Effects of Hydrolyzed Whey versus Other Whey Protein Supplements on the Physiological Response to 8 Weeks of Resistance Exercise in College-Aged Males

Abstract

Objective: The objective of this study was to compare the chronic effects of different whey protein forms on body composition and performance when supplemented with resistance training.

Methods: Resistance-trained men (N = 56, 21.4 ± 0.4 years, 79.5 ± 1.0 kg) participated in an 8-week resistance training regimen (2 upper-body sessions and 2 lower-body sessions per week) and received one of 4 double-blinded treatments: 30 g/serving carbohydrate placebo (PLA) or 30 g/serving protein from either (a) 80% whey protein concentrate (WPC), (b) high-lactoferrin-containing WPC (WPC-L), or (c) extensively hydrolyzed WPC (WPH). All subjects consumed 2 servings of treatment per day; specifically, once immediately before and after training and between meals on nontraining days. Blood collection, one repetition maximum (1RM) testing for bench press and hack squat, and body composition assessment using dual-energy x-ray absorptiometry (DXA) occurred prior to training and 48 hours following the last training session.

Results: Total body skeletal muscle mass increased in all groups (p < 0.0125). There were similar between-group increases in upper-body (4%–7%, analysis of covariance [ANCOVA] interaction p = 0.73) and lower-body (24%–35%, ANCOVA interaction p = 0.85) 1RM strength following the intervention. Remarkably, WPH reduced fat mass (−6%), which was significantly different from PLA (+4.4%, p < 0.0125). No time or between-group differences were present for serum markers of health, metabolism, or muscle damage, with the exception of blood urea nitrogen being significantly lower for WPH than WPC (p < 0.05) following the intervention.

Conclusions: WPH may augment fat loss but did not provide any other advantages when used in combination with resistance training. More mechanistic research is needed to examine how WPH affects adipose tissue physiology.

Key words:

• body composition
• exercise
• sports nutrition
• supplements and functional foods
• metabolism

ACKNOWLEDGMENTS

The authors thank all of the participants involved in the study as well as David Peebles, Dr. David Fukuda, Michael Young, Annie Maruska, Dr. Chris Poole, Dr. Kyle Sunderland, and Bryan Baranowski for their support.

FUNDING

AP Nutrition, Scivation Inc., and Progenex Inc. funded the study.

COMPETING INTERESTS

C.M.L. is currently the President and Owner of AP Nutrition, which provides consulting services to dietary supplement companies. However, his role in AP Nutrition has no conflicts of interest with these presented data. K.L.K. is currently Science Editor of Bodybuilding.com, which provides editorial content within the fitness industry, and is an online retailer and manufacturer of dietary supplements. However, her role at Bodybuilding.com has no conflicts of interest with these presented data. All other authors declare that they have no other competing interests.