A Dietary Supplement Containing Essential Amino Acids in Combination with Resistance Training Improves Body Composition and Physical Performance Parameters in Generally Healthy Adults: A Pragmatic Single Arm Study Original Research
Main Article Content
Keywords
lean body mass, muscular strength, protein
Abstract
Introduction: Essential amino acid (EAA) supplements are popular for increasing muscle mass and improving performance.
Methods: This pragmatic single arm study enrolled 30 participants (17F/13M) to consume a commercially available supplement providing 3.6 g/d EAA + arginine and complete supervised strength training (two, upper-body days, two, lower body days/week) over a 10-week period. DXA body composition, muscular strength (1 repetition max [1RM]) muscular endurance (number of repetitions to failure), and the Acute Recovery and Stress Scale (ARSS) were assessed at baseline and week 10.
Results: Participants (n=27 completers [15F/12M]; mean ± SD age 38.7 ± 8.6 y and BMI 29.4 ± 3.6 kg/m2) experienced statistically significant (p<0.05) reductions in total fat mass (-0.9 [-1.8, -0.1] kg) and visceral fat (-96 [-165, -26] g), with concurrent increases in total lean body mass (1.1 [0.4, 1.8] kg), upper body strength (~18% increase in bench press 1-RM), lower body strength (~40% increase in angled leg-press 1-RM), and muscular endurance (~75% increased repetitions to failure for both exercises). Additionally, participants demonstrated improvements in all stress and recovery outcomes within the ARSS.
Conclusions: These results demonstrate the potential value of EAA supplementation as part of a comprehensive approach to support physical performance and body composition in previously untrained or recreationally trained adults.
References
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20. Josse AR, Tang JE, Tarnopolsky MA, Phillips SM. Body composition and strength changes in women with milk and resistance exercise. Med Sci Sports Exerc. Jun 2010;42(6):1122-30. doi:10.1249/MSS.0b013e3181c854f6. https://journals.lww.com/acsm-msse/fulltext/2010/06000/body_composition_and_strength_changes_in_women.11.aspx
21. Kerksick CM, Rasmussen CJ, Lancaster SL, et al. The effects of protein and amino acid supplementation on performance and training adaptations during ten weeks of resistance training. J Strength Cond Res. Aug 2006;20(3):643-53.
22. Wilkinson DJ, Bukhari SSI, Phillips BE, et al. Effects of leucine-enriched essential amino acid and whey protein bolus dosing upon skeletal muscle protein synthesis at rest and after exercise in older women. Clin Nutr. Dec 2018;37(6 Pt A):2011-2021. doi:10.1016/j.clnu.2017.09.008. https://www.sciencedirect.com/science/article/pii/S0261561417313407
23. Paddon-Jones D, Sheffield-Moore M, Katsanos CS, Zhang XJ, Wolfe RR. Differential stimulation of muscle protein synthesis in elderly humans following isocaloric ingestion of amino acids or whey protein. Exp Gerontol. Feb 2006;41(2):215-9. doi:10.1016/j.exger.2005.10.006. https://www.sciencedirect.com/science/article/abs/pii/S0531556505002548
24. Bukhari SS, Phillips BE, Wilkinson DJ, et al. Intake of low-dose leucine-rich essential amino acids stimulates muscle anabolism equivalently to bolus whey protein in older women at rest and after exercise. Am J Physiol Endocrinol Metab. Jun 15 2015;308(12):E1056-65. doi:10.1152/ajpendo.00481.2014. https://journals.physiology.org/doi/full/10.1152/ajpendo.00481.2014
25. Matsui Y, Takayanagi S, Ohira T, et al. Effect of a leucine-enriched essential amino acids mixture on muscle recovery. J Phys Ther Sci. Jan 2019;31(1):95-101. doi:10.1589/jpts.31.95. https://www.jstage.jst.go.jp/article/jpts/31/1/31_jpts-2018-338/_article
2. Tipton KD, Ferrando AA, Phillips SM, Doyle D, Jr., Wolfe RR. Postexercise net protein synthesis in human muscle from orally administered amino acids. Am J Physiol. Apr 1999;276(4):E628-34. doi:10.1152/ajpendo.1999.276.4.E628. https://journals.physiology.org/doi/full/10.1152/ajpendo.1999.276.4.E628
3. Biolo G, Tipton KD, Klein S, Wolfe RR. An abundant supply of amino acids enhances the metabolic effect of exercise on muscle protein. Am J Physiol. Jul 1997;273(1 Pt 1):E122-9. doi:10.1152/ajpendo.1997.273.1.E122. https://journals.physiology.org/doi/abs/10.1152/ajpendo.1997.273.1.E122
4. Fujita S, Dreyer HC, Drummond MJ, et al. Nutrient signalling in the regulation of human muscle protein synthesis. J Physiol. Jul 15 2007;582(Pt 2):813-23. doi:10.1113/jphysiol.2007.134593. https://physoc.onlinelibrary.wiley.com/doi/epdf/10.1113/jphysiol.2007.134593
5. Volpi E, Kobayashi H, Sheffield-Moore M, Mittendorfer B, Wolfe RR. Essential amino acids are primarily responsible for the amino acid stimulation of muscle protein anabolism in healthy elderly adults. Am J Clin Nutr. Aug 2003;78(2):250-8. doi:10.1093/ajcn/78.2.250. https://www.sciencedirect.com/science/article/pii/S0002916522032920
6. Wu G. Amino acids: biochemistry and nutrition CRC Press; 2013.
7. Institute of Medicine. Protein and amino acids. Dietary Reference Intakes: the essential guide to nutrient requirements. Washington (DC): Institute of Medicine, National Academies Press; 2006.
8. Fryar CD, Kruszon-Moran D, Gu Q, Ogden CL. Mean body weight, height, waist circumference, and body mass index among adults: United States, 1999–2000 through 2015–2016. National Health Statistics Reports; no 122 Hyattsville, MD: National Center for Health Statistics. 2018.
9. Hou Y, Wu G. Nutritionally Essential Amino Acids. Adv Nutr. Nov 1 2018;9(6):849-851. doi:10.1093/advances/nmy054. https://www.sciencedirect.com/science/article/pii/S216183132201273X
10. Spillane M, Emerson C, Willoughby DS. The effects of 8 weeks of heavy resistance training and branched-chain amino acid supplementation on body composition and muscle performance. Nutr Health. Oct 2012;21(4):263-73. doi:10.1177/0260106013510999. https://journals.sagepub.com/doi/10.1177/0260106013510999
11. Willoughby DS, Stout JR, Wilborn CD. Effects of resistance training and protein plus amino acid supplementation on muscle anabolism, mass, and strength. Amino Acids. 2007;32(4):467-77. doi:10.1007/s00726-006-0398-7. https://link.springer.com/article/10.1007/s00726-006-0398-7
12. NSCA’s Guide to Tests and Assessments. (2012). (T. A. Miller Ed.). Champaign, IL: Human Kinetics.
13. Ferrando AA, Wolfe RR, Hirsch KR, et al. International Society of Sports Nutrition Position Stand: Effects of essential amino acid supplementation on exercise and performance. J Int Soc Sports Nutr. Dec 2023;20(1):2263409. doi:10.1080/15502783.2023.2263409. https://www.tandfonline.com/doi/full/10.1080/15502783.2023.2263409
14. Phillips SM. The impact of protein quality on the promotion of resistance exercise-induced changes in muscle mass. Nutr Metab (Lond). 2016;13:64. doi:10.1186/s12986-016-0124-8. https://nutritionandmetabolism.biomedcentral.com/articles/10.1186/s12986-016-0124-8
15. Churchward-Venne TA, Burd NA, Phillips SM. Nutritional regulation of muscle protein synthesis with resistance exercise: strategies to enhance anabolism. Nutr Metab (Lond). May 17 2012;9(1):40. doi:10.1186/1743-7075-9-40. https://nutritionandmetabolism.biomedcentral.com/articles/10.1186/1743-7075-9-40
16. Andersen LL, Tufekovic G, Zebis MK, et al. The effect of resistance training combined with timed ingestion of protein on muscle fiber size and muscle strength. Metabolism. Feb 2005;54(2):151-6. doi:10.1016/j.metabol.2004.07.012. https://www.sciencedirect.com/science/article/abs/pii/S0026049504003063
17. Bird SP, Tarpenning KM, Marino FE. Independent and combined effects of liquid carbohydrate/essential amino acid ingestion on hormonal and muscular adaptations following resistance training in untrained men. Eur J Appl Physiol. May 2006;97(2):225-38. doi:10.1007/s00421-005-0127-z. https://link.springer.com/article/10.1007/s00421-005-0127-z
18. Cribb PJ, Williams AD, Stathis CG, Carey MF, Hayes A. Effects of whey isolate, creatine, and resistance training on muscle hypertrophy. Med Sci Sports Exerc. Feb 2007;39(2):298-307. doi:10.1249/01.mss.0000247002.32589.ef. https://journals.lww.com/acsm-msse/fulltext/2007/02000/effects_of_whey_isolate,_creatine,_and_resistance.12.aspx
19. Hulmi JJ, Kovanen V, Selanne H, Kraemer WJ, Hakkinen K, Mero AA. Acute and long-term effects of resistance exercise with or without protein ingestion on muscle hypertrophy and gene expression. Amino Acids. Jul 2009;37(2):297-308. doi:10.1007/s00726-008-0150-6. https://link.springer.com/article/10.1007/s00726-008-0150-6
20. Josse AR, Tang JE, Tarnopolsky MA, Phillips SM. Body composition and strength changes in women with milk and resistance exercise. Med Sci Sports Exerc. Jun 2010;42(6):1122-30. doi:10.1249/MSS.0b013e3181c854f6. https://journals.lww.com/acsm-msse/fulltext/2010/06000/body_composition_and_strength_changes_in_women.11.aspx
21. Kerksick CM, Rasmussen CJ, Lancaster SL, et al. The effects of protein and amino acid supplementation on performance and training adaptations during ten weeks of resistance training. J Strength Cond Res. Aug 2006;20(3):643-53.
22. Wilkinson DJ, Bukhari SSI, Phillips BE, et al. Effects of leucine-enriched essential amino acid and whey protein bolus dosing upon skeletal muscle protein synthesis at rest and after exercise in older women. Clin Nutr. Dec 2018;37(6 Pt A):2011-2021. doi:10.1016/j.clnu.2017.09.008. https://www.sciencedirect.com/science/article/pii/S0261561417313407
23. Paddon-Jones D, Sheffield-Moore M, Katsanos CS, Zhang XJ, Wolfe RR. Differential stimulation of muscle protein synthesis in elderly humans following isocaloric ingestion of amino acids or whey protein. Exp Gerontol. Feb 2006;41(2):215-9. doi:10.1016/j.exger.2005.10.006. https://www.sciencedirect.com/science/article/abs/pii/S0531556505002548
24. Bukhari SS, Phillips BE, Wilkinson DJ, et al. Intake of low-dose leucine-rich essential amino acids stimulates muscle anabolism equivalently to bolus whey protein in older women at rest and after exercise. Am J Physiol Endocrinol Metab. Jun 15 2015;308(12):E1056-65. doi:10.1152/ajpendo.00481.2014. https://journals.physiology.org/doi/full/10.1152/ajpendo.00481.2014
25. Matsui Y, Takayanagi S, Ohira T, et al. Effect of a leucine-enriched essential amino acids mixture on muscle recovery. J Phys Ther Sci. Jan 2019;31(1):95-101. doi:10.1589/jpts.31.95. https://www.jstage.jst.go.jp/article/jpts/31/1/31_jpts-2018-338/_article
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Feb 15, 2025
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A Dietary Supplement Containing Essential Amino Acids in Combination with Resistance Training Improves Body Composition and Physical Performance Parameters in Generally Healthy Adults: A Pragmatic Single Arm Study: Original Research. (2025). Journal of Exercise and Nutrition, 8(1). https://doi.org/10.53520/jen2025.103188
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Copyright, 2025 by the authors. This work is licensed under the Creative Commons Attribution 4.0 International License.
How to Cite
A Dietary Supplement Containing Essential Amino Acids in Combination with Resistance Training Improves Body Composition and Physical Performance Parameters in Generally Healthy Adults: A Pragmatic Single Arm Study: Original Research. (2025). Journal of Exercise and Nutrition, 8(1). https://doi.org/10.53520/jen2025.103188