WHEY PROTEIN MORE EFFECTIVE THAN SOY PROTEIN IN PROMOTING LEAN BODY MASS GAINS IN RESISTANCE TRAINING
Volk, B. M., Quann, E. E., Ballard, K. D., Kupchak, B. R., Gomez, A. L., & Kraemer, W. J. (2012). Whey protein supplementation results in greater gains in lean body mass compared to soy protein during a progressive 9-month resistance training program. Presentation 1853 at the 59th Annual Meeting of the American College of Sports Medicine, San Francisco, California; May 29-June 2, 2012.
"Whey and soy are two quality protein sources used by athletes. Few studies have directly compared their ability to promote gains in lean body mass." This study compared the effect of daily supplementation with whey protein and soy protein on lean body mass responses to a 9-month progressive resistance training program in non-resistance trained men and women. The whey-protein group (N = 19) and soy-protein group were provided with ~22 g carbohydrate plus 21 g of either whey protein concentrate or soy isolate. Ss participated in a supervised, whole-body non-linear periodized resistance training program for nine months (three times per week). Body composition was assessed every three months via dual x-ray energy absorptiometry.
Average daily protein intake, including the supplement, was 1.4 g/kg body weight. Despite consuming similar calories and protein during the intervention, gains in lean body mass were significantly greater in the whey group than the soy group. There were no significant differences in body mass and fat mass responses between groups.
Implication. Whey protein supplementation was more effective than soy protein in promoting gains in lean body mass in response to chronic resistance training.
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