EFFECTS OF CONTINUOUS AND INTERMITTENT ON POSTPRANDIAL LIPEMIA

Abstract

PURPOSE The purpose of this study was to examine the effectiveness of continuous (CON) and intermittent (INT) cardiorespiratory exercise in the attenuation of postprandial lipemia (PPL) and lipoprotein metabolism. METHODS Subjects were 12 sedentary males (n = 3) and females (n = 9), aged 26 ± .6 y (M ± SE), VO2max 38.3 ± 1.7, and BMI 23.2 ± 0.8. Following a 24-h dietary and activity control period, subjects consumed a high-fat meal (HFM) containing 1.5g fat (88% of calories), 0.05g pro, and 0.4g CHO per kg body weight, for three trials: no exercise baseline (BL), CON, and INT. Exercise trials were treadmill running for 30 min at 60% VO2max. INT was conducted in one session of three bouts, each lasting 10 min with 20 min rest periods separating the three bouts. Blood was collected prior to HFM and at 2, 4, 6, and 8 h post-HFM. 12-h before blood collection, subjects participated in CON, INT or BL. Trials were performed in random order. RESULTS Caloric expenditure (CON 238.2 ± 12.4 kcal; INT 235.8 ± 11.3), VO2 (CON 1.6 ± 0.02 L/min, 62.7%; INT 1.6 ± 0.02, 62.3%), and RER (CON 0.94 ± 0.003; INT 0.92 ± 0.007) were not significantly different between exercise trials. However, HR (CON 158 ± .9; INT 157 ± .9) and RPE (CON 13 ± .3; INT 11 ± .3) were significantly higher in CON compared to INT. Plasma analysis indicated TG incremental area under the curve (AUCI) (BL 385.8+99.6 mg/dl; CON 324.6 ± 86.6; INT 252.9 ± 76.1) and TG incremental Peak (PeakI) (BL 89.5 ± 20.6 mg/dl; CON 76.2 ± 15.3; INT 63.0 ± 14.8) were significantly lower in INT compared to BL, but CON was not different from INT or BL. Analysis of HDL-C, HDL2-C, and HDL3-C comparing 0h versus 8h between trials, were not significantly different. CONCLUSIONS In sedentary individuals, INT reduces PPL greater than BL, but CON does not. Supported by NIH T32 Postdoctoral Training Grant, and UMC Foods for the 21st Century.