The Influence of Multiple Bouts of Resistance Exercise on Postprandial Triacylglycerol Concentrations

Abstract

Studies have consistently shown that an acute bout of aerobic exercise lowers postprandial triacylglycerol (TAG) concentrations but findings for resistance exercise have been inconsistent and the evidence is inconclusive. This is possibly because the energy expenditure elicited in an acute bout of resistance exercise is typically lower than that elicited during aerobic exercise. One way to increase the energy expenditure of resistance exercise is to perform multiple bouts over the course of a day. PURPOSE: To examine the effect of multiple bouts of resistance exercise performed throughout a single day on postprandial TAG concentrations. METHODS: Following University Ethical Advisory Committee approval, 14 healthy males (age 25.4 ± 3.3 years, height 1.76 ± 0.06 m, body mass 73.1 ± 10.1 kg, mean ± SD) volunteered to complete two, 2-d trials, exercise and control, one-week apart. The order of the trials was randomised and balanced. On day one of the exercise trial participants performed five, 45-min bouts of weight lifting. Each bout consisted of 4 sets of 15 repetitions of 5 different exercises at 30–40% of one repetition maximum. There was a 15 min rest interval after the first two bouts, a 105 min lunch break after the third bout and a 15 min rest interval between the fourth and fifth bout. On day one of the control trial participants were inactive. On day two of each trial participants reported to the laboratory in the morning after an overnight fast. A cannula was inserted into an antecubital vein and a baseline blood sample was obtained. Participants then consumed a test meal (0.89 g fat, 1.23 g carbohydrate, 0.4 g protein, 60 kJ per kg body mass). Further blood samples were obtained at hourly intervals for 6 h for the determination of plasma TAG concentration. RESULTS: Mean (±SD) area under the curve values for total TAG concentration on the control and exercise trials were as follows: control 10.22 ± 4.23 mmol-6h-L−1, exercise 8.93 ± 3.67 mmol·h-L−1. These differences did not reach statistical significance (p < 0.139, Student's t-test for correlated data). The total area under the 6-h plasma TAG concentration versus time curve was lower in ten out of 14 participants on the exercise compared with the control trial. Of the remaining four participants, area under the curve values were similar between trials in two cases and higher on the exercise trial in two cases. CONCLUSION: These data suggest that multiple bouts of resistance exercise may have the potential to reduce plasma TAG concentrations but further data are required to confirm this.