The effects of a 12-week resistance training program combined with casein or whey protein supplementation on body composition, muscle strength, and markers of satellite cell activation in older males

Resistance training and protein supplementation have been shown to increase muscle mass and strength, and thus may be an effective method to combat muscle wasting (sarcopenia) that occurs with aging. Thirty-six males (62.5 yrs, 177 cm and 95.25 kg) were randomly assigned to ingest either whey isolate protein, casein protein or carbohydrate while participating in a 12-week high intensity resistance training program. Resistance training increased both upper and lower body strength, body mass and lean muscle mass while decreasing body fat percentage. However, no effects from training were observed on serum anabolic hormones and indirect markers of satellite cell activation. A trend towards significantly higher lower body strength was observed in the whey isolate (p=0.053) and casein (p=0.086) groups, respectively, compared to carbohydrate placebo group. The present study suggests protein supplementation in conjunction with high intensity resistance training may be important in combating sarcopenia.