Effect of branched-chain amino acids (BCAA), glucose, and glucose plus BCAA on endurance performance in rats.
OBJECTIVE
The purpose of this study was to assess the effects of pre-exercise administration of branched-chain amino acids (BCAA), glucose, and glucose plus BCAA on time to exhaustion during treadmill exercise in rats.


METHODS
Wistar rats were injected intraperitoneally with 1 mL of saline (0.9% NaCl), BCAA (30 mg), glucose (100 mg), or glucose plus BCAA 5 min before either 45 min of submaximal exercise (N = 32) or running to exhaustion (N = 24). After the submaximal exercise test, blood was collected for the measurement of ammonia, BCAA, free tryptophan (free TRP), glucose, free fatty acid, and lactic acid, and muscle samples were taken from the m. soleus for determination of glycogen content.


RESULTS
Mean run time to exhaustion was significantly longer after BCAA administration (158+/-26 min) compared with that after saline (118+/-35 min)(P<0.05) but not compared with that after glucose administration (179+/-21 min). When glucose is administered before exercise, the supplementary administration of BCAA had no additional effect on performance (171+/-12 min). The data on blood ammonia, ratio of free TRP/BCAA, and muscle glycogen did not provide a clue for explaining the higher endurance performance after BCAA supplementation.


CONCLUSIONS
The results support the hypothesis that the effect of BCAA administration on performance could be related to carbohydrate availability during exercise.
Calders
P
P
Department of Pediatric Cardiology, and Institute of Kinesiology and Sport Sciences, University of Ghent, Belgium.
Matthys
D
D
Derave
W
W
Pannier
J L
JL
D000597:Amino Acids, Branched-Chain / Q000097:blood / Q000494:pharmacology*; D000641:Ammonia / Q000097:blood; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D005069:Evaluation Studies as Topic; D005260:Female; D005947:Glucose / Q000494:pharmacology*; D006003:Glycogen / Q000378:metabolism; D019344:Lactic Acid / Q000097:blood; D009043:Motor Activity / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000378:metabolism; D010805:Physical Conditioning, Animal / Q000502:physiology*; D010807:Physical Endurance / Q000187:drug effects*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar
D000597:Amino Acids, Branched-Chain; D001786:Blood Glucose; D019344:Lactic Acid; D000641:Ammonia; D006003:Glycogen; D005947:Glucose