The average PEDro score of these studies was 8.7, indicating an overall high level of methodological quality. Table 1 summarizes the studies meeting inclusion criteria. Table 1 Summary of studies meeting inclusion criteria Study Subjects Supplementation Protein PR-171 manufacturer matched with control? Anthropometric and/or body composition assessment method Training protocol Strength results Body composition results Antonio et al.,  19 untrained young women 18.3 g EAA or an equal dose of cellullose placebo
taken (collectively) SB431542 in vivo 20 minutes pre and post-exercise No DXA Periodized progressive resistance training consisting of exercises for all major muscle groups performed 3 days/wk for 6 wks Total weight lifted at the 12 RM intensity did not significantly change
in either group No significant body composition changes occurred in either group Goddard et al.,  17 untrained older men (60–80 y) 12 g of essential amino acids and 72 g (total) of fructose and dextrose consumed immediately after exercise No Computed tomography (CT). Progressive resistance training consisting of knee extensions preformed 3 days/wk for 12 wks Training produced a significant increase in 1RM strength and measures of maximal SB202190 concentration torque, no differences between groups No significant differences in muscle CSA increase between groups Rankin et al.,  13 untrained young men Chocolate milk (providing a protein dose of 0.21 g/kg) or a CHO-electrolyte beverage (Gatorade) immediately after exercise No Dual X-ray absorptiometry (DXA) and multiple upper & lower body circumference measurements Periodized progressive resistance training consisting of exercises for all major muscle groups performed 3 days/wk for 10 wks 1 RM strength increased in all exercises, with no significant difference between groups No significant differences in fat reduction, mean mass gain, or circumference
changes between groups Andersen et al.,  22 untrained young men 25 g protein (combination dipyridamole of whey, casein, egg white, and glutamine) or 25 g maltodextrin immediately before and after exercise No Muscle biopsy Periodized progressive resistance training consisting of lower body exercises performed 3 days/wk for 14 wks Squat jump height increased only in the protein group, whereas countermovement jump height and peak torque during slow isokinetic muscle contraction increased similarly in both groups. The protein group showed hypertrophy of type I & II muscle fibers, whereas no significant change occurred in the CHO group Bird et al.