Improved insulin sensitivity after a single bout of exercise is curvilinearly related to exercise energy expenditure

Faidon Magkos , Yannis Tsekouras , Stavros A Kavouras , Bettina Mittendorfer , Labros S Sidossis (1)

1 Department of Nutrition and Dietetics

A single bout of moderate-intensity exercise increases whole-body insulin sensitivity for 12-48 hours post-exercise. However, the relationship between exercise energy expenditure and the improvement in insulin sensitivity is not known. We hypothesized that the exercise-induced increase in whole-body insulin sensitivity, assessed with the homeostasis model assessment of insulin resistance (HOMA IR}), is directly related to the energy expended during exercise. We studied 30 recreationally active, non-obese men (age: 27±5 years, body mass index: 24±2 kg/m 2}) in the post-absorptive state on two separate occasions: once after exercising at 60% of peak oxygen consumption for 30-120 min on the preceding afternoon (expending a total of 1.28-5.76 MJ) and once after an equivalent period of rest; blood samples were obtained the following morning. Exercise-induced changes in HOMA IR} were curvilinearly related to exercise energy expenditure (r=-0.666, P=0.001) with a threshold of ~3.77 MJ (900 kcal) for improvements in HOMA IR} to manifest. In particular, HOMA IR} was reduced by 32±24% (P=0.003) in subjects who expended more than 3.77 MJ during exercise, but did not change for those who expended fewer than 3.77 MJ (-2±21%, P=0.301). Furthermore, the magnitude of change in HOMA IR} after exercise was directly associated with baseline (i.e., resting) HOMA IR}(r=-0.508, P=0.004); this relationship persisted in multivariate analysis. We conclude that improved whole-body insulin resistance after a single bout of exercise is curvilinearly related to exercise energy expenditure, and requires unfeasible amounts of exercise for most sedentary individuals.

Mots clés: Medicine

Faidon Magkos, Yannis Tsekouras, Stavros A Kavouras, Bettina Mittendorfer, Labros S Sidossis. Improved insulin sensitivity after a single bout of exercise is curvilinearly related to exercise energy expenditure. Clinical Science, 2007, 114 (1), pp.59-64. ⟨10.1042/CS20070134⟩. ⟨hal-00479378⟩