Efficacy of whey protein supplementation on resistance exercise-induced changes in lean mass, muscle strength, and physical function in mobility-limited older adults

J Gerontol A Biol Sci Med Sci. 2013 Jun;68(6):682-90. doi: 10.1093/gerona/gls221. Epub 2012 Oct 31.


Background: Whey protein supplementation may augment resistance exercise-induced increases in muscle strength and mass. Further studies are required to determine whether this effect extends to mobility-limited older adults. The objectives of the study were to compare the effects of whey protein concentrate (WPC) supplementation to an isocaloric control on changes in whole-body lean mass, mid-thigh muscle cross-sectional area, muscle strength, and stair-climbing performance in older mobility-limited adults in response to 6 months of resistance training (RT).

Methods: Eighty mobility-limited adults aged 70-85 years were randomized to receive WPC (40g/day) or an isocaloric control for 6 months. All participants also completed a progressive high-intensity RT intervention. Sample sizes were calculated based on the primary outcome of change in whole-body lean mass to give 80% power for a 0.05-level, two-sided test.

Results: Lean mass increased 1.3% and 0.6% in the WPC and control groups, respectively. Muscle cross-sectional area was increased 4.6% and 2.9% in the WPC and control groups, respectively, and muscle strength increased 16%-50% in WPC and control groups. Stair-climbing performance also improved in both groups. However, there were no statistically significant differences in the change in any of these variables between groups.

Conclusions: These data suggest that WPC supplementation at this dose does not offer additional benefit to the effects of RT in mobility-limited older adults.

Trial registration: ClinicalTrials.gov NCT00635739.

Keywords: Nutrition; Physical function; Sarcopenia..

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Absorptiometry, Photon / methods
  • Aged
  • Aged, 80 and over
  • Aging*
  • Body Composition / drug effects*
  • Case-Control Studies
  • Dietary Supplements*
  • Double-Blind Method
  • Energy Intake*
  • Female
  • Humans
  • Male
  • Milk Proteins / administration & dosage*
  • Muscle Strength / drug effects*
  • Muscle Stretching Exercises*
  • Muscle, Skeletal / metabolism*
  • Physical Endurance / drug effects*
  • Range of Motion, Articular / drug effects
  • Treatment Outcome
  • Whey Proteins


  • Milk Proteins
  • Whey Proteins

Associated data

  • ClinicalTrials.gov/NCT00635739