 The experimental group consumed daily (20g) of a cysteine-rich whey protein isolate (Immunocal®) compared to daily (20g) casein-the control protein - over a period of 135 days (4.5 months).In addition, all subjects performed the same resistance training program 3 times per week over the 135-day period.Eighty-four (84) subjects completed the 135-day study period.