Does Protein Supplementation Support Adaptations to Arduous Concurrent Exercise Training? A Systematic Review and Meta-Analysis with Military Based Applications

Abstract

We evaluated the impact of protein supplementation on adaptations to arduous concurrent training in healthy adults with potential applications to individuals undergoing military training. Peer-reviewed papers published in English meeting the population, intervention, comparison and outcome criteria were included. Database searches were completed in PubMed, Web of science and SPORTDiscus. Study quality was evaluated using the COnsensus based standards for the selection of health status measurement instruments checklist. Of 11 studies included, nine focused on performance, six on body composition and four on muscle recovery. Cohen’s d effect sizes showed that protein supplementation improved performance outcomes in response to concurrent training (ES = 0.89, 95% CI = 0.08–1.70). When analysed separately, improvements in muscle strength (SMD = +4.92 kg, 95% CI = −2.70–12.54 kg) were found, but not in aerobic endurance. Gains in fat-free mass (SMD = +0.75 kg, 95% CI = 0.44–1.06 kg) and reductions in fat-mass (SMD = −0.99, 95% CI = −1.43–0.23 kg) were greater with protein supplementation. Most studies did not report protein turnover, nitrogen balance and/or total daily protein intake. Therefore, further research is warranted. However, our findings infer that protein supplementation may support lean-mass accretion and strength gains during arduous concurrent training in physical active populations, including military recruits.

Whey Protein Supplementation Effects on Body Composition, Performance, and Blood Biomarkers During Army Initial Entry Training

“…Interestingly individuals 10 kg above average week one BM consumed only 1.7 g/kg/day of protein. Organizational recommendations and systematic reviews of the literature suggest that daily protein intakes should be between 1.6 and 2 ( 50 ) and 1.7 and 2.2 g/kg/day ( 51 ). Therefore, individuals with lower BM in our cohort were able to consume protein intakes on the higher end of the recommended ranges whereas individuals with higher BM were closer to the lower end of this range.…”

“…Previous work in British IET, suggests that nitrogen balance can be attained, at least in the initial weeks, by consumption of 1.5 g/kg/day of protein intake ( 53 ). Additionally, a meta-analysis summarizing the literature on supplementation in strenuous military environments suggested protein intakes between 1.7 and 2.2 g/kg/day are recommended ( 51 ). Here we report that the CHO group consumed on average 2.2 g/kg/day.…”

A Guide to Different Intensities of Exercise, Vaccination, and Sports Nutrition in the Course of Preparing Elite Athletes for the Management of Upper Respiratory Infections during the COVID-19 Pandemic: A Narrative Review

“…However, both positive and negative results have been obtained due to chronic protein supplementation or a proteinrich diet intake. Data from a systematic review and meta-analysis showed that protein supplementation during resistance exercise training does not improve muscle strength, size, or functional ability [88].…”

Current and Novel Reviews in Sports Nutrition

“…For this Special Issue, research leaders in sports nutrition were approached and invited to submit current reviews in their areas of expertise [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. The topics are novel and wide-ranging, and include updates and insights on protein [ 11 , 12 ], dietary patterns and nutritional interventions to support sleep, older athletes, and sports performance [ 13 , 14 , 15 ], pre-exercise nutrition [ 16 ], supplementation with betaine, iron, and creatine [ 17 , 18 , 19 ], and sports nutrition research methodologies for body composition and muscle glycogen analysis [ 20 , 21 ]. A major emphasis in all of the papers was a focus on strengths and weaknesses for various sports nutrition strategies, and insights for future research.…”

“…Kerksick et al [ 11 ] defined the role that proper doses of plant proteins can have in supporting health, the environment, and exercise training adaptations. The systematic review and meta-analysis by Chapman et al [ 12 ] concluded that protein supplementation improves strength and muscle mass during intensive and long-term training. Nutritional interventions, such as supplementation with tart cherry juice, kiwifruit, 20–40 grams of protein rich in tryptophan, and glycine late in the day were recommended as useful sleep-enhancement strategies for athletes in the narrative review by Gratwicke et al [ 13 ].…”