Cited by 32Muscle metabolism and nutritionSports Performance and TrainingCardiovascular and exercise physiology

Protein Intake to Maximize Whole-Body Anabolism during Postexercise Recovery in Resistance-Trained Men with High Habitual Intakes is Severalfold Greater than the Current Recommended Dietary Allowance

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Mazzulla, Michael, Abou Sawan, Sidney, Williamson, Eric, Hannaian, Sarkis J, Volterman, Kimberly A, West, Daniel W D, Moore, Daniel R·2020·The Journal of Nutrition

Abstract

Background Dietary protein supports resistance exercise-induced anabolism primarily via the stimulation of protein synthesis rates. The indicator amino acid oxidation (IAAO) technique provides a noninvasive estimate of the protein intake that maximizes whole-body protein synthesis rates and net protein balance.Objective We utilized IAAO to determine the maximal anabolic response to postexercise protein ingestion in resistance-trained men.Methods Seven resistance-trained men (mean ± SD age 24 ± 3 y; weight 80 ± 9 kg; 11 ± 5% body fat; habitual protein intake 2.3 ± 0.6 g·kg-1·d-1) performed a bout of whole-body resistance exercise prior to ingesting hourly mixed meals, which provided a variable amount of protein (0.20-3.00 g·kg-1·d-1) as crystalline amino acids modeled after egg protein. Steady-state protein kinetics were modeled with oral l-[1-13C]-phenylalanine. Breath and urine samples were taken at isotopic steady state to determine phenylalanine flux (PheRa), phenylalanine excretion (F13CO2; reciprocal of protein synthesis), and net balance (protein synthesis - PheRa). Total amino acid oxidation was estimated from the ratio of urinary urea and creatinine.Results Mixed model biphasic linear regression revealed a plateau in F13CO2 (mean: 2.00; 95% CI: 1.62, 2.38 g protein·kg-1·d-1) (r2 = 0.64; P ˂ 0.01) and in net balance (mean: 2.01; 95% CI: 1.44, 2.57 g protein·kg-1·d-1) (r2 = 0.63; P ˂ 0.01). Ratios of urinary urea and creatinine concentrations increased linearly (r = 0.84; P ˂ 0.01) across the range of protein intakes.Conclusions A breakpoint protein intake of ∼2.0 g·kg-1·d-1, which maximized whole-body anabolism in resistance-trained men after exercise, is greater than previous IAAO-derived estimates for nonexercising men and is at the upper range of current general protein recommendations for athletes. The capacity to enhance whole-body net balance may be greater than previously suggested to maximize muscle protein synthesis in resistance-trained athletes accustomed to a high habitual protein intake. This trial was registered at clinicaltrials.gov as NCT03696264.

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  • Our current findings support the hypothesis that higher daily protein ingestion may be needed to increase LBM in young and maybe older healthy subjects.

    “Our current findings in some way support the hypothesis that higher daily protein ingestion may be needed to increase LBM in young 108 and maybe older healthy subjects. 109”

    From Systematic review and meta-analysis of protein intake to support muscle mass and function in healthy adults (2022) · cites this paper as [108]

    The Introduction links dietary protein and postexercise net protein balance to lean-mass accretion, and the Discussion reports that about 2.0 g/kg/day maximized postexercise whole-body anabolism in resistance-trained men. But the study did not show an increase in LBM: its participants were seven young, resistance-trained men, and the Discussion cautions that whole-body measures may not determine muscle-specific effects. The separate citation following the claim about older subjects is not assessed here. (LLM, conf=0.86)

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Authors
Mazzulla, M., Abou Sawan, S., Williamson, E., Hannaian, S. J., Volterman, K. A., West, D. W. D., & Moore, D. R.
Affiliations
University of Toronto (CA)
Corresponding author
Moore, Daniel R
Venue
The Journal of Nutrition
Publisher
Elsevier BV
Published
2020-03
Volume
150
Issue
3
Pages
505-511
ISSN
0022-3166 (ISSN-L)
OpenAlex
W2981043136
Cited by
32
References
63
Citations by year
2026: 1 · 2025: 4 · 2024: 3 · 2023: 4 · 2022: 4 · 2021: 9 · 2020: 6 · 2019: 1
FWCI
2.65
Type
journal article
Language
en
Open access
Locations
  • Journal of Nutrition (publishedVersion)
  • PubMed (publishedVersion)
Funders
Ajinomoto Innovation Alliance Program
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Muscle metabolism and nutrition
  • Health Sciences › Medicine › Orthopedics and Sports Medicine › Sports Performance and Training
  • Health Sciences › Medicine › Complementary and alternative medicine › Cardiovascular and exercise physiology
Keywords
resistance training, post-exercise recovery, whole-body protein synthesis, net protein balance, indicator amino acid oxidation, phenylalanine kinetics, protein kinetics, RDA, resistance-trained men, amino acid oxidation, mixed meal, egg proteins, muscle protein anabolism
MeSH terms
Adult, Breath Tests, Creatinine, Dietary Proteins, Humans, Male, Metabolism, Phenylalanine, Urea, Exercise, Resistance Training, Young Adult, Recommended Dietary Allowances

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