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Brook MS, Stokes T, Gorissen SH, Bass JJ, McGlory C, Cegielski J, Wilkinson DJ, Phillips BE, Smith K, Phillips SM, Atherton PJ. Declines in muscle protein synthesis account for short-term muscle disuse atrophy in humans in the absence of increased muscle protein breakdown. J Cachexia Sarcopenia Muscle 2022; 13:2005-2016. [PMID: 35606155 PMCID: PMC9397550 DOI: 10.1002/jcsm.13005] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 03/30/2022] [Accepted: 04/04/2022] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND We determined the short-term (i.e. 4 days) impacts of disuse atrophy in relation to muscle protein turnover [acute fasted-fed muscle protein synthesis (MPS)/muscle protein breakdown (MPB) and integrated MPS/estimated MPB]. METHODS Healthy men (N = 9, 22 ± 2 years, body mass index 24 ± 3 kg m-2 ) underwent 4 day unilateral leg immobilization. Vastus lateralis (VL) muscle thickness (MT) and extensor strength and thigh lean mass (TLM) were measured. Bilateral VL muscle biopsies were collected on Day 4 at t = -120, 0, 90, and 180 min to determine integrated MPS, estimated MPB, acute fasted-fed MPS (l-[ring-13 C6 ]-phe), and acute fasted tracer decay rate representative of MPB (l-[15 N]-phe and l-[2 H8 ]-phe). Protein turnover cell signalling was measured by immunoblotting. RESULTS Immobilization decreased TLM [pre: 7477 ± 1196 g, post: 7352 ± 1209 g (P < 0.01)], MT [pre: 2.67 ± 0.50 cm, post: 2.55 ± 0.51 cm (P < 0.05)], and strength [pre: 260 ± 43 N m, post: 229 ± 37 N m (P < 0.05)] with no change in control legs. Integrated MPS decreased in immob vs. control legs [control: 1.55 ± 0.21% day-1 , immob: 1.29 ± 0.17% day-1 (P < 0.01)], while tracer decay rate (i.e. MPB) (control: 0.02 ± 0.006, immob: 0.015 ± 0.015) and fractional breakdown rate (FBR) remained unchanged [control: 1.44 ± 0.51% day-1 , immob: 1.73 ± 0.35% day-1 (P = 0.21)]. Changes in MT correlated with those in MPS but not FBR. MPS increased in the control leg following feeding [fasted: 0.043 ± 0.012% h-1 , fed: 0.065 ± 0.017% h-1 (P < 0.05)] but not in immob [fasted: 0.034 ± 0.014% h-1 , fed: 0.049 ± 0.023% h-1 (P = 0.09)]. There were no changes in markers of MPB with immob (P > 0.05). CONCLUSIONS Human skeletal muscle disuse atrophy is driven by declines in MPS, not increases in MPB. Pro-anabolic therapies to mitigate disuse atrophy would likely be more effective than therapies aimed at attenuating protein degradation.
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Affiliation(s)
- Matthew S. Brook
- MRC‐Versus Arthritis Centre for Musculoskeletal Ageing Research and NIHR Nottingham BRC, Centre Of Metabolism, Ageing and Physiology (COMAP), School of MedicineUniversity of NottinghamDerbyUK
- School of Life SciencesUniversity of NottinghamNottinghamUK
| | - Tanner Stokes
- Department of KinesiologyMcMaster UniversityHamiltonONCanada
| | | | - Joseph J. Bass
- MRC‐Versus Arthritis Centre for Musculoskeletal Ageing Research and NIHR Nottingham BRC, Centre Of Metabolism, Ageing and Physiology (COMAP), School of MedicineUniversity of NottinghamDerbyUK
| | - Chris McGlory
- School of Kinesiology and Health StudiesQueen's UniversityKingstonONCanada
| | - Jessica Cegielski
- MRC‐Versus Arthritis Centre for Musculoskeletal Ageing Research and NIHR Nottingham BRC, Centre Of Metabolism, Ageing and Physiology (COMAP), School of MedicineUniversity of NottinghamDerbyUK
| | - Daniel J. Wilkinson
- MRC‐Versus Arthritis Centre for Musculoskeletal Ageing Research and NIHR Nottingham BRC, Centre Of Metabolism, Ageing and Physiology (COMAP), School of MedicineUniversity of NottinghamDerbyUK
| | - Bethan E. Phillips
- MRC‐Versus Arthritis Centre for Musculoskeletal Ageing Research and NIHR Nottingham BRC, Centre Of Metabolism, Ageing and Physiology (COMAP), School of MedicineUniversity of NottinghamDerbyUK
| | - Ken Smith
- MRC‐Versus Arthritis Centre for Musculoskeletal Ageing Research and NIHR Nottingham BRC, Centre Of Metabolism, Ageing and Physiology (COMAP), School of MedicineUniversity of NottinghamDerbyUK
| | | | - Philip J. Atherton
- MRC‐Versus Arthritis Centre for Musculoskeletal Ageing Research and NIHR Nottingham BRC, Centre Of Metabolism, Ageing and Physiology (COMAP), School of MedicineUniversity of NottinghamDerbyUK
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Horstman AMH, Huppertz T. Milk proteins: Processing, gastric coagulation, amino acid availability and muscle protein synthesis. Crit Rev Food Sci Nutr 2022; 63:10267-10282. [PMID: 35611879 DOI: 10.1080/10408398.2022.2078782] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
It is well-known that the postprandial muscle protein synthetic response to protein ingestion is regulated on various levels, including dietary protein digestion and amino acid (AA) absorption, splanchnic AA retention, the availability of dietary protein-derived AA in the circulation, delivery of AA to the muscle, uptake of AA by the muscle, and intramuscular signaling. AA availability after consumption of dairy products is primarily determined by the rate of gastric emptying of milk proteins, which is mainly linked to coagulation of milk proteins in the stomach. Caseins form gastric coagula, which make their gastric emptying and subsequent postprandial aminoacidemia notably slower than that of whey proteins. Only recently, the role of processing, food structure, preservation and matrix on coagulation herein has been getting attention. In this review we describe various processes, that affect gastric coagulation of caseins and therewith control gastric emptying, such as the conversion to caseinate, heat treatment in the presence of whey proteins, conversion to stirred yoghurt and enzymatic hydrolysis. Modulating product characteristics by processing can be very useful to steer the gastric behavior of protein, and the subsequent digestion and AA absorption and muscle anabolic response to maintain or increase muscle mass.
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Affiliation(s)
| | - Thom Huppertz
- Research & Development, FrieslandCampina, Amersfoort, The Netherlands
- Food Quality and Design, Wageningen University & Research, Wageningen, The Netherlands
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Pinckaers PJM, Trommelen J, Snijders T, van Loon LJC. The Anabolic Response to Plant-Based Protein Ingestion. Sports Med 2021; 51:59-74. [PMID: 34515966 PMCID: PMC8566416 DOI: 10.1007/s40279-021-01540-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2021] [Indexed: 12/17/2022]
Abstract
There is a global trend of an increased interest in plant-based diets. This includes an increase in the consumption of plant-based proteins at the expense of animal-based proteins. Plant-derived proteins are now also frequently applied in sports nutrition. So far, we have learned that the ingestion of plant-derived proteins, such as soy and wheat protein, result in lower post-prandial muscle protein synthesis responses when compared with the ingestion of an equivalent amount of animal-based protein. The lesser anabolic properties of plant-based versus animal-derived proteins may be attributed to differences in their protein digestion and amino acid absorption kinetics, as well as to differences in amino acid composition between these protein sources. Most plant-based proteins have a low essential amino acid content and are often deficient in one or more specific amino acids, such as lysine and methionine. However, there are large differences in amino acid composition between various plant-derived proteins or plant-based protein sources. So far, only a few studies have directly compared the muscle protein synthetic response following the ingestion of a plant-derived protein versus a high(er) quality animal-derived protein. The proposed lower anabolic properties of plant- versus animal-derived proteins may be compensated for by (i) consuming a greater amount of the plant-derived protein or plant-based protein source to compensate for the lesser quality; (ii) using specific blends of plant-based proteins to create a more balanced amino acid profile; (iii) fortifying the plant-based protein (source) with the specific free amino acid(s) that is (are) deficient. Clinical studies are warranted to assess the anabolic properties of the various plant-derived proteins and their protein sources in vivo in humans and to identify the factors that may or may not compromise the capacity to stimulate post-prandial muscle protein synthesis rates. Such work is needed to determine whether the transition towards a more plant-based diet is accompanied by a transition towards greater dietary protein intake requirements.
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Affiliation(s)
- Philippe J M Pinckaers
- Department of Human Biology, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre+, P.O. Box 616, 6200 MD, Maastricht, The Netherlands
| | - Jorn Trommelen
- Department of Human Biology, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre+, P.O. Box 616, 6200 MD, Maastricht, The Netherlands
| | - Tim Snijders
- Department of Human Biology, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre+, P.O. Box 616, 6200 MD, Maastricht, The Netherlands
| | - Luc J C van Loon
- Department of Human Biology, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre+, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
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4
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Borack MS, Dickinson JM, Fry CS, Reidy PT, Markofski MM, Deer RR, Jennings K, Volpi E, Rasmussen BB. Effect of the lysosomotropic agent chloroquine on mTORC1 activation and protein synthesis in human skeletal muscle. Nutr Metab (Lond) 2021; 18:61. [PMID: 34118944 PMCID: PMC8199655 DOI: 10.1186/s12986-021-00585-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 05/28/2021] [Indexed: 11/16/2022] Open
Abstract
Background Previous work in HEK-293 cells demonstrated the importance of amino acid-induced mTORC1 translocation to the lysosomal surface for stimulating mTORC1 kinase activity and protein synthesis. This study tested the conservation of this amino acid sensing mechanism in human skeletal muscle by treating subjects with chloroquine—a lysosomotropic agent that induces in vitro and in vivo lysosome dysfunction. Methods mTORC1 signaling and muscle protein synthesis (MPS) were determined in vivo in a randomized controlled trial of 14 subjects (10 M, 4 F; 26 ± 4 year) that ingested 10 g of essential amino acids (EAA) after receiving 750 mg of chloroquine (CHQ, n = 7) or serving as controls (CON, n = 7; no chloroquine). Additionally, differentiated C2C12 cells were used to assess mTORC1 signaling and myotube protein synthesis (MyPS) in the presence and absence of leucine and the lysosomotropic agent chloroquine. Results mTORC1, S6K1, 4E-BP1 and rpS6 phosphorylation increased in both CON and CHQ 1 h post EAA ingestion (P < 0.05). MPS increased similarly in both groups (CON, P = 0.06; CHQ, P < 0.05). In contrast, in C2C12 cells, 1 mM leucine increased mTORC1 and S6K1 phosphorylation (P < 0.05), which was inhibited by 2 mg/ml chloroquine. Chloroquine (2 mg/ml) was sufficient to disrupt mTORC1 signaling, and MyPS. Conclusions Chloroquine did not inhibit amino acid-induced activation of mTORC1 signaling and skeletal MPS in humans as it does in C2C12 muscle cells. Therefore, different in vivo experimental approaches are required for confirming the precise role of the lysosome and amino acid sensing in human skeletal muscle. Trial registration NCT00891696. Registered 29 April 2009.
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Affiliation(s)
- Michael S Borack
- Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA.,Department of Nutrition and Metabolism, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA.,Center for the Study of Aging and Human Development, Duke University, Durham, NC, USA
| | - Jared M Dickinson
- Department of Nutrition and Metabolism, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA.,Sealy Center On Aging, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA.,Department of Health Sciences, Central Washington University, Ellensburg, WA, USA
| | - Christopher S Fry
- Department of Nutrition and Metabolism, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA.,Sealy Center On Aging, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA.,Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington, KY, USA
| | - Paul T Reidy
- Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA.,Department of Nutrition and Metabolism, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA.,Department of Kinesiology, Nutrition and Health, Miami of Ohio University, Oxford, OH, USA
| | - Melissa M Markofski
- Sealy Center On Aging, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA.,Department of Health and Human Performance, University of Houston, Houston, TX, USA
| | - Rachel R Deer
- Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA.,Sealy Center On Aging, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA
| | - Kristofer Jennings
- Department of Preventive Medicine and Population Health, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA.,Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Elena Volpi
- Department of Internal Medicine/Geriatrics, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA.,Sealy Center On Aging, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA
| | - Blake B Rasmussen
- Department of Nutrition and Metabolism, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA. .,Sealy Center On Aging, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555-1124, USA.
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5
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Lamon S, Morabito A, Arentson-Lantz E, Knowles O, Vincent GE, Condo D, Alexander SE, Garnham A, Paddon-Jones D, Aisbett B. The effect of acute sleep deprivation on skeletal muscle protein synthesis and the hormonal environment. Physiol Rep 2021; 9:e14660. [PMID: 33400856 PMCID: PMC7785053 DOI: 10.14814/phy2.14660] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 11/08/2020] [Indexed: 12/18/2022] Open
Abstract
Chronic sleep loss is a potent catabolic stressor, increasing the risk of metabolic dysfunction and loss of muscle mass and function. To provide mechanistic insight into these clinical outcomes, we sought to determine if acute sleep deprivation blunts skeletal muscle protein synthesis and promotes a catabolic environment. Healthy young adults (N = 13; seven male, six female) were subjected to one night of total sleep deprivation (DEP) and normal sleep (CON) in a randomized cross‐over design. Anabolic and catabolic hormonal profiles were assessed across the following day. Postprandial muscle protein fractional synthesis rate (FSR) was assessed between 13:00 and 15:00 and gene markers of muscle protein degradation were assessed at 13:00. Acute sleep deprivation reduced muscle protein synthesis by 18% (CON: 0.072 ± 0.015% vs. DEP: 0.059 ± 0.014%·h‐1, p = .040). In addition, sleep deprivation increased plasma cortisol by 21% (p = .030) and decreased plasma testosterone by 24% (p = .029). No difference was found in the markers of protein degradation. A single night of total sleep deprivation is sufficient to induce anabolic resistance and a procatabolic environment. These acute changes may represent mechanistic precursors driving the metabolic dysfunction and body composition changes associated with chronic sleep deprivation.
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Affiliation(s)
- Séverine Lamon
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Aimee Morabito
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Emily Arentson-Lantz
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, TX, USA
| | - Olivia Knowles
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | | | - Dominique Condo
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia.,Center for Sport Research (CSR), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Sarah Elizabeth Alexander
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Andrew Garnham
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Douglas Paddon-Jones
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, TX, USA
| | - Brad Aisbett
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
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6
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Protein Intake and Exercise-Induced Skeletal Muscle Hypertrophy: An Update. Nutrients 2020; 12:nu12072023. [PMID: 32646013 PMCID: PMC7400877 DOI: 10.3390/nu12072023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/01/2020] [Accepted: 07/01/2020] [Indexed: 12/29/2022] Open
Abstract
Skeletal muscle mass is critical for sport performance and in many pathological conditions. The combination of protein intake and resistance exercise is the most efficient strategy to promote skeletal muscle hypertrophy and remodeling. However, to be really efficient, certain conditions need to be considered. The amount, type and source of proteins do all matter as well as the timing of ingestion and spreading over the whole day. Optimizing those conditions favor a positive net protein balance, which in the long term, may result in muscle mass accretion. Last but not least, it is also essential to take the nutritional status and the exercise training load into consideration when looking for maintenance or gain of skeletal muscle mass.
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Lynch HM, Buman MP, Dickinson JM, Ransdell LB, Johnston CS, Wharton CM. No Significant Differences in Muscle Growth and Strength Development When Consuming Soy and Whey Protein Supplements Matched for Leucine Following a 12 Week Resistance Training Program in Men and Women: A Randomized Trial. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E3871. [PMID: 32486007 PMCID: PMC7312446 DOI: 10.3390/ijerph17113871] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 05/19/2020] [Accepted: 05/25/2020] [Indexed: 02/08/2023]
Abstract
There are conflicting reports regarding the efficacy of plant versus animal-derived protein to support muscle and strength development with resistance training. The purpose of this study was to determine whether soy and whey protein supplements matched for leucine would comparably support strength increases and muscle growth following 12 weeks of resistance training. Sixty-one untrained young men (n = 19) and women (n = 42) (18-35 year) enrolled in this study, and 48 completed the trial (17 men, 31 women). All participants engaged in supervised resistance training 3×/week and consumed 19 grams of whey protein isolate or 26 grams of soy protein isolate, both containing 2 g (grams) of leucine. Multi-level modeling indicated that total body mass (0.68 kg; 95% CI: 0.08, 1.29 kg; p < 0.001), lean body mass (1.54 kg; 95% CI: 0.94, 2.15 kg; p < 0.001), and peak torque of leg extensors (40.27 Nm; 95% CI: 28.98, 51.57 Nm, p < 0.001) and flexors (20.44 Nm; 95% CI: 12.10, 28.79 Nm; p < 0.001) increased in both groups. Vastus lateralis muscle thickness tended to increase, but this did not reach statistical significance (0.12 cm; 95% CI: -0.01, 0.26 cm; p = 0.08). No differences between groups were observed (p > 0.05). These data indicate that increases in lean mass and strength in untrained participants are comparable when strength training and supplementing with soy or whey matched for leucine.
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Affiliation(s)
- Heidi M. Lynch
- Department of Kinesiology, Point Loma Nazarene University, San Diego, CA 92106, USA
| | - Matthew P. Buman
- College of Health Solutions, Arizona State University, Phoenix, AZ 85004, USA; (M.P.B.); (C.S.J.); (C.M.W.)
| | - Jared M. Dickinson
- Health Sciences, Central Washington University, Ellensburg, WA 98926, USA;
| | - Lynda B. Ransdell
- College of Health and Human Services, Northern Arizona University, Flagstaff, AZ 86011, USA;
| | - Carol S. Johnston
- College of Health Solutions, Arizona State University, Phoenix, AZ 85004, USA; (M.P.B.); (C.S.J.); (C.M.W.)
| | - Christopher M. Wharton
- College of Health Solutions, Arizona State University, Phoenix, AZ 85004, USA; (M.P.B.); (C.S.J.); (C.M.W.)
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The Effect of Carbohydrate Ingestion Following Eccentric Resistance Exercise on AKT/mTOR and ERK Pathways: A Randomized, Double-Blinded, Crossover Study. Int J Sport Nutr Exerc Metab 2019; 29:664-670. [DOI: 10.1123/ijsnem.2019-0075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 05/09/2019] [Accepted: 06/09/2019] [Indexed: 11/18/2022]
Abstract
Purpose: To determine the acute effects of carbohydrate (CHO) ingestion following a bout of maximal eccentric resistance exercise on key anabolic kinases of mammalian target of rapamycin and extracellular signal-regulated kinase (ERK) pathways. The authors’ hypothesis was that the activation of anabolic signaling pathways known to be upregulated by resistance exercise would be further stimulated by the physiological hyperinsulinemia resulting from CHO supplementation. Methods: Ten resistance-trained men were randomized in a crossover, double-blind, placebo (PLA)-controlled manner to ingest either a noncaloric PLA or 3 g/kg of CHO beverage throughout recovery from resistance exercise. Muscle biopsies were collected at rest, immediately after a single bout of intense lower body resistance exercise, and after 3 hr of recovery. Results: CHO ingestion elevated plasma glucose and insulin concentrations throughout recovery compared with PLA ingestion. The ERK pathway (phosphorylation of ERK1/2 [Thr202/Tyr204], RSK [Ser380], and p70S6K [Thr421/Ser424]) was markedly activated immediately after resistance exercise, without any effect of CHO supplementation. The phosphorylation state of AKT (Thr308) was unchanged postexercise in the PLA trial and increased at 3 hr of recovery above resting with ingestion of CHO compared with PLA. Despite stimulating-marked phosphorylation of AKT, CHO ingestion did not enhance resistance exercise–induced phosphorylation of p70S6K (Thr389) and rpS6 (Ser235/236 and Ser240/244). Conclusion: CHO supplementation after resistance exercise and hyperinsulinemia does not influence the ERK pathway nor the mTORC1 target p70S6K and its downstream proteins, despite the increased AKT phosphorylation.
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Slater GJ, Dieter BP, Marsh DJ, Helms ER, Shaw G, Iraki J. Is an Energy Surplus Required to Maximize Skeletal Muscle Hypertrophy Associated With Resistance Training. Front Nutr 2019; 6:131. [PMID: 31482093 PMCID: PMC6710320 DOI: 10.3389/fnut.2019.00131] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 08/02/2019] [Indexed: 01/11/2023] Open
Abstract
Resistance training is commonly prescribed to enhance strength/power qualities and is achieved via improved neuromuscular recruitment, fiber type transition, and/ or skeletal muscle hypertrophy. The rate and amount of muscle hypertrophy associated with resistance training is influenced by a wide array of variables including the training program, plus training experience, gender, genetic predisposition, and nutritional status of the individual. Various dietary interventions have been proposed to influence muscle hypertrophy, including manipulation of protein intake, specific supplement prescription, and creation of an energy surplus. While recent research has provided significant insight into optimization of dietary protein intake and application of evidence based supplements, the specific energy surplus required to facilitate muscle hypertrophy is unknown. However, there is clear evidence of an anabolic stimulus possible from an energy surplus, even independent of resistance training. Common textbook recommendations are often based solely on the assumed energy stored within the tissue being assimilated. Unfortunately, such guidance likely fails to account for other energetically expensive processes associated with muscle hypertrophy, the acute metabolic adjustments that occur in response to an energy surplus, or individual nuances like training experience and energy status of the individual. Given the ambiguous nature of these calculations, it is not surprising to see broad ranging guidance on energy needs. These estimates have never been validated in a resistance training population to confirm the "sweet spot" for an energy surplus that facilitates optimal rates of muscle gain relative to fat mass. This review not only addresses the influence of an energy surplus on resistance training outcomes, but also explores other pertinent issues, including "how much should energy intake be increased," "where should this extra energy come from," and "when should this extra energy be consumed." Several gaps in the literature are identified, with the hope this will stimulate further research interest in this area. Having a broader appreciation of these issues will assist practitioners in the establishment of dietary strategies that facilitate resistance training adaptations while also addressing other important nutrition related issues such as optimization of fuelling and recovery goals. Practical issues like the management of satiety when attempting to increase energy intake are also addressed.
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Affiliation(s)
- Gary John Slater
- School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, QLD, Australia
- Australian Institute of Sport, Canberra, ACT, Australia
| | - Brad P. Dieter
- Department of Pharmaceutical Sciences, Washington State University, WA Spokane, WA, United States
| | | | - Eric Russell Helms
- Auckland University of Technology, Sports Performance Research Institute New Zealand, Auckland, New Zealand
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10
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Jonker R, Deutz NEP, Schols AMWJ, Veley EA, Harrykissoon R, Zachria AJ, Engelen MPKJ. Whole body protein anabolism in COPD patients and healthy older adults is not enhanced by adding either carbohydrates or leucine to a serving of protein. Clin Nutr 2019; 38:1684-1691. [PMID: 30150004 PMCID: PMC6377853 DOI: 10.1016/j.clnu.2018.08.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 07/27/2018] [Accepted: 08/04/2018] [Indexed: 11/21/2022]
Abstract
BACKGROUND & AIMS Carbohydrates (CHO) and leucine (LEU) both have insulinotropic properties, and could therefore enhance the protein anabolic capacity of dietary proteins, which are important nutrients in preventing muscle loss in patients with Chronic Obstructive Pulmonary Disease (COPD). LEU is also known to activate protein anabolic signaling pathways independent of insulin. Based on our previous findings in COPD, we hypothesized that whole body protein anabolism is enhanced to a comparable extent by the separate and combined co-ingestion of CHO and LEU with protein. METHODS To disentangle the protein anabolic effects of CHO and/or free LEU when co-ingested with a high-quality protein, we studied 10 patients with moderate to very severe COPD and dyspnea (GOLD: II-IV, mMRC dyspnea scale ≥ 2), at risk for muscle loss, and 10 healthy age- and gender-matched controls. On four occasions, in a single-blind randomized crossover design, each subject ingested a drink containing 0.6 g/kg fat-free mass (ffm) hydrolyzed casein protein with, a) no add-ons (protein), b) 0.3 g/kg ffm CHO (protein + CHO), c) 0.095 g/kg ffm leucine (protein + LEU), d) both add-ons (protein + CHO + LEU). Whole body protein breakdown (PB), protein synthesis (PS), and net protein balance (= PS - PB) were measured by IV primed and continuous infusion of L-[ring-2H5]-phenylalanine and L-[13C9,15N]-tyrosine. L-[15N]-phenylalanine was added to the protein drinks to measure splanchnic extraction. RESULTS In both groups, whole body PS, PB and net protein balance responses were comparable between the four protein drinks, despite higher postprandial plasma LEU concentrations for the LEU supplemented drinks (P < 0.05), and higher insulin concentrations for the CHO supplemented drinks as compared to the protein only drink (P < 0.05). CONCLUSIONS Adding CHO and/or LEU to a serving of high-quality protein does not further augment whole body protein anabolism in dyspneic COPD patients at risk for muscle loss or healthy older adults. TRIAL REGISTRY ClinicalTrials.gov; No. NCT01734473; URL: www.clinicaltrials.gov.
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Affiliation(s)
- Renate Jonker
- Center for Translational Research in Aging & Longevity, Dept. of Health and Kinesiology, Texas A&M University, College Station, TX, USA
| | - Nicolaas E P Deutz
- Center for Translational Research in Aging & Longevity, Dept. of Health and Kinesiology, Texas A&M University, College Station, TX, USA
| | - Annemie M W J Schols
- NUTRIM School for Nutrition, Toxicology and Metabolism, Dept. of Respiratory Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Eugene A Veley
- Dept. of Medicine, Div. of Pulmonary & Critical Care Medicine, Baylor Scott & White Medical Center, College Station, TX, USA
| | - Rajesh Harrykissoon
- Center for Pulmonary and Sleep Disorders, College Station Medical Center, College Station, TX, USA
| | - Anthony J Zachria
- Center for Pulmonary and Sleep Disorders, College Station Medical Center, College Station, TX, USA
| | - Mariëlle P K J Engelen
- Center for Translational Research in Aging & Longevity, Dept. of Health and Kinesiology, Texas A&M University, College Station, TX, USA.
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11
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Iraki J, Fitschen P, Espinar S, Helms E. Nutrition Recommendations for Bodybuilders in the Off-Season: A Narrative Review. Sports (Basel) 2019; 7:E154. [PMID: 31247944 PMCID: PMC6680710 DOI: 10.3390/sports7070154] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 06/21/2019] [Accepted: 06/24/2019] [Indexed: 01/26/2023] Open
Abstract
Many nutrition practices often used by bodybuilders lack scientific support and can be detrimental to health. Recommendations during the dieting phase are provided in the scientific literature, but little attention has been devoted to bodybuilders during the off-season phase. During the off-season phase, the goal is to increase muscle mass without adding unnecessary body fat. This review evaluated the scientific literature and provides nutrition and dietary supplement recommendations for natural bodybuilders during the off-season phase. A hyper-energetic diet (~10-20%) should be consumed with a target weight gain of ~0.25-0.5% of bodyweight/week for novice/intermediate bodybuilders. Advanced bodybuilders should be more conservative with the caloric surplus and weekly weight gain. Sufficient protein (1.6-2.2 g/kg/day) should be consumed with optimal amounts 0.40-0.55 g/kg per meal and distributed evenly throughout the day (3-6 meals) including within 1-2 hours pre- and post-training. Fat should be consumed in moderate amounts (0.5-1.5 g/kg/day). Remaining calories should come from carbohydrates with focus on consuming sufficient amounts (≥3-5 g/kg/day) to support energy demands from resistance exercise. Creatine monohydrate (3-5 g/day), caffeine (5-6 mg/kg), beta-alanine (3-5 g/day) and citrulline malate (8 g/day) might yield ergogenic effects that can be beneficial for bodybuilders.
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Affiliation(s)
- Juma Iraki
- Iraki Nutrition AS, 2008 Fjerdingby, Norway.
| | | | | | - Eric Helms
- Sport Performance Research Institute New Zealand (SPRINZ) at AUT Millennium, Auckland University of Technology, Auckland 0632, New Zealand
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12
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Hamarsland H, Aas SN, Nordengen AL, Holte K, Garthe I, Paulsen G, Cotter M, Børsheim E, Benestad HB, Raastad T. Native Whey Induces Similar Post Exercise Muscle Anabolic Responses as Regular Whey, Despite Greater Leucinemia, in Elderly Individuals. J Nutr Health Aging 2019; 23:42-50. [PMID: 30569067 PMCID: PMC6332708 DOI: 10.1007/s12603-018-1105-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 06/06/2018] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Elderly muscle seems less sensitive to the anabolic stimulus of a meal. Changes in blood concentrations of leucine are suggested as one important trigger of the anabolic response in muscle. The aim of this study was to investigate whether native whey protein, containing high amounts of leucine, may be a more potent stimulator of muscle protein synthesis (MPS) in elderly than regular whey protein (WPC-80) or milk. DESIGN Randomized controlled partial crossover. SETTING Norwegian School of Sport Sciences. PARTICIPANTS 21 healthy elderly men and women (≥70 years). INTERVENTION Participants received either 20 g of WPC-80 and native whey (n = 11) on separate days in a crossover design, or milk (n = 10). Supplements were ingested immediately and two hours after a bout of lower body heavy-load resistance exercise. MEASUREMENTS Blood samples and muscle biopsies were collected to measure blood concentrations of amino acids by gas-chromatography mass spectrometry (GCMS), phosphorylation of p70S6K, 4E-BP1 and eEF-2 by immunoblotting and mixed muscle fractional synthetic rate (FSR) by use of [2H5]phenylalanine-infusion, GCMS and isotope-ratio mass spectrometry. RESULTS Native whey increased blood leucine concentrations more than WPC-80 (P < 0.05), but not p70S6K phosphorylation or mixed muscle FSR. Both whey supplements increased blood leucine concentrations (P < 0.01) and P70S6K phosphorylation more than milk (P = 0.014). Native whey reached higher mixed muscle FSR values than milk (P = 0.026) 1-3h after exercise. CONCLUSIONS Despite greater increases in blood leucine concentrations than WPC-80 and milk, native whey was only superior to milk concerning increases in MPS and phosphorylation of P70S6K during a 5-hour post-exercise period in elderly individuals.
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Affiliation(s)
- H Hamarsland
- Håvard Hamarsland, Department of Physical Performance, Norwegian School of Sport Sciences, P.O. Box 4014 Ullevål Stadion, 0806 Oslo, Norway, Tel: +47 93445916.
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13
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van Vliet S, Smith GI, Porter L, Ramaswamy R, Reeds DN, Okunade AL, Yoshino J, Klein S, Mittendorfer B. The muscle anabolic effect of protein ingestion during a hyperinsulinaemic euglycaemic clamp in middle-aged women is not caused by leucine alone. J Physiol 2018; 596:4681-4692. [PMID: 30054913 DOI: 10.1113/jp276504] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 07/26/2018] [Indexed: 12/30/2022] Open
Abstract
KEY POINTS It has been suggested that leucine is primarily responsible for the increase in muscle protein synthesis after protein ingestion because leucine uniquely activates the mTOR-p70S6K signalling cascade. We compared the effects of ingesting protein or an amount of leucine equal to that in the protein during a hyperinsulinaemic-euglycaemic clamp (to eliminate potential confounding as a result of differences in the insulinogenic effect of protein and leucine ingestion) on muscle anabolic signalling and protein turnover in 28 women. We found that protein, but not leucine, ingestion increased muscle p-mTORSer2448 and p-p70S6KThr389 , although only protein, and not leucine, ingestion decreased muscle p-eIF2αSer51 and increased muscle protein synthesis. ABSTRACT It has been suggested that leucine is primarily responsible for the increase in muscle protein synthesis (MPS) after protein ingestion because leucine uniquely activates the mTOR-p70S6K signalling cascade. We tested this hypothesis by measuring muscle p-mTORSer2448 , p-p70S6KThr389 and p-eIF2αSer51 , as well as protein turnover (by stable isotope labelled amino acid tracer infusion in conjunction with leg arteriovenous blood and muscle tissue sampling), in 28 women who consumed either 0.45 g protein kg-1 fat-free mass (containing 0.0513 g leucine kg-1 fat-free mass) or a control drink (n = 14) or 0.0513 g leucine kg-1 fat-free mass or a control drink (n = 14) during a hyperinsulinaemic-euglycaemic clamp procedure (HECP). Compared to basal conditions, the HECP alone (without protein or leucine ingestion) suppressed muscle protein breakdown by ∼20% and increased p-mTORSer2448 and p-p70S6KThr389 by >50% (all P < 0.05) but had no effect on p-eIF2αSer51 and MPS. Both protein and leucine ingestion further increased p-mTORSer2448 and p-p70S6KThr389 , although only protein, and not leucine, ingestion decreased (by ∼35%) p-eIF2αSer51 and increased (by ∼100%) MPS (all P < 0.05). Accordingly, leg net protein balance changed from negative (loss) during basal conditions to equilibrium during the HECP alone and the HECP with concomitant leucine ingestion and to positive (gain) during the HECP with concomitant protein ingestion. These results provide new insights into the regulation of MPS by demonstrating that leucine and mTOR signalling alone are not responsible for the muscle anabolic effect of protein ingestion during physiological hyperinsulinaemia, most probably because they fail to signal to eIF2α to initiate translation and/or additional amino acids are needed to sustain translation.
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Affiliation(s)
| | | | | | - Raja Ramaswamy
- Department of Radiology, Washington University School of Medicine, St Louis, MO, USA
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14
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Kato H, Suzuki K, Bannai M, Moore DR. Branched-Chain Amino Acids Are the Primary Limiting Amino Acids in the Diets of Endurance-Trained Men after a Bout of Prolonged Exercise. J Nutr 2018; 148:925-931. [PMID: 29746639 DOI: 10.1093/jn/nxy048] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 02/20/2018] [Indexed: 11/13/2022] Open
Abstract
Background The indicator amino acid oxidation (IAAO) method estimates the protein intake required to maximize whole-body protein synthesis and identify the daily protein requirement in a variety of populations. However, it is unclear whether the greater requirements for endurance athletes previously determined by the IAAO reflect an increased demand for all or only some amino acids. Objective The aim of this study was to determine the primary rate-limiting amino acids in endurance-trained athletes after prolonged exercise, by measuring the oxidation of ingested [1-13C]phenylalanine in response to variable amino acid intake. Methods Five endurance-trained men (means ± SDs: age, 26 ± 7 y; body weight, 66.9 ± 9.5 kg; maximal oxygen consumption, 63.3 ± 4.3 mL · kg-1 · min-1) performed 5 trials that involved 2 d of controlled diet (1.4 g protein · kg-1 · d-1) and running (10 km on day 1 and 5 km on day 2) prior to performing an acute bout of endurance exercise (20-km treadmill run) on day 3. During recovery on day 3, participants consumed test diets as 8 isocaloric hourly meals providing sufficient energy and carbohydrate but a variable amino acid intake. The test diets, consumed in random order, were deficient (BASE: 0.8 g · kg-1 · d-1) and sufficient (SUF; 1.75 g · kg-1 · d-1) amino acid diets modeled after egg protein, and BASE supplemented with branched-chain amino acids (BCAA diet; 1.03 g · kg-1 · d-1), essential amino acids (EAA diet; 1.23 g · kg-1 · d-1), or nonessential amino acids (NEAA diet; 1.75 g · kg-1 · d-1). Whole-body phenylalanine flux (Q), 13CO2 excretion (F13CO2), and phenylalanine oxidation (OX) were determined according to standard IAAO methodology. Results There was no effect of amino acid intake on Q (P = 0.43). F13CO2 was significantly (all P < 0.01) lower than BASE for the BCAA (∼32%), EAA (∼31%), and SUF (∼36%) diet treatments. F13CO2 for the NEAA diet was ∼18% lower than for BASE (P < 0.05) but ∼28% greater than for SUF (P < 0.05). OX was similarly decreased (∼24-41%) in all conditions compared with BASE (all P < 0.05). Conclusion Our results suggest that the BCAAs may be the primary rate-liming amino acids in the greater daily protein requirement of endurance trained men. This trial was registered at clinicaltrials.gov as NCT02628249.
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Affiliation(s)
- Hiroyuki Kato
- Frontier Research Laboratories, Institute for Innovation, Ajinomoto Co., Inc., Kawasaki, Kanagawa, Japan.,Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Katsuya Suzuki
- Frontier Research Laboratories, Institute for Innovation, Ajinomoto Co., Inc., Kawasaki, Kanagawa, Japan
| | - Makoto Bannai
- Frontier Research Laboratories, Institute for Innovation, Ajinomoto Co., Inc., Kawasaki, Kanagawa, Japan
| | - Daniel R Moore
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
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15
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Recent Perspectives Regarding the Role of Dietary Protein for the Promotion of Muscle Hypertrophy with Resistance Exercise Training. Nutrients 2018; 10:nu10020180. [PMID: 29414855 PMCID: PMC5852756 DOI: 10.3390/nu10020180] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 02/01/2018] [Accepted: 02/01/2018] [Indexed: 12/14/2022] Open
Abstract
Skeletal muscle supports locomotion and serves as the largest site of postprandial glucose disposal; thus it is a critical organ for physical and metabolic health. Skeletal muscle mass is regulated by the processes of muscle protein synthesis (MPS) and muscle protein breakdown (MPB), both of which are sensitive to external loading and aminoacidemia. Hyperaminoacidemia results in a robust but transient increase in rates of MPS and a mild suppression of MPB. Resistance exercise potentiates the aminoacidemia-induced rise in MPS that, when repeated over time, results in gradual radial growth of skeletal muscle (i.e., hypertrophy). Factors that affect MPS include both quantity and composition of the amino acid source. Specifically, MPS is stimulated in a dose-responsive manner and the primary amino acid agonist of this process is leucine. MPB also appears to be regulated in part by protein intake, which can exert a suppressive effect on MPB. At high protein doses the suppression of MPB may interfere with skeletal muscle adaptation following resistance exercise. In this review, we examine recent advancements in our understanding of how protein ingestion impacts skeletal muscle growth following resistance exercise in young adults during energy balance and energy restriction. We also provide practical recommendations for exercisers who wish to maximize the hypertrophic response of skeletal muscle during resistance exercise training.
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16
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van Vliet S, Shy EL, Abou Sawan S, Beals JW, West DW, Skinner SK, Ulanov AV, Li Z, Paluska SA, Parsons CM, Moore DR, Burd NA. Consumption of whole eggs promotes greater stimulation of postexercise muscle protein synthesis than consumption of isonitrogenous amounts of egg whites in young men. Am J Clin Nutr 2017; 106:1401-1412. [PMID: 28978542 DOI: 10.3945/ajcn.117.159855] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 08/31/2017] [Indexed: 11/14/2022] Open
Abstract
Background: Protein in the diet is commonly ingested from whole foods that contain various macro- and micronutrients. However, the effect of consuming protein within its natural whole-food matrix on postprandial protein metabolism remains understudied in humans.Objective: We aimed to compare the whole-body and muscle protein metabolic responses after the consumption of whole eggs with egg whites during exercise recovery in young men.Design: In crossover trials, 10 resistance-trained men [aged 21 ± 1 y; 88 ± 3 kg; body fat: 16% ± 1% (means ± SEMs)] received primed continuous l-[ring-2H5]phenylalanine and l-[1-13C]leucine infusions and performed a single bout of resistance exercise. After exercise, participants consumed intrinsically l-[5,5,5-2H3]leucine-labeled whole eggs (18 g protein, 17 g fat) or egg whites (18 g protein, 0 g fat). Repeated blood and muscle biopsy samples were collected to assess whole-body leucine kinetics, intramuscular signaling, and myofibrillar protein synthesis.Results: Plasma appearance rates of protein-derived leucine were more rapid after the consumption of egg whites than after whole eggs (P = 0.01). Total plasma availability of leucine over the 300-min postprandial period was similar (P= 0.75) between the ingestion of whole eggs (68% ± 1%) and egg whites (66% ± 2%), with no difference in whole-body net leucine balance (P = 0.27). Both whole-egg and egg white conditions increased the phosphorylation of mammalian target of rapamycin complex 1, ribosomal protein S6 kinase 1, and eukaryotic translation initiation factor 4E-binding protein 1 during postexercise recovery (all P < 0.05). However, whole-egg ingestion increased the postexercise myofibrillar protein synthetic response to a greater extent than did the ingestion of egg whites (P= 0.04).Conclusions: We show that the ingestion of whole eggs immediately after resistance exercise resulted in greater stimulation of myofibrillar protein synthesis than did the ingestion of egg whites, despite being matched for protein content in young men. Our data indicate that the ingestion of nutrient- and protein-dense foods differentially stimulates muscle anabolism compared with protein-dense foods. This trial was registered at clinicaltrials.gov as NCT03117127.
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Affiliation(s)
| | - Evan L Shy
- Departments of Kinesiology and Community Health
| | - Sidney Abou Sawan
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | | | - Daniel Wd West
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | | | - Alexander V Ulanov
- Roy J Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL; and
| | - Zhong Li
- Roy J Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL; and
| | | | | | - Daniel R Moore
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Nicholas A Burd
- Departments of Kinesiology and Community Health, .,Division of Nutritional Sciences; and
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17
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Gorissen SH, Burd NA, Kramer IF, van Kranenburg J, Gijsen AP, Rooyackers O, van Loon LJ. Co-ingesting milk fat with micellar casein does not affect postprandial protein handling in healthy older men. Clin Nutr 2017; 36:429-437. [DOI: 10.1016/j.clnu.2015.12.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 11/06/2015] [Accepted: 12/11/2015] [Indexed: 01/07/2023]
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18
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Deane CS, Wilkinson DJ, Phillips BE, Smith K, Etheridge T, Atherton PJ. "Nutraceuticals" in relation to human skeletal muscle and exercise. Am J Physiol Endocrinol Metab 2017; 312:E282-E299. [PMID: 28143855 PMCID: PMC5406990 DOI: 10.1152/ajpendo.00230.2016] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 01/25/2017] [Accepted: 01/25/2017] [Indexed: 12/16/2022]
Abstract
Skeletal muscles have a fundamental role in locomotion and whole body metabolism, with muscle mass and quality being linked to improved health and even lifespan. Optimizing nutrition in combination with exercise is considered an established, effective ergogenic practice for athletic performance. Importantly, exercise and nutritional approaches also remain arguably the most effective countermeasure for muscle dysfunction associated with aging and numerous clinical conditions, e.g., cancer cachexia, COPD, and organ failure, via engendering favorable adaptations such as increased muscle mass and oxidative capacity. Therefore, it is important to consider the effects of established and novel effectors of muscle mass, function, and metabolism in relation to nutrition and exercise. To address this gap, in this review, we detail existing evidence surrounding the efficacy of a nonexhaustive list of macronutrient, micronutrient, and "nutraceutical" compounds alone and in combination with exercise in relation to skeletal muscle mass, metabolism (protein and fuel), and exercise performance (i.e., strength and endurance capacity). It has long been established that macronutrients have specific roles and impact upon protein metabolism and exercise performance, (i.e., protein positively influences muscle mass and protein metabolism), whereas carbohydrate and fat intakes can influence fuel metabolism and exercise performance. Regarding novel nutraceuticals, we show that the following ones in particular may have effects in relation to 1) muscle mass/protein metabolism: leucine, hydroxyl β-methylbutyrate, creatine, vitamin-D, ursolic acid, and phosphatidic acid; and 2) exercise performance: (i.e., strength or endurance capacity): hydroxyl β-methylbutyrate, carnitine, creatine, nitrates, and β-alanine.
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Affiliation(s)
- Colleen S Deane
- Medical Research Council-Arthritis Research UK Centre of Excellence for Musculoskeletal Ageing Research and Clinical, Metabolic, and Molecular Physiology, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
- Faculty of Health and Social Science, Bournemouth University, Bournemouth, United Kingdom; and
- Department of Sport and Health Science, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Daniel J Wilkinson
- Medical Research Council-Arthritis Research UK Centre of Excellence for Musculoskeletal Ageing Research and Clinical, Metabolic, and Molecular Physiology, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
| | - Bethan E Phillips
- Medical Research Council-Arthritis Research UK Centre of Excellence for Musculoskeletal Ageing Research and Clinical, Metabolic, and Molecular Physiology, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
| | - Kenneth Smith
- Medical Research Council-Arthritis Research UK Centre of Excellence for Musculoskeletal Ageing Research and Clinical, Metabolic, and Molecular Physiology, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
| | - Timothy Etheridge
- Department of Sport and Health Science, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Philip J Atherton
- Medical Research Council-Arthritis Research UK Centre of Excellence for Musculoskeletal Ageing Research and Clinical, Metabolic, and Molecular Physiology, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom;
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19
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Poortmans JR, Carpentier A. Protein metabolism and physical training: any need for amino acid supplementation? ACTA ACUST UNITED AC 2016. [DOI: 10.1186/s41110-016-0022-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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20
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Mitchell CJ, D'Souza RF, Zeng N, McGregor RA, Fanning AC, Poppitt SD, Cameron-Smith D. Understanding the sensitivity of muscle protein synthesis to dairy protein in middle-aged men. Int Dairy J 2016. [DOI: 10.1016/j.idairyj.2016.07.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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21
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Egan B. Protein intake for athletes and active adults: Current concepts and controversies. NUTR BULL 2016. [DOI: 10.1111/nbu.12215] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- B. Egan
- School of Health and Human Performance; Dublin City University; Dublin Ireland
- Food for Health Ireland; University College Dublin; Dublin Ireland
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22
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Kato H, Suzuki H, Inoue Y, Takimoto T, Suzuki K, Kobayashi H. Co-ingestion of carbohydrate with leucine-enriched essential amino acids does not augment acute postexercise muscle protein synthesis in a strenuous exercise-induced hypoinsulinemic state. SPRINGERPLUS 2016; 5:1299. [PMID: 27547673 PMCID: PMC4978655 DOI: 10.1186/s40064-016-2736-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 07/01/2016] [Indexed: 12/01/2022]
Abstract
Strenuous exercise following overnight fasting increases fat oxidation during exercise, which can modulate training adaptation. However, such exercise induces muscle protein catabolism by decreasing blood insulin concentrations and increasing amino acid oxidation during the exercise. Leucine-enriched essential amino acids (LEAAs) enhance muscle protein synthesis (MPS) at rest and after exercise. However, it remains to be clarified if the co-ingestion of carbohydrate with LEAAs induces an additional increase in MPS, particularly in a hypoinsulinemic state induced by strenuous exercise. Eight-week-old male Sprague–Dawley rats were made to perform strenuous jump exercise (height 35 cm, 200 jumps, 3-s intervals), after which they ingested distilled water and 1 g/kg LEAAs with or without 1 g/kg of glucose. The fractional synthesis rate was determined by measuring the incorporation of l-[ring-2H5]-phenylalanine into skeletal muscle protein. Immediately after the exercise, plasma insulin concentration was significantly lower than that at the basal level. Co-ingestion of glucose with LEAAs alleviated the reduction in plasma insulin concentration, while LEAA ingestion alone did not. LEAA administration with or without glucose led to a higher MPS compared with water administration (P < 0.05). However, the co-ingestion of glucose with LEAAs did not induce further increases in MPS compared with LEAA ingestion alone. Thus, the co-ingestion of glucose with LEAAs does not additionally increase MPS under a strenuous exercise–induced hypoinsulinemic state when glucose is co-ingested with a dose of LEAAs that maximally stimulates MPS.
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Affiliation(s)
- Hiroyuki Kato
- Frontier Research Laboratories, Institute for Innovation, Ajinomoto Co., Inc, Kawasaki, Kanagawa Japan
| | - Hiromi Suzuki
- Frontier Research Laboratories, Institute for Innovation, Ajinomoto Co., Inc, Kawasaki, Kanagawa Japan
| | - Yoshiko Inoue
- Frontier Research Laboratories, Institute for Innovation, Ajinomoto Co., Inc, Kawasaki, Kanagawa Japan
| | - Tetsuya Takimoto
- Frontier Research Laboratories, Institute for Innovation, Ajinomoto Co., Inc, Kawasaki, Kanagawa Japan
| | - Katsuya Suzuki
- Frontier Research Laboratories, Institute for Innovation, Ajinomoto Co., Inc, Kawasaki, Kanagawa Japan
| | - Hisamine Kobayashi
- Frontier Research Laboratories, Institute for Innovation, Ajinomoto Co., Inc, Kawasaki, Kanagawa Japan
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Moberg M, Apró W, Ekblom B, van Hall G, Holmberg HC, Blomstrand E. Activation of mTORC1 by leucine is potentiated by branched-chain amino acids and even more so by essential amino acids following resistance exercise. Am J Physiol Cell Physiol 2016; 310:C874-84. [PMID: 27053525 DOI: 10.1152/ajpcell.00374.2015] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 03/31/2016] [Indexed: 12/31/2022]
Abstract
Protein synthesis is stimulated by resistance exercise and intake of amino acids, in particular leucine. Moreover, activation of mammalian target of rapamycin complex 1 (mTORC1) signaling by leucine is potentiated by the presence of other essential amino acids (EAA). However, the contribution of the branched-chain amino acids (BCAA) to this effect is yet unknown. Here we compare the stimulatory role of leucine, BCAA, and EAA ingestion on anabolic signaling following exercise. Accordingly, eight trained volunteers completed four sessions of resistance exercise during which they ingested either placebo, leucine, BCAA, or EAA (including the BCAA) in random order. Muscle biopsies were taken at rest, immediately after exercise, and following 90 and 180 min of recovery. Following 90 min of recovery the activity of S6 kinase 1 (S6K1) was greater than at rest in all four trials (Placebo<Leucine<BCAA<EAA; P < 0.05 time × supplement), with a ninefold increase in the EAA trial. At this same time point, phosphorylation of eukaryotic translation initiation factor 4E (eIF4E)-binding protein 1 (4E-BP1) at Thr(37/46) was unaffected by supplementation, while that of Thr(46) alone exhibited a pattern similar to that of S6K1, being 18% higher with EAA than BCAA. However, after 180 min of recovery this difference between EAA and BCAA had disappeared, although with both these supplements the increases were still higher than with leucine (40%, P < 0.05) and placebo (100%, P < 0.05). In summary, EAA ingestion appears to stimulate translation initiation more effectively than the other supplements, although the results also suggest that this effect is primarily attributable to the BCAA.
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Affiliation(s)
- Marcus Moberg
- Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden;
| | - William Apró
- Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Björn Ekblom
- Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Gerrit van Hall
- Clinical Metabolomics Core Facility, Rigshopitalet and Department of Biomedical Sciences, Rigshospitalet, University of Copenhagen, Copenhagen Denmark
| | - Hans-Christer Holmberg
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden; and
| | - Eva Blomstrand
- Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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24
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Reidy PT, Rasmussen BB. Role of Ingested Amino Acids and Protein in the Promotion of Resistance Exercise-Induced Muscle Protein Anabolism. J Nutr 2016; 146:155-83. [PMID: 26764320 PMCID: PMC4725426 DOI: 10.3945/jn.114.203208] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 06/03/2015] [Accepted: 11/25/2015] [Indexed: 12/16/2022] Open
Abstract
The goal of this critical review is to comprehensively assess the evidence for the molecular, physiologic, and phenotypic skeletal muscle responses to resistance exercise (RE) combined with the nutritional intervention of protein and/or amino acid (AA) ingestion in young adults. We gathered the literature regarding the translational response in human skeletal muscle to acute exposure to RE and protein/AA supplements and the literature describing the phenotypic skeletal muscle adaptation to RE and nutritional interventions. Supplementation of protein/AAs with RE exhibited clear protein dose-dependent effects on translational regulation (protein synthesis) through mammalian target of rapamycin complex 1 (mTORC1) signaling, which was most apparent through increases in p70 ribosomal protein S6 kinase 1 (S6K1) phosphorylation, compared with postexercise recovery in the fasted or carbohydrate-fed state. These acute findings were critically tested via long-term exposure to RE training (RET) and protein/AA supplementation, and it was determined that a diminishing protein/AA supplement effect occurs over a prolonged exposure stimulus after exercise training. Furthermore, we found that protein/AA supplements, combined with RET, produced a positive, albeit minor, effect on the promotion of lean mass growth (when assessed in >20 participants/treatment); a negligible effect on muscle mass; and a negligible to no additional effect on strength. A potential concern we discovered was that the majority of the exercise training studies were underpowered in their ability to discern effects of protein/AA supplementation. Regardless, even when using optimal methodology and large sample sizes, it is clear that the effect size for protein/AA supplementation is low and likely limited to a subset of individuals because the individual variability is high. With regard to nutritional intakes, total protein intake per day, rather than protein timing or quality, appears to be more of a factor on this effect during long-term exercise interventions. There were no differences in strength or mass/muscle mass on RET outcomes between protein types when a leucine threshold (>2 g/dose) was reached. Future research with larger sample sizes and more homogeneity in design is necessary to understand the underlying adaptations and to better evaluate the individual variability in the muscle-adaptive response to protein/AA supplementation during RET.
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Affiliation(s)
- Paul T Reidy
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, TX
| | - Blake B Rasmussen
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, TX
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The muscle protein synthetic response to food ingestion. Meat Sci 2015; 109:96-100. [DOI: 10.1016/j.meatsci.2015.05.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Revised: 05/12/2015] [Accepted: 05/15/2015] [Indexed: 01/07/2023]
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Pasiakos SM, McClung HL, Margolis LM, Murphy NE, Lin GG, Hydren JR, Young AJ. Human Muscle Protein Synthetic Responses during Weight-Bearing and Non-Weight-Bearing Exercise: A Comparative Study of Exercise Modes and Recovery Nutrition. PLoS One 2015; 10:e0140863. [PMID: 26474292 PMCID: PMC4608805 DOI: 10.1371/journal.pone.0140863] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 10/01/2015] [Indexed: 12/05/2022] Open
Abstract
Effects of conventional endurance (CE) exercise and essential amino acid (EAA) supplementation on protein turnover are well described. Protein turnover responses to weighted endurance exercise (i.e., load carriage, LC) and EAA may differ from CE, because the mechanical forces and contractile properties of LC and CE likely differ. This study examined muscle protein synthesis (MPS) and whole-body protein turnover in response to LC and CE, with and without EAA supplementation, using stable isotope amino acid tracer infusions. Forty adults (mean ± SD, 22 ± 4 y, 80 ± 10 kg, VO2peak 4.0 ± 0.5 L∙min-1) were randomly assigned to perform 90 min, absolute intensity-matched (2.2 ± 0.1 VO2 L∙m-1) LC (performed on a treadmill wearing a vest equal to 30% of individual body mass, mean ± SD load carried 24 ± 3 kg) or CE (cycle ergometry performed at the same absolute VO2 as LC) exercise, during which EAA (10 g EAA, 3.6 g leucine) or control (CON, non-nutritive) drinks were consumed. Mixed-muscle and myofibrillar MPS were higher during exercise for LC than CE (mode main effect, P < 0.05), independent of dietary treatment. EAA enhanced mixed-muscle and sarcoplasmic MPS during exercise, regardless of mode (drink main effect, P < 0.05). Mixed-muscle and sarcoplasmic MPS were higher in recovery for LC than CE (mode main effect, P < 0.05). No other differences or interactions (mode x drink) were observed. However, EAA attenuated whole-body protein breakdown, increased amino acid oxidation, and enhanced net protein balance in recovery compared to CON, regardless of exercise mode (P < 0.05). These data show that, although whole-body protein turnover responses to absolute VO2-matched LC and CE are the same, LC elicited a greater muscle protein synthetic response than CE.
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Affiliation(s)
- Stefan M. Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America
- * E-mail:
| | - Holly L. McClung
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Lee M. Margolis
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Nancy E. Murphy
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Gregory G. Lin
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Jay R. Hydren
- Military Performance Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Andrew J. Young
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America
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Burd NA, Gorissen SH, van Vliet S, Snijders T, van Loon LJ. Differences in postprandial protein handling after beef compared with milk ingestion during postexercise recovery: a randomized controlled trial. Am J Clin Nutr 2015; 102:828-36. [PMID: 26354539 DOI: 10.3945/ajcn.114.103184] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 07/30/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Protein consumed after resistance exercise increases postexercise muscle protein synthesis rates. To date, dairy protein has been studied extensively, with little known about the capacity of other protein-dense foods to augment postexercise muscle protein synthesis rates. OBJECTIVE We aimed to compare protein digestion and absorption kinetics, postprandial amino acid availability, anabolic signaling, and the subsequent myofibrillar protein synthetic response after the ingestion of milk compared with beef during recovery from resistance-type exercise. DESIGN In crossover trials, 12 healthy young men performed a single bout of resistance exercise. Immediately after cessation of exercise, participants ingested 30 g protein by consuming isonitrogenous amounts of intrinsically l-[1-(13)C]phenylalanine-labeled beef or milk. Blood and muscle biopsy samples were collected at rest and after exercise during primed continuous infusions of l-[ring-(2)H5]phenylalanine and l-[ring-3,5-(2)H2]tyrosine to assess protein digestion and absorption kinetics, plasma amino acid availability, anabolic signaling, and subsequent myofibrillar protein synthesis rates in vivo in young men. RESULTS Beef protein-derived phenylalanine appeared more rapidly in circulation compared with milk ingestion (P < 0.001). The availability of phenylalanine during the 5-h postexercise period tended to be higher after beef (64% ± 3%) ingestion than after milk ingestion (57% ± 3%; P = 0.08). Both beef and milk ingestion were followed by an increase in the phosphorylation of mammalian target of rapamycin complex 1 and 70-kDa S6 protein kinase 1 during postexercise recovery. Milk ingestion increased myofibrillar protein synthesis rates to a greater extent than did beef ingestion during the 0- to 2-h postexercise phase (P = 0.013). However, the increase in myofibrillar protein synthesis rates did not differ between milk and beef ingestion during the entire 0- to 5-h postexercise phase (P = 0.114). CONCLUSIONS Both milk and beef ingestion augment the postexercise myofibrillar protein synthetic response in young men, with a stronger stimulation of myofibrillar protein synthesis during the early postprandial stage after milk ingestion. This trial was registered at www.clinicaltrials.gov as NCT01578590.
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Affiliation(s)
- Nicholas A Burd
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, Netherlands
| | - Stefan H Gorissen
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, Netherlands
| | - Stephan van Vliet
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, Netherlands
| | - Tim Snijders
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, Netherlands
| | - Luc Jc van Loon
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, Netherlands
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Arentson-Lantz E, Clairmont S, Paddon-Jones D, Tremblay A, Elango R. Protein: A nutrient in focus. Appl Physiol Nutr Metab 2015. [DOI: 10.1139/apnm-2014-0530] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Protein is an essential component of a healthy diet and is a focus of research programs seeking to optimize health at all stages of life. The focus on protein as a nutrient often centers on its thermogenic and satiating effect, and when included as part of a healthy diet, its potential to preserve lean body mass. A growing body of literature, including stable isotope based studies and longer term dietary interventions, suggests that current dietary protein recommendations may not be sufficient to promote optimal muscle health in all populations. A protein intake moderately higher than current recommendations has been widely endorsed by many experts and working groups and may provide health benefits for aging populations. Further, consuming moderate amounts of high-quality protein at each meal may optimally stimulate 24-h muscle protein synthesis and may provide a dietary platform that favors the maintenance of muscle mass and function while promoting successful weight management in overweight and obese individuals. Dietary protein has the potential to serve as a key nutrient for many health outcomes and benefits might be increased when combined with adequate physical activity. Future studies should focus on confirming these health benefits from dietary protein with long-term randomized controlled studies.
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Affiliation(s)
- Emily Arentson-Lantz
- Division of Rehabilitation Science, University of Texas Medical Branch, Galveston, TX 77555-0144, USA
| | | | - Douglas Paddon-Jones
- Division of Rehabilitation Science, University of Texas Medical Branch, Galveston, TX 77555-0144, USA
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, TX 77555-0147, USA
| | - Angelo Tremblay
- Département de kinésiologie - Faculté de médecine, Université Laval, QC G1V 0A6, Canada
| | - Rajavel Elango
- Child and Family Research Institute, BC Children’s Hospital, Vancouver, BC V5Z 4H4, Canada
- Department of Pediatrics, University of British Columbia, BC V6H 3V4, Canada
- School of Population and Public Health, University of British Columbia, BC V6T 1Z3, Canada
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Markofski MM, Dickinson JM, Drummond MJ, Fry CS, Fujita S, Gundermann DM, Glynn EL, Jennings K, Paddon-Jones D, Reidy PT, Sheffield-Moore M, Timmerman KL, Rasmussen BB, Volpi E. Effect of age on basal muscle protein synthesis and mTORC1 signaling in a large cohort of young and older men and women. Exp Gerontol 2015; 65:1-7. [PMID: 25735236 DOI: 10.1016/j.exger.2015.02.015] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 02/25/2015] [Accepted: 02/27/2015] [Indexed: 12/21/2022]
Abstract
The rate of muscle loss with aging is higher in men than women. However, women have smaller muscles throughout the adult life. Protein content is a major determinant of skeletal muscle size. This study was designed to determine if age and sex differentially impact basal muscle protein synthesis and mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling. We performed a secondary data analysis on a cohort of 215 healthy, non-obese (BMI<30kg·m(-2)) young (18-40y; 74 men, 52 women) and older (60-87y; 57 men, 32 women) adults. The database contained information on physical characteristics, basal muscle protein fractional synthetic rate (FSR; n=215; stable isotope methodology) and mTORC1 signaling (n=125, Western blotting). FSR and mTORC1 signaling were measured at rest and after an overnight fast. mTORC1 and S6K1 phosphorylation were higher (p<0.05) in older subjects with no sex differences. However, there were no age or sex differences or interaction for muscle FSR (p>0.05). Body mass index, fat free mass, or body fat was not a significant covariate and did not influence the results. We conclude that age and sex do not influence basal muscle protein synthesis. However, basal mTORC1 hyperphosphorylation in the elderly may contribute to insulin resistance and the age-related anabolic resistance of skeletal muscle protein metabolism to nutrition and exercise.
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Affiliation(s)
- Melissa M Markofski
- Sealy Center on Aging, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA
| | - Jared M Dickinson
- Department of Nutrition and Metabolism, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA; Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA
| | - Micah J Drummond
- Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA
| | - Christopher S Fry
- Sealy Center on Aging, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA; Department of Nutrition and Metabolism, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA; Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA
| | - Satoshi Fujita
- Sealy Center on Aging, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA; Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA
| | - David M Gundermann
- Department of Nutrition and Metabolism, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA; Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA
| | - Erin L Glynn
- Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA
| | - Kristofer Jennings
- Sealy Center on Aging, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA; Department of Preventive Medicine and Community Health, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA
| | - Douglas Paddon-Jones
- Sealy Center on Aging, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA; Department of Nutrition and Metabolism, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA; Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA
| | - Paul T Reidy
- Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA
| | - Melinda Sheffield-Moore
- Sealy Center on Aging, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA; Department of Internal Medicine, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA
| | - Kyle L Timmerman
- Sealy Center on Aging, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA; Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA
| | - Blake B Rasmussen
- Sealy Center on Aging, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA; Department of Nutrition and Metabolism, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA; Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA
| | - Elena Volpi
- Sealy Center on Aging, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA; Department of Internal Medicine, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA.
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Rankin P, Stevenson E, Cockburn E. The effect of milk on the attenuation of exercise-induced muscle damage in males and females. Eur J Appl Physiol 2015; 115:1245-61. [PMID: 25673557 DOI: 10.1007/s00421-015-3121-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 01/29/2015] [Indexed: 01/28/2023]
Abstract
PURPOSE The consumption of 500 ml milk following muscle damaging exercise can attenuate decreases in muscle functional capacity and increases in markers of muscle damage and soreness in males. There has been no similar research in female participants. Therefore, the aim of this study was to investigate the effects of milk consumption on exercise-induced muscle damage (EIMD) in males and females. METHODS Thirty-two team sport players (male n = 16; female n = 16) were randomly, but equally divided into four groups: male milk, male carbohydrate, female milk, and female carbohydrate. Immediately following muscle damaging exercise, participants consumed either 500 ml of milk or 500 ml of an energy-matched carbohydrate solution. Skeletal troponin I (sTnI), creatine kinase (CK), peak torque, counter movement jump height, 20 m sprint performance and passive and active soreness were recorded prior to and 24, 48 and 72 h post-EIMD. RESULTS For females, milk had a likely/very likely beneficial effect on attenuating losses in peak torque at 60°/s from baseline to 24, 48 and 72 h, and a likely beneficial effect in minimising decrements in sprint performance and soreness over 72 h. Milk was unlikely to have a negative effect on serum markers of damage from baseline to 48 and 72 h. For males, milk had an unclear effect on muscle function variables. Milk had a most likely/likely beneficial effect on limiting muscle soreness from baseline to 72 h, and a possible beneficial effect on attenuating increases in CK. The effect on sTnI was unlikely to be negative from baseline-72 h. Overall gender comparisons provided many unclear outcomes. However, female participants demonstrated smaller increases in sprint time, passive soreness, active soreness (non-dominant leg) and sTnI values. CONCLUSION Consumption of 500 ml of milk post-EIMD can limit decrements in muscle function in females, and limit increases in soreness and serum markers of muscle damage in females and males.
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Affiliation(s)
- P Rankin
- Department of Science and Health, Institute of Technology Carlow, Carlow, Ireland,
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31
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Pasiakos SM, Margolis LM, Orr JS. Optimized dietary strategies to protect skeletal muscle mass during periods of unavoidable energy deficit. FASEB J 2014; 29:1136-42. [DOI: 10.1096/fj.14-266890] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 12/01/2014] [Indexed: 12/14/2022]
Affiliation(s)
- Stefan M. Pasiakos
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Lee M. Margolis
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Jeb S. Orr
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
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32
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Spillane M, Schwarz N, Willoughby DS. Heavy resistance training and peri-exercise ingestion of a multi-ingredient ergogenic nutritional supplement in males: effects on body composition, muscle performance and markers of muscle protein synthesis. J Sports Sci Med 2014; 13:894-903. [PMID: 25435783 PMCID: PMC4234960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Accepted: 08/29/2014] [Indexed: 06/04/2023]
Abstract
This study determined the effects of heavy resistance training and peri-exercise ergogenic multi-ingredient nutritional supplement ingestion on blood and skeletal markers of muscle protein synthesis (MPS), body composition, and muscle performance. Twenty-four college-age males were randomly assigned to either a multi-ingredient SizeOn Maximum Performance (SIZE) or protein/carbohydrate/creatine (PCC) comparator supplement group in a double-blind fashion. Body composition and muscle performance were assessed, and venous blood samples and muscle biopsies were obtained before and after 6 weeks of resistance training and supplementation. Data were analyzed by 2-way ANOVA (p ≤ 0.05). Total body mass, body water, and fat mass were not differentially affected (p > 0.05). However, fat-free mass was significantly increased in both groups in response to resistance training (p = 0.037). Lower-body muscle strength (p = 0.029) and endurance (p = 0.027) were significantly increased with resistance training, but not supplementation (p > 0.05). Serum insulin, IGF-1, GH, and cortisol were not differentially affected (p > 0.05). Muscle creatine content was significantly increased in both groups from supplementation (p = 0.044). Total muscle protein (p = 0.038), MHC 1 (p = 0.041), MHC 2A, (p = 0.029), total IRS- (p = 0.041), and total Akt (p = 0.011) were increased from resistance training, but not supplementation. In response to heavy resistance training when compared to PCC, the peri-exercise ingestion of SIZE did not preferentially improve body composition, muscle performance, and markers indicative of MPS. Key pointsIn response to 42 days of heavy resistance training and either SizeOn Maximum Performance or protein/carbohydrate/creatine supplementation, similar increases in muscle mass and strength in both groups occurred; however, the increases were not different between supplement groups.The supplementation of SizeOn Maximum Performance had no preferential effect on augmenting serum insulin, IGF-1, and GH, or in decreasing cortisol.While resistance training was effective in increasing total creatine content in skeletal muscle, myofibrillar protein, and the content of total IRS-1 and Akt, it was not preferentially due to SizeOn Maximum Performance supplementation.At the daily dose of 50 g, SizeOn Maximum Performance supplementation for 42 days combined with resistance training does not increases muscle mass and strength due to its ability to elevate serum hormones and growth factors or in its ability to augment skeletal muscle signaling pathway markers indicative of muscle protein synthesis when compared to an equivalent daily dose of protein/carbohydrate/creatine.
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Affiliation(s)
- Mike Spillane
- Department of Health, Human Performance, and Recreation, Baylor University , Waco, TX, USA
| | - Neil Schwarz
- Department of Health, Human Performance, and Recreation, Baylor University , Waco, TX, USA
| | - Darryn S Willoughby
- Department of Health, Human Performance, and Recreation, Baylor University , Waco, TX, USA
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Pasiakos SM, Carbone JW. Assessment of skeletal muscle proteolysis and the regulatory response to nutrition and exercise. IUBMB Life 2014; 66:478-84. [PMID: 25052691 DOI: 10.1002/iub.1291] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 07/01/2014] [Indexed: 01/07/2023]
Abstract
Skeletal muscle proteolysis is highly regulated, involving complex intramuscular proteolytic systems that recognize and degrade muscle proteins, and recycle free amino acid precursors for protein synthesis and energy production. Autophagy-lysosomal, calpain, and caspase systems are contributors to muscle proteolysis, although the ubiquitin proteasome system (UPS) is the primary mechanism by which actomyosin fragments are degraded in healthy muscle. The UPS is sensitive to mechanical force and nutritional deprivation, as recent reports have demonstrated increased proteolytic gene expression and activity of the UPS in response to resistance and endurance exercise, and short-term negative energy balance. However, consuming dietary protein alone (or free amino acids), or as a primary component of a mixed meal, may attenuate intramuscular protein loss by down-regulating proteolytic gene expression and the catabolic activity of the UPS. Although these studies provide novel insight regarding the intramuscular regulation of skeletal muscle mass, the role of proteolysis in the regulation of skeletal muscle protein turnover in healthy human muscle is not well described. This article provides a contemporary review of the intramuscular regulation of skeletal muscle proteolysis in healthy muscle, methodological approaches to assess proteolysis, and highlights the effects of nutrition and exercise on skeletal muscle proteolysis.
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Affiliation(s)
- Stefan M Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
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Gorissen SHM, Burd NA, Hamer HM, Gijsen AP, Groen BB, van Loon LJC. Carbohydrate coingestion delays dietary protein digestion and absorption but does not modulate postprandial muscle protein accretion. J Clin Endocrinol Metab 2014; 99:2250-8. [PMID: 24628553 DOI: 10.1210/jc.2013-3970] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Dietary protein digestion and absorption is an important factor modulating muscle protein accretion. However, there are few data available on the effects of coingesting other macronutrients with protein on digestion and absorption kinetics and the subsequent muscle protein synthetic response. OBJECTIVE The objective of the study was to determine the impact of carbohydrate coingestion with protein on dietary protein digestion and absorption and muscle protein accretion in healthy young and older men. DESIGN Twenty-four healthy young (aged 21± 1 y, body mass index 21.8 ±0.5 kg/m(2)) and 25 older (aged 75 ± 1 y, body mass index 25.4 ± 0.6 kg/m(2)) men received a primed continuous L-[ring-(2)H5]-phenylalanine and L-[ring-3,5-(2)H2]-tyrosine infusion and ingested 20 g intrinsically L-[1-(13)C]-phenylalanine-labeled protein with (Pro+CHO) or without (Pro) 60 g carbohydrate. Plasma samples and muscle biopsies were collected in a postabsorptive and postprandial state. RESULTS Carbohydrate coingestion delayed the appearance of exogenous phenylalanine in the circulation (P = .001). Dietary protein-derived phenylalanine availability over the 5-hour postprandial period was lower in the older (62 ± 2%) when compared with the young subjects (74 ± 2%; P = .007), with no differences between conditions (P = .20). Carbohydrate coingestion did not modulate postprandial muscle protein synthesis rates (0.035 ± 0.003 vs 0.043 ± 0.004 and 0.033 ± 0.002 vs 0.035 ± 0.003%/h after Pro vs Pro+CHO in the young and older group, respectively). In accordance, no differences in muscle protein-bound L-[1-(13)C]-phenylalanine enrichments were observed between conditions (0.020 ± 0.002 vs 0.020 ± 0.002 and 0.019 ± 0.003 vs 0.022 ± 0.004 mole percent excess after Pro vs Pro+CHO in the young and older subjects, respectively). CONCLUSION Carbohydrate coingestion with protein delays dietary protein digestion and absorption but does not modulate postprandial muscle protein accretion in healthy young or older men.
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Affiliation(s)
- Stefan H M Gorissen
- Top Institute Food and Nutrition (S.H.M.G., N.A.B., H.M.H., L.J.C.v.L.), 6709 PA Wageningen, The Netherlands; Department of Human Movement Sciences (S.H.M.G., N.A.B., H.M.H., B.B.G., L.J.C.v.L.), NUTRIM School for Nutrition, Toxicology, and Metabolism, and Department of Human Biology (A.P.G.), NUTRIM, Maastricht University Medical Centre+, 6200 MD Maastricht, The Netherlands
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35
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Reidy PT, Walker DK, Dickinson JM, Gundermann DM, Drummond MJ, Timmerman KL, Cope MB, Mukherjea R, Jennings K, Volpi E, Rasmussen BB. Soy-dairy protein blend and whey protein ingestion after resistance exercise increases amino acid transport and transporter expression in human skeletal muscle. J Appl Physiol (1985) 2014; 116:1353-64. [PMID: 24699854 DOI: 10.1152/japplphysiol.01093.2013] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Increasing amino acid availability (via infusion or ingestion) at rest or postexercise enhances amino acid transport into human skeletal muscle. It is unknown whether alterations in amino acid availability, from ingesting different dietary proteins, can enhance amino acid transport rates and amino acid transporter (AAT) mRNA expression. We hypothesized that the prolonged hyperaminoacidemia from ingesting a blend of proteins with different digestion rates postexercise would enhance amino acid transport into muscle and AAT expression compared with the ingestion of a rapidly digested protein. In a double-blind, randomized clinical trial, we studied 16 young adults at rest and after acute resistance exercise coupled with postexercise (1 h) ingestion of either a (soy-dairy) protein blend or whey protein. Phenylalanine net balance and transport rate into skeletal muscle were measured using stable isotopic methods in combination with femoral arteriovenous blood sampling and muscle biopsies obtained at rest and 3 and 5 h postexercise. Phenylalanine transport into muscle and mRNA expression of select AATs [system L amino acid transporter 1/solute-linked carrier (SLC) 7A5, CD98/SLC3A2, system A amino acid transporter 2/SLC38A2, proton-assisted amino acid transporter 1/SLC36A1, cationic amino acid transporter 1/SLC7A1] increased to a similar extent in both groups (P < 0.05). However, the ingestion of the protein blend resulted in a prolonged and positive net phenylalanine balance during postexercise recovery compared with whey protein (P < 0.05). Postexercise myofibrillar protein synthesis increased similarly between groups. We conclude that, while both protein sources enhanced postexercise AAT expression, transport into muscle, and myofibrillar protein synthesis, postexercise ingestion of a protein blend results in a slightly prolonged net amino acid balance across the leg compared with whey protein.
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Affiliation(s)
- P T Reidy
- Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas; Department of Nutrition & Metabolism, University of Texas Medical Branch, Galveston, Texas
| | - D K Walker
- Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas; Department of Nutrition & Metabolism, University of Texas Medical Branch, Galveston, Texas
| | - J M Dickinson
- Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas; Department of Nutrition & Metabolism, University of Texas Medical Branch, Galveston, Texas; Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas
| | - D M Gundermann
- Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas; Department of Nutrition & Metabolism, University of Texas Medical Branch, Galveston, Texas
| | - M J Drummond
- Department of Nutrition & Metabolism, University of Texas Medical Branch, Galveston, Texas; Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas
| | - K L Timmerman
- Department of Nutrition & Metabolism, University of Texas Medical Branch, Galveston, Texas
| | - M B Cope
- DuPont Nutrition & Health, St. Louis, Missouri
| | - R Mukherjea
- DuPont Nutrition & Health, St. Louis, Missouri
| | - K Jennings
- Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, Texas; and
| | - E Volpi
- Department of Internal Medicine/Geriatrics, University of Texas Medical Branch, Galveston, Texas; Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas
| | - B B Rasmussen
- Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas; Department of Nutrition & Metabolism, University of Texas Medical Branch, Galveston, Texas; Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas;
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36
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Schoenfeld BJ, Aragon AA, Krieger JW. The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. J Int Soc Sports Nutr 2013; 10:53. [PMID: 24299050 PMCID: PMC3879660 DOI: 10.1186/1550-2783-10-53] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Accepted: 11/20/2013] [Indexed: 11/10/2022] Open
Abstract
Protein timing is a popular dietary strategy designed to optimize the adaptive response to exercise. The strategy involves consuming protein in and around a training session in an effort to facilitate muscular repair and remodeling, and thereby enhance post-exercise strength- and hypertrophy-related adaptations. Despite the apparent biological plausibility of the strategy, however, the effectiveness of protein timing in chronic training studies has been decidedly mixed. The purpose of this paper therefore was to conduct a multi-level meta-regression of randomized controlled trials to determine whether protein timing is a viable strategy for enhancing post-exercise muscular adaptations. The strength analysis comprised 478 subjects and 96 ESs, nested within 41 treatment or control groups and 20 studies. The hypertrophy analysis comprised 525 subjects and 132 ESs, nested with 47 treatment or control groups and 23 studies. A simple pooled analysis of protein timing without controlling for covariates showed a small to moderate effect on muscle hypertrophy with no significant effect found on muscle strength. In the full meta-regression model controlling for all covariates, however, no significant differences were found between treatment and control for strength or hypertrophy. The reduced model was not significantly different from the full model for either strength or hypertrophy. With respect to hypertrophy, total protein intake was the strongest predictor of ES magnitude. These results refute the commonly held belief that the timing of protein intake in and around a training session is critical to muscular adaptations and indicate that consuming adequate protein in combination with resistance exercise is the key factor for maximizing muscle protein accretion.
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37
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Figueiredo VC, Cameron-Smith D. Is carbohydrate needed to further stimulate muscle protein synthesis/hypertrophy following resistance exercise? J Int Soc Sports Nutr 2013; 10:42. [PMID: 24066806 PMCID: PMC3850644 DOI: 10.1186/1550-2783-10-42] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2013] [Accepted: 09/22/2013] [Indexed: 11/24/2022] Open
Abstract
It is now well established that protein supplementation after resistance exercise promotes increased muscle protein synthesis, which ultimately results in greater net muscle accretion, relative to exercise alone or exercise with supplementary carbohydrate ingestion. However, it is not known whether combining carbohydrate with protein produces a greater anabolic response than protein alone. Recent recommendations have been made that the composition of the ideal supplement post-exercise would be a combination of a protein source with a high glycemic index carbohydrate. This is based on the hypothesis that insulin promotes protein synthesis, thus maximising insulin secretion will maximally potentiate this action. However, it is still controversial as to whether raising insulin level, within the physiological range, has any effect to further stimulate muscle protein synthesis. The present commentary will review the evidence underpinning the recommendation to consume carbohydrates in addition to a protein supplementation after resistance exercise for the specific purpose of increasing muscle mass. The paucity of data will be discussed, thus our conclusions are that further studies are necessary prior to any conclusions that enable evidence-based recommendations to be made.
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Affiliation(s)
- Vandré Casagrande Figueiredo
- The Liggins Institute, Faculty of Medical and Science Health, University of Auckland, 85 Park Road, Grafton, Private Bag 92019, Auckland 1023, New Zealand.
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