Effect of creatine and beta-alanine supplementation on performance and endocrine responses in strength/power athletes.
The effects of creatine and creatine plus beta-alanine on strength, power, body composition, and endocrine changes were examined during a 10-wk resistance training program in collegiate football players. Thirty-three male subjects were randomly assigned to either a placebo (P), creatine (C), or creatine plus beta-alanine (CA) group. During each testing session subjects were assessed for strength (maximum bench press and squat), power (Wingate anaerobic power test, 20-jump test), and body composition. Resting blood samples were analyzed for total testosterone, cortisol, growth hormone, IGF-1, and sex hormone binding globulin. Changes in lean body mass and percent body fat were greater (P < 0.05) in CA compared to C or P. Significantly greater strength improvements were seen in CA and C compared to P. Resting testosterone concentrations were elevated in C, however, no other significant endocrine changes were noted. Results of this study demonstrate the efficacy of creatine and creatine plus beta-alanine on strength performance. Creatine plus beta-alanine supplementation appeared to have the greatest effect on lean tissue accruement and body fat composition.
Hoffman
Jay
J
Dept. of Health and Exercise Science, The College of New Jersey, Ewing, NJ 08628, USA.
Ratamess
Nicholas
N
Kang
Jie
J
Mangine
Gerald
G
Faigenbaum
Avery
A
Stout
Jeffrey
J
D000328:Adult; D015308:Anaerobic Threshold; D001823:Body Composition / Q000187:drug effects*; D003401:Creatine / Q000008:administration & dosage* / Q000494:pharmacology; D019587:Dietary Supplements; D004311:Double-Blind Method; D004357:Drug Synergism; D005538:Football; D013006:Growth Hormone / Q000097:blood; D006339:Heart Rate; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D010807:Physical Endurance / Q000502:physiology*; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism; D013739:Testosterone / Q000097:blood; D016896:Treatment Outcome; D014891:Weight Lifting; D015091:beta-Alanine / Q000008:administration & dosage* / Q000494:pharmacology
D012738:Sex Hormone-Binding Globulin; D015091:beta-Alanine; D013739:Testosterone; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D003401:Creatine; D006854:Hydrocortisone