Energy replacement diminishes the postprandial triglyceride-lowering effect from accumulated walking in older women.

Abstract

Dietary replacement of an acute exercise-induced energy deficit offsets the postprandial triglyceride (TG)-lowering effect of exercise in young boys and middle-aged men. It is unclear whether these findings are observed when exercise is accumulated in older adults. This study examined the effect of accumulating short bouts of exercise, with and without dietary replacement of an exercise-induced energy deficit, on postprandial TG in older women. Seventeen older women (≥ 65years) underwent three, 8-h trials: (1) control, (2) accumulated walking and (3) accumulated walking with energy replacement. During the control trial, participants rested for 8h. The accumulated walking trials comprised twenty 1.5min brisk walking bouts performed at a pre-determined self-selected pace separated by 15min seated rest. In each trial, participants consumed a standardised breakfast and lunch. The breakfast in the accumulated walking with energy replacement trial included replacement of the energy deficit (0.62MJ, 149kcal) induced by exercise. Venous blood samples were collected fasted and at 2, 4, 6 and 8h after breakfast. Time-averaged postprandial serum TG concentrations over 8h were lower after accumulated walking than control and accumulated walking with energy replacement (mean ± SD: 1.46 ± 0.93 vs 1.71 ± 1.01 vs 1.60 ± 0.98mmol/L, respectively: main effect of trial p = 0.017). There was little difference between control and accumulated walking with energy replacement. Replacing the energy expenditure induced by accumulating 30min of brisk walking in short (1.5min) bouts diminishes the postprandial TG-lowering effect in older women.