TY - JOUR

T1 - Improved insulin sensitivity after a single bout of exercise is curvilinearly related to exercise energy expenditure

AU - Magkos, Faidon

AU - Tsekouras, Yannis

AU - Kavouras, Stavros A

AU - Mittendorfer, Bettina

AU - Sidossis, Labros S

N1 - (Ekstern)

PY - 2008

Y1 - 2008

N2 - A single bout of moderate-intensity exercise increases whole-body insulin sensitivity for 12-48 h 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 HOMAIR (homoeostasis model assessment of insulin resistance), 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/m2) in the post-absorptive state on two separate occasions: once after exercising at 60% of VO22peak (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 HOMAIR were curvilinearly related to exercise energy expenditure (r=-0.666, P=0.001) with a threshold of approx. 3.77 MJ (900 kcal) for improvements in HOMAIR to be manifested. In particular, HOMAIR 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 HOMAIR after exercise was directly associated with baseline (i.e. resting) HOMAIR (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.

AB - A single bout of moderate-intensity exercise increases whole-body insulin sensitivity for 12-48 h 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 HOMAIR (homoeostasis model assessment of insulin resistance), 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/m2) in the post-absorptive state on two separate occasions: once after exercising at 60% of VO22peak (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 HOMAIR were curvilinearly related to exercise energy expenditure (r=-0.666, P=0.001) with a threshold of approx. 3.77 MJ (900 kcal) for improvements in HOMAIR to be manifested. In particular, HOMAIR 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 HOMAIR after exercise was directly associated with baseline (i.e. resting) HOMAIR (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.

KW - Adult

KW - Blood Glucose/metabolism

KW - Energy Metabolism/physiology

KW - Exercise/physiology

KW - Fasting/blood

KW - Homeostasis/physiology

KW - Humans

KW - Insulin/blood

KW - Insulin Resistance/physiology

KW - Male

KW - Oxygen Consumption/physiology

U2 - 10.1042/CS20070134

DO - 10.1042/CS20070134

M3 - Journal article

C2 - 17635103

VL - 114

SP - 59

EP - 64

JO - Clinical Science

JF - Clinical Science

SN - 0143-5221

IS - 1

ER -