Does habitual dietary intake influence myofiber hypertrophy in response to resistance training? A cluster analysis
- 1 August 2009
- journal article
- research article
- Published by Canadian Science Publishing in Applied Physiology, Nutrition, and Metabolism
- Vol. 34 (4), 632-639
- https://doi.org/10.1139/h09-038
Abstract
Although resistance exercise training (RT) is a common intervention to stimulate muscle protein synthesis and increase skeletal muscle mass, the optimal daily protein and total energy intakes sufficient to support RT-mediated muscle growth are as yet unclear. Further, the efficacy of RT varies widely among adults of all ages and whether this is attributable to interindividual differences in nutrition is not known. To determine if self-selected daily intake of macronutrients and specific components of dietary protein and fat are predictive of the magnitude of RT-mediated muscle growth, detailed 4-day dietary records were analyzed on 60 subjects previously clustered (K-means cluster analysis) as non-, modest, and extreme responders (non, n = 16; mod, n = 29; xtr, n = 15), based on the magnitudes of change in vastus lateralis myofiber cross-sectional area following a 16-week, 3-day-per-week, high-intensity RT. Despite the marked contrast between 60% myofiber hypertrophy in xtr and zero growth in non, we found no differences among response clusters in daily intakes of energy (mean ± SEM: non 102 ± 8; mod 111 ± 6; xtr 109 ± 5 kJ·kg–1·day–1), protein (non 0.97 ± 0.08; mod 1.07 ± 0.07; xtr 1.05 ± 0.06 g·kg–1·day–1), carbohydrate (non 3.02 ± 0.24; mod 3.18 ± 0.20; xtr 3.14 ± 0.17 g·kg–1·day–1), and fat (non 0.95 ± 0.09; mod 1.05 ± 0.08; xtr 1.03 ± 0.08 g·kg–1·day–1), which generally met or exceeded dietary recommendations. There were no cluster differences in intakes of branched chain amino acids known to stimulate muscle protein synthesis. Using the novel K-means clustering approach, we conclude from this preliminary study that protein and energy intakes were sufficient to facilitate modest and extreme muscle growth during RT and intrinsic or extrinsic factors other than nutrient ingestion apparently impaired the anabolic response in nonresponders.Keywords
This publication has 49 references indexed in Scilit:
- Under-reporting of energy intake is more prevalent in a healthy dietary pattern clusterBritish Journal of Nutrition, 2008
- Potent myofiber hypertrophy during resistance training in humans is associated with satellite cell-mediated myonuclear addition: a cluster analysisJournal of Applied Physiology, 2008
- Load-mediated downregulation of myostatin mRNA is not sufficient to promote myofiber hypertrophy in humans: a cluster analysisJournal of Applied Physiology, 2007
- Stimulation of net muscle protein synthesis by whey protein ingestion before and after exerciseAmerican Journal of Physiology-Endocrinology and Metabolism, 2007
- Efficacy of myonuclear addition may explain differential myofiber growth among resistance-trained young and older men and womenAmerican Journal of Physiology-Endocrinology and Metabolism, 2006
- Resistance training reduces whole-body protein turnover and improves net protein retention in untrained young malesApplied Physiology, Nutrition, and Metabolism, 2006
- Effects of resistance training and protein plus amino acid supplementation on muscle anabolism, mass, and strengthAmino Acids, 2006
- Exogenous amino acids stimulate human muscle anabolism without interfering with the response to mixed meal ingestionAmerican Journal of Physiology-Endocrinology and Metabolism, 2005
- Effect of carbohydrate intake on net muscle protein synthesis during recovery from resistance exerciseJournal of Applied Physiology, 2004
- Timing of postexercise protein intake is important for muscle hypertrophy with resistance training in elderly humansJournal Of Physiology-London, 2001