 Of these, 67 subjects (34 in the Immunocal® group and 33 in the control group) complied and used at least 80% of the study product and completed at least 80% of their training sessions.The key findings of the study showed increases in muscle strength in both groups after resistance training, however, significant additional increases were observed in muscle strength with addition of a cysteine rich whey protein (Immunocal®) versus casein by approximately 10% when expressed in kg per kg body weight (BW) and in kg per kg lean body mass (LBM) (p <0.05), hence the potential impact to perform daily tasks.Whey protein (lactalbumin) is widely used by bodybuilders and other athletes due to current view by nutrition professionals and the American College of Sport Medicine that the protein needs of athletes may me higher than those of non-athletes [2].