Another recent endurance substrate paper

[Tivers@aol.com]

Authors DR Pendergast, JJ Leddy, JT Venkatraman
Title   A perspective on fat intake in athletes
Full source Journal of the American College of Nutrition, 2000, Vol 19, Iss 
3, pp 345-350

Performance in endurance events is dependent upon the maximal aerobic power, 
the percentage of that power that can be sustained and the availability of 
substrates (carbohydrates [CHO] and fats). The purpose of this paper is to 
present a perspective of recent studies that demonstrate the role of fat 
intake and oxidation on endurance performance. Studies have shown that 
fatigue is associated with reduced muscle glycogen and that increasing muscle 
glycogen or blood glucose prolongs performance while increasing fat and 
decreasing CHO decreases performance. This has led to an emphasis on CHO 
intake in athletes in endurance sports, which quite often leads to low 
caloric intake. It is well known that trained subjects have higher levels of 
fat oxidative capacity, which spares glycogen during endurance sports. Data 
from recent studies in trained athletes, who were fed iso-caloric high-fat 
diets (42% to 55%) that maintained adequate CHO levels, have shown an 
increase in endurance in both men and women when compared to diets composed 
of low fat intake (10% to 15%). The magnitude of the effect on endurance was 
significant at high percentages of maximal aerobic power and increased as the 
percentage of maximal aerobic power decreased. Based on this review, a 
baseline diet comprising 20% protein, 30% CHO and 30% fat, with the remaining 
20% of the calories distributed between CHO and fat based on the intensity 
and duration of the sport, is recommended for discussion and future research.