Effect of Whey Protein Form on Physiological Response to Chronic Resistance Exercise in Trained Men (LB806)

Abstract

Fifty‐six men (21.4±0.4 yrs) were randomly assigned to one of four double‐blinded treatments: 60 g/d maltodextrin (PLA) or 60 g/d whey protein from either a) 80% whey protein concentrate (WPC80), b) high lactoferrin WPC80 (WPC80+), or c) hydrolyzed WPC80 (WPH). All subjects participated in an 8‐week resistance training program. Two‐way repeated measures ANCOVAs were used for statistical analyses. No between‐ or within‐group (p>0.05 and p>0.0125, respectively) changes were observed for 12‐hour fasted blood lipids, glucose, WBC, CK or other clinical chemistry markers of safety; however, all groups reduced (p<0.0125) creatinine. Urea nitrogen decreased in WPH (‐18.06%, p<0.0125), which differed (p<0.05) from WPC80 (+16.91%). All groups similarly increased (p<0.0125) upper‐ and lower‐body 1RM strength and 80RM muscular endurance. LBM and total body muscle mass increased (p<0.0125) in all groups, as did BM in all groups except WPH (+0.64 kg; p=0.114). Only WPH significantly reduced FM (‐5.94%) and %FAT (‐1.60%), which was significantly different from PLA (+9.10% and +0.64%, respectively). Therefore, in trained men, whey protein form provides similar responses to an 8‐week heavy resistance training program on measures of total body muscle mass, strength, anaerobic endurance, blood lipids and clinical safety markers. However, WPH appears to significantly augment fat loss and may increase nitrogen retention.