POSTPRANDIAL LIPEMIA IN ENDURANCE-TRAINED PEOPLE DURING A SHORT INTERRUPTION TO TRAINING

This study examined changes in postprandial lipemia in endurance-train ed people during a short interruption to training. Nine men and one wo man (ages 18-55 yr) undertook fat tolerance tests after 15 h, 60 h, an d 6.5 days without exercise. The test meal (1.2 g fat, 1.1 g carbohydr ate, 66 kJ/kg body mass) was consumed after a 12-h fast. Postprandial lipemia increased rapidly with detraining (area under plasma triacylgl ycerol vs, time curve: 8.42 +/- 1.40, 11.35 +/- 1.38, and 11.97 mM x 6 h at 15 h, 60 h and 6.5 days, respectively). In the fasted state, pla sma triacylglycerol concentration (0.85 +/- 0.15, 1.09 +/- 0.12, and 1 .10 +/- 0.11 mM at 15 h, 60 h and 6.5 days, respectively) and the rati o of total cholesterol to high-density-lipoprotein cholesterol increas ed with detraining. Values were significantly higher at 60 h and 6.5 d ays than values at 15 h (P < 0.05) for each of these three variables. The serum insulin response was higher (P < 0.05) at 6.5 days than at 1 5 h (81.6 +/- 11.3, 87.6 +/- 11.4, and 94.5 +/- 9.4 mu IU/ml x 6 h at 15 h, 60 h, and 6.5 days, respectively). Frequent exercise is needed t o maintain a low level of postprandial lipemia and insulinemia in trai ned people.