < 0.05) in glycemia in both trials (means ± SE: 3.6 ± 0.5 vs. 3.1 ± 0.5 mmol/l for sprint and control, respectively). The subsequent short cycling sprint opposed a further fall in glycemia for 120 min, whereas in the absence of a sprint, glycemia decreased further (3.6 ± 1.22 mmol/l; P < 0.05) after exercise. The stabilization of glycemia in the sprint trial was associated with elevated levels of catecholamines, growth hormone, and cortisol. In contrast, these hormones remained at stable or near-stable levels in the control trial. Changes in insulin and free fatty acid levels were similar in the sprint and control trials.

CONCLUSIONS—These results suggest that after moderate-intensity exercise, it is preferable for young individuals with insulin-treated, complication-free type 1 diabetes to engage in a 10-s maximal sprint to acutely oppose a further fall in glycemia than to only rest. The addition of the sprint after moderate-intensity exercise provides another means to reduce the risk of hypoglycemia in active individuals with type 1 diabetes.

Footnotes

  • A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.

    The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

    • Accepted December 7, 2005.
    • Received September 20, 2005.
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