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 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.
Helge
J W
JW
Copenhagen Muscle Research Centre, August Krogh Institute, University of Copenhagen, Denmark. jhelge@aki.ku.dk
Wulff
B
B
Kiens
B
B
D000222:Adaptation, Physiological; D000328:Adult; D000704:Analysis of Variance; D001706:Biopsy; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D004734:Energy Metabolism / Q000502:physiology; D015444:Exercise / Q000502:physiology; D006339:Heart Rate; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000737:chemistry; D010101:Oxygen Consumption; D010806:Physical Education and Training; D010807:Physical Endurance / Q000187:drug effects*; D011897:Random Allocation; D013997:Time Factors
D004040:Dietary Carbohydrates; D004041:Dietary Fats