Effects of Diet Compositions Administered Before Exercise on Prolonged Running
【Supercategory：7. DESCENTE SPORTS SCIENCE Subcategory：7.4 Vol.4】
The purpose of this studys was to investigate the effect of pre-exercise diet on the performance and metabolism on long distance runners.
The subjects took mixed or high carbohydrate diet for 3 days. Then they were subjected to eat newly prepared high protein or high carbohydrate diet just 3.5 hours before prolonged running after over night fasting.
Prolonged running were carried out on the treadmill at the speed of 65% or 80% of VO₂ max. Oxygen uptake, CO₂ output and heart rate were measured. Performance time was also recorded. On the other hand, venous blood was sampled every 30 min for determination of glucose, lactate, NEFA and hormones (catecholamines, cortisol, insulin).
1) Metabolic Response to Controlled Diet
The level of glucose was higher in case of high protein diet than the case of high carbohydrate diet at rest and during running. By raising work load, glucose increased significantly during initial 30 min particularly when high protein diet was administered. On the contrary, lactate was lower in case of high protein diet. The concentration of NEFA was higher in case of high protein diet and increased significantly by raising work load.
2) Hormonal Response to Controlled Diet
The level of catecholamines, cortisol and insulin showed significant response to the change of food constituents. The response was exaggerated by loading exercise and the high protein diet induced high catecholamine and high cortisol level as well as insulin. However, one subject (AI) showed completely different response. i.e. low catecholamine, cortisol and insulin levels by administration of high protein diet.
Performance was significantly affected in every case except for AI by administration of high protein diet, that is, they showed short performance time.
The results indicate that food constituents, particularly the constituent of diet taken just before exercise, have an important role in the efficiency of prolonged exercise.
DESCENTE SPORTS SCIENCE Vol.7/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE
The subjects took mixed or high carbohydrate diet for 3 days. Then they were subjected to eat newly prepared high protein or high carbohydrate diet just 3.5 hours before prolonged running after over night fasting.
Prolonged running were carried out on the treadmill at the speed of 65% or 80% of VO₂ max. Oxygen uptake, CO₂ output and heart rate were measured. Performance time was also recorded. On the other hand, venous blood was sampled every 30 min for determination of glucose, lactate, NEFA and hormones (catecholamines, cortisol, insulin).
1) Metabolic Response to Controlled Diet
The level of glucose was higher in case of high protein diet than the case of high carbohydrate diet at rest and during running. By raising work load, glucose increased significantly during initial 30 min particularly when high protein diet was administered. On the contrary, lactate was lower in case of high protein diet. The concentration of NEFA was higher in case of high protein diet and increased significantly by raising work load.
2) Hormonal Response to Controlled Diet
The level of catecholamines, cortisol and insulin showed significant response to the change of food constituents. The response was exaggerated by loading exercise and the high protein diet induced high catecholamine and high cortisol level as well as insulin. However, one subject (AI) showed completely different response. i.e. low catecholamine, cortisol and insulin levels by administration of high protein diet.
Performance was significantly affected in every case except for AI by administration of high protein diet, that is, they showed short performance time.
The results indicate that food constituents, particularly the constituent of diet taken just before exercise, have an important role in the efficiency of prolonged exercise.
DESCENTE SPORTS SCIENCE Vol.7/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE
| Researcher | Masateru Sugiura*1, Takashi Sakurai*2, Yoshihiko Sumie Shinjo*2, Michiko Yamashiro*2 |
|---|---|
| University or institution | *1 Department of Physiology *2 Department of Nutrition School of Health Sciences, Faculty of Medicine University of the Ryukyus |
Keywords
pre-exercise, long distance runners, high carbohydrate diet, high protein, prolonged running, Metabolic Response, Hormonal Response