The aim of this study was to evaluate the effects of egg white protein compared to carbohydrate intake prior to exercise on fat free mass (FFM), one repetition maximum (1RM) muscle strength and blood biochemistry in female athletes. Thirty healthy female collegiate athletes were recruited for this study and matched by sport type, body fat percentage and 1RM leg curl muscle strength. Participants were randomly divided into two groups: protein group (15.0 g egg white protein; 75 kcal) and carbohydrate group (17.5 g maltodextrin, 78 kcal). Supplements were administered daily at the same time in a double-blind manner prior to training during an 8-week period. Measurements were performed before and after the 8-week regimen. The mean dietary energy intake did not change throughout the study period. FFM and 1RM assessments (i.e., leg curl, leg extension, squat, and bench press) increased in both groups. Furthermore, serum urea and serum citrulline levels after the 8-week regimen increased significantly only in the protein group. Our findings indicated that compared to the carbohydrate supplement, the protein supplement was associated with some changes in protein metabolites but not with changes in body composition or muscle strength.

Hutyuu-city, Tokyo 183 -8526

No abstract

Summary This study was undertaken to investigate the effects of isoenergetic and increased amounts of egg white protein one hour before a run on the changes in the postexercise blood biochemistry and the rating of the perceived exertion (RPE). Twenty-four male distance runners were divided into four groups. Venous blood samples were collected at three time points: just before the experiment (Pre), just after a 12,000 m run (Post 0 h) and one hour after the run (Post 1 h). After the first blood sampling, each participant consumed one of the four isoenergetic supplements (86 kcal); 0 g, 5 g, 10 g, or 20 g of egg white protein. The blood glucose, free amino acid, and branched chain amino acid (BCAA) levels in the 0 g, 5 g, and 10 g protein groups were higher at Post 0 h than at Pre. The pre-exercise intake of the 20 g protein group showed the smallest changes in the blood biochemicals. The RPE scores were significantly higher at Post 0 h, and did not vary among the four protein groups. Accordingly, the pre-exercise carbohydrate intakes significantly altered the postexercise blood biochemisty findings, but the pre-exercise protein intake did not. Furthermore, the changes in the RPE scores in our present study were not explained by changes in the serum free tryptophan or the BCAA levels, and an increased dietary intake of egg white protein might not prevent post-exercise increases in the RPE scores. Key Words egg white protein, isoenergetic intakes, male runners, RPE, cortisol Various carbohydrate (CHO)-protein supplements containing 10 to 20 g of protein are currently being sold in Japan. Several studies have reported that CHOprotein supplements cause significant improvement in the time to fatigue and a reduction in muscle damage in endurance athletes ( 1 -6 ). However, few studies have reported regarding the level of the pre-exercise intake of proteins that significantly affects either the onset of central fatigue or the homeostasis of blood biochemistry after exercise.Several factors that cause peripheral fatigue during exercise have been identified, one of which is a change in the brain's 5-hydroxytryptamine (5-HT) level ( 7 -10 ); an increase in the ratio of free tryptophan (unbound to albumin, Trp) to branched chain amino acids (BCAA) and/or in the amount of Trp uptake by the brain which might contribute to the increased synthesis of 5-HT in the brain during endurance exercise. BCAA ingestion increases the BCAA concentration in the serum, reduces both the Trp uptake by the brain and 5-HT synthesis, and thereby delays mental fatigue (by preventing an increase in the rate of perceived exertion (RPE)) ( 7 -10 ). In some situations, BCAA intake improves physical performance ( 8 ), thus suggesting that the ingestion of BCAA during endurance exercise delays fatigue. It is interesting to note that egg white protein contains 22 g of BCAA/100 g ( 11 ), and is one of the most important BCAA derivatives in our daily dietary lives. Although there are some studies on whey ( 12 ), milk ( 13 ) and soy ( 14 ) as sources of die...