This study compared the postprandial triacylglycerol (TACT) response to a h
igh-fat meal in trained and untrained normolipidemic young adults after 2 d
ays' abstinence from exercise. Fifty-three subjects (11 endurance-trained m
en, 9 endurance-trained women, 10 sprint/strength-trained men, 11 untrained
men, 11 untrained women) consumed a meal (1.2 g fat, 1.1 g carbohydrate, 6
6 kJ per kg body mass) after a 12-h fast. Venous blood samples were obtaine
d in the fasted state and at intervals until 6 h. Postprandial responses we
re the areas under the plasma or serum concentration-vs.-time curves. Neith
er fasting TAG concentrations nor the postprandial TAG response differed be
tween trained and untrained subjects. The insulinemic response was 29% lowe
r in endurance-trained men than in untrained men [mean difference -37.4 (95
% confidence interval -62.9 to -22.9) mu IU/ml x h, P = 0.01]. Responses of
plasma glucose, serum insulin, and plasma nonesterified fatty acids were a
ll lower for endurance-trained men than for untrained men. These findings s
uggest that, in young adults, no effect of training on postprandial lipemia
can be detected after 60 h without exercise. The effect on postprandial in
sulinemia may persist for longer.