Effect of Whey and Soy Protein Supplementation Combined With Resistance Training in Young Adults

Int J Sport Nutr Exerc Metab. 2006 Jun;16(3):233-44. doi: 10.1123/ijsnem.16.3.233.

Abstract

The purpose was to compare changes in lean tissue mass, strength, and myofibrillar protein catabolism resulting from combining whey protein or soy protein with resistance training. Twenty-seven untrained healthy subjects (18 female, 9 male) age 18 to 35 y were randomly assigned (double blind) to supplement with whey protein (W; 1.2 g/kg body mass whey protein + 0.3 g/kg body mass sucrose power, N = 9: 6 female, 3 male), soy protein (S; 1.2 g/kg body mass soy protein + 0.3 g/kg body mass sucrose powder, N= 9: 6 female, 3 male) or placebo (P; 1.2 g/kg body mass maltodextrine + 0.3 g/kg body mass sucrose powder, N = 9: 6 female, 3 male) for 6 wk. Before and after training, measurements were taken for lean tissue mass (dual energy X-ray absorptiometry), strength (1-RM for bench press and hack squat), and an indicator of myofibrillar protein catabolism (urinary 3-methylhistidine). Results showed that protein supplementation during resistance training, independent of source, increased lean tissue mass and strength over isocaloric placebo and resistance training (P < 0.05). We conclude that young adults who supplement with protein during a structured resistance training program experience minimal beneficial effects in lean tissue mass and strength.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorptiometry, Photon
  • Adolescent
  • Adult
  • Biomarkers / urine
  • Dietary Supplements
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Methylhistidines / urine*
  • Milk Proteins / administration & dosage
  • Milk Proteins / pharmacology*
  • Muscle Proteins / biosynthesis
  • Muscle Proteins / metabolism*
  • Muscle, Skeletal / diagnostic imaging
  • Muscle, Skeletal / drug effects*
  • Physical Education and Training / methods
  • Soybean Proteins / administration & dosage
  • Soybean Proteins / pharmacology*
  • Torque
  • Weight Lifting* / physiology
  • Whey Proteins

Substances

  • Biomarkers
  • Methylhistidines
  • Milk Proteins
  • Muscle Proteins
  • Soybean Proteins
  • Whey Proteins
  • 3-methylhistidine