Both soy and whey protein supplementation during resistance training increased lean tissue mass and strength over sugar placebo. Candow DG, et al studied whey protein or soy protein in combination with resistance exercise in 27 untrained healthy subjects (18 female, 9 male) age 18 to 35 years. Participants were randomly assigned (double blind) to supplement with whey protein, soy protein or placebo for 6 weeks. Lean tissue mass, strength, and an indicator of myofibrillar protein catabolism were measured before and after training. Results showed that both soy and whey protein supplementation during resistance training increased lean tissue mass and strength over placebo with equal calorie diet and resistance training (P < 0.05). (17)
