Effect of energy expenditure on postprandial triacylglycerol in adolescent boys

This study examined the effects of 30 and 60 min of moderate intensity exercise on postprandial triacylglycerol concentration [TAG] in 11 healthy, 13-year-old boys. The boys completed three counterbalanced conditions. On day 1, they either rested (CON), or jogged for 30 min (EX30) or 60 min (EX60) at 55% peak [Formula: see text] Following a 12-h fast, on day 2 a capillary blood sample was taken for fasting [TAG] before a high fat milkshake was consumed. Further blood samples were taken every hour over a 6-h postprandial rest period for [TAG]. The estimated energy expenditure for EX30 (982 kJ) was doubled in EX60 (1967 kJ). Differences in fasting [TAG] between the conditions were small (ES = 0.23, P = 0.35). Differences in postprandial TAG over time between conditions were identified (ES = 0.41, P = 0.03). Mean [TAG] was lower in EX60 than CON (-33 to -3%, P = 0.03) with a similar strong trend for EX30 (-29 to 1%, P = 0.06); EX60 and EX30 were not different from each other (-21 to 14%, P = 0.62). The total area under the [TAG] versus time curve was different between conditions (ES = 0.42, P = 0.03). Again, EX60 was lower than CON (-31 to -2%, P = 0.02) with a strong trend for EX30 (-31 to 4%, P = 0.06); EX30 and EX60 were not different from each other (-17 to 16%, P = 0.58). This study shows for the first time that both 30 and 60 min of jogging, with energy expenditures equivalent to 982 and 1,967 kJ, attenuates postprandial [TAG] in adolescent boys, but not in a dose-dependent manner.