17th Annual ECSS-Congress, Bruges 2012

Abstract details

Abstract-ID: 1325
Session: [MO-PM26] TT Small Sided Games
Lecture room: G106
Date & time: 03.07.2014 / 14:00 - 15:00
Title of the paper: Effect of continuous compared with accumulated exercise on insulin sensitivity
Authors: Burns, S.F., Chan, Y.M., Balasekaran, G.
Institution: Nanyang Technological University
Department: Physical Education and Sports Science
Country: Singapore
Abstract text Introduction Expert guidelines recommend physical activity is accumulated in bouts with a minimum duration of 10 min, to achieve the 30 min per day necessary for good health (Haskell et al., 2007). Whilst the concept of accumulating exercise is attractive the evidence for its efficacy on health is limited (Murphy et al., 2009). The present study compared the effect of accumulating three 10 minute bouts of exercise with one 30 minute continuous bout of exercise on insulin sensitivity in young healthy males. Methods Following ethical approval, 12 healthy males (aged 24.4 1.9 y, BMI 21.8 1.2 kg/m2, maximum oxygen uptake 43.8 6.7 ml/kg/min, mean SD) completed three 2-day trials at least 5 days apart in a randomised repeated measures design. On day 1 the participants rested (no exercise) or walked on a treadmill at 70% of maximum oxygen uptake in either three 10-min bouts (accumulated) of exercise with 20 min rest between each or one continuous 30-min bout (continuous) of exercise. On day 2, participants came to the laboratory at 0800 and consumed a 75 g oral glucose tolerance test (OGTT). Venous blood samples were obtained in the fasted state and at 15, 30, 60, 90 and 120 minutes after the OGTT. Fasting insulin sensitivity was calculated using the homeostasis model assessment 2 index (HOMA2). Whole body insulin sensitivity was calculated from fasting and OGTT measures using the Matsuda index; 10000 / √[(fasting glucose fasting insulin) (mean OGTT glucose concentration mean OGTT insulin concentration)]. One-way ANOVA (repeated measures) with post-hoc Bonferroni comparisons were used to determine differences in fasting and whole body insulin sensitivity among trials. Data are mean SD. Results Fasting insulin sensitivity (HOMA2) was significantly different among trials (no exercise, 176 54; accumulated, 183 45; continuous, 239 103) (main effect of trial, P=0.033). Post-hoc tests were not significant but the most likely improvement in insulin sensitivity was on the continuous exercise trial compared with the no exercise trial (P=0.064). Similarly, whole body insulin sensitivity (Matsuda) differed among trials (no exercise, 176 54; accumulated, 183 45; continuous, 239 103) (main effect of trial, P=0.048) with post-hoc tests suggesting an improvement in insulin sensitivity on the continuous exercise trial compared with the no exercise trial (P=0.058). Discussion These data suggest that continuous but not accumulated exercise in line with the minimal recommended duration of 30 minutes per day leads to improvements in insulin sensitivity. References Haskell WL, Lee I-M, Pate RR, Powell KE, Blair SN, Franklin BA, Macera CA, Heath GW, Thompson PD, Bauman A (2007). Circulation. 116:1081-1093. Murphy MH, Blair SN, Murtagh, EM (2009). Sports Med. 39:29-43.
Topic: Physiology
Keyword I: insulin sensitivity
Keyword II: accumulated exercise
Keyword III: continuous exercise