Effect of 4h preexercise high carbohydrate and high fat meal ingestion on endurance performance and metabolism.
The effect of a single high carbohydrate meal (HCM) and high fat meal (HFM) given 4 h before cycling exercises was determined for performance and metabolism. On the morning of the day of the trial, 10 endurance-trained collegiate males consumed either a single HCM (4669 kj; 79% CHO, 10% F and 11% P) or HFM (4711 kj; 30% CHO, 61% F and 9% P) as a 4 h preexercise meal. The intensity of exercise required was 65% of the maximal oxygen consumption (VO2max) for the first 120 min of exercise, followed by an increased dose of 80% VO2max. Endurance capacity did not differ between the HCM (128 +/- 3 min [SEM]) and HFM (122 +/- 3 min) trials. There was no significant difference in blood glucose levels in the HCM and HFM trials. A significantly higher (p < 0.01) serum insulin level in the HCM trials over the HFM trials was only observed at the start of exercise. Blood lactate levels (< 2.6 mM) during cycling remained below the anaerobic threshold. Respiratory exchange ratio in the HCM trials was significantly higher (p < 0.05 or p < 0.01) than that in HFM trials during the first 40 min of exercise. This was accompanied by significantly lower (p < 0.05 or p < 0.01) levels in serum free fatty acid and beta-HOB for the HCM trial. There was no significant difference between both diet regimens as to heart rate, oxygen consumption and perceived exertion during exercise. These results suggest that a single HCM and HFM given 4 h before exercise influences fuel utilization in the initial stages of prolonged cycling, but these meals may have little effect on endurance capacity.
Department of Exercise Science, Sapporo Medical University, Japan.
G
G
Okano
Y
Y
Sato
Y
Y
Takumi
M
M
Sugawara
D000328:Adult; D001642:Bicycling / Q000502:physiology; D001786:Blood Glucose / Q000378:metabolism; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000502:physiology*; D012420:Running / Q000502:physiology
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D007328:Insulin