Dietary carbohydrate and intensity of interval swim training

Am J Clin Nutr. 1990 Dec;52(6):1058-63. doi: 10.1093/ajcn/52.6.1058.


We tested the effects of 9 d of a high-carbohydrate diet (80% of calories as CHO, 80% CHO diet) vs. a moderate-CHO diet (43% of calories as CHO, 43% CHO diet) on the abilities of collegiate swimmers to maintain a high intensity of interval swim training. Interval swim times and other physiological indices were recorded the last 5 d of each diet. Swim-interval distances ranged from 50-m interval sets to continuous 3000-m swims. There were no diet effects on mean swim velocities for any interval distance, and mean (+/- SEM) velocities for all swims were identical for both diets. There were no diet effects on the physiological indices; however, postswim blood lactate concentrations were higher after the 80% CHO diet. When mean +/- SEM daily caloric intake is 19.56 +/- 2.16 MJ (4675 +/- 516 kcal) for swimmers undertaking swim training to develop aerobic capacity, an 80% CHO diet provides no advantage over a 43% CHO diet for maintaining interval-swim-training intensity.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blood Glucose / analysis
  • Dietary Carbohydrates / administration & dosage*
  • Fatty Acids, Nonesterified / blood
  • Heart Rate
  • Humans
  • Lactates / blood
  • Male
  • Physical Education and Training*
  • Physical Exertion / physiology*
  • Surveys and Questionnaires
  • Swimming*


  • Blood Glucose
  • Dietary Carbohydrates
  • Fatty Acids, Nonesterified
  • Lactates