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Enhanced amino acid sensitivity of myofibrillar protein synthesis persists for up to 24 h after resistance exercise in young men.
J Nutr. 2011 Apr 01; 141(4):568-73.JN

Abstract

We aimed to determine whether an exercise-mediated enhancement of muscle protein synthesis to feeding persisted 24 h after resistance exercise. We also determined the impact of different exercise intensities (90% or 30% maximal strength) or contraction volume (work-matched or to failure) on the response at 24 h of recovery. Fifteen men (21 ± 1 y, BMI = 24.1 ± 0.8 kg · m(-2)) received a primed, constant infusion of l-[ring-(13)C(6)]phenylalanine to measure muscle protein synthesis after protein feeding at rest (FED; 15 g whey protein) and 24 h after resistance exercise (EX-FED). Participants performed unilateral leg exercises: 1) 4 sets at 90% of maximal strength to failure (90FAIL); 2) 30% work-matched to 90FAIL (30WM); or 3) 30% to failure (30FAIL). Regardless of condition, rates of mixed muscle protein and sarcoplasmic protein synthesis were similarly stimulated at FED and EX-FED. In contrast, protein ingestion stimulated rates of myofibrillar protein synthesis above fasting rates by 0.016 ± 0.002%/h and the response was enhanced 24 h after resistance exercise, but only in the 90FAIL and 30FAIL conditions, by 0.038 ± 0.012 and 0.041 ± 0.010, respectively. Phosphorylation of protein kinase B on Ser473 was greater than FED at EX-FED only in 90FAIL, whereas phosphorylation of mammalian target of rapamycin on Ser2448 was significantly increased at EX-FED above FED only in the 30FAIL condition. Our results suggest that resistance exercise performed until failure confers a sensitizing effect on human skeletal muscle for at least 24 h that is specific to the myofibrillar protein fraction.

Authors+Show Affiliations

Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, Ontario L8S 4K1, Canada.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

21289204

Citation

Burd, Nicholas A., et al. "Enhanced Amino Acid Sensitivity of Myofibrillar Protein Synthesis Persists for Up to 24 H After Resistance Exercise in Young Men." The Journal of Nutrition, vol. 141, no. 4, 2011, pp. 568-73.
Burd NA, West DW, Moore DR, et al. Enhanced amino acid sensitivity of myofibrillar protein synthesis persists for up to 24 h after resistance exercise in young men. J Nutr. 2011;141(4):568-73.
Burd, N. A., West, D. W., Moore, D. R., Atherton, P. J., Staples, A. W., Prior, T., Tang, J. E., Rennie, M. J., Baker, S. K., & Phillips, S. M. (2011). Enhanced amino acid sensitivity of myofibrillar protein synthesis persists for up to 24 h after resistance exercise in young men. The Journal of Nutrition, 141(4), 568-73. https://doi.org/10.3945/jn.110.135038
Burd NA, et al. Enhanced Amino Acid Sensitivity of Myofibrillar Protein Synthesis Persists for Up to 24 H After Resistance Exercise in Young Men. J Nutr. 2011 Apr 1;141(4):568-73. PubMed PMID: 21289204.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Enhanced amino acid sensitivity of myofibrillar protein synthesis persists for up to 24 h after resistance exercise in young men. AU - Burd,Nicholas A, AU - West,Daniel W D, AU - Moore,Daniel R, AU - Atherton,Philip J, AU - Staples,Aaron W, AU - Prior,Todd, AU - Tang,Jason E, AU - Rennie,Michael J, AU - Baker,Steven K, AU - Phillips,Stuart M, Y1 - 2011/02/02/ PY - 2011/2/4/entrez PY - 2011/2/4/pubmed PY - 2011/5/25/medline SP - 568 EP - 73 JF - The Journal of nutrition JO - J Nutr VL - 141 IS - 4 N2 - We aimed to determine whether an exercise-mediated enhancement of muscle protein synthesis to feeding persisted 24 h after resistance exercise. We also determined the impact of different exercise intensities (90% or 30% maximal strength) or contraction volume (work-matched or to failure) on the response at 24 h of recovery. Fifteen men (21 ± 1 y, BMI = 24.1 ± 0.8 kg · m(-2)) received a primed, constant infusion of l-[ring-(13)C(6)]phenylalanine to measure muscle protein synthesis after protein feeding at rest (FED; 15 g whey protein) and 24 h after resistance exercise (EX-FED). Participants performed unilateral leg exercises: 1) 4 sets at 90% of maximal strength to failure (90FAIL); 2) 30% work-matched to 90FAIL (30WM); or 3) 30% to failure (30FAIL). Regardless of condition, rates of mixed muscle protein and sarcoplasmic protein synthesis were similarly stimulated at FED and EX-FED. In contrast, protein ingestion stimulated rates of myofibrillar protein synthesis above fasting rates by 0.016 ± 0.002%/h and the response was enhanced 24 h after resistance exercise, but only in the 90FAIL and 30FAIL conditions, by 0.038 ± 0.012 and 0.041 ± 0.010, respectively. Phosphorylation of protein kinase B on Ser473 was greater than FED at EX-FED only in 90FAIL, whereas phosphorylation of mammalian target of rapamycin on Ser2448 was significantly increased at EX-FED above FED only in the 30FAIL condition. Our results suggest that resistance exercise performed until failure confers a sensitizing effect on human skeletal muscle for at least 24 h that is specific to the myofibrillar protein fraction. SN - 1541-6100 UR - https://www.unboundmedicine.com/medline/citation/21289204/Enhanced_amino_acid_sensitivity_of_myofibrillar_protein_synthesis_persists_for_up_to_24_h_after_resistance_exercise_in_young_men_ L2 - https://academic.oup.com/jn/article-lookup/doi/10.3945/jn.110.135038 DB - PRIME DP - Unbound Medicine ER -