Acute Effects of Premeal Versus Postmeal Exercise on Postprandial Hypertriglyceridemia

Objective: The objective of this study was to examine the effects of the timing of exercise relative to the consumption of a fat-rich meal (81% fat) on postprandial hypertriglyceridemia. Design: A single bout of exercise was either completed 30 minutes before the fat meal (EM trial) or initiated 90 minutes after the fat meal (ME trial). A third trial, fat meal only, served as a control (CON trial). The trials performed in a random order, and venous blood samples were drawn before and 1.5, 3.5, 5.5, and 7.5 hours after the meal for the determination of triglycerides, glycerol, insulin, glucose, and free fatty acids. Participants: Ten untrained healthy males 25.2 ± 0.9 years old (mean ± SE) with maximal oxygen uptake (VO₂max) of 46.6 ± 3.0 mL · kg^-1 · min^-1. Intervention: Walking exercise performed at 50% VO₂max for 90 minutes. Main Outcome Measure: Postprandial hypertriglyceridemia, which was quantified by calculating the area under the triglycerides curve over the 7.5-hour postprandial period. Results: The mean incremental area under the curve (total area adjusted to baseline) describing postprandial hypertriglyceridemia was lower both in the EM trial (3.16 ± 0.99 mmol · L^-1 · 8 h) and in the ME trial (2.96 ± 0.69 mmol · L^-1 · 8 h) compared with CON trial (6.18 ± 1.10 mmol · L^-1 · 8 h; P < 0.05). The corresponding areas under the curve describing the postprandial insulinemia were not different between trials (ME: 38.56 ± 8.36 uIU · mL ^-1 · 8 h; EM: 21.65 ± 3.80 uIU · mL ^-1 · 8 h; CON: 25.06 ± 5.15 uIU · mL ^-1 · 8 h; P > 0.05). Conclusion: A single bout of moderate intensity exercise decreases postprandial hypertriglyceridemia irrespective of the timing of the exercise relative to a high-fat meal.