Poster Topical Area: Sports Nutrition

Location: Auditorium

Poster Board Number: 241

P25-010 - β-hydroxy, β-methylbutyrate (HMB) supplementation does not promote superior gains in lean mass or strength following resistance training in young men.

Sunday, Jun 10
8:00 AM – 6:00 PM

Objective:  We examined the effects of whey protein with calcium-HMB compared to whey protein with leucine supplemented twice daily on lean mass, strength, and recovery during 12 weeks of intense undulating periodized resistance training (RT).

Methods: Twenty-six recreationally trained men (≥2x/week RT experience, aged 23±2y) performed 8 weeks of undulating periodized RT, in which the repetition number/intensity varied for each of the 3 sessions/week (Phase 1). Phase 1 was followed by a 2-week overreaching period, during which the training volume increased to 5x/week (Phase 2), and ended with 2-week taper of reduced training volume (Phase 3). Participants were randomized to ingest: whey protein (25g) with added HMB (1.5g) (Whey+HMB; n=13) or whey protein (25g) with added leucine (1.5g) (Whey+Leu; n=13), twice daily. Fat and bone-free mass (FBFM) was quantified by dual-energy X-ray absorptiometry (DXA) scans at weeks 0, 4, 8, 10, and 12. B-mode ultrasound was used to assess vastus lateralis muscle thickness (MT) and cross-sectional area (CSA) at weeks 0, 8 and 12. Systemic hormone concentrations and one-repetition maximum (1-RM) strength tests were conducted throughout Phase 1, Phase 2 and upon completion of Phase 3.

Results: In response to RT, FBFM increased similarly in Whey+HMB and Whey+Leu (2.3±1.2kg and 2.6±1.9kg, respectively; p=0.59). Whey+HMB and Whey+Leu groups exhibited comparable changes from baseline in vastus lateralis CSA (6±4% and 7±4%, respectively) and MT (5±6% and 5±6%, respectively). Circulating creatine kinase and cortisol concentrations increased significantly (p≤0.05) from baseline at Phase 2; however, there were no between-group differences at any phase. Participants increased their 1-RM for squat (33±10kg and 35±17kg), bench-press (11±5kg and 11±7kg) and deadlift (25±12 and 34±22, p≤ 0.01), with no significant differences between Whey+HMB and Whey+Leu respectively (p>0.05). Total 1-RM strength recovered similarly at week 12 from overreaching (Week 9 and 10) Whey+HMB (20±9kg) and Whey+Leu (28±22kg) (p>0.05).

Conclusions: There are no superior effects of Whey+HMB compared to Whey+Leu on muscle size or strength following 12 weeks of RT in young men.

CoAuthors: Edwin Wong , Student – McMaster; Dr. Everson Nunes, Professor – Federal University of Santa Catarina; Josh Vandeweerd, Student – McMaster; Kenneth Noguchi , Student – McMaster; Kevin Murphy, Student – McMaster; Robert Mortin, Graduate student – McMaster; Dr. Steven Baker, MSc, MD, FRCPC, CSCN – McMaster University; Dr. Stuart Phillips, PhD, Tier 1 Canada Research Chair – McMaster University

Josie S. Jakubowski

MSc Student
McMaster Univeristy
Oakville, Ontario, Canada