The elevation of postprandial plasma triglycerides (PPTG) in the blood is an independent risk factor for atherosclerosis. Although acute exercise typically attenuates PPTG, the effect of exercise intensity on PPTG is less well established, particularly in well-controlled conditions for physical activities and diet.
Purpose: We sought to determine the efficacy of exercise at 65% V˙O2max with an extended sitting time and isoenergetic intermittent walking exercise at a self-selected walking speed (approximately 25% V˙O2max) on PPTG compared with that of a sitting control condition. In a randomized crossover design, nine healthy young men completed three trials with a >1-wk interval between trials. After 2 d of activity and diet normalization, participants performed prolonged sitting nonexercise control (CON), prolonged sitting with subsequent 1-h running at 65% V˙O2max (MOD), or isoenergetic intermittent walking at approximately 25% V˙O2max (LOW) on day 3. This was followed on day 4 by a 6-h high-fat tolerance test.
Results: MOD and LOW reduced incremental triglyceride (TG) area under the curve (TG AUCI) compared with that in CON by 33.6% (P < 0.005) and 19.8% (P < 0.05), respectively. MOD also reduced TG AUCI compared with that in LOW by 17.2% (P < 0.03). The reduced TG AUCI in MOD was accompanied by reduced plasma glucose response and enhanced fat oxidation compared with those in LOW and CON (for all, P < 0.05), respectively.
Conclusions: Both MOD and LOW were effective in reducing PPTG compared with CON. However, MOD was more effective in reducing PPTG compared with LOW.