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Pavis GF, Abdelrahman DR, Murton AJ, Wall BT, Stephens FB, Dirks ML. Nasogastric bolus administration of a protein-rich drink augments insulinaemia and aminoacidaemia but not whole-body protein turnover or muscle protein synthesis versus oral administration. Clin Sci (Lond) 2024; 138:43-60. [PMID: 38112515 DOI: 10.1042/cs20231126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 12/15/2023] [Accepted: 12/19/2023] [Indexed: 12/21/2023]
Abstract
Nasogastric feeding of protein-rich liquids is a nutritional support therapy that attenuates muscle mass loss. However, whether administration via a nasogastric tube per se augments whole-body or muscle protein anabolism compared with oral administration is unknown. Healthy participants were administered a protein-rich drink (225 ml containing 21 g protein) orally (ORAL; n=13; age 21 ± 1 year; BMI 22.2 ± 0.6 kg·m-2) or via a nasogastric tube (NG; n=13; age 21 ± 1 yr; BMI 23.9 ± 0.9 kg·m-2) in a parallel group design, balanced for sex. L-[ring-2H5]-phenylalanine and L-[3,3-2H2]-tyrosine were infused to measure postabsorptive and postprandial whole-body protein turnover. Skeletal muscle biopsies were collected at -120, 0, 120 and 300 min relative to drink administration to quantify temporal myofibrillar fractional synthetic rates (myoFSR). Drink administration increased serum insulin and plasma amino acid concentrations, and to a greater extent and duration in NG versus ORAL (all interactions P<0.05). Drink administration increased whole-body protein synthesis (P<0.01), suppressed protein breakdown (P<0.001), and created positive net protein balance (P<0.001), but to a similar degree in ORAL and NG (interactions P>0.05). Drink administration increased myoFSR from the postabsorptive state (P<0.01), regardless of route of administration in ORAL and in NG (interaction P>0.05). Nasogastric bolus administration of a protein-rich drink induces insulinaemia and aminoacidaemia to a greater extent than oral administration, but the postprandial increase in whole-body protein turnover and muscle protein synthesis was equivalent between administration routes. Nasogastric administration is a potent intervention to increase postprandial amino acid availability. Future work should assess its utility in overcoming impaired sensitivity to protein feeding, such as that seen in ageing, disuse, and critical care.
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Affiliation(s)
- George F Pavis
- Nutritional Physiology Group, Department of Public Health and Sport Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, Devon, U.K
| | - Doaa R Abdelrahman
- Department of Surgery, University of Texas Medical Branch, Galveston, TX, U.S.A
- Sealy Center on Aging, University of Texas Medical Branch, Galveston, TX, U.S.A
| | - Andrew J Murton
- Department of Surgery, University of Texas Medical Branch, Galveston, TX, U.S.A
- Sealy Center on Aging, University of Texas Medical Branch, Galveston, TX, U.S.A
| | - Benjamin T Wall
- Nutritional Physiology Group, Department of Public Health and Sport Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, Devon, U.K
| | - Francis B Stephens
- Nutritional Physiology Group, Department of Public Health and Sport Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, Devon, U.K
| | - Marlou L Dirks
- Nutritional Physiology Group, Department of Public Health and Sport Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, Devon, U.K
- Human and Animal Physiology, Wageningen University, Wageningen, The Netherlands
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Ferrando AA, Wolfe RR, Hirsch KR, Church DD, Kviatkovsky SA, Roberts MD, Stout JR, Gonzalez DE, Sowinski RJ, Kreider RB, Kerksick CM, Burd NA, Pasiakos SM, Ormsbee MJ, Arent SM, Arciero PJ, Campbell BI, VanDusseldorp TA, Jager R, Willoughby DS, Kalman DS, Antonio J. International Society of Sports Nutrition Position Stand: Effects of essential amino acid supplementation on exercise and performance. J Int Soc Sports Nutr 2023; 20:2263409. [PMID: 37800468 PMCID: PMC10561576 DOI: 10.1080/15502783.2023.2263409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 09/21/2023] [Indexed: 10/07/2023] Open
Abstract
Position Statement: The International Society of Sports Nutrition (ISSN) presents this position based on a critical examination of literature surrounding the effects of essential amino acid (EAA) supplementation on skeletal muscle maintenance and performance. This position stand is intended to provide a scientific foundation to athletes, dietitians, trainers, and other practitioners as to the benefits of supplemental EAA in both healthy and resistant (aging/clinical) populations. EAAs are crucial components of protein intake in humans, as the body cannot synthesize them. The daily recommended intake (DRI) for protein was established to prevent deficiencies due to inadequate EAA consumption. The following conclusions represent the official position of the Society: 1. Initial studies on EAAs' effects on skeletal muscle highlight their primary role in stimulating muscle protein synthesis (MPS) and turnover. Protein turnover is critical for replacing degraded or damaged muscle proteins, laying the metabolic foundation for enhanced functional performance. Consequently, research has shifted to examine the effects of EAA supplementation - with and without the benefits of exercise - on skeletal muscle maintenance and performance. 2. Supplementation with free-form EAAs leads to a quick rise in peripheral EAA concentrations, which in turn stimulates MPS. 3. The safe upper limit of EAA intake (amount), without inborn metabolic disease, can easily accommodate additional supplementation. 4. At rest, stimulation of MPS occurs at relatively small dosages (1.5-3.0 g) and seems to plateau at around 15-18 g. 5. The MPS stimulation by EAAs does not require non-essential amino acids. 6. Free-form EAA ingestion stimulates MPS more than an equivalent amount of intact protein. 7. Repeated EAA-induced MPS stimulation throughout the day does not diminish the anabolic effect of meal intake. 8. Although direct comparisons of various formulas have yet to be investigated, aging requires a greater proportion of leucine to overcome the reduced muscle sensitivity known as "anabolic resistance." 9. Without exercise, EAA supplementation can enhance functional outcomes in anabolic-resistant populations. 10. EAA requirements rise in the face of caloric deficits. During caloric deficit, it's essential to meet whole-body EAA requirements to preserve anabolic sensitivity in skeletal muscle.
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Affiliation(s)
- Arny A. Ferrando
- University of Arkansas for Medical Sciences, Center for Translational Research in Aging and Longevity, Department of Geriatrics, Little Rock, AR, USA
| | - Robert R. Wolfe
- University of Arkansas for Medical Sciences, Center for Translational Research in Aging and Longevity, Department of Geriatrics, Little Rock, AR, USA
| | - Katie R. Hirsch
- University of South Carolina, Department of Exercise Science, Arnold School of Public Health, Columbia, SC, USA
| | - David D. Church
- University of Arkansas for Medical Sciences, Center for Translational Research in Aging and Longevity, Department of Geriatrics, Little Rock, AR, USA
| | - Shiloah A. Kviatkovsky
- University of Arkansas for Medical Sciences, Center for Translational Research in Aging and Longevity, Department of Geriatrics, Little Rock, AR, USA
| | | | - Jeffrey R. Stout
- University of Central Florida, School of Kinesiology and Rehabilitation Sciences, Orlando, FL, USA
| | - Drew E. Gonzalez
- Texas A&M University, Exercise & Sport Nutrition Lab, Department of Kinesiology and Sports Management, College Station, TX, USA
| | - Ryan J. Sowinski
- Texas A&M University, Exercise & Sport Nutrition Lab, Department of Kinesiology and Sports Management, College Station, TX, USA
| | - Richard B. Kreider
- Texas A&M University, Exercise & Sport Nutrition Lab, Department of Kinesiology and Sports Management, College Station, TX, USA
| | - Chad M. Kerksick
- Lindenwood University, Exercise and Performance Nutrition Laboratory, College of Science, Technology, and Health, St Charles, MO, USA
| | - Nicholas A. Burd
- University of Illinois Urbana-Champaign, Department of Kinesiology and Community Health, Urbana, IL, USA
| | - Stefan M. Pasiakos
- National Institutes of Health, Office of Dietary Supplements, Bethesda, MD, USA
| | - Michael J. Ormsbee
- Florida State University, Institute of Sports Sciences and Medicine, Nutrition and Integrative Physiology, Tallahassee, FL, USA
| | - Shawn M. Arent
- University of South Carolina, Department of Exercise Science, Arnold School of Public Health, Columbia, SC, USA
| | - Paul J. Arciero
- University of Pittsburgh, Department of Sports Medicine and Nutrition, Pittsburgh, PA, USA
- Skidmore College, Health and Physiological Sciences, Saratoga Springs, NY, USA
| | - Bill I. Campbell
- University of South Florida, Performance & Physique Enhancement Laboratory, Tampa, FL, USA
| | - Trisha A. VanDusseldorp
- Bonafede Health, LLC, JDS Therapeutics, Harrison, NY, USA
- Jacksonville University, Department of Health and Exercise Sciences, Jacksonville, FL, USA
| | | | - Darryn S. Willoughby
- University of Mary Hardin-Baylor, Human Performance Lab, School of Exercise and Sport Science, Belton, TX, USA
| | - Douglas S. Kalman
- Nova Southeastern University, Dr. Kiran C Patel College of Osteopathic Medicine, Department of Nutrition, Davie, FL, USA
| | - Jose Antonio
- Nova Southeastern University, Department of Health and Human Performance, Davie, FL, USA
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Wilkinson K, Koscien CP, Monteyne AJ, Wall BT, Stephens FB. Association of postprandial postexercise muscle protein synthesis rates with dietary leucine: A systematic review. Physiol Rep 2023; 11:e15775. [PMID: 37537134 PMCID: PMC10400406 DOI: 10.14814/phy2.15775] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 06/20/2023] [Accepted: 07/05/2023] [Indexed: 08/05/2023] Open
Abstract
BACKGROUND Dietary protein ingestion augments post (resistance) exercise muscle protein synthesis (MPS) rates. It is thought that the dose of leucine ingested within the protein (leucine threshold hypothesis) and the subsequent plasma leucine variables (leucine trigger hypothesis; peak magnitude, rate of rise, and total availability) determine the magnitude of the postprandial postexercise MPS response. METHODS A quantitative systematic review was performed extracting data from studies that recruited healthy adults, applied a bout of resistance exercise, ingested a bolus of protein within an hour of exercise, and measured plasma leucine concentrations and MPS rates (delta change from basal). RESULTS Ingested leucine dose was associated with the magnitude of the MPS response in older, but not younger, adults over acute (0-2 h, r2 = 0.64, p = 0.02) and the entire postprandial (>2 h, r2 = 0.18, p = 0.01) period. However, no single plasma leucine variable possessed substantial predictive capacity over the magnitude of MPS rates in younger or older adults. CONCLUSION Our data provide support that leucine dose provides predictive capacity over postprandial postexercise MPS responses in older adults. However, no threshold in older adults and no plasma leucine variable was correlated with the magnitude of the postexercise anabolic response.
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Affiliation(s)
- Kiera Wilkinson
- Nutritional Physiology Research Group, Public Health and Sport Sciences, Faculty of Health and Life SciencesUniversity of ExeterExeterUK
| | - Christopher P. Koscien
- Nutritional Physiology Research Group, Public Health and Sport Sciences, Faculty of Health and Life SciencesUniversity of ExeterExeterUK
| | - Alistair J. Monteyne
- Nutritional Physiology Research Group, Public Health and Sport Sciences, Faculty of Health and Life SciencesUniversity of ExeterExeterUK
| | - Benjamin T. Wall
- Nutritional Physiology Research Group, Public Health and Sport Sciences, Faculty of Health and Life SciencesUniversity of ExeterExeterUK
| | - Francis B. Stephens
- Nutritional Physiology Research Group, Public Health and Sport Sciences, Faculty of Health and Life SciencesUniversity of ExeterExeterUK
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Salimi K, Alvandi M, Saberi Pirouz M, Rakhshan K, Howatson G. Regulating eEF2 and eEF2K in skeletal muscle by exercise. Arch Physiol Biochem 2023:1-12. [PMID: 36633938 DOI: 10.1080/13813455.2023.2164898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 12/15/2022] [Accepted: 12/29/2022] [Indexed: 01/13/2023]
Abstract
Skeletal muscle is a flexible and adaptable tissue that strongly responds to exercise training. The skeletal muscle responds to exercise by increasing muscle protein synthesis (MPS) when energy is available. One of protein synthesis's major rate-limiting and critical regulatory steps is the translation elongation pathway. The process of translation elongation in skeletal muscle is highly regulated. It requires elongation factors that are intensely affected by various physiological stimuli such as exercise and the total available energy of cells. Studies have shown that exercise involves the elongation pathway by numerous signalling pathways. Since the elongation pathway, has been far less studied than the other translation steps, its comprehensive prospect and quantitative understanding remain in the dark. This study highlights the current understanding of the effect of exercise training on the translation elongation pathway focussing on the molecular factors affecting the pathway, including Ca2+, AMPK, PKA, mTORC1/P70S6K, MAPKs, and myostatin. We further discussed the mode and volume of exercise training intervention on the translation elongation pathway.What is the topic of this review? This review summarises the impacts of exercise training on the translation elongation pathway in skeletal muscle focussing on eEF2 and eEF2K.What advances does it highlight? This review highlights mechanisms and factors that profoundly influence the translation elongation pathway and argues that exercise might modulate the response. This review also combines the experimental observations focussing on the regulation of translation elongation during and after exercise. The findings widen our horizon to the notion of mechanisms involved in muscle protein synthesis (MPS) through translation elongation response to exercise training.
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Affiliation(s)
- Kia Salimi
- Department of Exercise Physiology, Faculty of Sport and Exercise Sciences, University of Tehran, Tehran, Iran
| | - Masoomeh Alvandi
- Department of Biological Science in Sport and Health, University of Shahid Beheshti, Tehran, Iran
| | - Mahdi Saberi Pirouz
- Student Research Committee, Iran University of Medical Sciences, Tehran, Iran
| | - Kamran Rakhshan
- Department of Medical Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Electrophysiology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Glyn Howatson
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
- Water Research Group, North West University, Potchefstroom, South Africa
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The effects of glucagon and the target of rapamycin (TOR) on skeletal muscle protein synthesis and age-dependent sarcopenia in humans. Clin Nutr ESPEN 2021; 44:15-25. [PMID: 34330459 DOI: 10.1016/j.clnesp.2021.06.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 06/21/2021] [Indexed: 01/07/2023]
Abstract
BACKGROUND AND AIMS Human target of rapamycin (TOR) is a kinase that stimulates protein synthesis in the skeletal muscle in response to amino acids and physical activity. METHODS A comprehensive literature search was conducted on the PubMed database from its inception up to May 2021 to retrieve information on the effects of TOR and glucagon on muscle function. Articles written in English regarding human subjects were included. RESULTS l-leucine activates TOR to initiate protein synthesis in the skeletal muscle. Glucagon has a crucial role suppressing skeletal muscle protein synthesis by increasing l-leucine oxidation and the irreversible loss of this amino acid. Glucagon-induced l-leucine oxidation suppresses TOR and attenuates the ability of skeletal muscle to synthesize proteins. Conditions associated with increased glucagon secretion typically feature reduced ability to synthesize proteins in the skeletal muscle that may evolve into sarcopenia. Animal protein ingestion, unlike vegetable protein, stimulates glucagon secretion. High intake of animal protein increases l-leucine oxidation and promotes the use of amino acids as fuel. Sarcopenia and arterial stiffness characteristically occur together in conditions featuring insulin resistance, such as aging. Insulin resistance mediates the relationship between aging and sarcopenia and arterial stiffness. The loss of skeletal muscle fibers that characterizes sarcopenia is followed by collagen and lipid accumulation. Likewise, insulin resistance is associated with arterial stiffness and intima-media thickening due to adaptive accretion of collagen and lipids in the arterial wall. CONCLUSIONS Human TOR participates in the pathogenesis of sarcopenia and arterial stiffness, although its effects remain to be fully elucidated.
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Understanding the effects of nutrition and post-exercise nutrition on skeletal muscle protein turnover: Insights from stable isotope studies. CLINICAL NUTRITION OPEN SCIENCE 2021. [DOI: 10.1016/j.nutos.2021.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Arent SM, Cintineo HP, McFadden BA, Chandler AJ, Arent MA. Nutrient Timing: A Garage Door of Opportunity? Nutrients 2020; 12:nu12071948. [PMID: 32629950 PMCID: PMC7400240 DOI: 10.3390/nu12071948] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 06/26/2020] [Accepted: 06/28/2020] [Indexed: 12/11/2022] Open
Abstract
Nutrient timing involves manipulation of nutrient consumption at specific times in and around exercise bouts in an effort to improve performance, recovery, and adaptation. Its historical perspective centered on ingestion during exercise and grew to include pre- and post-training periods. As research continued, translational focus remained primarily on the impact and outcomes related to nutrient consumption during one specific time period to the exclusion of all others. Additionally, there seemed to be increasing emphasis on outcomes related to hypertrophy and strength at the expense of other potentially more impactful performance measures. As consumption of nutrients does not occur at only one time point in the day, the effect and impact of energy and macronutrient availability becomes an important consideration in determining timing of additional nutrients in and around training and competition. This further complicates the confining of the definition of “nutrient timing” to one very specific moment in time at the exclusion of all other time points. As such, this review suggests a new perspective built on evidence of the interconnectedness of nutrient impact and provides a pragmatic approach to help frame nutrient timing more inclusively. Using this approach, it is argued that the concept of nutrient timing is constrained by reliance on interpretation of an “anabolic window” and may be better viewed as a “garage door of opportunity” to positively impact performance, recovery, and athlete availability.
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Affiliation(s)
- Shawn M. Arent
- Department of Exercise Science, University of South Carolina, Columbia, SC 29208, USA; (H.P.C.); (B.A.M.); (A.J.C.)
- Correspondence: ; Tel.: +1-803-576-8394
| | - Harry P. Cintineo
- Department of Exercise Science, University of South Carolina, Columbia, SC 29208, USA; (H.P.C.); (B.A.M.); (A.J.C.)
| | - Bridget A. McFadden
- Department of Exercise Science, University of South Carolina, Columbia, SC 29208, USA; (H.P.C.); (B.A.M.); (A.J.C.)
| | - Alexa J. Chandler
- Department of Exercise Science, University of South Carolina, Columbia, SC 29208, USA; (H.P.C.); (B.A.M.); (A.J.C.)
| | - Michelle A. Arent
- Department of Health Promotion, Education, and Behavior, University of South Carolina, Columbia, SC 29208, USA;
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Acute Effect of the Timing of Resistance Exercise and Nutrient Intake on Muscle Protein Breakdown. Nutrients 2020; 12:nu12041177. [PMID: 32331476 PMCID: PMC7230944 DOI: 10.3390/nu12041177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 04/17/2020] [Accepted: 04/20/2020] [Indexed: 11/21/2022] Open
Abstract
Background: Combining resistance exercise (RE) with nutrient intake stimulates muscle protein net balance. However, it is still unclear whether the optimal timing of nutrient intake is before or after RE, especially on muscle protein breakdown (MPB) for an augmented muscle anabolic response. The aim of this study was to investigate the effect of a substantial mixed meal (i.e., nutrient- and protein-dense whole foods) before or after RE, compared with RE without a meal on the acute response of MPB in a crossover-design study. Methods: Eight healthy young men performed three trials: (1) meal intake before RE (Pre), (2) meal intake after RE (Post), and (3) RE without meal intake (No). Plasma insulin and 3-methylhistidine (3-MH), an MPB marker, were measured. Results: Time course change in plasma insulin level after RE was significantly higher in the Post condition than in the Pre and No conditions. The area under the curve of 3-MH concentration was significantly lower in the Post condition than in the Pre and No conditions. Conclusions: These results suggest that a substantial mixed meal immediately after RE may effectively suppress MPB in the morning.
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9
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Is There a Postworkout Anabolic Window of Opportunity for Nutrient Consumption? Clearing up Controversies. J Orthop Sports Phys Ther 2018; 48:911-914. [PMID: 30702982 DOI: 10.2519/jospt.2018.0615] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nutrient timing is a popular strategy for enhancing muscular adaptations and athletic performance. From the standpoint of muscle hypertrophy, the concept of a "postworkout anabolic window of opportunity" has been proposed, whereby a limited time exists after training to optimize accretion of muscle proteins. Some researchers have gone so far as to claim that the timing of nutritional consumption is even more critical to muscle development than the absolute daily consumption of nutrients. Thus, the purpose of this paper is to review the current literature as to the relevance of the anabolic window of opportunity, and draw evidence-based conclusions for application into practice. J Orthop Sports Phys Ther 2018;48(12):911-914. doi:10.2519/jospt.2018.0615.
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METTLER JONIA, MAGEE DILLONM, DOUCET BARBARAM. High-Frequency Neuromuscular Electrical Stimulation Increases Anabolic Signaling. Med Sci Sports Exerc 2018; 50:1540-1548. [DOI: 10.1249/mss.0000000000001610] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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11
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Kerksick CM, Arent S, Schoenfeld BJ, Stout JR, Campbell B, Wilborn CD, Taylor L, Kalman D, Smith-Ryan AE, Kreider RB, Willoughby D, Arciero PJ, VanDusseldorp TA, Ormsbee MJ, Wildman R, Greenwood M, Ziegenfuss TN, Aragon AA, Antonio J. International society of sports nutrition position stand: nutrient timing. J Int Soc Sports Nutr 2017; 14:33. [PMID: 28919842 PMCID: PMC5596471 DOI: 10.1186/s12970-017-0189-4] [Citation(s) in RCA: 209] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 08/14/2017] [Indexed: 12/30/2022] Open
Abstract
The International Society of Sports Nutrition (ISSN) provides an objective and critical review regarding the timing of macronutrients in reference to healthy, exercising adults and in particular highly trained individuals on exercise performance and body composition. The following points summarize the position of the ISSN:Nutrient timing incorporates the use of methodical planning and eating of whole foods, fortified foods and dietary supplements. The timing of energy intake and the ratio of certain ingested macronutrients may enhance recovery and tissue repair, augment muscle protein synthesis (MPS), and improve mood states following high-volume or intense exercise. Endogenous glycogen stores are maximized by following a high-carbohydrate diet (8–12 g of carbohydrate/kg/day [g/kg/day]); moreover, these stores are depleted most by high volume exercise. If rapid restoration of glycogen is required (< 4 h of recovery time) then the following strategies should be considered:aggressive carbohydrate refeeding (1.2 g/kg/h) with a preference towards carbohydrate sources that have a high (> 70) glycemic index the addition of caffeine (3–8 mg/kg) combining carbohydrates (0.8 g/kg/h) with protein (0.2–0.4 g/kg/h)
Extended (> 60 min) bouts of high intensity (> 70% VO2max) exercise challenge fuel supply and fluid regulation, thus carbohydrate should be consumed at a rate of ~30–60 g of carbohydrate/h in a 6–8% carbohydrate-electrolyte solution (6–12 fluid ounces) every 10–15 min throughout the entire exercise bout, particularly in those exercise bouts that span beyond 70 min. When carbohydrate delivery is inadequate, adding protein may help increase performance, ameliorate muscle damage, promote euglycemia and facilitate glycogen re-synthesis. Carbohydrate ingestion throughout resistance exercise (e.g., 3–6 sets of 8–12 repetition maximum [RM] using multiple exercises targeting all major muscle groups) has been shown to promote euglycemia and higher glycogen stores. Consuming carbohydrate solely or in combination with protein during resistance exercise increases muscle glycogen stores, ameliorates muscle damage, and facilitates greater acute and chronic training adaptations. Meeting the total daily intake of protein, preferably with evenly spaced protein feedings (approximately every 3 h during the day), should be viewed as a primary area of emphasis for exercising individuals. Ingestion of essential amino acids (EAA; approximately 10 g)either in free form or as part of a protein bolus of approximately 20–40 g has been shown to maximally stimulate muscle protein synthesis (MPS). Pre- and/or post-exercise nutritional interventions (carbohydrate + protein or protein alone) may operate as an effective strategy to support increases in strength and improvements in body composition. However, the size and timing of a pre-exercise meal may impact the extent to which post-exercise protein feeding is required. Post-exercise ingestion (immediately to 2-h post) of high-quality protein sources stimulates robust increases in MPS. In non-exercising scenarios, changing the frequency of meals has shown limited impact on weight loss and body composition, with stronger evidence to indicate meal frequency can favorably improve appetite and satiety. More research is needed to determine the influence of combining an exercise program with altered meal frequencies on weight loss and body composition with preliminary research indicating a potential benefit. Ingesting a 20–40 g protein dose (0.25–0.40 g/kg body mass/dose) of a high-quality source every three to 4 h appears to most favorably affect MPS rates when compared to other dietary patterns and is associated with improved body composition and performance outcomes. Consuming casein protein (~ 30–40 g) prior to sleep can acutely increase MPS and metabolic rate throughout the night without influencing lipolysis.
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Affiliation(s)
- Chad M Kerksick
- Exercise and Performance Nutrition Laboratory, School of Health Sciences, Lindenwood University, St. Charles, MO USA
| | - Shawn Arent
- IFNH Center for Health & Human Performance, Department of Kinesiology & Health, Rutgers University, New Brunswick, NJ USA
| | - Brad J Schoenfeld
- Health Science Department, Program of Exercise Science, CUNY Lehman College, Bronx, NY USA
| | - Jeffrey R Stout
- Institute of Exercise Physiology and Wellness, University of Central Florida, Orlando, FL USA
| | - Bill Campbell
- Performance & Physique Enhancement Laboratory, Exercise Science Program, University of South Florida, Tampa, FL USA
| | - Colin D Wilborn
- Human Performance Lab, Department of Exercise Sport Science, University of Mary Hardin-Baylor, Belton, TX USA
| | - Lem Taylor
- Human Performance Lab, Department of Exercise Sport Science, University of Mary Hardin-Baylor, Belton, TX USA
| | - Doug Kalman
- Department of Athletics, Florida International University, Miami, FL USA
| | - Abbie E Smith-Ryan
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina-Chapel Hill, Chapel Hill, NC USA
| | - Richard B Kreider
- Exercise & Sport Nutrition Lab, Human Clinical Research Facility, Department of Health & Kinesiology, Texas A&M University, College Station, TX USA
| | - Darryn Willoughby
- Exercise and Biochemical Nutrition Laboratory, Department of Health, Human Performance, and Recreation, Baylor University, Waco, TX USA
| | - Paul J Arciero
- Human Nutrition and Metabolism Laboratory, Health and Exercise Sciences Department, Skidmore College, Saratoga Springs, NY 12866 USA
| | - Trisha A VanDusseldorp
- Department of Exercise Science and Sport Management, Kennesaw State University, Kennesaw, GA USA
| | - Michael J Ormsbee
- Department of Nutrition, Food and Exercise Sciences, Institute of Sport Sciences and Medicine, Florida State University, Tallahassee, FL USA.,University of KwaZulu-Natal, Biokinetics, Exercise and Leisure Studies, Durban, 4000 South Africa
| | | | - Mike Greenwood
- Exercise & Sport Nutrition Lab, Human Clinical Research Facility, Department of Health & Kinesiology, Texas A&M University, College Station, TX USA
| | | | - Alan A Aragon
- Department of Family Environmental Sciences, California State University, Northridge, CA USA
| | - Jose Antonio
- Department of Health and Human Performance, Nova Southeastern University, Davie, FL USA
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12
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Jäger R, Kerksick CM, Campbell BI, Cribb PJ, Wells SD, Skwiat TM, Purpura M, Ziegenfuss TN, Ferrando AA, Arent SM, Smith-Ryan AE, Stout JR, Arciero PJ, Ormsbee MJ, Taylor LW, Wilborn CD, Kalman DS, Kreider RB, Willoughby DS, Hoffman JR, Krzykowski JL, Antonio J. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr 2017; 14:20. [PMID: 28642676 PMCID: PMC5477153 DOI: 10.1186/s12970-017-0177-8] [Citation(s) in RCA: 326] [Impact Index Per Article: 46.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 06/05/2017] [Indexed: 01/03/2023] Open
Abstract
The International Society of Sports Nutrition (ISSN) provides an objective and critical review related to the intake of protein for healthy, exercising individuals. Based on the current available literature, the position of the Society is as follows:An acute exercise stimulus, particularly resistance exercise, and protein ingestion both stimulate muscle protein synthesis (MPS) and are synergistic when protein consumption occurs before or after resistance exercise.For building muscle mass and for maintaining muscle mass through a positive muscle protein balance, an overall daily protein intake in the range of 1.4-2.0 g protein/kg body weight/day (g/kg/d) is sufficient for most exercising individuals, a value that falls in line within the Acceptable Macronutrient Distribution Range published by the Institute of Medicine for protein.Higher protein intakes (2.3-3.1 g/kg/d) may be needed to maximize the retention of lean body mass in resistance-trained subjects during hypocaloric periods.There is novel evidence that suggests higher protein intakes (>3.0 g/kg/d) may have positive effects on body composition in resistance-trained individuals (i.e., promote loss of fat mass).Recommendations regarding the optimal protein intake per serving for athletes to maximize MPS are mixed and are dependent upon age and recent resistance exercise stimuli. General recommendations are 0.25 g of a high-quality protein per kg of body weight, or an absolute dose of 20-40 g.Acute protein doses should strive to contain 700-3000 mg of leucine and/or a higher relative leucine content, in addition to a balanced array of the essential amino acids (EAAs).These protein doses should ideally be evenly distributed, every 3-4 h, across the day.The optimal time period during which to ingest protein is likely a matter of individual tolerance, since benefits are derived from pre- or post-workout ingestion; however, the anabolic effect of exercise is long-lasting (at least 24 h), but likely diminishes with increasing time post-exercise.While it is possible for physically active individuals to obtain their daily protein requirements through the consumption of whole foods, supplementation is a practical way of ensuring intake of adequate protein quality and quantity, while minimizing caloric intake, particularly for athletes who typically complete high volumes of training. Rapidly digested proteins that contain high proportions of essential amino acids (EAAs) and adequate leucine, are most effective in stimulating MPS. Different types and quality of protein can affect amino acid bioavailability following protein supplementation. Athletes should consider focusing on whole food sources of protein that contain all of the EAAs (i.e., it is the EAAs that are required to stimulate MPS). Endurance athletes should focus on achieving adequate carbohydrate intake to promote optimal performance; the addition of protein may help to offset muscle damage and promote recovery. Pre-sleep casein protein intake (30-40 g) provides increases in overnight MPS and metabolic rate without influencing lipolysis.
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Affiliation(s)
| | - Chad M. Kerksick
- Exercise and Performance Nutrition Laboratory, School of Health Sciences, Lindenwood University, St. Charles, MO USA
| | - Bill I. Campbell
- Performance & Physique Enhancement Laboratory, University of South Florida, Tampa, FL USA
| | - Paul J. Cribb
- Metabolic Precision Certifications, Queensland, Australia
| | | | | | | | | | - Arny A. Ferrando
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR USA
| | - Shawn M. Arent
- IFNH Center for Health & Human Performance, Department of Kinesiology & Health, Rutgers, the State University of New Jersey, New Brunswick, New Jersey USA
| | - Abbie E. Smith-Ryan
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC USA
| | - Jeffrey R. Stout
- Institute of Exercise Physiology and Wellness, University of Central Florida, Orlando, FL USA
| | - Paul J. Arciero
- Human Nutrition and Metabolism Laboratory, Health and Exercise Sciences Department, Skidmore College, Saratoga Springs, NY 12866 USA
| | - Michael J. Ormsbee
- Department of Nutrition, Food and Exercise Sciences, Institute of Sport Sciences and Medicine, Florida State University, Tallahassee, USA
- Biokinetics, Exercise and Leisure Studies, University of KwaZulu-Natal, Durban, 4000 South Africa
| | - Lem W. Taylor
- Human Performance Laboratory, University of Mary Hardin-Baylor UMHB, Belton, TX 76513 USA
| | - Colin D. Wilborn
- Human Performance Laboratory, University of Mary Hardin-Baylor UMHB, Belton, TX 76513 USA
| | - Doug S. Kalman
- Department of Nutrition & Endocrinology, QPS, Miami, FL USA
| | - Richard B. Kreider
- Exercise & Sport Nutrition Lab, Human Clinical Research Facility, Department of Health & Kinesiology, Texas A&M University, College Station, TX USA
| | - Darryn S. Willoughby
- Exercise and Biochemical Nutrition Laboratory, Department of Health, Human Performance, and Recreation, Baylor University, Waco, TX USA
| | - Jay R. Hoffman
- Institute of Exercise Physiology and Wellness, University of Central Florida, Orlando, FL USA
| | | | - Jose Antonio
- Department of Health and Human Performance, Nova Southeastern University, Davie, FL USA
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Smith JW, Krings BM, Peterson TJ, Rountree JA, Zak RB, McAllister MJ. Ingestion of an Amino Acid Electrolyte Beverage during Resistance Exercise Does Not Impact Fluid Shifts into Muscle or Performance. Sports (Basel) 2017; 5:sports5020036. [PMID: 29910396 PMCID: PMC5968991 DOI: 10.3390/sports5020036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 06/06/2017] [Accepted: 06/07/2017] [Indexed: 11/16/2022] Open
Abstract
The purpose of this study was to investigate the impact of ingesting an amino acid-electrolyte (AAE) beverage during upper body resistance exercise on transient muscle hypertrophy, exercise performance, markers of muscle damage, and recovery. Participants (n = 15) performed three sets of six repetitions—bench press, lat pull down, incline press, and seated row—followed by three sets of eight repetitions at 75% of the estimated 1 repetition maximum—triceps kickback, hammer curl, triceps push down, and preacher curl—with 90 s of rest between sets. The final set of the push down/preacher curl was performed to failure. Prior to and immediately post-exercise, as well as 24, 48, and 72 h post exercise, cross-sectional muscle thickness was measured. Blood samples were collected prior to exercise, as well as 24, 48, and 72 h post-exercise for serum creatine kinase (CK) analysis. No treatment effect was found for muscle cross-sectional area, repetitions to failure, or serum CK. A main effect (p < 0.001) was observed in the change in serum CK levels in the days following the resistance exercise session. The findings of this study suggest that the acute ingestion of a AAE beverage does not alter acute muscle thickness, performance, perceived soreness and weakness, or markers of muscle damage.
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Affiliation(s)
- JohnEric W Smith
- Department of Kinesiology, Mississippi State University, Mississippi State, MS 39762, USA.
| | - Ben M Krings
- Department of Kinesiology, Mississippi State University, Mississippi State, MS 39762, USA.
| | - Timothy J Peterson
- Department of Kinesiology, Mississippi State University, Mississippi State, MS 39762, USA.
| | - Jaden A Rountree
- Department of Kinesiology, Mississippi State University, Mississippi State, MS 39762, USA.
| | - Roksana B Zak
- School of Health and Kinesiology, University of Nebraska-Omaha, Omaha, NE 68182, USA.
| | - Matthew J McAllister
- Department of Kinesiology, Mississippi State University, Mississippi State, MS 39762, USA.
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14
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Schoenfeld BJ, Aragon A, Wilborn C, Urbina SL, Hayward SE, Krieger J. Pre- versus post-exercise protein intake has similar effects on muscular adaptations. PeerJ 2017; 5:e2825. [PMID: 28070459 PMCID: PMC5214805 DOI: 10.7717/peerj.2825] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 11/22/2016] [Indexed: 11/26/2022] Open
Abstract
The purpose of this study was to test the anabolic window theory by investigating muscle strength, hypertrophy, and body composition changes in response to an equal dose of protein consumed either immediately pre- versus post-resistance training (RT) in trained men. Subjects were 21 resistance-trained men (>1 year RT experience) recruited from a university population. After baseline testing, participants were randomly assigned to 1 of 2 experimental groups: a group that consumed a supplement containing 25 g protein and 1 g carbohydrate immediately prior to exercise (PRE-SUPP) (n = 9) or a group that consumed the same supplement immediately post-exercise (POST-SUPP) (n = 12). The RT protocol consisted of three weekly sessions performed on non-consecutive days for 10 weeks. A total-body routine was employed with three sets of 8–12 repetitions for each exercise. Results showed that pre- and post-workout protein consumption had similar effects on all measures studied (p > 0.05). These findings refute the contention of a narrow post-exercise anabolic window to maximize the muscular response and instead lends support to the theory that the interval for protein intake may be as wide as several hours or perhaps more after a training bout depending on when the pre-workout meal was consumed.
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Affiliation(s)
- Brad Jon Schoenfeld
- Department of Health Sciences, Herbert H. Lehman College, City University of New York , Bronx , NY , United States
| | - Alan Aragon
- Department of Nutrition, California State University , Northridge , CA , United States
| | - Colin Wilborn
- Graduate School and Research, University of Mary Hardin Baylor , Belton , TX , United States
| | - Stacie L Urbina
- Graduate School and Research, University of Mary Hardin Baylor , Belton , TX , United States
| | - Sara E Hayward
- Graduate School and Research, University of Mary Hardin Baylor , Belton , TX , United States
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15
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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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16
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Moro T, Tinsley G, Bianco A, Marcolin G, Pacelli QF, Battaglia G, Palma A, Gentil P, Neri M, Paoli A. Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males. J Transl Med 2016; 14:290. [PMID: 27737674 PMCID: PMC5064803 DOI: 10.1186/s12967-016-1044-0] [Citation(s) in RCA: 394] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Accepted: 10/03/2016] [Indexed: 01/10/2023] Open
Abstract
Background Intermittent fasting (IF) is an increasingly popular dietary approach used for weight loss and overall health. While there is an increasing body of evidence demonstrating beneficial effects of IF on blood lipids and other health outcomes in the overweight and obese, limited data are available about the effect of IF in athletes. Thus, the present study sought to investigate the effects of a modified IF protocol (i.e. time-restricted feeding) during resistance training in healthy resistance-trained males. Methods Thirty-four resistance-trained males were randomly assigned to time-restricted feeding (TRF) or normal diet group (ND). TRF subjects consumed 100 % of their energy needs in an 8-h period of time each day, with their caloric intake divided into three meals consumed at 1 p.m., 4 p.m., and 8 p.m. The remaining 16 h per 24-h period made up the fasting period. Subjects in the ND group consumed 100 % of their energy needs divided into three meals consumed at 8 a.m., 1 p.m., and 8 p.m. Groups were matched for kilocalories consumed and macronutrient distribution (TRF 2826 ± 412.3 kcal/day, carbohydrates 53.2 ± 1.4 %, fat 24.7 ± 3.1 %, protein 22.1 ± 2.6 %, ND 3007 ± 444.7 kcal/day, carbohydrates 54.7 ± 2.2 %, fat 23.9 ± 3.5 %, protein 21.4 ± 1.8). Subjects were tested before and after 8 weeks of the assigned diet and standardized resistance training program. Fat mass and fat-free mass were assessed by dual-energy x-ray absorptiometry and muscle area of the thigh and arm were measured using an anthropometric system. Total and free testosterone, insulin-like growth factor 1, blood glucose, insulin, adiponectin, leptin, triiodothyronine, thyroid stimulating hormone, interleukin-6, interleukin-1β, tumor necrosis factor α, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides were measured. Bench press and leg press maximal strength, resting energy expenditure, and respiratory ratio were also tested. Results After 8 weeks, the 2 Way ANOVA (Time * Diet interaction) showed a decrease in fat mass in TRF compared to ND (p = 0.0448), while fat-free mass, muscle area of the arm and thigh, and maximal strength were maintained in both groups. Testosterone and insulin-like growth factor 1 decreased significantly in TRF, with no changes in ND (p = 0.0476; p = 0.0397). Adiponectin increased (p = 0.0000) in TRF while total leptin decreased (p = 0.0001), although not when adjusted for fat mass. Triiodothyronine decreased in TRF, but no significant changes were detected in thyroid-stimulating hormone, total cholesterol, high-density lipoprotein, low-density lipoprotein, or triglycerides. Resting energy expenditure was unchanged, but a significant decrease in respiratory ratio was observed in the TRF group. Conclusions Our results suggest that an intermittent fasting program in which all calories are consumed in an 8-h window each day, in conjunction with resistance training, could improve some health-related biomarkers, decrease fat mass, and maintain muscle mass in resistance-trained males.
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Affiliation(s)
- Tatiana Moro
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Grant Tinsley
- Department of Kinesiology & Sport Management, Texas Tech University, Lubbock, TX, USA
| | - Antonino Bianco
- Sport and Exercise Sciences Research Unit, University of Palermo, Palermo, Italy
| | - Giuseppe Marcolin
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | | | - Giuseppe Battaglia
- Sport and Exercise Sciences Research Unit, University of Palermo, Palermo, Italy
| | - Antonio Palma
- Sport and Exercise Sciences Research Unit, University of Palermo, Palermo, Italy
| | - Paulo Gentil
- College of Physical Education and Dance, Federal University of Goias, Goiania, Brazil
| | - Marco Neri
- Italian Fitness Federation, Ravenna, Italy
| | - Antonio Paoli
- Department of Biomedical Sciences, University of Padova, Padua, Italy.
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17
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Phillips SM. The impact of protein quality on the promotion of resistance exercise-induced changes in muscle mass. Nutr Metab (Lond) 2016; 13:64. [PMID: 27708684 PMCID: PMC5041535 DOI: 10.1186/s12986-016-0124-8] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 09/21/2016] [Indexed: 12/20/2022] Open
Abstract
Protein supplementation during resistance exercise training augments hypertrophic gains. Protein ingestion and the resultant hyperaminoacidemia provides the building blocks (indispensable amino acids - IAA) for, and also triggers an increase in, muscle protein synthesis (MPS), suppression of muscle protein breakdown (MPB), and net positive protein balance (i.e., MPS > MPB). The key amino acid triggering the rise in MPS is leucine, which stimulates the mechanistic target of rapamycin complex-1, a key signalling protein, and triggers a rise in MPS. As such, ingested proteins with a high leucine content would be advantageous in triggering a rise in MPS. Thus, protein quality (reflected in IAA content and protein digestibility) has an impact on changes in MPS and could ultimately affect skeletal muscle mass. Protein quality has been measured by the protein digestibility-corrected amino acid score (PDCAAS); however, the digestible indispensable amino acid score (DIAAS) has been recommended as a better method for protein quality scoring. Under DIAAS there is the recognition that amino acids are individual nutrients and that protein quality is contingent on IAA content and ileal (as opposed to fecal) digestibility. Differences in protein quality may have important ramifications for exercise-induced changes in muscle mass gains made with resistance exercise as well as muscle remodelling. Thus, the purpose of this review is a critical appraisal of studies examining the effects of protein quality in supplementation on changes in muscle mass and strength as well as body composition during resistance training.
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Affiliation(s)
- Stuart M. Phillips
- Department of Kinesiology, McMaster University, 1280 Main St., West Hamilton, ON L8S 4K1 Canada
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18
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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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19
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Potgieter S. Sport nutrition: A review of the latest guidelines for exercise and sport nutrition from the American College of Sport Nutrition, the International Olympic Committee and the International Society for Sports Nutrition. SOUTH AFRICAN JOURNAL OF CLINICAL NUTRITION 2016. [DOI: 10.1080/16070658.2013.11734434] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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20
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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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21
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Morton RW, McGlory C, Phillips SM. Nutritional interventions to augment resistance training-induced skeletal muscle hypertrophy. Front Physiol 2015; 6:245. [PMID: 26388782 PMCID: PMC4558471 DOI: 10.3389/fphys.2015.00245] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 08/17/2015] [Indexed: 11/16/2022] Open
Abstract
Skeletal muscle mass is regulated by a balance between muscle protein synthesis (MPS) and muscle protein breakdown (MPB). In healthy humans, MPS is more sensitive (varying 4–5 times more than MPB) to changes in protein feeding and loading rendering it the primary locus determining gains in muscle mass. Performing resistance exercise (RE) followed by the consumption of protein results in an augmentation of MPS and, over time, can lead to muscle hypertrophy. The magnitude of the RE-induced increase in MPS is dictated by a variety of factors including: the dose of protein, source of protein, and possibly the distribution and timing of post-exercise protein ingestion. In addition, RE variables such as frequency of sessions, time under tension, volume, and training status play roles in regulating MPS. This review provides a brief overview of our current understanding of how RE and protein ingestion can influence gains in skeletal muscle mass in young, healthy individuals. It is the goal of this review to provide nutritional recommendations for optimal skeletal muscle adaptation. Specifically, we will focus on how the manipulation of protein intake during the recovery period following RE augments the adaptive response.
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Affiliation(s)
- Robert W Morton
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University Hamilton, ON, Canada
| | - Chris McGlory
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University Hamilton, ON, Canada
| | - Stuart M Phillips
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University Hamilton, ON, Canada
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23
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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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Abstract
Dietary protein ingestion following exercise increases muscle protein synthesis rates, stimulates net muscle protein accretion, and facilitates the skeletal muscle adaptive response to prolonged exercise training. Furthermore, recent studies show that protein ingestion before and during exercise also increases muscle protein synthesis rates during resistance- and endurance-type exercise. Therefore, protein ingestion before and during prolonged exercise may represent an effective dietary strategy to enhance the skeletal muscle adaptive response to each exercise session by extending the window of opportunity during which the muscle protein synthetic response is facilitated. Protein ingestion during exercise has also been suggested to improve performance capacity acutely. However, recent studies investigating the impact of protein ingestion during exercise on time trial performance, as opposed to time to exhaustion, do not report ergogenic benefits of protein ingestion. Therefore, it is concluded that protein ingestion with carbohydrate during exercise does not further improve exercise performance when compared with the ingestion of ample amounts of carbohydrate only.
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Affiliation(s)
- Luc J C van Loon
- Department of Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre+, PO Box 616, 6200 MD, Maastricht, The Netherlands,
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Ogasawara R, Sato K, Matsutani K, Nakazato K, Fujita S. The order of concurrent endurance and resistance exercise modifies mTOR signaling and protein synthesis in rat skeletal muscle. Am J Physiol Endocrinol Metab 2014; 306:E1155-62. [PMID: 24691029 DOI: 10.1152/ajpendo.00647.2013] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Concurrent training, a combination of endurance (EE) and resistance exercise (RE) performed in succession, may compromise the muscle hypertrophic adaptations induced by RE alone. However, little is known about the molecular signaling interactions underlying the changes in skeletal muscle adaptation during concurrent training. Here, we used an animal model to investigate whether EE before or after RE affects the molecular signaling associated with muscle protein synthesis, specifically the interaction between RE-induced mammalian target of rapamycin complex 1 (mTORC1) signaling and EE-induced AMP-activated protein kinase (AMPK) signaling. Male Sprague-Dawley rats were divided into five groups: an EE group (treadmill, 25 m/min, 60 min), an RE group (maximum isometric contraction via percutaneous electrical stimulation for 3 × 10 s, 5 sets), an EE before RE group, an EE after RE group, and a nonexercise control group. Phosphorylation of p70S6K, a marker of mTORC1 activity, was significantly increased 3 h after RE in both the EE before RE and EE after RE groups, but the increase was smaller in latter. Furthermore, protein synthesis was greatly increased 6 h after RE in the EE before RE group. Increases in the phosphorylation of AMPK and Raptor were observed only in the EE after RE group. Akt and mTOR phosphorylation were increased in both groups, with no between-group differences. Our results suggest that the last bout of exercise dictates the molecular responses and that mTORC1 signaling induced by any prior bout of RE may be downregulated by a subsequent bout of EE.
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Affiliation(s)
- Riki Ogasawara
- Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan; The Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Shiga, Japan;
| | - Koji Sato
- Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan; Ritsumeikan Global Innovation Research Organization, Ritsumeikan University, Kusatsu, Shiga, Japan; and
| | - Kenji Matsutani
- Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Koichi Nakazato
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Satoshi Fujita
- Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
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26
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Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr 2014; 11:20. [PMID: 24864135 PMCID: PMC4033492 DOI: 10.1186/1550-2783-11-20] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Accepted: 04/29/2014] [Indexed: 12/19/2022] Open
Abstract
The popularity of natural bodybuilding is increasing; however, evidence-based recommendations for it are lacking. This paper reviewed the scientific literature relevant to competition preparation on nutrition and supplementation, resulting in the following recommendations. Caloric intake should be set at a level that results in bodyweight losses of approximately 0.5 to 1%/wk to maximize muscle retention. Within this caloric intake, most but not all bodybuilders will respond best to consuming 2.3-3.1 g/kg of lean body mass per day of protein, 15-30% of calories from fat, and the reminder of calories from carbohydrate. Eating three to six meals per day with a meal containing 0.4-0.5 g/kg bodyweight of protein prior and subsequent to resistance training likely maximizes any theoretical benefits of nutrient timing and frequency. However, alterations in nutrient timing and frequency appear to have little effect on fat loss or lean mass retention. Among popular supplements, creatine monohydrate, caffeine and beta-alanine appear to have beneficial effects relevant to contest preparation, however others do not or warrant further study. The practice of dehydration and electrolyte manipulation in the final days and hours prior to competition can be dangerous, and may not improve appearance. Increasing carbohydrate intake at the end of preparation has a theoretical rationale to improve appearance, however it is understudied. Thus, if carbohydrate loading is pursued it should be practiced prior to competition and its benefit assessed individually. Finally, competitors should be aware of the increased risk of developing eating and body image disorders in aesthetic sport and therefore should have access to the appropriate mental health professionals.
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Affiliation(s)
- Eric R Helms
- Sport Performance Research in New Zealand (SPRINZ) at AUT Millennium Institute, AUT University, 17 Antares Place, Mairangi Bay, Auckland 0632, New Zealand
| | | | - Peter J Fitschen
- Division of Nutritional Sciences, University of Illinois, Urbana, IL, USA
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Matsumoto T, Nakamura K, Matsumoto H, Sakai R, Kuwahara T, Kadota Y, Kitaura Y, Sato J, Shimomura Y. Bolus ingestion of individual branched-chain amino acids alters plasma amino acid profiles in young healthy men. SPRINGERPLUS 2014; 3:35. [PMID: 25674427 PMCID: PMC4320164 DOI: 10.1186/2193-1801-3-35] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 12/26/2013] [Indexed: 12/17/2022]
Abstract
Physiological conditions in humans affect plasma amino acid profiles that might have potential for medical use. Because the branched-chain amino acids (BCAAs) leucine, isoleucine and valine are used as medicines and supplements, we investigated the acute effects of individual BCAAs (10-90 mg/kg body weight) or mixed BCAAs ingested as a bolus on plasma amino acid profiles in young healthy men. Plasma leucine levels rapidly increased and peaked around 30 min after leucine ingestion. Concentrations of plasma isoleucine, valine and phenylalanine subsequently decreased after ingestion, and those of methionine and tyrosine tended to decrease. The effects of ingested leucine on other plasma amino acids were biphasic, being higher at lower doses (10-20 mg/kg body weight). Isoleucine or valine intake also caused corresponding plasma amino acid concentrations to rapidly elevate, and peaks at 30-40 min after ingestion were much higher than that of plasma leucine after leucine ingestion. However, the increase in plasma isoleucine and valine concentrations essentially did not affect those of other plasma amino acids. The rate of decline among peak plasma BCAA concentrations was the highest for leucine, followed by isoleucine and valine. Oral mixed BCAAs promoted the decline in plasma isoleucine and valine concentrations. These results suggest that plasma leucine is a regulator of the plasma concentrations of BCAAs, methionine and aromatic amino acids.
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Affiliation(s)
- Takuya Matsumoto
- Department of General Medicine/Family and Community Medicine, Nagoya University Graduate School of Medicine, Nagoya, 466-8560 Japan
| | - Koichi Nakamura
- Laboratory of Nutritional Biochemistry, Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601 Japan
| | - Hideki Matsumoto
- Institute for Innovation, Ajinomoto Co., Inc., Kawasaki, 210-8681 Japan
| | - Ryosei Sakai
- Institute for Innovation, Ajinomoto Co., Inc., Kawasaki, 210-8681 Japan
| | - Tomomi Kuwahara
- Institute for Innovation, Ajinomoto Co., Inc., Kawasaki, 210-8681 Japan
| | - Yoshihiro Kadota
- Laboratory of Nutritional Biochemistry, Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601 Japan
| | - Yasuyuki Kitaura
- Laboratory of Nutritional Biochemistry, Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601 Japan
| | - Juichi Sato
- Department of General Medicine/Family and Community Medicine, Nagoya University Graduate School of Medicine, Nagoya, 466-8560 Japan
| | - Yoshiharu Shimomura
- Laboratory of Nutritional Biochemistry, Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601 Japan
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Guimarães-Ferreira L, Cholewa JM, Naimo MA, Zhi XIA, Magagnin D, de Sá RBDP, Streck EL, Teixeira TDS, Zanchi NE. Synergistic effects of resistance training and protein intake: practical aspects. Nutrition 2014; 30:1097-103. [PMID: 24751198 DOI: 10.1016/j.nut.2013.12.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 12/19/2013] [Accepted: 12/24/2013] [Indexed: 12/27/2022]
Abstract
Resistance training is a potent stimulus to increase skeletal muscle mass. The muscle protein accretion process depends on a robust synergistic action between protein intake and overload. The intake of protein after resistance training increases plasma amino acids, which results in the activation of signaling molecules leading to increased muscle protein synthesis (MPS) and muscle hypertrophy. Although both essential and non-essential amino acids are necessary for hypertrophy, the intake of free L-leucine or high-leucine whole proteins has been specifically shown to increase the initiation of translation that is essential for elevated MPS. The literature supports the use of protein intake following resistance-training sessions to enhance MPS; however, less understood are the effects of different protein sources and timing protocols on MPS. The sum of the adaptions from each individual training session is essential to muscle hypertrophy, and thus highlights the importance of an optimal supplementation protocol. The aim of this review is to present recent findings reported in the literature and to discuss the practical application of these results. In that light, new speculations and questions will arise that may direct future investigations. The information and recommendations generated in this review should be of benefit to clinical dietitians as well as those engaged in sports.
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Affiliation(s)
- Lucas Guimarães-Ferreira
- Laboratory of Experimental Physiology and Biochemistry, Center of Physical Education and Sports, Federal University of Espirito Santo, Vitória/ES, Brazil
| | - Jason Michael Cholewa
- Department of Kinesiology Recreation and Sport Studies, Coastal Carolina University, Conway, South Carolina, USA
| | - Marshall Alan Naimo
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
| | - X I A Zhi
- Exercise Physiology Laboratory, Department of Exercise Physiology, Beijing Sport University, Beijing, PR China; Exercise Physiology and Biochemistry Laboratory, College of Physical Education, Jinggangshan University, Ji'an, Jiangxi, PR China
| | - Daiane Magagnin
- Postgraduate Program in Health Sciences, Health Sciences Unit, Universidade do Extremo Sul Catarinense, Criciúma/SC, Brazil
| | - Rafaele Bis Dal Ponte de Sá
- Postgraduate Program in Health Sciences, Health Sciences Unit, Universidade do Extremo Sul Catarinense, Criciúma/SC, Brazil
| | - Emilio Luiz Streck
- Postgraduate Program in Health Sciences, Health Sciences Unit, Universidade do Extremo Sul Catarinense, Criciúma/SC, Brazil
| | - Tamiris da Silva Teixeira
- Postgraduate Program in Health Sciences, Health Sciences Unit, Universidade do Extremo Sul Catarinense, Criciúma/SC, Brazil
| | - Nelo Eidy Zanchi
- Postgraduate Program in Health Sciences, Health Sciences Unit, Universidade do Extremo Sul Catarinense, Criciúma/SC, Brazil.
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Ferreira MP, Li R, Cooke M, Kreider RB, Willoughby DS. Periexercise coingestion of branched-chain amino acids and carbohydrate in men does not preferentially augment resistance exercise-induced increases in phosphatidylinositol 3 kinase/protein kinase B-mammalian target of rapamycin pathway markers indicative of muscle protein synthesis. Nutr Res 2014; 34:191-8. [PMID: 24655485 DOI: 10.1016/j.nutres.2013.12.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 12/19/2013] [Accepted: 12/30/2013] [Indexed: 01/18/2023]
Abstract
The effects of a single bout of resistance exercise (RE) in conjunction with periexercise branched-chain amino acid (BCAA) and carbohydrate (CHO) ingestion on skeletal muscle signaling markers indicative of muscle protein synthesis were determined. It was hypothesized that CHO + BCAA would elicit a more profound effect on these signaling markers compared with CHO. Twenty-seven males were randomly assigned to CHO, CHO + BCAA, or placebo (PLC) groups. Four sets of leg presses and leg extensions were performed at 80% 1 repetition maximum. Supplements were ingested 30 minutes and immediately before and after RE. Venous blood and muscle biopsy samples were obtained immediately before supplement ingestion and 0.5, 2, and 6 hours after RE. Serum insulin and glucose and phosphorylated levels of muscle insulin receptor substrate 1 (IRS-1), protein kinase B, mammalian target of rapamycin, phosphorylated 70S6 kinase, and 4E binding protein 1 were assessed. Data were analyzed by 2-way repeated-measures analysis of variance. Significant group × time interactions were observed for glucose and insulin (P < .05) showing that CHO and CHO + BCAA were significantly greater than PLC. Significant time main effects were observed for IRS-1 (P = .001), protein kinase B (P = .031), mammalian target of rapamycin (P = .003), and phosphorylated 70S6 kinase (P = .001). Carbohydrate and CHO + BCAA supplementation significantly increased IRS-1 compared with PLC (P = .002). However, periexercise coingestion of CHO and BCAA did not augment RE-induced increases in skeletal muscle signaling markers indicative of muscle protein synthesis when compared with CHO.
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Affiliation(s)
- Maria Pontes Ferreira
- Department of Nutrition and Food Science, Wayne State University, Detroit, MI 48202, USA
| | - Rui Li
- Department of Health Sciences, Northeastern University, Boston, MA 02115, USA
| | - Matthew Cooke
- College of Health and Biomedicine, Victoria University, Melbourne, VIC, 8001, Australia
| | - Richard B Kreider
- Department of Health and Kinesiology, Texas A&M University, College Station, TX 78743, USA
| | - Darryn S Willoughby
- Department of Health, Human Performance, and Recreation, Baylor University, Waco, TX 76798, USA.
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30
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Adams GR, Bamman MM. Characterization and regulation of mechanical loading-induced compensatory muscle hypertrophy. Compr Physiol 2013; 2:2829-70. [PMID: 23720267 DOI: 10.1002/cphy.c110066] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In mammalian systems, skeletal muscle exists in a dynamic state that monitors and regulates the physiological investment in muscle size to meet the current level of functional demand. This review attempts to consolidate current knowledge concerning development of the compensatory hypertrophy that occurs in response to a sustained increase in the mechanical loading of skeletal muscle. Topics covered include: defining and measuring compensatory hypertrophy, experimental models, loading stimulus parameters, acute responses to increased loading, hyperplasia, myofiber-type adaptations, the involvement of satellite cells, mRNA translational control, mechanotransduction, and endocrinology. The authors conclude with their impressions of current knowledge gaps in the field that are ripe for future study.
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Affiliation(s)
- Gregory R Adams
- Department of Physiology and Biophysics, University of California Irvine, Irvine, California, USA.
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31
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Dreyer HC, Strycker LA, Senesac HA, Hocker AD, Smolkowski K, Shah SN, Jewett BA. Essential amino acid supplementation in patients following total knee arthroplasty. J Clin Invest 2013; 123:4654-66. [PMID: 24135139 DOI: 10.1172/jci70160] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 09/03/2013] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND By the year 2030, 3.48 million older U.S. adults are projected to undergo total knee arthroplasty (TKA). Following this surgery, considerable muscle atrophy occurs, resulting in decreased strength and impaired functional mobility. Essential amino acids (EAAs) have been shown to attenuate muscle loss during periods of reduced activity and may be beneficial for TKA patients. METHODS We used a double-blind, placebo-controlled, randomized clinical trial with 28 older adults undergoing TKA. Patients were randomized to ingest either 20 g of EAAs (n = 16) or placebo (n = 12) twice daily between meals for 1 week before and 2 weeks after TKA. At baseline, 2 weeks, and 6 weeks after TKA, an MRI was performed to determine mid-thigh muscle and adipose tissue volume. Muscle strength and functional mobility were also measured at these times. RESULTS TKA patients receiving placebo exhibited greater quadriceps muscle atrophy, with a -14.3 ± 3.6% change from baseline to 2 weeks after surgery compared with -3.4 ± 3.1% for the EAA group (F = 5.16, P = 0.036) and a -18.4 ± 2.3% change from baseline to 6 weeks after surgery for placebo versus -6.2 ± 2.2% for the EAA group (F = 14.14, P = 0.001). EAAs also attenuated atrophy in the nonoperated quadriceps and in the hamstring and adductor muscles of both extremities. The EAA group performed better at 2 and 6 weeks after surgery on functional mobility tests (all P < 0.05). Change in quadriceps muscle atrophy was significantly associated with change in functional mobility (F = 5.78, P = 0.021). CONCLUSION EAA treatment attenuated muscle atrophy and accelerated the return of functional mobility in older adults following TKA. TRIAL REGISTRATION Clinicaltrials.gov NCT00760383.
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Abstract
As the incidence rate of lifestyle-related chronic conditions such as cardiovascular disease, obesity, and type 2 diabetes continues to increase, the importance of regular exercise and a healthy diet for improving or maintaining good health is critical. Exercise training is known to improve fitness and many health risk factors, as well as to improve the performance of competitive athletes. It has become increasingly clear, however, that nutrient intake before, during, and after exercise sessions has a powerful influence on the adaptive response to the exercise stimuli. In this review, the science behind nutrient timing will be discussed as it relates to exercise performance, recovery, and training adaptation. Evidence will be provided that validates intake of appropriate nutrients before, during, and immediately after exercise not only to improve exercise performance but also to maximize the training response. Ultimately, the combined response to exercise and proper nutrient intake leads to not only better performance in athletes but also greater health benefits for all exercisers.
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Affiliation(s)
- John L. Ivy
- Exercise Physiology and Metabolism Laboratory, Department of Kinesiology and Health Education, University of Texas at Austin, Austin, Texas (JLI)
- Integrative Physiology Laboratory, Department of Biology, Hamline University, Saint Paul, Minnesota (LMFS)
| | - Lisa M. Ferguson-Stegall
- Exercise Physiology and Metabolism Laboratory, Department of Kinesiology and Health Education, University of Texas at Austin, Austin, Texas (JLI)
- Integrative Physiology Laboratory, Department of Biology, Hamline University, Saint Paul, Minnesota (LMFS)
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33
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Murakami T, Yoshinaga M. Induction of amino acid transporters expression by endurance exercise in rat skeletal muscle. Biochem Biophys Res Commun 2013; 439:449-52. [PMID: 24016666 DOI: 10.1016/j.bbrc.2013.08.094] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 08/29/2013] [Indexed: 12/21/2022]
Abstract
We here investigated whether an acute bout of endurance exercise would induce the expression of amino acid transporters that regulate leucine transport across plasma and lysosomal membranes in rat skeletal muscle. Rats ran on a motor-driven treadmill at a speed of 28 m/min for 90 min. Immediately after the exercise, we observed that expression of mRNAs encoding L-type amino acid transporter 1 (LAT1) and CD98 was induced in the gastrocnemius, soleus, and extensor digitorum longus (EDL) muscles. Sodium-coupled neutral amino acid transporter 2 (SNAT2) mRNA was also induced by the exercise in those three muscles. Expression of proton-assisted amino acid transporter 1 (PAT1) mRNA was slightly but not significantly induced by a single bout of exercise in soleus and EDL muscles. Exercise-induced mRNA expression of these amino acid transporters appeared to be attenuated by repeated bouts of the exercise. These results suggested that the expression of amino acid transporters for leucine may be induced in response to an increase in the requirement for this amino acid in the cells of working skeletal muscles.
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Affiliation(s)
- Taro Murakami
- Department of Nutrition, Shigakkan University, 55 Nakoyama, Yokone-Machi, Ohbu 474-8651, Japan.
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34
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Reidy PT, Walker DK, Dickinson JM, Gundermann DM, Drummond MJ, Timmerman KL, Fry CS, Borack MS, Cope MB, Mukherjea R, Jennings K, Volpi E, Rasmussen BB. Protein blend ingestion following resistance exercise promotes human muscle protein synthesis. J Nutr 2013; 143:410-6. [PMID: 23343671 PMCID: PMC3738242 DOI: 10.3945/jn.112.168021] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
High-quality proteins such as soy, whey, and casein are all capable of promoting muscle protein synthesis postexercise by activating the mammalian target of rapamycin (mTORC1) signaling pathway. We hypothesized that a protein blend of soy and dairy proteins would capitalize on the unique properties of each individual protein and allow for optimal delivery of amino acids to prolong the fractional synthetic rate (FSR) following resistance exercise (RE). In this double-blind, randomized, clinical trial, 19 young adults were studied before and after ingestion of ∼19 g of protein blend (PB) or ∼18 g whey protein (WP) consumed 1 h after high-intensity leg RE. We examined mixed-muscle protein FSR by stable isotopic methods and mTORC1 signaling with western blotting. Muscle biopsies from the vastus lateralis were collected at rest (before RE) and at 3 postexercise time points during an early (0-2 h) and late (2-4 h) postingestion period. WP ingestion resulted in higher and earlier amplitude of blood branched-chain amino acid (BCAA) concentrations. PB ingestion created a lower initial rise in blood BCAA but sustained elevated levels of blood amino acids later into recovery (P < 0.05). Postexercise FSR increased equivalently in both groups during the early period (WP, 0.078 ± 0.009%; PB, 0.088 ± 0.007%); however, FSR remained elevated only in the PB group during the late period (WP, 0.074 ± 0.010%; PB, 0.087 ± 0.003%) (P < 0.05). mTORC1 signaling similarly increased between groups, except for no increase in S6K1 phosphorylation in the WP group at 5 h postexercise (P < 0.05). We conclude that a soy-dairy PB ingested following exercise is capable of prolonging blood aminoacidemia, mTORC1 signaling, and protein synthesis in human skeletal muscle and is an effective postexercise nutritional supplement.
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Affiliation(s)
- Paul T. Reidy
- Division of Rehabilitation Sciences,Department of Nutrition and Metabolism
| | - Dillon K. Walker
- Division of Rehabilitation Sciences,Department of Nutrition and Metabolism
| | - Jared M. Dickinson
- Division of Rehabilitation Sciences,Department of Nutrition and Metabolism
| | | | | | | | | | - Michael S. Borack
- Division of Rehabilitation Sciences,Department of Nutrition and Metabolism
| | | | | | - Kristofer Jennings
- Department of Preventative Medicine and Community Health, University of Texas Medical Branch, Galveston, TX; and
| | - Elena Volpi
- Department of Internal Medicine/Geriatrics,Sealy Center on Aging, and
| | - Blake B. Rasmussen
- Division of Rehabilitation Sciences,Department of Nutrition and Metabolism,Sealy Center on Aging, and,To whom correspondence should be addressed. E-mail:
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35
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Breen L, Phillips SM. Interactions between exercise and nutrition to prevent muscle waste during ageing. Br J Clin Pharmacol 2013; 75:708-15. [PMID: 22957963 PMCID: PMC3575937 DOI: 10.1111/j.1365-2125.2012.04456.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2012] [Accepted: 08/27/2012] [Indexed: 12/19/2022] Open
Abstract
The underlying cause of sarcopenia and dynapenia (age-related strength loss) are not fully elucidated, but may be the result, or combination, of alterations in lifestyle or inflammatory and endocrine profiles. What is clear is that functional ability is limited and mortality risk is elevated. Mechanistically, muscle atrophy is the result of the prolonged periods of net negative muscle protein balance, brought about by the imbalance between muscle protein synthesis (MPS) and muscle protein breakdown (MPB). Contractile loading of skeletal muscle, through resistive-type exercise and amino acid ingestion both act as a strong stimulus for MPS and, when combined, can induce a net positive protein balance and muscle hypertrophy. Given that MPS in older muscles displays a blunted response to anabolic stimuli compared with the young, the combined effect and manipulation of contractile and nutrient interventions to optimize muscle anabolism could be extremely important for counteracting sarcopenia. Specifically, the dose, absorption kinetics, leucine content, but less-so the timing of ingestion, are important determinants of the mRNA translational signalling response regulating MPS. In addition, resistance exercise-induced rates of MPS and hypertrophy appear to be dependent on exercise volume (to achieve maximal muscle fibre recruitment), as opposed to the absolute load that is lifted. A number of recent studies in young adults lend weight to this notion by showing that contraction can be manipulated; allowing low load weight lifting to effectively stimulate rates of MPS to a level comparable with traditional high loads, a finding with important implications for older adults interested in undertaking resistance exercise.
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Affiliation(s)
- Leigh Breen
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
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36
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Aragon AA, Schoenfeld BJ. Nutrient timing revisited: is there a post-exercise anabolic window? J Int Soc Sports Nutr 2013; 10:5. [PMID: 23360586 PMCID: PMC3577439 DOI: 10.1186/1550-2783-10-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 01/25/2013] [Indexed: 12/19/2022] Open
Abstract
Nutrient timing is a popular nutritional strategy that involves the consumption of combinations of nutrients--primarily protein and carbohydrate--in and around an exercise session. Some have claimed that this approach can produce dramatic improvements in body composition. It has even been postulated that the timing of nutritional consumption may be more important than the absolute daily intake of nutrients. The post-exercise period is widely considered the most critical part of nutrient timing. Theoretically, consuming the proper ratio of nutrients during this time not only initiates the rebuilding of damaged muscle tissue and restoration of energy reserves, but it does so in a supercompensated fashion that enhances both body composition and exercise performance. Several researchers have made reference to an anabolic “window of opportunity” whereby a limited time exists after training to optimize training-related muscular adaptations. However, the importance - and even the existence - of a post-exercise ‘window’ can vary according to a number of factors. Not only is nutrient timing research open to question in terms of applicability, but recent evidence has directly challenged the classical view of the relevance of post-exercise nutritional intake with respect to anabolism. Therefore, the purpose of this paper will be twofold: 1) to review the existing literature on the effects of nutrient timing with respect to post-exercise muscular adaptations, and; 2) to draw relevant conclusions that allow practical, evidence-based nutritional recommendations to be made for maximizing the anabolic response to exercise.
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37
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Hida A, Hasegawa Y, Mekata Y, Usuda M, Masuda Y, Kawano H, Kawano Y. Effects of egg white protein supplementation on muscle strength and serum free amino acid concentrations. Nutrients 2012. [PMID: 23201768 PMCID: PMC3497008 DOI: 10.3390/nu4101504] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The aim of this study was to evaluate the effects of egg white protein compared to carbohydrate intake prior to exercise on fat free mass (FFM), one repetition maximum (1RM) muscle strength and blood biochemistry in female athletes. Thirty healthy female collegiate athletes were recruited for this study and matched by sport type, body fat percentage and 1RM leg curl muscle strength. Participants were randomly divided into two groups: protein group (15.0 g egg white protein; 75 kcal) and carbohydrate group (17.5 g maltodextrin, 78 kcal). Supplements were administered daily at the same time in a double-blind manner prior to training during an 8-week period. Measurements were performed before and after the 8-week regimen. The mean dietary energy intake did not change throughout the study period. FFM and 1RM assessments (i.e., leg curl, leg extension, squat, and bench press) increased in both groups. Furthermore, serum urea and serum citrulline levels after the 8-week regimen increased significantly only in the protein group. Our findings indicated that compared to the carbohydrate supplement, the protein supplement was associated with some changes in protein metabolites but not with changes in body composition or muscle strength.
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Affiliation(s)
- Azumi Hida
- Department of Nutritional Science, Faculty of Applied Bio-Science, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya, Tokyo 156-8502, Japan; (A.H.); (Y.H.)
| | - Yuko Hasegawa
- Department of Nutritional Science, Faculty of Applied Bio-Science, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya, Tokyo 156-8502, Japan; (A.H.); (Y.H.)
| | - Yuko Mekata
- Faculty of Health and Nutrition, Bunkyo University, 1100 Gyouya, Chigasaki-City, Kanagawa 253-8550, Japan;
| | - Mika Usuda
- Institute of Technology R&D Division, Kewpie Corporation, 5-13-1 Sumiyoshi-cho, Fuchu-City, Tokyo 183-0034, Japan; (M.U.); (Y.M.)
| | - Yasunobu Masuda
- Institute of Technology R&D Division, Kewpie Corporation, 5-13-1 Sumiyoshi-cho, Fuchu-City, Tokyo 183-0034, Japan; (M.U.); (Y.M.)
| | - Hitoshi Kawano
- Tokyo Metropolitan Institute for Neuroscience, 2-1-6 Kamikitazawa, Setagaya, Tokyo 156-8506, Japan;
| | - Yukari Kawano
- Department of Nutritional Science, Faculty of Applied Bio-Science, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya, Tokyo 156-8502, Japan; (A.H.); (Y.H.)
- Author to whom correspondence should be addressed; ; Tel./Fax: +81-3-5477-2453
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BURKE LOUISEM, HAWLEY JOHNA, ROSS MEGANL, MOORE DANIELR, PHILLIPS STUARTM, SLATER GARYR, STELLINGWERFF TRENT, TIPTON KEVIND, GARNHAM ANDREWP, COFFEY VERNONG. Preexercise Aminoacidemia and Muscle Protein Synthesis after Resistance Exercise. Med Sci Sports Exerc 2012; 44:1968-77. [DOI: 10.1249/mss.0b013e31825d28fa] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Reduced AMPK-ACC and mTOR signaling in muscle from older men, and effect of resistance exercise. Mech Ageing Dev 2012; 133:655-64. [PMID: 23000302 DOI: 10.1016/j.mad.2012.09.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 08/20/2012] [Accepted: 09/07/2012] [Indexed: 11/20/2022]
Abstract
AMP-activated protein kinase (AMPK) is a key energy-sensitive enzyme that controls numerous metabolic and cellular processes. Mammalian target of rapamycin (mTOR) is another energy/nutrient-sensitive kinase that controls protein synthesis and cell growth. In this study we determined whether older versus younger men have alterations in the AMPK and mTOR pathways in skeletal muscle, and examined the effect of a long term resistance type exercise training program on these signaling intermediaries. Older men had decreased AMPKα2 activity and lower phosphorylation of AMPK and its downstream signaling substrate acetyl-CoA carboxylase (ACC). mTOR phosphylation also was reduced in muscle from older men. Exercise training increased AMPKα1 activity in older men, however, AMPKα2 activity, and the phosphorylation of AMPK, ACC and mTOR, were not affected. In conclusion, older men have alterations in the AMPK-ACC and mTOR pathways in muscle. In addition, prolonged resistance type exercise training induces an isoform-selective up regulation of AMPK activity.
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40
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Phillips SM, Van Loon LJC. Dietary protein for athletes: from requirements to optimum adaptation. J Sports Sci 2012; 29 Suppl 1:S29-38. [PMID: 22150425 DOI: 10.1080/02640414.2011.619204] [Citation(s) in RCA: 231] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Opinion on the role of protein in promoting athletic performance is divided along the lines of how much aerobic-based versus resistance-based activity the athlete undertakes. Athletes seeking to gain muscle mass and strength are likely to consume higher amounts of dietary protein than their endurance-trained counterparts. The main belief behind the large quantities of dietary protein consumption in resistance-trained athletes is that it is needed to generate more muscle protein. Athletes may require protein for more than just alleviation of the risk for deficiency, inherent in the dietary guidelines, but also to aid in an elevated level of functioning and possibly adaptation to the exercise stimulus. It does appear, however, that there is a good rationale for recommending to athletes protein intakes that are higher than the RDA. Our consensus opinion is that leucine, and possibly the other branched-chain amino acids, occupy a position of prominence in stimulating muscle protein synthesis; that protein intakes in the range of 1.3-1.8 g · kg(-1) · day(-1) consumed as 3-4 isonitrogenous meals will maximize muscle protein synthesis. These recommendations may also be dependent on training status: experienced athletes would require less, while more protein should be consumed during periods of high frequency/intensity training. Elevated protein consumption, as high as 1.8-2.0 g · kg(-1) · day(-1) depending on the caloric deficit, may be advantageous in preventing lean mass losses during periods of energy restriction to promote fat loss.
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Affiliation(s)
- Stuart M Phillips
- Department of Kinesiology, Exercise Metabolism Research Group, McMaster University, Hamilton, Ontario, Canada.
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41
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Churchward-Venne TA, Burd NA, Phillips SM. Nutritional regulation of muscle protein synthesis with resistance exercise: strategies to enhance anabolism. Nutr Metab (Lond) 2012; 9:40. [PMID: 22594765 PMCID: PMC3464665 DOI: 10.1186/1743-7075-9-40] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 05/17/2012] [Indexed: 01/16/2023] Open
Abstract
Provision of dietary amino acids increases skeletal muscle protein synthesis (MPS), an effect that is enhanced by prior resistance exercise. As a fundamentally necessary process in the enhancement of muscle mass, strategies to enhance rates of MPS would be beneficial in the development of interventions aimed at increasing skeletal muscle mass particularly when combined with chronic resistance exercise. The purpose of this review article is to provide an update on current findings regarding the nutritional regulation of MPS and highlight nutrition based strategies that may serve to maximize skeletal muscle protein anabolism with resistance exercise. Such factors include timing of protein intake, dietary protein type, the role of leucine as a key anabolic amino acid, and the impact of other macronutrients (i.e. carbohydrate) on the regulation of MPS after resistance exercise. We contend that nutritional strategies that serve to maximally stimulate MPS may be useful in the development of nutrition and exercise based interventions aimed at enhancing skeletal muscle mass which may be of interest to elderly populations and to athletes.
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Affiliation(s)
| | - Nicholas A Burd
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Stuart M Phillips
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
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Abstract
PURPOSE OF REVIEW The rapid muscle loss that accompanies varying diseased states (cachexia) is due to an imbalance between muscle protein synthesis (MPS) and muscle protein breakdown In the current review, we will discuss and summarize recent evidence in order to provide practical recommendations on exercise and nutrient interventions for cachectic populations. RECENT FINDINGS Resistance exercise is a potent stimulus for MPS, but cachexia patients may not be best placed to lift the heavy loads that, it was previously assumed, were a prerequisite for muscle hypertrophy. However, recent evidence from our lab shows that lower loads can effectively stimulate MPS and lead to hypertrophy. Protein ingestion potentiates resistance exercise-induced rates of MPS. The source and dose of the ingested protein are important to consider when attempting to maximize postresistance exercise MPS. Specifically, rapidly digested, leucine-rich protein sources may stimulate greater postexercise rates of MPS than other protein sources, as leucine acts as a key anabolic signal for mRNA translation. Furthermore, individuals undergoing relatively slow muscle atrophy (i.e., in sarcopenic elderly) respond positively to larger doses (40 g) of amino acids following exercise, whereas the response appears to plateau after moderate doses (20 g) in healthy, young adults. SUMMARY Emerging evidence shows that manipulating traditional exercise loading and nutrient strategies may ameliorate cachexia.
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Affiliation(s)
- Leigh Breen
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
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43
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Walker DK, Dickinson JM, Timmerman KL, Drummond MJ, Reidy PT, Fry CS, Gundermann DM, Rasmussen BB. Exercise, amino acids, and aging in the control of human muscle protein synthesis. Med Sci Sports Exerc 2012; 43:2249-58. [PMID: 21606874 DOI: 10.1249/mss.0b013e318223b037] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In this review, we discuss recent research in the field of human skeletal muscle protein metabolism characterizing the acute regulation of mammalian target of rapamycin complex (mTORC) 1 signaling and muscle protein synthesis (MPS) by exercise, amino acid nutrition, and aging. Resistance exercise performed in the fasted state stimulates mixed MPS within 1 h after exercise, which can remain elevated for 48 h. We demonstrate that the activation of mTORC1 signaling (and subsequently enhanced translation initiation) is required for the contraction-induced increase in MPS. In comparison, low-intensity blood flow restriction (BFR) exercise stimulates MPS and mTORC1 signaling to an extent similar to traditional, high-intensity resistance exercise. We also show that mTORC1 signaling is required for the essential amino acid (EAA)-induced increase in MPS. Ingestion of EAAs (or protein) shortly after resistance exercise enhances MPS and mTORC1 signaling compared with resistance exercise or EAAs alone. In older adults, the ability of the skeletal muscle to respond to anabolic stimuli is impaired. For example, in response to an acute bout of resistance exercise, older adults are less able to activate mTORC1 or increase MPS during the first 24 h of postexercise recovery. However, BFR exercise can overcome this impairment. Aging is not associated with a reduced response to EAAs provided the EAA content is sufficient. Therefore, we propose that exercise combined with EAA should be effective not only in improving muscle repair and growth in response to training in athletes, but that strategies such as EAA combined with resistance exercise (or BFR exercise) may be very useful as a countermeasure for sarcopenia and other clinical conditions associated with muscle wasting.
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Affiliation(s)
- Dillon K Walker
- Department of Nutrition & Metabolism, University of Texas Medical Branch, Galveston, TX 77555-1144, USA
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44
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Ishii N, Ogasawara R, Kobayashi K, Nakazato K. Roles played by protein metabolism and myogenic progenitor cells in exercise-induced muscle hypertrophy and their relation to resistance training regimens. JOURNAL OF PHYSICAL FITNESS AND SPORTS MEDICINE 2012. [DOI: 10.7600/jpfsm.1.83] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Fry CS, Rasmussen BB. Skeletal muscle protein balance and metabolism in the elderly. Curr Aging Sci 2011; 4:260-8. [PMID: 21529326 PMCID: PMC5096733 DOI: 10.2174/1874609811104030260] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Revised: 05/06/2010] [Accepted: 05/06/2010] [Indexed: 05/30/2023]
Abstract
The loss of lean muscle mass occurring with advancing age is termed sarcopenia. This condition often leads to a concomitant loss of strength, increased frailty and risk of falls and an overall loss of functional independence in the elderly. Muscle protein metabolism is a dynamic process characterized by the balance between the synthesis and breakdown of muscle proteins. A disturbance of this equilibrium can lead to the loss of muscle mass, and a perturbation of muscle protein turnover with aging has been proposed to play a role in the development of sarcopenia. However, basal muscle protein synthesis and breakdown rates do not differ between young and old adults, which has led to the hypothesis that older adults are resistant to anabolic stimuli. In support of this hypothesis, older adults have either no response or a blunted response to nutrients, insulin and resistance exercise, and this anabolic resistance is likely a key factor in the loss of skeletal muscle mass with aging. Recent studies have investigated potential interventions to overcome this anabolic resistance. In particular, combining resistance exercise with essential amino acid supplementation restores the muscle protein anabolic response in older men. The novel rehabilitation technique of performing light resistance exercise during blood flow restriction was also successful in overcoming the anabolic resistance to exercise. Future research is needed to determine whether these novel interventions will be successful in preventing sarcopenia and improving muscle strength and function in older adults.
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Affiliation(s)
- Christopher S. Fry
- Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas, U.S.A
| | - Blake B. Rasmussen
- Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas, U.S.A
- Department of Physical Therapy, University of Texas Medical Branch, Galveston, Texas, U.S.A
- Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas, U.S.A
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46
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Breen L, Phillips SM. Skeletal muscle protein metabolism in the elderly: Interventions to counteract the 'anabolic resistance' of ageing. Nutr Metab (Lond) 2011; 8:68. [PMID: 21975196 PMCID: PMC3201893 DOI: 10.1186/1743-7075-8-68] [Citation(s) in RCA: 316] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Accepted: 10/05/2011] [Indexed: 12/19/2022] Open
Abstract
Age-related muscle wasting (sarcopenia) is accompanied by a loss of strength which can compromise the functional abilities of the elderly. Muscle proteins are in a dynamic equilibrium between their respective rates of synthesis and breakdown. It has been suggested that age-related sarcopenia is due to: i) elevated basal-fasted rates of muscle protein breakdown, ii) a reduction in basal muscle protein synthesis (MPS), or iii) a combination of the two factors. However, basal rates of muscle protein synthesis and breakdown are unchanged with advancing healthy age. Instead, it appears that the muscles of the elderly are resistant to normally robust anabolic stimuli such as amino acids and resistance exercise. Ageing muscle is less sensitive to lower doses of amino acids than the young and may require higher quantities of protein to acutely stimulate equivalent muscle protein synthesis above rest and accrue muscle proteins. With regard to dietary protein recommendations, emerging evidence suggests that the elderly may need to distribute protein intake evenly throughout the day, so as to promote an optimal per meal stimulation of MPS. The branched-chain amino acid leucine is thought to play a central role in mediating mRNA translation for MPS, and the elderly should ensure sufficient leucine is provided with dietary protein intake. With regards to physical activity, lower, than previously realized, intensity high-volume resistance exercise can stimulate a robust muscle protein synthetic response similar to traditional high-intensity low volume training, which may be beneficial for older adults. Resistance exercise combined with amino acid ingestion elicits the greatest anabolic response and may assist elderly in producing a 'youthful' muscle protein synthetic response provided sufficient protein is ingested following exercise.
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Affiliation(s)
- Leigh Breen
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Stuart M Phillips
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
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Gran P, Cameron-Smith D. The actions of exogenous leucine on mTOR signalling and amino acid transporters in human myotubes. BMC PHYSIOLOGY 2011; 11:10. [PMID: 21702994 PMCID: PMC3141572 DOI: 10.1186/1472-6793-11-10] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 06/25/2011] [Indexed: 01/18/2023]
Abstract
Background The branched-chain amino acid (BCAA) leucine has been identified to be a key regulator of skeletal muscle anabolism. Activation of anabolic signalling occurs via the mammalian target of rapamycin (mTOR) through an undefined mechanism. System A and L solute carriers transport essential amino acids across plasma membranes; however it remains unknown whether an exogenous supply of leucine regulates their gene expression. The aim of the present study was to investigate the effects of acute and chronic leucine stimulation of anabolic signalling and specific amino acid transporters, using cultured primary human skeletal muscle cells. Results Human myotubes were treated with leucine, insulin or co-treated with leucine and insulin for 30 min, 3 h or 24 h. Activation of mTOR signalling kinases were examined, together with putative nutrient sensor human vacuolar protein sorting 34 (hVps34) and gene expression of selected amino acid transporters. Phosphorylation of mTOR and p70S6K was transiently increased following leucine exposure, independently to insulin. hVps34 protein expression was also significantly increased. However, genes encoding amino acid transporters were differentially regulated by insulin and not leucine. Conclusions mTOR signalling is transiently activated by leucine within human myotubes independently of insulin stimulation. While this occurred in the absence of changes in gene expression of amino acid transporters, protein expression of hVps34 increased.
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Affiliation(s)
- Petra Gran
- Molecular Nutrition Unit, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, Australia
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48
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Slater G, Phillips SM. Nutrition guidelines for strength sports: sprinting, weightlifting, throwing events, and bodybuilding. J Sports Sci 2011; 29 Suppl 1:S67-77. [PMID: 21660839 DOI: 10.1080/02640414.2011.574722] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Strength and power athletes are primarily interested in enhancing power relative to body weight and thus almost all undertake some form of resistance training. While athletes may periodically attempt to promote skeletal muscle hypertrophy, key nutritional issues are broader than those pertinent to hypertrophy and include an appreciation of the sports supplement industry, the strategic timing of nutrient intake to maximize fuelling and recovery objectives, plus achievement of pre-competition body mass requirements. Total energy and macronutrient intakes of strength-power athletes are generally high but intakes tend to be unremarkable when expressed relative to body mass. Greater insight into optimization of dietary intake to achieve nutrition-related goals would be achieved from assessment of nutrient distribution over the day, especially intake before, during, and after exercise. This information is not readily available on strength-power athletes and research is warranted. There is a general void of scientific investigation relating specifically to this unique group of athletes. Until this is resolved, sports nutrition recommendations for strength-power athletes should be directed at the individual athlete, focusing on their specific nutrition-related goals, with an emphasis on the nutritional support of training.
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Affiliation(s)
- Gary Slater
- Faculty of Science, Health and Education, School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, Queensland, Australia.
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49
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Beelen M, Zorenc A, Pennings B, Senden JM, Kuipers H, van Loon LJC. Impact of protein coingestion on muscle protein synthesis during continuous endurance type exercise. Am J Physiol Endocrinol Metab 2011; 300:E945-54. [PMID: 21364122 DOI: 10.1152/ajpendo.00446.2010] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This study investigates the impact of protein coingestion with carbohydrate on muscle protein synthesis during endurance type exercise. Twelve healthy male cyclists were studied during 2 h of fasted rest followed by 2 h of continuous cycling at 55% W(max). During exercise, subjects received either 1.0 g·kg(-1)·h(-1) carbohydrate (CHO) or 0.8 g·kg(-1)·h(-1) carbohydrate with 0.2 g·kg(-1)·h(-1) protein hydrolysate (CHO+PRO). Continuous intravenous infusions with l-[ring-(13)C(6)]phenylalanine and l-[ring-(2)H(2)]tyrosine were applied, and blood and muscle biopsies were collected to assess whole body protein turnover and muscle protein synthesis rates at rest and during exercise conditions. Protein coingestion stimulated whole body protein synthesis and oxidation rates during exercise by 22 ± 3 and 70 ± 17%, respectively (P < 0.01). Whole body protein breakdown rates did not differ between experiments. As a consequence, whole body net protein balance was slightly negative in CHO and positive in the CHO+PRO treatment (-4.9 ± 0.3 vs. 8.0 ± 0.3 μmol Phe·kg(-1)·h(-1), respectively, P < 0.01). Mixed muscle protein fractional synthetic rates (FSR) were higher during exercise compared with resting conditions (0.058 ± 0.006 vs. 0.035 ± 0.006%/h in CHO and 0.070 ± 0.011 vs. 0.038 ± 0.005%/h in the CHO+PRO treatment, respectively, P < 0.05). FSR during exercise did not differ between experiments (P = 0.46). We conclude that muscle protein synthesis is stimulated during continuous endurance type exercise activities when carbohydrate with or without protein is ingested. Protein coingestion does not further increase muscle protein synthesis rates during continuous endurance type exercise.
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Affiliation(s)
- Milou Beelen
- Department of Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
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Symons TB, Sheffield-Moore M, Mamerow MM, Wolfe RR, Paddon-Jones D. The anabolic response to resistance exercise and a protein-rich meal is not diminished by age. J Nutr Health Aging 2011; 15:376-81. [PMID: 21528164 PMCID: PMC3280506 DOI: 10.1007/s12603-010-0319-z] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVES The synergistic effect of resistance exercise and protein ingestion on muscle protein anabolism in young adults has been well described. However, it is unclear if this relationship is maintained in older adults who are at greater risk of sarcopenic muscle loss. To this end, we sought to determine if the synergistic response to a bout of resistance exercise and a protein-rich lean beef meal was altered by age. SETTING The University of Texas Medical Branch, Clinical Research Center, Galveston, Texas. PARTICIPANTS Healthy young (n=7, 29±3 y) and older (n=7, 67±2 y) adults. DESIGN Mixed muscle fractional synthesis rate (FSR) was calculated during a 3 h post-absorptive/rest period and again during a 5 h period following ingestion of a protein-rich meal (340 g lean beef) and bout of resistance exercise (6 sets of 8 repetitions of isotonic knee extension exercise at 80% one repetition maximum). MEASUREMENTS Venous blood samples and vastus lateralis muscle biopsy samples were obtained during a primed (2.0 µmol/kg) constant infusion (0.08 µmol∙kg(-1)min(-1)) of L- [ring-13C6] phenylalanine. RESULTS Mixed muscle FSR increased by approximately 108% in both young [pre: 0.073±0.008; post: 0.156±0.021(SE) %/h, p<0.001] and older adults (pre: 0.075±0.004; post: 0.152±0.017 %/h, p=0.003) following the meal and resistance exercise bout. CONCLUSION Aging does not diminish the increase in muscle protein synthesis following a high-quality protein rich meal and bout of resistance exercise.
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Affiliation(s)
- T B Symons
- Division of Rehabilitation Sciences, The University of Texas Medical Branch, Galveston, Texas 77555-1144, USA
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