Research article - (2017)16, 230 - 238
No Effect of a Whey Growth Factor Extract during Resistance Training on Strength, Body Composition, or Hypertrophic Gene Expression in Resistance-Trained Young Men
Michael J. Dale1, Alison M. Coates1, Peter R.C. Howe2, Grant R. Tomkinson1,3, Matthew T. Haren4, Andrew Brown5, Marissa Caldow6, David Cameron-Smith7, Jonathan D. Buckley1,
1Alliance for Research in Exercise, Nutrition and Activity (ARENA), Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia
2Clinical Nutrition Research Centre, University of Newcastle, Callaghan, NSW, Australia
3Department of Kinesiology and Public Health Education, University of North Dakota, North Dakota, USA
4Centre for Population Health Research, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia
5Murray Goulburn Co-Operative Ltd, Parkville, Melbourne, Australia
6Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, Australia
7Liggins Institute, University of Auckland, Auckland, New Zealand

Jonathan D. Buckley
✉ Alliance for Research in Exercise, Nutrition and Activity (ARENA), University of South Australia, GPO Box 2471, Adelaide, Australia 5001
Email: jon.buckley@unisa.edu.au
Received: 24-01-2017 -- Accepted: 20-03-2017
Published (online): 01-06-2017
ABSTRACT

Growth factors can be isolated from bovine milk to form a whey growth factor extract (WGFE). This study examined whether WGFE promoted activation of the AKT/mTOR pathway enabling increased lean tissue mass and strength in resistance trained men. Forty six men with >6 months of resistance training (RT) experience performed 12 weeks of RT. Participants consumed 20 g/day of whey protein and were randomised to receive either 1.6 g WGFE/day (WGFE; n = 22) or 1.6 g cellulose/day (control, CONT; n = 24). The primary outcome was leg press one-repetition maximum (LP1-RM) which was assessed at baseline, 6 and 12 weeks. At baseline and 12 weeks body composition was assessed by dual energy x-ray absorptiometry, and muscle protein synthesis and gene expression were assessed (vastus lateralis biopsy) in a sub-sample (WGFE n = 10, CONT n = 10) pre- and 3 hr post-training. RT increased LP1-RM (+34.9%) and lean tissue mass (+2.3%; p < 0.05) with no difference between treatments (p > 0.48, treatment x time). Post-exercise P70s6k phosphorylation increased acutely, FOXO3a phosphorylation was unaltered. There were no differences in kinase signalling or gene expression between treatments. Compared with CONT, WGFE did not result in greater increases in lean tissue mass or strength in experienced resistance trained men.
Key words: Nutritional supplement, lean tissue mass, gene expression, P70s6k, FOXO3a

Key Points
  • Resistance training increased phosphorylation and activation of p70s6k and suppressed Atrogin 1, but with no difference between treatment and control.
  • Supplementation with WGFE during resistance training in resistance-trained young men did not enhance increases in muscle strength or lean tissue mass.
  • Enhancement of strength increases with WGFE supplementation may occur in less well-trained individuals.








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No Effect of a Whey Growth Factor Extract during Resistance Training on Strength, Body Composition, or Hypertrophic Gene Expression in Resistance-Trained Young Men
Michael J. Dale, Alison M. Coates, Peter R.C. Howe, Grant R. Tomkinson, Matthew T. Haren, Andrew Brown, Marissa Caldow, David Cameron-Smith, Jonathan D. Buckley
2017(16), 230 - 238.
DOI: https://doi.org/