Different patterns of brisk walking are equally effective in decreasing postprandial lipaemia

OBJECTIVE: To compare the effects of different patterns of brisk walking on day-long plasma triacylglycerol concentrations in sedentary adults. DESIGN: A three-trial, repeated measures design in which subjects were stud ied in the fasted state and throughout a day during which they consumed thr ee standardized, mixed meals. On different occasions, subjects undertook no exercise (control), walked briskly for 10 min before each meal (short walk s) or walked briskly for 30 min before breakfast (long walk). SUBJECTS: Seven postmenopausal sedentary women and three sedentary men aged between 34 and 66 y, with body mass index between 24 and 35 kg/m(2). MEASUREMENTS: Plasma concentrations of triacylglycerol, non-esterified fatt y acids, glucose and insulin, metabolic rate and whole-body substrate oxida tion in the fasted state and at hourly intervals for 3 h after each meal. RESULTS: Postprandial plasma triacylglycerol concentrations were lower (P = 0.009) during the walking trials than during the control trial (average va lues: control 2.08 +/- 0.28 mmol/l;short walks 1.83 +/- 0.22 mmol/l; long w alk 1.84 +/- 0.22 mmol/l (mean +/- s.e.) but did not differ between the two patterns of walking. The difference between control and walking trials inc reased as successive meals were consumed (interaction of trial x meal P = 0 .03), Plasma triacylglycerol concentration increased during the 3 h after b reakfast, changed little after lunch and decreased after the evening meal ( interaction of meal x time P = 0.001). When both walking trials were treate d as one condition, walking increased postprandial fat oxidation (average v alues: control, 0.066 +/- 0.009 g/min;walking 0.074 +/- 0.008 g/min; P < 0. 01). CONCLUSIONS: Thirty minutes of brisk walking, undertaken in one session or accumulated throughout a day, reduces postprandial plasma triacylglycerol c oncentrations and increases fat oxidation.