Impact of a fat-rich diet on endurance in man: role of the dietary period


Medicine & Science in Sports & Exercise: March 1998 - Volume 30 - Issue 3 - pp 456-461
Applied Sciences: Physical Fitness and Performance

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 carbohydrate-rich diet on endurance performance.

Methods: Fifteen untrained males were randomly assigned to consume a fat-rich(T-FAT) or a carbohydrate-rich diet (T-CHO) while following an endurance training program. Endurance performance at 80% of pretraining˙VO2max was measured before, after 2 wk, and after 4 wk.

Results: Time to exhaustion, when exercising at the same absolute workload, was similar in T-FAT and T-CHO at all tests and was significantly increased by 166% and 150% in T-FAT and T-CHO, respectively, after 4 wk. Maximal oxygen uptake increased by 9% in both groups (P < 0.05). After 4 wk, RER was significantly 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 similarly after both 2 and 4 wk of adaptation to training and a fat-rich or a carbohydrate-rich diet.

Copenhagen Muscle Research Centre, August Krogh Institute, University of Copenhagen DK-2200 N, DENMARK

Submitted for publication December 1996.

Accepted for publication September 1997.

© Williams & Wilkins 1998. All Rights Reserved.