Effect of dietary fat on metabolic adjustments to maximal VO2 and endurance in runners.

Journal Article

The present study examined the effects of dietary manipulations on six trained runners. The percent energy contributions from carbohydrate, fat, and protein were 61/24/14, 50/38/12, and 73/15/12 for the normal (N), fat (F), and carbohydrate (C) diets, respectively. Expiratory gases and blood responses to a maximum (VO2max) and a prolonged treadmill run were determined following 7 d on each diet. Free fatty acids (FFA), triglycerides, glycerol, glucose, and lactate were measured. Dietary assessment of subjects' N diet indicated that they were consuming approximately 700 kcal.d-1 less than estimated daily expenditures. Running time to exhaustion was greatest after the F diet (91.2 +/- 9.5 min, P < 0.05) as compared with the C (75.8 +/- 7.6 min, P < 0.05) and N (69.3 +/- 7.2 min, P < 0.05) diets. VO2max was also higher on the F diet (66.4 +/- 2.7 ml.kg-1 x min-1, P < 0.05) as compared with the C (59.6 +/- 2.8 ml.kg-1 x min-1, P < 0.05) and N (63.7 +/- 2.6 ml.kg-1 x min-1, P < 0.05) diets. Plasma FFA levels were higher (P < 0.05) and glycerol levels were lower (P < 0.05) during the F diet than during the C and N diets. Other biochemical measures did not differ significantly among diets. These data suggest that increased availability of FFA, consequent to the F diet, may provide for enhanced oxidative potential as evidenced by an increase in VO2max and running time. This implies that restriction of dietary fat may be detrimental to endurance performance.

Full Text

Duke Authors

Cited Authors

  • Muoio, DM; Leddy, JJ; Horvath, PJ; Awad, AB; Pendergast, DR

Published Date

  • January 1, 1994

Published In

Volume / Issue

  • 26 / 1

Start / End Page

  • 81 - 88

PubMed ID

  • 8133743

International Standard Serial Number (ISSN)

  • 0195-9131

Language

  • eng

Conference Location

  • United States