IMPACT OF A FAT-RICH DIET ON ENDURANCE IN MAN - ROLE OF THE DIETARY PERIOD

Objective: The aim of the present study was to evaluate the effect of duration on the interaction between training and a fat-rich or a carbo hydrate-rich diet on endurance performance. Methods: Fifteen untrained males were randomly assigned to consume a fat-rich (T-FAT) or a carbo hydrate-rich diet (T-CHO) while following an endurance training progra m. Endurance performance at 80% of pretraining (V)over dot O-2max was measured before, after 2 wk, and after 4 wk. Results: Time to exhausti on, when exercising at the same absolute workload, was similar in T-FA T and T-CHO at all tests and was significantly increased by 166% and 1 50% in T-FAT and T-CHO, respectively, after 4 wk. Maximal oxygen uptak e increased by 9% in both groups (P < 0.05). After 4 wk, RER was signi ficantly lower during exercise in T-FAT both compared with the initial test and with T-CHO, while no changes appeared in T-CHO. Conclusions: The present findings showed that endurance performance was enhanced s imilarly after both 2 and 4 wk of adaptation to training and a fat-ric h or a carbohydrate-rich diet.