| Autor: |
McKenna CF; Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois., Salvador AF; Division of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois., Hughes RL; Division of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois., Scaroni SE; Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois., Alamilla RA; Division of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois., Askow AT; Division of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois., Paluska SA; Division of Family Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois., Dilger AC; Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois., Holscher HD; Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois.; Division of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois.; Division of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois., De Lisio M; School of Human Kinetics and Cellular and Molecular Medicine, University of Ottawa, Ontario, Canada., Khan NA; Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois.; Division of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois.; Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois., Burd NA; Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois.; Division of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois. |
| Abstrakt: |
Protein intake above the recommended dietary allowance (RDA) and resistance training are known anabolic stimuli to support healthy aging. Specifically, protein supplementation after resistance exercise and nightly are strategies to maximize utilization of protein intake above the RDA in healthy adults. As such, the primary objective was to examine the efficacy of protein supplementation and nutritional counseling resulting in either moderate (MOD: ∼1.0 g·kg -1 ·day -1 ) or higher (HIGH: ∼1.6 g·kg -1 ·day -1 ) protein intake during resistance training on strength (one-repetition maximum, 1-RM; isokinetic and isometric peak torque) in healthy middle-aged adults. Exploratory analyses include diet-exercise effects on lean body mass (LBM), clinical biomarkers, gut microbiota, and diet composition. In all, 50 middle-aged adults (age: 50 ± 8 yr, BMI: 27.2 ± 4.1 kg/m 2 ) were randomized to either MOD or HIGH protein intake during a 10-wk resistance training program (3 × wk). Participants received dietary counseling and consumed either 15 g (MOD) or 30 g (HIGH) of protein from lean beef in the immediate postexercise period and each evening. Maximal strength (1-RM) for all upper and lower body exercises significantly increased with no effect of protein intake ( P < 0.050). There was a main effect of time for LBM ( P < 0.005). Cardiovascular, renal, or glycemic biomarkers were not affected by the intervention. Gut microbiota were associated with several health outcomes ( P < 0.050). In conclusion, higher protein intake above moderate amounts does not potentiate resistance training adaptations in previously untrained middle-aged adults. This trial was registered at clinicaltrials.gov as NCT03029975. NEW & NOTEWORTHY Our research evaluates the efficacy of higher in comparison with moderate animal-based protein intake on resistance exercise training-induced muscle strength, clinical biomarkers, and gut microbiota in middle-aged adults through a dietary counseling-controlled intervention. Higher protein intake did not potentiate training adaptations, nor did the intervention effect disease biomarkers. Both diet and exercise modified gut microbiota composition. Collectively, moderate amounts of high-quality, animal-based protein is sufficient to promote resistance exercise adaptations at the onset of aging. |
