Protein supplementation increases adaptations to endurance training: A systematic review and meta-analysis

Yen-Nung Lin; Tzu-Tian Tseng; Pim Knuiman; Wing P Chan; Shan-Hong Wu; Chi-Lin Tsai; Chih-Yang Hsu

doi:10.1016/j.clnu.2020.12.012

Protein supplementation increases adaptations to endurance training: A systematic review and meta-analysis

Clin Nutr. 2021 May;40(5):3123-3132. doi: 10.1016/j.clnu.2020.12.012. Epub 2020 Dec 15.

Authors

Yen-Nung Lin¹, Tzu-Tian Tseng², Pim Knuiman³, Wing P Chan⁴, Shan-Hong Wu⁵, Chi-Lin Tsai², Chih-Yang Hsu²

Affiliations

¹ Department of Physical Medicine and Rehabilitation, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan; Graduate Institute of Injury Prevention and Control, Taipei Medical University, Taipei, Taiwan. Electronic address: semitune@gmail.com.
² Department of Physical Medicine and Rehabilitation, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan.
³ School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom.
⁴ Department of Radiology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan; Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
⁵ Graduate Institute of Injury Prevention and Control, Taipei Medical University, Taipei, Taiwan; Department of Traditional Chinese Medicine, Taipei Medical University Hospital, Taipei, Taiwan.

PMID: 33358231
DOI: 10.1016/j.clnu.2020.12.012

Abstract

Background: Trials that assessed the impact of protein supplementation on endurance training adaptations have reported conflicting findings.

Objective: To determine the impact of protein supplementation during chronic endurance training on aerobic capacity, body composition and exercise performance in healthy and clinical populations.

Design: A systematic database search was conducted for randomised controlled trials addressing the effects of protein supplementation during endurance training on aerobic capacity, body composition and exercise performance in PubMed, Embase, Web of Science, and CINAHL. Meta-analyses were performed to outline the overall effects of protein supplementation with all studies containing endurance training components. The effects of endurance training and add-on effects of protein supplementation were evaluated by the meta-analyses with endurance training-focused studies.

Results: Nineteen studies and 1162 participants contributed to the analyses. Compared with the control group, the protein supplementation group demonstrated greater improvements in aerobic capacity measured by mixed peak oxygen uptake (V̇O_2peak) and peak workload power (W_peak) (standardised mean difference [SMD] = 0.36, 95% confidence interval [CI]: 0.05 to 0.67), and V̇O_2peak (mean difference [MD] = 0.89 mL‧kg^-1‧min^-1, 95% CI: 0.07 to 1.70); had a greater lean mass gain (MD = 0.32 kg, 95% CI: 0.07 to 0.58); and had a greater improvement in time trial performance (MD = -29.1s, 95% CI:-55.3 to -3.0). Secondary analyses showed that, in addition to the substantial improvement in V̇O_2peak (MD = 3.67 mL‧kg^-1‧min^-1, 95% CI: 2.32 to 5.03) attributed to endurance training, protein supplementation provided an additional 26.4% gain in V̇O_2peak (MD = 0.97 mL‧kg^-1‧min^-1, 95% CI: -0.03 to 1.97).

Conclusion: Protein supplementation further increased aerobic capacity, stimulated lean mass gain, and improved time trial performance during chronic endurance training in healthy and clinical populations. PROSPERO REGISTRATION NUMBER: (CRD42020155239).

Keywords: Aerobic exercise; Cardiorespiratory fitness; Dietary proteins; Muscle proteins; Nutritional supplement; Oxygen consumption.

Publication types

Meta-Analysis
Research Support, Non-U.S. Gov't
Systematic Review

MeSH terms

Adaptation, Physiological
Body Composition / drug effects
Dietary Proteins / administration & dosage
Dietary Proteins / pharmacology*
Dietary Supplements*
Endurance Training / methods*
Humans
Physical Endurance / drug effects*

Substances

Dietary Proteins