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Margolis LM, Pasiakos SM. Performance nutrition for cold-weather military operations. Int J Circumpolar Health 2023; 82:2192392. [PMID: 36934427 PMCID: PMC10026745 DOI: 10.1080/22423982.2023.2192392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/20/2023] Open
Abstract
.High daily energy expenditure without compensatory increases in energy intake results in severe energy deficits during cold-weather military operations. The severity of energy deficits has been proportionally linked to declines in body mass, negative protein balance, suppression of androgen hormones, increases in systemic inflammation and degraded physical performance. Food availability does not appear to be the predominant factor causing energy deficits; providing additional rations or supplement snack bars does not reduce the severity of the energy deficits. Nutrition interventions that allow greater energy intake could be effective for reducing energy deficits during cold-weather military operations. One potential intervention is to increase energy density (i.e. energy per unit mass of food) by increasing dietary fat. Our laboratory recently reported that self-selected higher energy intakes and reductions in energy deficits were primarily driven by fat intake (r = 0.891, r2 = 0.475), which, of the three macronutrients. Further, soldiers who ate more fat lost less body mass, had lower inflammation, and maintained net protein balance compared to those who ate less fat. These data suggest that consuming high-fat energy-dense foods may be a viable nutritional intervention that mitigates the negative physiological effects of energy deficit and sustains physical performance during cold-weather military operations.
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Affiliation(s)
- Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Stefan M Pasiakos
- Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
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Margolis LM, Pasiakos SM, Howard EE. High-fat ketogenic diets and ketone monoester supplements differentially affect substrate metabolism during aerobic exercise. Am J Physiol Cell Physiol 2023; 325:C1144-C1153. [PMID: 37721006 PMCID: PMC10635661 DOI: 10.1152/ajpcell.00359.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/07/2023] [Accepted: 09/07/2023] [Indexed: 09/19/2023]
Abstract
Chronically adhering to high-fat ketogenic diets or consuming ketone monoester supplements elicits ketosis. Resulting changes in substrate metabolism appear to be drastically different between ketogenic diets and ketone supplements. Consuming a ketogenic diet increases fatty acid oxidation with concomitant decreases in endogenous carbohydrate oxidation. Increased fat oxidation eventually results in an accumulation of circulating ketone bodies, which are metabolites of fatty acids that serve as an alternative source of fuel. Conversely, consuming ketone monoester supplements rapidly increases circulating ketone body concentrations that typically exceed those achieved by adhering to ketogenic diets. Rapid increases in ketone body concentrations with ketone monoester supplementation elicit a negative feedback inhibition that reduces fatty acid mobilization during aerobic exercise. Supplement-derived ketosis appears to have minimal impact on sparing of muscle glycogen or minimizing of carbohydrate oxidation during aerobic exercise. This review will discuss the substrate metabolic and associated aerobic performance responses to ketogenic diets and ketone supplements.
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Affiliation(s)
- Lee M Margolis
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States
| | - Stefan M Pasiakos
- Office of Dietary Supplements, U.S. Department of Health and Human Services, National Institutes of Health, Bethesda, Maryland, United States
| | - Emily E Howard
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States
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Margolis LM, Pasiakos SM. Low carbohydrate availability impairs hypertrophy and anaerobic performance. Curr Opin Clin Nutr Metab Care 2023; 26:347-352. [PMID: 37057671 DOI: 10.1097/mco.0000000000000934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Abstract
PURPOSE OF REVIEW Highlight contemporary evidence examining the effects of carbohydrate restriction on the intracellular regulation of muscle mass and anaerobic performance. RECENT FINDINGS Low carbohydrate diets increase fat oxidation and decrease fat mass. Emerging evidence suggests that dietary carbohydrate restriction increases protein oxidation, thereby limiting essential amino acid availability necessary to stimulate optimal muscle protein synthesis and promote muscle recovery. Low carbohydrate feeding for 24 h increases branched-chain amino acid (BCAA) oxidation and reduces myogenic regulator factor transcription compared to mixed-macronutrient feeding. When carbohydrate restriction is maintained for 8 to 12 weeks, the alterations in anabolic signaling, protein synthesis, and myogenesis likely contribute to limited hypertrophic responses to resistance training. The blunted hypertrophic response to resistance training when carbohydrate availability is low does not affect muscle strength, whereas persistently low muscle glycogen does impair anaerobic output during high-intensity sprint and time to exhaustion tests. SUMMARY Dietary carbohydrate restriction increases BCAA oxidation and impairs muscle hypertrophy and anaerobic performance, suggesting athletes who need to perform high-intensity exercise should consider avoiding dietary strategies that restrict carbohydrate.
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Affiliation(s)
| | - Stefan M Pasiakos
- Performance Divisions, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
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Beckner ME, Thompson L, Radcliffe PN, Cherian R, Wilson M, Barringer N, Margolis LM, Karl JP. Sex differences in body composition and serum metabolome responses to sustained, physical training suggest enhanced fat oxidation in women compared with men. Physiol Genomics 2023; 55:235-247. [PMID: 37012051 DOI: 10.1152/physiolgenomics.00180.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
Abstract
Sex differences in energy metabolism during acute, sub-maximal exercise are well documented. Whether these sex differences influence metabolic and physiologic responses to sustained, physically demanding activities is not well characterized. This study aimed to identify sex differences within changes in the serum metabolome in relation to changes in body composition, physical performance, and circulating markers of endocrine and metabolic status during a 17-day military training exercise. Blood was collected, and body composition and lower-body power measured before and after training on 72 cadets (18 women). Total daily energy expenditure (TDEE) was assessed using doubly labeled water in a subset. TDEE was greater in men (4,085±482kcal/d) than women (2,982±472kcal/d, p<0.001), but not after adjustment for dry lean mass (DLM). Men tended to lose more DLM than women (-0.2[-0.3,-0.1] vs. -0.0[-0.0,0.0] kg, p=0.063, Cohen's d=0.50) and have greater reductions in lower body power (-244[-314,-174] vs. -130[-209,-51] Watts, p=0.085, d=0.49). Reductions in DLM and lower body power were correlated (r=0.325, p=0.006). Women demonstrated greater fat oxidation than men (Δfat mass/DLM: -0.20[-0.24,-0.17] vs. -0.15[-0.17,-0.13] kg, p=0.012, d=0.64). Metabolites within pathways of fatty acid, endocannabinoid, lysophospholipid, phosphatidylcholine, phosphatidylethanolamine, and plasmalogen metabolism increased in women relative to men. Independent of sex, changes in metabolites related to lipid metabolism were inversely associated with changes in body mass and positively associated with changes in endocrine and metabolic status. These data suggest that during sustained military training, women preferentially mobilize fat stores compared with men, which may be beneficial for mitigating loss of lean mass and lower body power.
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Affiliation(s)
- Meaghan E Beckner
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
- Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Lauren Thompson
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Patrick N Radcliffe
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
- Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Rebecca Cherian
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Marques Wilson
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Nicholas Barringer
- Medical Center of Excellence Joint Base San Antonio-Fort Sam, Houston, TX, United States
| | - Lee M Margolis
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - J Philip Karl
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
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Margolis LM, Marlatt KL, Berryman CE, Howard EE, Murphy NE, Carrigan CT, Harris MN, Beyl RA, Ravussin E, Pasiakos SM, Rood JC. Metabolic Adaptations and Substrate Oxidation are Unaffected by Exogenous Testosterone Administration during Energy Deficit in Men. Med Sci Sports Exerc 2023; 55:661-669. [PMID: 36563086 DOI: 10.1249/mss.0000000000003089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
INTRODUCTION/PURPOSE The effects of testosterone on energy and substrate metabolism during energy deficit are unknown. The objective of this study was to determine the effects of weekly testosterone enanthate (TEST; 200 mg·wk -1 ) injections on energy expenditure, energy substrate oxidation, and related gene expression during 28 d of energy deficit compared with placebo (PLA). METHODS After a 14-d energy balance phase, healthy men were randomly assigned to TEST ( n = 24) or PLA ( n = 26) for a 28-d controlled diet- and exercise-induced energy deficit (55% below total energy needs by reducing energy intake and increasing physical activity). Whole-room indirect calorimetry and 24-h urine collections were used to measure energy expenditure and energy substrate oxidation during balance and deficit. Transcriptional regulation of energy and substrate metabolism was assessed using quantitative reverse transcription-polymerase chain reaction from rested/fasted muscle biopsy samples collected during balance and deficit. RESULTS Per protocol design, 24-h energy expenditure increased ( P < 0.05) and energy intake decreased ( P < 0.05) in TEST and PLA during deficit compared with balance. Carbohydrate oxidation decreased ( P < 0.05), whereas protein and fat oxidation increased ( P < 0.05) in TEST and PLA during deficit compared with balance. Change (∆; deficit minus balance) in 24-h energy expenditure was associated with ∆activity factor ( r = 0.595), but not ∆fat-free mass ( r = 0.147). Energy sensing (PRKAB1 and TP53), mitochondria (TFAM and COXIV), fatty acid metabolism (CD36/FAT, FABP, CPT1b, and ACOX1) and storage (FASN), and amino acid metabolism (BCAT2 and BCKHDA) genes were increased ( P < 0.05) during deficit compared with balance, independent of treatment. CONCLUSIONS These data demonstrate that increased physical activity and not exogenous testosterone administration is the primary determinate of whole-body and skeletal muscle metabolic adaptations during diet- and exercise-induced energy deficit.
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Affiliation(s)
- Lee M Margolis
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA
| | | | | | - Emily E Howard
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA
| | - Nancy E Murphy
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA
| | - Christopher T Carrigan
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA
| | | | - Robbie A Beyl
- Pennington Biomedical Research Center, Baton Rouge, LA
| | - Eric Ravussin
- Pennington Biomedical Research Center, Baton Rouge, LA
| | - Stefan M Pasiakos
- Military Performance Division, US Army Research Institute of Environmental Medicine, Natick, MA
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Howard EE, Allen JT, Coleman JL, Small SD, Karl JP, O'Fallon KS, Margolis LM. Ketone Monoester Plus Carbohydrate Supplementation Does Not Alter Exogenous and Plasma Glucose Oxidation or Metabolic Clearance Rate During Exercise in Men Compared with Carbohydrate Alone. J Nutr 2023:S0022-3166(23)35281-7. [PMID: 36893935 DOI: 10.1016/j.tjnut.2023.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 02/21/2023] [Accepted: 03/01/2023] [Indexed: 03/11/2023] Open
Abstract
BACKGROUND Increasing β-hydroxybutyrate (βHB) availability through ketone monoester plus carbohydrate (KE+CHO) supplementation is suggested to enhance physical performance by sparing glucose use during exercise. However, no studies have examined the effect of ketone supplementation on glucose kinetics during exercise. OBJECTIVES This exploratory study primarily aimed to determine the effect of KE+CHO supplementation on glucose oxidation and physical performance during steady-state exercise compared with carbohydrate. METHODS Using a randomly assigned, crossover design (clinicaltrials.gov, NCT04737694), 12 men consumed KE+CHO (573 mg ketone monoester/kg body mass, 110 g glucose) or carbohydrate (110 g glucose) before and during 90 min of steady-state treadmill exercise [54 ± 3% peak oxygen uptake (V̇˙O2peak)] wearing a weighted vest (30% body mass; 25 ± 3 kg). Glucose oxidation and turnover were determined using indirect calorimetry and stable isotopes. Participants performed an unweighted time to exhaustion (TTE; 85% V̇˙O2peak) after steady-state exercise and a weighted (25 ± 3 kg) 6.4 km time trial (TT) the next day after consuming a bolus of KE+CHO or carbohydrate. Data were analyzed by paired t-tests and mixed model ANOVA. RESULTS βHB concentrations were higher (P < 0.05) after exercise [2.1 mM (95% CI: 1.6, .6)] and the TT [2.6 mM (2.1, 3.1)] in KE+CHO compared with carbohydrate. TTE was lower [-104 s (-201, -8)], and TT performance was slower [141 s (19,262)] in KE+CHO than in carbohydrate (P < 0.05). Exogenous [-0.01 g/min (-0.07, 0.04)] and plasma [-0.02 g/min (-0.08, 0.04)] glucose oxidation and metabolic clearance rate {MCR [0.38 mg·kg-1·min-1 (-0.79, 1.54)]} were not different, and glucose rate of appearance [-0.51 mg·kg-1·min-1 (-0.97, -0.04)], and disappearance [-0.50 mg·kg-1·min-1 (-0.96, -0.04)] were lower (P < 0.05) in KE+CHO compared with carbohydrate during steady-state exercise. CONCLUSIONS In the current study, the rates of exogenous and plasma glucose oxidation and MCR were not different between treatments during steady-state exercise, suggesting blood glucose utilization is similar between KE+CHO and carbohydrate. KE+CHO supplementation also results in lower physical performance compared with carbohydrate. This trial was registered at www. CLINICALTRIALS gov as NCT04737694.
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Affiliation(s)
- Emily E Howard
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Jillian T Allen
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Julie L Coleman
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA, United States; Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Stephanie D Small
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA, United States; Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States; Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - J Philip Karl
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Kevin S O'Fallon
- Soldier Effectiveness Directorate, United States Army Combat Capabilities Development Command Soldier Center, Natick, MA, United States
| | - Lee M Margolis
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA, United States.
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Hatch-McChesney A, Radcliffe PN, Pitts KP, Karis AJ, O'Brien RP, Krieger S, Nelman-Gonzalez M, Diak DM, Mehta SK, Crucian B, McClung JP, Smith TJ, Margolis LM, Karl JP. Changes in Immune Function during Initial Military Training. Med Sci Sports Exerc 2023; 55:548-557. [PMID: 36563092 PMCID: PMC9924970 DOI: 10.1249/mss.0000000000003079] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
PURPOSE Initial military training (IMT) is a transitionary period wherein immune function may be suppressed and infection risk heightened due to physical and psychological stress, communal living, and sleep deprivation. This study characterized changes in biomarkers of innate and adaptive immune function, and potential modulators of those changes, in military recruits during IMT. METHODS Peripheral leukocyte distribution and mitogen-stimulated cytokine profiles were measured in fasted blood samples, Epstein-Barr (EBV), varicella zoster (VZV), and herpes simplex 1 (HSV1) DNA was measured in saliva by quantitative polymerase chain reaction as an indicator of latent herpesvirus reactivation, and diet quality was determined using the healthy eating index measured by food frequency questionnaire in 61 US Army recruits (97% male) at the beginning (PRE) and end (POST) of 22-wk IMT. RESULTS Lymphocytes and terminally differentiated cluster of differentiation (CD)4+ and CD8+ T cells increased PRE to POST, whereas granulocytes, monocytes, effector memory CD4+ and CD8+ T cells, and central memory CD8+ T cells decreased ( P ≤ 0.02). Cytokine responses to anti-CD3/CD28 stimulation were higher POST compared with PRE, whereas cytokine responses to lipopolysaccharide stimulation were generally blunted ( P < 0.05). Prevalence of EBV reactivation was higher at POST ( P = 0.04), but neither VZV nor HSV1 reactivation was observed. Diet quality improvements were correlated with CD8+ cell maturation and blunted proinflammatory cytokine responses to anti-CD3/CD28 stimulation. CONCLUSIONS Lymphocytosis, maturation of T-cell subsets, and increased T-cell reactivity were evident POST compared with PRE IMT. Although EBV reactivation was more prevalent at POST, no evidence of VZV or HSV1 reactivation, which are more common during severe stress, was observed. Findings suggest increases in the incidence of EBV reactivation were likely appropriately controlled by recruits and immune-competence was not compromised at the end of IMT.
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Affiliation(s)
| | | | | | - Anthony J Karis
- U.S. Army Research Institute of Environmental Medicine, Natick, MA
| | - Rory P O'Brien
- U.S. Army Maneuver Center of Excellence, Fort Benning, GA
| | | | | | | | | | | | - James P McClung
- U.S. Army Research Institute of Environmental Medicine, Natick, MA
| | - Tracey J Smith
- U.S. Army Research Institute of Environmental Medicine, Natick, MA
| | - Lee M Margolis
- U.S. Army Research Institute of Environmental Medicine, Natick, MA
| | - J Philip Karl
- U.S. Army Research Institute of Environmental Medicine, Natick, MA
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Beckner ME, Thompson L, Radcliffe PN, Cherian RV, Wilson M, Barringer N, Margolis LM, Karl JP. Sex differences in body composition and serum metabolome responses to sustained, physical training suggest enhanced fat oxidation in women compared with men. Physiol Genomics 2023. [PMID: 36779667 DOI: 10.1152/physiolgenomics.00169.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
Sex differences in energy metabolism during acute, sub-maximal exercise are well documented. Whether these sex differences influence metabolic and physiologic responses to sustained, physically demanding activities is not well characterized. This study aimed to identify sex differences within changes in the serum metabolome in relation to changes in body composition, physical performance, and endocrine status during a 17-day military training exercise. Blood was collected, and body composition and lower-body power were measured before and after the training on 72 cadets (18 women). Total daily energy expenditure (TDEE) was assessed in a subset throughout. TDEE was greater in men (4,085±482kcal/d) than women (2,982±472kcal/d, p<0.001), but not after adjustment for dry lean mass (DLM). Men tended to lose more DLM than women (-0.2[-0.3,-0.1] vs. -0.0[-0.0,0.0] kg, p=0.063, Cohen's d=0.50) and have greater reductions in lower body power (-244[-314,-174] vs. -130[-209,-51] Watts, p=0.085, d=0.49). Reductions in DLM and lower body power were correlated (r=0.325, p=0.006). Women demonstrated greater fat oxidation than men (Δfat mass/DLM: -0.20[-0.24,-0.17] vs. -0.15[-0.17,-0.13] kg, p=0.012, d=0.64). Metabolites within pathways of fatty acid, endocannabinoid, lysophospholipid, phosphatidylcholine, phosphatidylethanolamine, and plasmalogen metabolism increased in women relative to men. Independent of sex, changes in metabolites related to lipid metabolism were inversely associated with changes in body mass and positively associated with changes in endocrine and metabolic status. These data suggest that during sustained military training, women preferentially mobilize fat stores compared with men, which may be beneficial for mitigating loss of lean mass and lower body power.
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Affiliation(s)
- Meaghan E Beckner
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Lauren Thompson
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Patrick N Radcliffe
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Rebecca V Cherian
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Marques Wilson
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Nicholas Barringer
- Medical Center of Excellence Joint Base San Antonio-Fort Sam Houston, TX, United States
| | - Lee M Margolis
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - J Philip Karl
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
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Beckner ME, Lieberman HR, Hatch-McChesney A, Allen JT, Niro PJ, Thompson LA, Karl JP, Gwin JA, Margolis LM, Hennigar SR, McClung JP, Pasiakos SM. Effects of energy balance on cognitive performance, risk-taking, ambulatory vigilance and mood during simulated military sustained operations (SUSOPS). Physiol Behav 2023; 258:114010. [PMID: 36349660 DOI: 10.1016/j.physbeh.2022.114010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 10/19/2022] [Accepted: 10/26/2022] [Indexed: 11/06/2022]
Abstract
Sustained operations (SUSOPS) require military personnel to conduct combat and training operations while experiencing physical and cognitive stress and limited sleep. These operations are often conducted in a state of negative energy balance and are associated with degraded cognitive performance and mood. Whether maintaining energy balance can mitigate these declines is unclear. This randomized crossover study assessed the effects of energy balance on cognitive performance, risk-taking propensity, ambulatory vigilance, and mood during a simulated 72-h SUSOPS. METHODS Ten male Soldiers (mean ± SE; 22.4 ± 1.7 y; body weight 87.3 ± 1.1 kg) completed two, 72-h simulated SUSOPS in random order, separated by 7 days of recovery. Each SUSOPS elicited ∼4500 kcal/d total energy expenditure and restricted sleep to 4 h/night. During SUSOPS, participants consumed either an energy-balanced or restricted diet that induced a 43 ± 3% energy deficit. A cognitive test battery was administered each morning and evening to assess: vigilance, working memory, grammatical reasoning, risk-taking propensity, and mood. Real-time ambulatory vigilance was assessed each morning, evening, and night via a wrist-worn monitoring device. RESULTS Participants exhibited heightened risk-taking propensity (p = 0.047) with lower self-reported self-control (p = 0.021) and fatigue (p = 0.013) during energy deficit compared to during energy balance. Vigilance accuracy (p < 0.001) and working memory (p = 0.040) performance decreased, and vigilance lapses increased (p < 0.001) during SUSOPS, but did not differ by diet. Percentage of correct responses to ambulatory vigilance stimuli varied during SUSOPS (p = 0.019) independent of diet, with generally poorer performance during the morning and night. Total mood disturbance (p = 0.001), fatigue (p < 0.001), tension (p = 0.003), and confusion (p = 0.036) increased whereas vigor decreased (p < 0.001) during SUSOPS, independent of diet. CONCLUSION Prolonged physical activity combined with sleep restriction is associated with impaired vigilance, memory, and mood state. Under such conditions, maintaining energy balance prevents increased risk-taking and improves self-control, but does not improve other aspects of cognitive function or mood. Given the small sample in the present study, replication in a larger cohort is warranted.
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Affiliation(s)
- Meaghan E Beckner
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Building 42, Natick, MA 01760, United States; Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Harris R Lieberman
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Building 42, Natick, MA 01760, United States.
| | - Adrienne Hatch-McChesney
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Building 42, Natick, MA 01760, United States
| | - Jillian T Allen
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Building 42, Natick, MA 01760, United States; Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Philip J Niro
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Building 42, Natick, MA 01760, United States
| | - Lauren A Thompson
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Building 42, Natick, MA 01760, United States
| | - J Philip Karl
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Building 42, Natick, MA 01760, United States
| | - Jess A Gwin
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Building 42, Natick, MA 01760, United States
| | - Lee M Margolis
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Building 42, Natick, MA 01760, United States
| | | | - James P McClung
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Building 42, Natick, MA 01760, United States
| | - Stefan M Pasiakos
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Building 42, Natick, MA 01760, United States
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Margolis LM, Carrigan CT, Murphy NE, DiBella MN, Wilson MA, Whitney CC, Howard EE, Pasiakos SM, Rivas DA. Carbohydrate intake in recovery from aerobic exercise differentiates skeletal muscle microRNA expression. Am J Physiol Endocrinol Metab 2022; 323:E435-E447. [PMID: 36044708 PMCID: PMC9639755 DOI: 10.1152/ajpendo.00110.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 11/22/2022]
Abstract
Posttranscriptional regulation by microRNA (miRNA) facilitates exercise and diet-induced skeletal muscle adaptations. However, the impact of diet on miRNA expression during postexercise recovery remains unclear. The objective of this study was to examine the effects of consuming carbohydrate or a nutrient-free control on skeletal muscle miRNA expression during 3 h of recovery from aerobic exercise. Using a randomized, crossover design, seven men (means ± SD, age: 21 ± 3 yr; body mass: 83 ± 13 kg; V̇o2peak: 43 ± 2 mL/kg/min) completed two-cycle ergometry glycogen depletion trials followed by 3 h of recovery while consuming either carbohydrate (CHO: 1 g/kg/h) or control (CON: nutrient free). Muscle biopsy samples were obtained under resting fasted conditions at baseline and at the end of the 3-h recovery (REC) period. miRNA expression was determined using unbiased RT-qPCR microarray analysis. Trials were separated by 7 days. Twenty-five miRNAs were different (P < 0.05) between CHO and CON at REC, with Let7i-5p and miR-195-5p being the most predictive of treatment. In vitro overexpression of Let7i-5p and miR-195-p5 in C2C12 skeletal muscle cells decreased (P < 0.05) the expression of protein breakdown (Foxo1, Trim63, Casp3, and Atf4) genes, ubiquitylation, and protease enzyme activity compared with control. Energy sensing (Prkaa1 and Prkab1) and glycolysis (Gsy1 and Gsk3b) genes were lower (P < 0.05) with Let7i-5p overexpression compared with miR-195-5p and control. Fat metabolism (Cpt1a, Scd1, and Hadha) genes were lower (P < 0.05) in miR-195-5p than in control. These data indicate that consuming CHO after aerobic exercise alters miRNA profiles compared with CON, and these differences may govern mechanisms facilitating muscle recovery.NEW & NOTEWORTHY Results provide novel insight into effects of carbohydrate intake on the expression of skeletal muscle microRNA during early recovery from aerobic exercise and reveal that Let7i-5p and miR-195-5p are important regulators of skeletal muscle protein breakdown to aid in facilitating muscle recovery.
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Affiliation(s)
- Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Christopher T Carrigan
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Nancy E Murphy
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Marissa N DiBella
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
- Oak Ridge Institute of Science and Education, Belcamp, Maryland
| | - Marques A Wilson
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Claire C Whitney
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Emily E Howard
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Stefan M Pasiakos
- Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Donato A Rivas
- Nutrition, Exercise Physiology and Sarcopenia Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts
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11
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Murphy RD, James KM, Ippolito JR, Barney DE, Miller KM, Murphy NE, Gwin JA, Pasiakos SM, McClung JP, Margolis LM, Hennigar SR. Mild to Moderate Food Deprivation Increases Hepcidin and Results in Hypoferremia and Tissue Iron Sequestration in Mice. J Nutr 2022; 152:2198-2208. [PMID: 35906187 DOI: 10.1093/jn/nxac167] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 06/23/2022] [Accepted: 07/22/2022] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Short-term starvation and severe food deprivation (FD) reduce dietary iron absorption and restricts iron to tissues, thereby limiting the amount of iron available for erythropoiesis. These effects may be mediated by increases in the iron regulatory hormone hepcidin; however, whether mild to moderate FD has similar effects on hepcidin and iron homeostasis is not known. OBJECTIVES To determine the effects of varying magnitudes and durations of FD on hepcidin and indicators of iron status in male and female mice. METHODS Male and female C57BL/6J mice (14 wk old; n = 170) were randomly assigned to consume AIN-93M diets ad libitum (AL) or varying magnitudes of FD (10%, 20%, 40%, 60%, 80%, or 100%). FD was based on the average amount of food consumed by the AL males or females, and food was split into morning and evening meals. Mice were euthanized at 48 h and 1, 2, and 3 wk, and hepcidin and indicators of iron status were measured. Data were analyzed by Pearson correlation and one-way ANOVA. RESULTS Liver hepcidin mRNA was positively correlated with the magnitude of FD at all time points (P < 0.05). At 3 wk, liver hepcidin mRNA increased 3-fold with 10% and 20% FD compared with AL and was positively associated with serum hepcidin (R = 0.627, P < 0.0001). Serum iron was reduced by ∼65% (P ≤ 0.01), and liver nonheme iron concentrations were ∼75% greater (P ≤ 0.01) with 10% and 20% FD for 3 wk compared with AL. Liver hepcidin mRNA at 3 wk was positively correlated with liver Bmp6 (R = 0.765, P < 0.0001) and liver gluconeogenic enzymes (R = >0.667, P < 0.05) but not markers of inflammation (P > 0.05). CONCLUSIONS FD increases hepcidin in male and female mice and results in hypoferremia and tissue iron sequestration. These findings suggest that increased hepcidin with FD may contribute to the disturbances in iron homeostasis with undernutrition.
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Affiliation(s)
- Robert D Murphy
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, USA
| | - Kelsey M James
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, USA
| | - James R Ippolito
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, USA
| | - David E Barney
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, USA
| | - Katelyn M Miller
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, USA
| | - Nancy E Murphy
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Jess A Gwin
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Stefan M Pasiakos
- Military Performance Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - James P McClung
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Lee M Margolis
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Stephen R Hennigar
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, USA
- Pennington Biomedical Research Center, Baton Rouge, LA, USA
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12
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Margolis LM, Karl JP, Wilson MM, Coleman JL, Whitney CC, Pasiakos SM. Serum Branched-chain Amino Acid Metabolites Increase When Aerobic Exercise Is Initiated With Low Muscle Glycogen. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000875968.80621.00] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Varanoske AN, Harris MN, Hebert C, Howard EE, Johannsen NM, Heymsfield SB, Greenway FL, Margolis LM, Lieberman HR, Church DD, Ferrando AA, Rood JC, Pasiakos SM. Testosterone Undecanoate Administration Prevents Fat-Free Mass Loss During Strenuous Multi-Stressor Military Operations. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000879496.07548.de] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Gwin JA, Hatch-McChesney A, Pitts KP, Karis AJ, McClung JP, Karl JP, Margolis LM. Initial Military Training Modulates The Serum Metabolome. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000876764.93965.ac] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Radcliffe PN, Karl JP, Hatch-McChesney A, Pitts KP, Karis AJ, Krieger S, Nelman-Gonzalez M, Makedonas G, Diak DM, Mehta S, Crucian BE, McClung JP, Smith TJ, Margolis LM. Changes In Leukocyte Distribution And T-cell Reactivity During Initial Military Training. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000876732.54114.cf] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Howard EE, Allen JT, Coleman JL, Small SD, O'Fallon KS, Margolis LM. Ketone Ester Plus Carbohydrate Supplementation Impairs Physical Performance And Decreases Glucose Turnover Versus Carbohydrate Alone. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000875976.50023.28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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17
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Howard EE, Shankaran M, Evans WJ, Berryman CE, Margolis LM, Lieberman HR, Karl JP, Young AJ, Montano MA, Matthews MD, Bizieff A, Nyangao E, Mohammed H, Harris MN, Hellerstein MK, Rood JC, Pasiakos SM. Effects of Testosterone on Mixed-Muscle Protein Synthesis and Proteome Dynamics During Energy Deficit. J Clin Endocrinol Metab 2022; 107:e3254-e3263. [PMID: 35532889 DOI: 10.1210/clinem/dgac295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Indexed: 11/19/2022]
Abstract
CONTEXT Effects of testosterone on integrated muscle protein metabolism and muscle mass during energy deficit are undetermined. OBJECTIVE The objective was to determine the effects of testosterone on mixed-muscle protein synthesis (MPS), proteome-wide fractional synthesis rates (FSR), and skeletal muscle mass during energy deficit. DESIGN This was a randomized, double-blind, placebo-controlled trial. SETTING The study was conducted at Pennington Biomedical Research Center. PARTICIPANTS Fifty healthy men. INTERVENTION The study consisted of 14 days of weight maintenance, followed by a 28-day 55% energy deficit with 200 mg testosterone enanthate (TEST, n = 24) or placebo (PLA, n = 26) weekly, and up to 42 days of ad libitum recovery feeding. MAIN OUTCOME MEASURES Mixed-MPS and proteome-wide FSR before (Pre), during (Mid), and after (Post) the energy deficit were determined using heavy water (days 1-42) and muscle biopsies. Muscle mass was determined using the D3-creatine dilution method. RESULTS Mixed-MPS was lower than Pre at Mid and Post (P < 0.0005), with no difference between TEST and PLA. The proportion of individual proteins with numerically higher FSR in TEST than PLA was significant by 2-tailed binomial test at Post (52/67; P < 0.05), but not Mid (32/67; P > 0.05). Muscle mass was unchanged during energy deficit but was greater in TEST than PLA during recovery (P < 0.05). CONCLUSIONS The high proportion of individual proteins with greater FSR in TEST than PLA at Post suggests exogenous testosterone exerted a delayed but broad stimulatory effect on synthesis rates across the muscle proteome during energy deficit, resulting in muscle mass accretion during subsequent recovery.
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Affiliation(s)
- Emily E Howard
- Military Nutrit ion Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Mahalakshmi Shankaran
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720, USA
| | - Willian J Evans
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720, USA
| | - Claire E Berryman
- Military Nutrit ion Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
- Department of Nutrition, Food, and Exercise Sciences, Florida State University, Tallahassee, FL 32306, USA
| | - Lee M Margolis
- Military Nutrit ion Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA
| | - Harris R Lieberman
- Military Nutrit ion Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA
| | - J Philip Karl
- Military Nutrit ion Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA
| | - Andrew J Young
- Military Nutrit ion Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA
| | - Monty A Montano
- MyoSyntax Corporation, Worcester, MA 01605, USA
- Harvard Medical School, Boston, MA 02115, USA
- Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Marcy D Matthews
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720, USA
| | - Alec Bizieff
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720, USA
| | - Edna Nyangao
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720, USA
| | - Hussein Mohammed
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720, USA
| | - Melissa N Harris
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Marc K Hellerstein
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720, USA
| | - Jennifer C Rood
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Stefan M Pasiakos
- Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA
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18
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Margolis LM, Hatch-McChesney A, Allen JT, DiBella MN, Carrigan CT, Murphy NE, Karl JP, Gwin JA, Hennigar SR, McClung JP, Pasiakos SM. Circulating and skeletal muscle microRNA profiles are more sensitive to sustained aerobic exercise than energy balance in males. J Physiol 2022; 600:3951-3963. [PMID: 35822542 DOI: 10.1113/jp283209] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/22/2022] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Circulating and skeletal muscle miRNA profiles are more sensitive to high levels of aerobic exercise-induced energy expenditures compared to energy status Changes in circulating miRNA in response to high levels of daily sustained aerobic exercise are not reflective of changes in skeletal muscle miRNA. ABSTRACT MicroRNA (miRNA) regulate molecular processes governing muscle metabolism. Physical activity and energy balance influence both muscle anabolism and metabolism, but whether circulating and skeletal muscle miRNA mediate those effects remains unknown. This study assessed the impact of sustained physical activity with participants in energy balance (BAL) or deficit (DEF) on circulating and skeletal muscle miRNA. Using a randomized cross-over design, 10 recreational active healthy males (mean ± SD; 22±5 yrs, 87±11 kg) completed 72 hours of high aerobic exercise-induced energy expenditures in BAL (689±852 kcal/d) or DEF (-2047±920 kcal/d). Blood and muscle samples were collected under rested/fasted conditions before (PRE) and immediately after 120-min load carriage exercise bout at the end (POST) of the 72 hours. Trials were separated by 7 days. Circulating and skeletal muscle miRNA were measured using microarray RT-qPCR. Independent of energy status, 36 circulating miRNA decreased (P<0.05), while 10 miRNA increased and 3 miRNA decreased in skeletal muscle (P<0.05) at POST compared to PRE. Of these, miR-122-5p, miR-221-3p, miR-222-3p, and miR-24-3p decreased in circulation and increased in skeletal muscle. Two circulating (miR-145-5p and miR-193a-5p) and 4 skeletal muscle (miR-21-5p, miR-372-3p, miR-34a-5p, and miR-9-5p) miRNA had time-by-treatment effects (P<0.05). These data suggest that changes in miRNA profiles are more sensitive to increased physical activity compared to energy status, and that changes in circulating miRNA in response to high levels of daily aerobic exercise are not reflective of changes in skeletal muscle miRNA. Graphical abstract legend In response to 72 hours of high aerobic exercise, circulating miRNA decreased and miRNA in skeletal muscle primarily increased. The changes in miRNA occurred independent of energy status (i.e., exercise-induced energy defcit or exercise plus increased energy intake to achieve energy balance), and circulating miRNA did not refect changes in skeletal muscle. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA
| | | | - Jillian T Allen
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA.,Oak Ridge Institute of Science and Technology, Belcamp, MD, USA
| | - Marissa N DiBella
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA.,Oak Ridge Institute of Science and Technology, Belcamp, MD, USA
| | - Christopher T Carrigan
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA
| | - Nancy E Murphy
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA
| | - J Philip Karl
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA
| | - Jess A Gwin
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA
| | - Stephen R Hennigar
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, USA
| | - James P McClung
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA
| | - Stefan M Pasiakos
- Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA
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19
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Varanoske AN, Harris MN, Hebert C, Howard EE, Johannsen NM, Heymsfield SB, Greenway FL, Margolis LM, Lieberman HR, Beyl RA, Church DD, Ferrando AA, Pasiakos SM, Rood JC. Testosterone Undecanoate Administration Prevents Declines in Fat-Free Mass but not Physical Performance During Simulated Multi-Stressor Military Operations. J Appl Physiol (1985) 2022; 133:426-442. [PMID: 35796614 PMCID: PMC9359646 DOI: 10.1152/japplphysiol.00190.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
CONTEXT Male military personnel conducting strenuous operations experience reduced testosterone, muscle mass, and performance. Pharmacological restoration of normal testosterone may attenuate performance decrements by mitigating muscle loss. Previously, administering testosterone enanthate (200 mg/week) during energy deficit prompted supraphysiological testosterone concentrations and lean mass gain without preventing isokinetic/isometric deterioration. Whether administering a practical dose of testosterone protects muscle and performance during strenuous operations is undetermined. OBJECTIVE Test the effects of a single dose of testosterone on body composition and military-relevant physical performance during a simulated operation. METHODS After a 7-day baseline phase (P1), 32 males (mean±SD; 77.1±12.3 kg, 26.5±4.4 years) received a single dose of either testosterone undecanoate (750 mg; TEST) or placebo (PLA) before a 20-day simulated military operation (P2), followed by a 23-day recovery (P3). Assessments included body composition and physical performance at the end of each phase and circulating endocrine biomarkers throughout the study. RESULTS Total and free testosterone concentrations in TEST were greater than PLA throughout most of P2 (p<0.05), but returned to P1 values during P3. Fat-free mass (FFM) was maintained from P1 to P2 in TEST (mean±SE; 0.41±0.65 kg, p=0.53), but decreased in PLA (-1.85±0.69 kg, p=0.01) and recovered in P3. Regardless of treatment, total body mass and fat mass decreased from P1 to P2 (p<0.05), but did not fully recover by P3. Physical performance decreased during P2 (p<0.05) and recovered by P3, regardless of treatment. CONCLUSIONS Administering testosterone undecanoate before a simulated military operation protected FFM but did not prevent decrements in physical performance.
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Affiliation(s)
- Alyssa N Varanoske
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Melissa N Harris
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - Callie Hebert
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - Emily E Howard
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Neil M Johannsen
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - Steven B Heymsfield
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - Frank L Greenway
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Harris R Lieberman
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Robbie A Beyl
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - David D Church
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging and Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Arny A Ferrando
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging and Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Stefan M Pasiakos
- Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Jennifer C Rood
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
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20
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Gwin JA, Hatch-McChesney A, Pitts KP, O'Brien RP, Karis AJ, Carrigan CT, McClung JP, Karl JP, Margolis LM. Initial military training modulates serum fatty acid and amino acid metabolites. Physiol Rep 2022; 10:e15385. [PMID: 35818300 PMCID: PMC9273871 DOI: 10.14814/phy2.15385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/21/2022] [Accepted: 06/26/2022] [Indexed: 11/24/2022] Open
Abstract
Initial military training (IMT) results in increased fat‐free mass (FFM) and decreased fat mass (FM). The underlying metabolic adaptations facilitating changes in body composition during IMT are unknown. The objective of this study was to assess changes in body composition and the serum metabolome during 22‐week US Army IMT. Fifty‐four volunteers (mean ± SD; 22 ± 3 year; 24.6 ± 3.7 kg/m2) completed this longitudinal study. Body composition measurements (InBody 770) and blood samples were collected under fasting, rested conditions PRE and POST IMT. Global metabolite profiling was performed to identify metabolites involved in energy, carbohydrate, lipid, and protein metabolism (Metabolon, Inc.). There was no change in body mass (POST‐PRE; 0.4 ± 5.1 kg, p = 0.59), while FM decreased (−1.7 ± 3.5 kg, p < 0.01), and FFM increased (2.1 ± 2.8 kg, p < 0.01) POST compared to PRE IMT. Of 677 identified metabolites, 340 differed at POST compared to PRE (p < 0.05, Q < 0.10). The majority of these metabolites were related to fatty acid (73%) and amino acid (26%) metabolism. Increases were detected in 41% of branched‐chain amino acid metabolites, 53% of histidine metabolites, and 35% of urea cycle metabolites. Decreases were detected in 93% of long‐chain fatty acid metabolites, while 58% of primary bile acid metabolites increased. Increases in amino acid metabolites suggest higher rates of protein turnover, while changes in fatty acid metabolites indicate increased fat oxidation, which likely contribute changes in body composition during IMT. Overall, changes in metabolomics profiles provide insight into metabolic adaptions underlying changes in body composition during IMT.
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Affiliation(s)
- Jess A Gwin
- U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
| | | | - Kenneth P Pitts
- U.S. Army Research Institute for the Behavioral and Social Sciences, Fort Benning, Georgia, USA
| | - Rory P O'Brien
- U.S. Army Maneuver Center of Excellence, Fort Benning, Georgia, USA
| | - Anthony J Karis
- U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
| | | | - James P McClung
- U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
| | - J Philip Karl
- U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
| | - Lee M Margolis
- U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
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21
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Margolis LM, Karl JP, Wilson MA, Coleman JL, Whitney CC, Pasiakos SM. Serum Branched-Chain Amino Acid Metabolites Increase in Males When Aerobic Exercise Is Initiated with Low Muscle Glycogen. Metabolites 2021; 11:metabo11120828. [PMID: 34940586 PMCID: PMC8708125 DOI: 10.3390/metabo11120828] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/21/2021] [Accepted: 11/29/2021] [Indexed: 12/03/2022] Open
Abstract
This study used global metabolomics to identify metabolic factors that might contribute to muscle anabolic resistance, which develops when aerobic exercise is initiated with low muscle glycogen using global metabolomics. Eleven men completed this randomized, crossover study, completing two cycle ergometry glycogen depletion trials, followed by 24 h of isocaloric refeeding to elicit low (LOW; 1.5 g/kg carbohydrate, 3.0 g/kg fat) or adequate (AD; 6.0 g/kg carbohydrate 1.0 g/kg fat) glycogen. Participants then performed 80 min of cycling (64 ± 3% VO2 peak) while ingesting 146 g carbohydrate. Serum was collected before glycogen depletion under resting and fasted conditions (BASELINE), and before (PRE) and after (POST) exercise. Changes in metabolite profiles were calculated by subtracting BASELINE from PRE and POST within LOW and AD. There were greater increases (p < 0.05, Q < 0.10) in 64% of branched-chain amino acids (BCAA) metabolites and 69% of acyl-carnitine metabolites in LOW compared to AD. Urea and 3-methylhistidine had greater increases (p < 0.05, Q < 0.10) in LOW compared to AD. Changes in metabolomics profiles indicate a greater reliance on BCAA catabolism for substrate oxidation when exercise is initiated with low glycogen stores. These findings provide a mechanistic explanation for anabolic resistance associated with low muscle glycogen, and suggest that exogenous BCAA requirements to optimize muscle recovery are likely greater than current recommendations.
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Affiliation(s)
- Lee M. Margolis
- U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA; (J.P.K.); (M.A.W.); (J.L.C.); (C.C.W.); (S.M.P.)
- Correspondence: ; Tel.: +508-206-2335
| | - J Philip Karl
- U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA; (J.P.K.); (M.A.W.); (J.L.C.); (C.C.W.); (S.M.P.)
| | - Marques A. Wilson
- U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA; (J.P.K.); (M.A.W.); (J.L.C.); (C.C.W.); (S.M.P.)
| | - Julie L. Coleman
- U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA; (J.P.K.); (M.A.W.); (J.L.C.); (C.C.W.); (S.M.P.)
- Oak Ridge Institute of Science and Education, Oak Ridge, TN 37830, USA
| | - Claire C. Whitney
- U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA; (J.P.K.); (M.A.W.); (J.L.C.); (C.C.W.); (S.M.P.)
| | - Stefan M. Pasiakos
- U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA; (J.P.K.); (M.A.W.); (J.L.C.); (C.C.W.); (S.M.P.)
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Small SD, Margolis LM. Impact of Dietary Carbohydrate Restriction versus Energy Restriction on Exogenous Carbohydrate Oxidation during Aerobic Exercise. Adv Nutr 2021; 13:S2161-8313(22)00076-X. [PMID: 34788795 PMCID: PMC8970824 DOI: 10.1093/advances/nmab124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Individuals with high physical activity levels, such as athletes and military personnel, are likely to experience periods of low muscle glycogen content. Reductions in glycogen stores are associated with impaired physical performance. Lower glycogen stores in these populations are likely due to sustained aerobic exercise coupled with sub-optimal carbohydrate or energy intake. Consuming exogenous carbohydrate during aerobic exercise may be an effective intervention to sustain physical performance during periods of low glycogen. However, research is limited in the area of carbohydrate recommendations to fuel performance during periods of sub-optimal carbohydrate and energy intake. Additionally, the studies that have investigated the effects of low glycogen stores on exogenous carbohydrate oxidation have yielded conflicting results. Discrepancies between studies may be the result of glycogen stores being lowered by restricting carbohydrate or restricting energy intake. This narrative review discusses the influence of low glycogen status resulting from carbohydrate restriction versus energy restriction on exogenous carbohydrate oxidation and examines the potential mechanism resulting in divergent responses in exogenous carbohydrate oxidation. Results from this review indicate that rates of exogenous carbohydrate oxidation can be maintained when glycogen content is lower following carbohydrate restrictions, but may be reduced following energy restriction. Reductions in exogenous carbohydrate oxidation following energy restriction appear to result from lower insulin sensitivity and glucose uptake. Exogenous carbohydrate may thus be an effective intervention to sustain performance following short-term energy adequate carbohydrate restriction, but may not be an effective ergogenic aid when glycogen stores are low due to energy restriction.
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Affiliation(s)
- Stephanie D Small
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA,Oak Ridge Institute of Science and Education, Oak Ridge, TN, USA
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23
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Abstract
PURPOSE OF REVIEW To highlight emerging evidence challenging traditional recommendations to increase carbohydrate intake to optimize performance at high altitude. RECENT FINDINGS Several studies have now clearly demonstrated that, compared with sea level, exogenous carbohydrate oxidation during aerobic exercise is blunted in lowlanders during initial exposure to high altitude. There is also no apparent ergogenic effect of ingesting carbohydrate during aerobic exercise on subsequent performance at high altitude, either initially after arriving or even after up to 22 days of acclimatization. The inability to oxidize and functionally benefit from exogenous carbohydrate intake during exercise after arriving at high altitude coincides with hyperinsulinemia, accelerated glycogenolysis, and reduced peripheral glucose uptake. Collectively, these responses are consistent with a hypoxia-mediated metabolic dysregulation reflective of insulin resistance. Parallel lines of evidence have also recently demonstrated roles for the gut microbiome in host metabolism, bioenergetics, and physiologic responses to high altitude, implicating the gut microbiome as one potential mediator of hypoxia-mediated metabolic dysregulation. SUMMARY Identification of novel and well tolerated nutrition and/or pharmacological approaches for alleviating hypoxia-mediated metabolic dysregulation and enhancing exogenous carbohydrate oxidation may be more effective for optimizing performance of lowlanders newly arrived at high altitude than traditional carbohydrate recommendations.
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Affiliation(s)
- Stefan M Pasiakos
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
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24
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Rivas DA, Peng F, Benard T, Ramos da Silva AS, Fielding RA, Margolis LM. miR-19b-3p is associated with a diametric response to resistance exercise in older adults and regulates skeletal muscle anabolism via PTEN inhibition. Am J Physiol Cell Physiol 2021; 321:C977-C991. [PMID: 34705586 PMCID: PMC8714992 DOI: 10.1152/ajpcell.00190.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Understanding paradoxical responses to anabolic stimulation and identifying the mechanisms for this inconsistency in mobility-limited older adults may provide new targets for the treatment of sarcopenia. Our laboratory has discovered that dysregulation in microRNA (miRNA) that target anabolic pathways is a potential mechanism resulting in age-associated decreases in skeletal muscle mass and function (sarcopenia). The objective of the current study was to assess circulating miRNA expression profiles in diametric response of leg lean mass in mobility-limited older individuals after a 6-mo progressive resistance exercise training intervention (PRET) and determine the influence of differentially expressing miRNA on regulation of skeletal muscle mass. Participants were dichotomized by gain (Gainers; mean +561.4 g, n = 33) or loss (Losers; mean −589.8 g, n = 40) of leg lean mass after PRET. Gainers significantly increased fat-free mass 2.4% vs. −0.4% for Losers. Six miRNA (miR-1-3p, miR-19b-3p, miR-92a, miR-126, miR-133a-3p, and miR-133b) were significantly identified to be differentially expressed between Gainers and Losers, with miR-19b-3p being the miRNA most highly associated with increases in fat-free mass. Using an aging mouse model, we then assessed if miR-19b-3p expression was different in young mice with larger muscle mass compared with older mice. Circulating and skeletal muscle miR-19b-3p expression was higher in young compared with old mice and was positively associated with muscle mass and grip strength. We then used a novel integrative approach to determine if differences in circulating miR-19b-3p potentially translate to augmented anabolic response in human skeletal muscle cells in vitro. Results from this analysis identified that overexpression of miR-19b-3p targeted and downregulated PTEN by 64% to facilitate significant ∼50% increase in muscle protein synthetic rate as measured with SUnSET. The combine results of these three models identify miR-19b-3p as a potent regulator of muscle anabolism that may contribute to an inter-individual response to PRET in mobility-limited older adults.
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Affiliation(s)
- Donato A Rivas
- Nutrition, Exercise Physiology and Sarcopenia Laboratory; Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, United States
| | - Fei Peng
- Nutrition, Exercise Physiology and Sarcopenia Laboratory; Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, United States
| | - Townsend Benard
- Nutrition, Exercise Physiology and Sarcopenia Laboratory; Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, United States
| | - Adelino Sanchez Ramos da Silva
- Nutrition, Exercise Physiology and Sarcopenia Laboratory; Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, United States.,School of Physical Education and Sport of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Roger A Fielding
- Nutrition, Exercise Physiology and Sarcopenia Laboratory; Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, United States
| | - Lee M Margolis
- Nutrition, Exercise Physiology and Sarcopenia Laboratory; Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, United States.,Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States
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25
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Varanoske AN, Shankaran M, Hennigar SR, Berryman CE, Margolis LM, Field TJ, Palacios H, Nyangau E, Mohammed H, Kelly AM, Anderson BJ, Evans WJ, McClung JP, Hellerstein MK, Pasiakos SM. Energy Restriction Suppresses Muscle Protein Synthesis, and High Protein Diets Extend Protein Half-Lives Across the Muscle Proteome in Obese Female Zucker Rats. J Nutr 2021; 151:2551-2563. [PMID: 34132333 DOI: 10.1093/jn/nxab181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/11/2021] [Accepted: 05/14/2021] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Effects of high protein (HP) diets and prolonged energy restriction (ER) on integrated muscle protein kinetics have not been determined. OBJECTIVE The objective of this study was to measure protein kinetics in response to prolonged ER and HP on muscle protein synthesis (MPS; absolute rates of synthesis) and muscle protein breakdown (MPB; half-lives) for proteins across the muscle proteome. METHODS Female 6-wk-old obese Zucker rats (Leprfa+/fa+, n = 48) were randomly assigned to one of four diets for 10 wk: ad libitum-standard protein (AL-SP; 15% kcal from protein), AL-HP (35% kcal from protein), ER-SP, and ER-HP (both fed 60% feed consumed by AL-SP). During week 10, heavy/deuterated water (2H2O) was administered by intraperitoneal injection, and isotopic steady-state was maintained via 2H2O in drinking water. Rats were euthanized after 1 wk, and mixed-MPS as well as fractional replacement rate (FRR), relative concentrations, and half-lives of individual muscle proteins were quantified in the gastrocnemius. Data were analyzed using 2-factor (energy × protein) ANOVAs and 2-tailed t-tests or binomial tests as appropriate. RESULTS Absolute MPS was lower in ER than AL for mixed-MPS (-29.6%; P < 0.001) and MPS of most proteins measured [23/26 myofibrillar, 48/60 cytoplasmic, and 46/60 mitochondrial (P < 0.05)], corresponding with lower gastrocnemius mass in ER compared with AL (-29.4%; P < 0.001). Although mixed-muscle protein half-life was not different between groups, prolonged half-lives were observed for most individual proteins in HP compared with SP in ER and AL (P < 0.001), corresponding with greater gastrocnemius mass in HP than SP (+5.3%; P = 0.043). CONCLUSIONS ER decreased absolute bulk MPS and most individual MPS rates compared with AL, and HP prolonged half-lives of most proteins across the proteome. These data suggest that HP, independent of energy intake, may reduce MPB, and reductions in MPS may contribute to lower gastrocnemius mass during ER by reducing protein deposition in obese female Zucker rats.
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Affiliation(s)
- Alyssa N Varanoske
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Mahalakshmi Shankaran
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA, USA
| | - Stephen R Hennigar
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA.,Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| | - Claire E Berryman
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA.,Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| | - Lee M Margolis
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Tyler J Field
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA, USA
| | - Hector Palacios
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA, USA
| | - Edna Nyangau
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA, USA
| | - Hussein Mohammed
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA, USA
| | - Alyssa M Kelly
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Bradley J Anderson
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - William J Evans
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA, USA
| | - James P McClung
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Marc K Hellerstein
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
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26
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Margolis LM, Wilson MA, Whitney CC, Carrigan CT, Murphy NE, Hatch-McChesney A, Pasiakos SM. Initiating aerobic exercise with low glycogen content reduces markers of myogenesis but not mTORC1 signaling. J Int Soc Sports Nutr 2021; 18:56. [PMID: 34246303 PMCID: PMC8272266 DOI: 10.1186/s12970-021-00455-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 06/22/2021] [Indexed: 12/29/2022] Open
Abstract
Background The effects of low muscle glycogen on molecular markers of protein synthesis and myogenesis before and during aerobic exercise with carbohydrate ingestion is unclear. The purpose of this study was to determine the effects of initiating aerobic exercise with low muscle glycogen on mTORC1 signaling and markers of myogenesis. Methods Eleven men completed two cycle ergometry glycogen depletion trials separated by 7-d, followed by randomized isocaloric refeeding for 24-h to elicit low (LOW; 1.5 g/kg carbohydrate, 3.0 g/kg fat) or adequate (AD; 6.0 g/kg carbohydrate, 1.0 g/kg fat) glycogen. Participants then performed 80-min of cycle ergometry (64 ± 3% VO2peak) while ingesting 146 g carbohydrate. mTORC1 signaling (Western blotting) and gene transcription (RT-qPCR) were determined from vastus lateralis biopsies before glycogen depletion (baseline, BASE), and before (PRE) and after (POST) exercise. Results Regardless of treatment, p-mTORC1Ser2448, p-p70S6KSer424/421, and p-rpS6Ser235/236 were higher (P < 0.05) POST compared to PRE and BASE. PAX7 and MYOGENIN were lower (P < 0.05) in LOW compared to AD, regardless of time, while MYOD was lower (P < 0.05) in LOW compared to AD at PRE, but not different at POST. Conclusion Initiating aerobic exercise with low muscle glycogen does not affect mTORC1 signaling, yet reductions in gene expression of myogenic regulatory factors suggest that muscle recovery from exercise may be reduced.
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Affiliation(s)
- Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Bldg. 42, Natick, MA, 01760, USA.
| | - Marques A Wilson
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Bldg. 42, Natick, MA, 01760, USA
| | - Claire C Whitney
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Bldg. 42, Natick, MA, 01760, USA
| | - Christopher T Carrigan
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Bldg. 42, Natick, MA, 01760, USA
| | - Nancy E Murphy
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Bldg. 42, Natick, MA, 01760, USA
| | - Adrienne Hatch-McChesney
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Bldg. 42, Natick, MA, 01760, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Bldg. 42, Natick, MA, 01760, USA
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Varanoske AN, Harris MN, Hebert C, Howard EE, Johannsen NM, Heymsfield SB, Greenway FL, Margolis LM, Lieberman HR, Church DD, Ferrando AA, Rood JC, Pasiakos SM. Effects of testosterone undecanoate on performance during multi-stressor military operations: A trial protocol for the Optimizing Performance for Soldiers II study. Contemp Clin Trials Commun 2021; 23:100819. [PMID: 34278044 PMCID: PMC8264529 DOI: 10.1016/j.conctc.2021.100819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 06/15/2021] [Accepted: 07/02/2021] [Indexed: 11/22/2022] Open
Abstract
Background Previously, young males administered 200 mg/week of testosterone enanthate during 28 days of energy deficit (EDef) gained lean mass and lost less total mass than controls (Optimizing Performance for Soldiers I study, OPS I). Despite that benefit, physical performance deteriorated similarly in both groups. However, some experimental limitations may have precluded detection of performance benefits, as performance measures employed lacked military relevance, and the EDef employed did not elicit the magnitude of stress typically experienced by Soldiers conducting operations. Additionally, the testosterone administered required weekly injections, elicited supra-physiological concentrations, and marked suppression of endogenous testosterone upon cessation. Therefore, this follow-on study will address those limitations and examine testosterone's efficacy for preserving Solder performance during strenuous operations. Methods In OPS II, 32 males will participate in a randomized, placebo-controlled, double-blind trial. After baseline testing, participants will be administered either testosterone undecanoate (750 mg) or placebo before completing four consecutive, 5-day cycles simulating a multi-stressor, sustained military operation (SUSOPS). SUSOPS will consist of two low-stress days (1000 kcal/day exercise-induced EDef; 8 h/night sleep), followed by three high-stress days (3000 kcal/day and 4 h/night). A 23-day recovery period will follow SUSOPS. Military relevant physical performance is the primary outcome. Secondary outcomes include 4-comparment body composition, muscle and whole-body protein turnover, intramuscular mechanisms, biochemistries, and cognitive function/mood. Conclusions OPS II will determine if testosterone undecanoate safely enhances performance, while attenuating muscle and total mass loss, without impairing cognitive function, during and in recovery from SUSOPS. Trial Registration ClinicalTrials.gov Identifier: NCT04120363.
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Key Words
- Anabolism
- And hypogonadism
- BIA, bioelectrical impedance analysis
- D2O, deuterium
- DSMB, data and safety monitoring board
- DXA, dual-energy x-ray absorptiometry
- ECW, extracellular water
- EDef, energy deficit
- EIEE, exercise-induced energy expenditure
- Energy deficit
- Exercise
- FBR, fractional breakdown rate
- FFM, fat-free mass
- FSR, fractional synthetic rate
- HR, heart rate
- HRR, heart rate reserve
- ICW, intracellular water
- ID, identification
- IRB, Institutional Review Board
- MRE, Meal
- Optimizing Performance for Soldiers Trial I, OPS II
- Optimizing Performance for Soldiers Trial II, PAR-Q+
- Pennington Biomedical Research Center, PLA
- Physical Activity Readiness Questionnaire+, PB
- Ready-to-Eat, OPS I
- Skeletal muscle
- Sleep deprivation
- TBW, total body water
- TDEE, total daily energy expenditure
- TDEI, total daily energy intake
- TEST, testosterone experimental group
- VO2max, maximal cardiorespiratory fitness
- VO2peak, peak oxygen uptake
- WBGT, wet bulb globe temperature
- placebo experimental group, PS
- protein breakdown, PBRC
- protein synthesis, Q
- ratings of perceived exertion, SUSOPS
- repetition maximum, RNA
- respiratory exchange ratio, RM
- ribonucleic acid, RPE
- sustained, multi-stressor military operations
- whole-body nitrogen flux, RER
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Affiliation(s)
- Alyssa N Varanoske
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Melissa N Harris
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Callie Hebert
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Emily E Howard
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Neil M Johannsen
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Steven B Heymsfield
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Frank L Greenway
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Harris R Lieberman
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - David D Church
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Arny A Ferrando
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Jennifer C Rood
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
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Coleman JL, Carrigan CT, Margolis LM. Body composition changes in physically active individuals consuming ketogenic diets: a systematic review. J Int Soc Sports Nutr 2021; 18:41. [PMID: 34090453 PMCID: PMC8180141 DOI: 10.1186/s12970-021-00440-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 05/11/2021] [Indexed: 12/28/2022] Open
Abstract
Background To achieve ideal strength/power to mass ratio, athletes may attempt to lower body mass through reductions in fat mass (FM), while maintaining or increasing fat-free mass (FFM) by manipulating their training regimens and diets. Emerging evidence suggests that consumption of high-fat, ketogenic diets (KD) may be advantageous for reducing body mass and FM, while retaining FFM. Methods A systematic review of the literature was conducted using PubMed and Cochrane Library databases to compare the effects of KD versus control diets (CON) on body mass and composition in physically active populations. Randomized and non-randomized studies were included if participants were healthy (free of chronic disease), physically active men or women age ≥ 18 years consuming KD (< 50 g carbohydrate/d or serum or whole blood β-hydroxybutyrate (βhb) > 0.5 mmol/L) for ≥14 days. Results Thirteen studies (9 parallel and 4 crossover/longitudinal) that met the inclusion criteria were identified. Aggregated results from the 13 identified studies show body mass decreased 2.7 kg in KD and increased 0.3 kg in CON. FM decreased by 2.3 kg in KD and 0.3 kg in CON. FFM decreased by 0.3 kg in KD and increased 0.7 kg in CON. Estimated energy balance based on changes in body composition was − 339 kcal/d in KD and 5 kcal/d in CON. Risk of bias identified some concern of bias primarily due to studies which allowed participants to self-select diet intervention groups, as well as inability to blind participants to the study intervention, and/or longitudinal study design. Conclusion KD can promote mobilization of fat stores to reduce FM while retaining FFM. However, there is variance in results of FFM across studies and some risk-of-bias in the current literature that is discussed in this systematic review. Supplementary Information The online version contains supplementary material available at 10.1186/s12970-021-00440-6.
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Affiliation(s)
- Julie L Coleman
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Building 42, Natick, MA, 01760, USA.,Oak Ridge Institute of Science and Education, Belcamp, MD, USA
| | - Christopher T Carrigan
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Building 42, Natick, MA, 01760, USA
| | - Lee M Margolis
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Building 42, Natick, MA, 01760, USA.
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Karl JP, Margolis LM, Fallowfield JL, Child RB, Martin NM, McClung JP. Military nutrition research: Contemporary issues, state of the science and future directions. Eur J Sport Sci 2021; 22:87-98. [PMID: 33980120 DOI: 10.1080/17461391.2021.1930192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The importance of diet and nutrition to military readiness and performance has been recognized for centuries as dietary nutrients sustain health, protect against illness, and promote resilience, performance and recovery. Contemporary military nutrition research is increasingly inter-disciplinary with emphasis often placed on the broad topics of (1) determining operational nutrition requirements in all environments, (2) characterizing nutritional practices of military personnel relative to the required (role/environment) standards, and (3) developing strategies for improving nutrient delivery and individual choices. This review discusses contemporary issues shared internationally by military nutrition research programmes, and highlights emerging topics likely to influence future military nutrition research and policy. Contemporary issues include improving the diet quality of military personnel, optimizing operational rations, and increasing understanding of biological factors influencing nutrient requirements. Emerging areas include the burgeoning field of precision nutrition and its technological enablers.
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Affiliation(s)
- J Philip Karl
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Lee M Margolis
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Joanne L Fallowfield
- Environmental Medicine and Science Division, Institute of Naval Medicine, Alverstoke, Hampshire, UK
| | - Robert B Child
- School of Chemical Engineering, University of Birmingham, Birmingham, UK
| | - Nicola M Martin
- New Zealand Army, New Zealand Defence Force, Upper Hutt, New Zealand
| | - James P McClung
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA, USA
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Margolis LM, Karl JP, Wilson MA, Coleman JL, Ferrando AA, Young AJ, Pasiakos SM. Metabolomic profiles are reflective of hypoxia-induced insulin resistance during exercise in healthy young adult males. Am J Physiol Regul Integr Comp Physiol 2021; 321:R1-R11. [PMID: 33949213 PMCID: PMC8321788 DOI: 10.1152/ajpregu.00076.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Hypoxia-induced insulin resistance appears to suppress exogenous glucose oxidation during metabolically matched aerobic exercise during acute (<8 h) high-altitude (HA) exposure. However, a better understanding of this metabolic dysregulation is needed to identify interventions to mitigate these effects. The objective of this study was to determine if differences in metabolomic profiles during exercise at sea level (SL) and HA are reflective of hypoxia-induced insulin resistance. Native lowlanders (n = 8 males) consumed 145 g (1.8 g/min) of glucose while performing 80-min of metabolically matched treadmill exercise at SL (757 mmHg) and HA (460 mmHg) after 5-h exposure. Exogenous glucose oxidation and glucose turnover were determined using indirect calorimetry and dual tracer technique ([13C]glucose and [6,6-2H2]glucose). Metabolite profiles were analyzed in serum as change (Δ), calculated by subtracting postprandial/exercised state SL (ΔSL) and HA (ΔHA) from fasted, rested conditions at SL. Compared with SL, exogenous glucose oxidation, glucose rate of disappearance, and glucose metabolic clearance rate (MCR) were lower (P < 0.05) during exercise at HA. One hundred and eighteen metabolites differed between ΔSL and ΔHA (P < 0.05, Q < 0.10). Differences in metabolites indicated increased glycolysis, tricarboxylic acid cycle, amino acid catabolism, oxidative stress, and fatty acid storage, and decreased fatty acid mobilization for ΔHA. Branched-chain amino acids and oxidative stress metabolites, Δ3-methyl-2-oxobutyrate (r = -0.738) and Δγ-glutamylalanine (r = -0.810), were inversely associated (P < 0.05) with Δexogenous glucose oxidation. Δ3-Hydroxyisobutyrate (r = -0.762) and Δ2-hydroxybutyrate/2-hydroxyisobutyrate (r = -0.738) were inversely associated (P < 0.05) with glucose MCR. Coupling global metabolomics and glucose kinetic data suggest that the underlying cause for diminished exogenous glucose oxidative capacity during aerobic exercise is acute hypoxia-mediated peripheral insulin resistance.
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Affiliation(s)
- Lee M Margolis
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - J Philip Karl
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Marques A Wilson
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Julie L Coleman
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts.,Oak Ridge Institute of Science and Education, Oak Ridge, Tennessee
| | - Arny A Ferrando
- Department of Geriatrics, Center for Translational Research in Aging and Longevity, Donald W. Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Andrew J Young
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts.,Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland
| | - Stefan M Pasiakos
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
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Hennigar SR, McClung JP, Hatch-McChesney A, Allen JT, Wilson MA, Carrigan CT, Murphy NE, Teien HK, Martini S, Gwin JA, Karl JP, Margolis LM, Pasiakos SM. Energy deficit increases hepcidin and exacerbates declines in dietary iron absorption following strenuous physical activity: a randomized-controlled cross-over trial. Am J Clin Nutr 2021; 113:359-369. [PMID: 33184627 DOI: 10.1093/ajcn/nqaa289] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 09/22/2020] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Strenuous physical activity promotes inflammation and depletes muscle glycogen, which may increase the iron regulatory hormone hepcidin. Hepcidin reduces dietary iron absorption and may contribute to declines in iron status frequently observed following strenuous physical activity. OBJECTIVES To determine the effects of strenuous physical activity on hepcidin and dietary iron absorption and whether energy deficit compared with energy balance modifies those effects. METHODS This was a randomized, cross-over, controlled-feeding trial in healthy male subjects (n = 10, mean ± SD age: 22.4 ± 5.4 y, weight: 87.3 ± 10.9 kg) with sufficient iron status (serum ferritin 77.0 ± 36.7 ng/mL). Rest measurements were collected before participants began a 72-h simulated sustained military operation (SUSOPS), designed to elicit high energy expenditure, glycogen depletion, and inflammation, followed by a 7-d recovery period. Two 72-h SUSOPS trials were performed where participants were randomly assigned to consume either energy matched (±10%) to their individual estimated total daily energy expenditure (BAL) or energy at 45% of total daily energy expenditure to induce energy deficit (DEF). On the rest day and at the completion of BAL and DEF, participants consumed a beverage containing 3.8 mg of a stable iron isotope, and plasma isotope appearance was measured over 6 h. RESULTS Muscle glycogen declined during DEF and was preserved during BAL (-188 ± 179 mmol/kg, P-adjusted < 0.01). Despite similar increases in interleukin-6, plasma hepcidin increased during DEF but not BAL, such that hepcidin was 108% greater during DEF compared with BAL (7.8 ± 12.2 ng/mL, P-adjusted < 0.0001). Peak plasma isotope appearance at 120 min was 74% lower with DEF (59 ± 38% change from 0 min) and 49% lower with BAL (117 ± 81%) compared with rest (230 ± 97%, P-adjusted < 0.01 for all comparisons). CONCLUSIONS Strenuous physical activity decreases dietary iron absorption compared with rest. Energy deficit exacerbates both the hepcidin response to physical activity and declines in dietary iron absorption compared with energy balance. This trial was registered at clinicaltrials.gov as NCT03524690.
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Affiliation(s)
- Stephen R Hennigar
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA.,Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute of Science and Technology, Belcamp, MD, USA
| | - James P McClung
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Adrienne Hatch-McChesney
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Jillian T Allen
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute of Science and Technology, Belcamp, MD, USA
| | - Marques A Wilson
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Christopher T Carrigan
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Nancy E Murphy
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Hilde K Teien
- Norwegian Defense Research Establishment, Kjeller, Norway
| | - Svein Martini
- Norwegian Defense Research Establishment, Kjeller, Norway
| | - Jess A Gwin
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute of Science and Technology, Belcamp, MD, USA
| | - J Philip Karl
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Lee M Margolis
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
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Gwin JA, Church DD, Hatch-McChesney A, Allen JT, Wilson MA, Varanoske AN, Carrigan CT, Murphy NE, Margolis LM, Carbone JW, Wolfe RR, Ferrando AA, Pasiakos SM. Essential amino acid-enriched whey enhances post-exercise whole-body protein balance during energy deficit more than iso-nitrogenous whey or a mixed-macronutrient meal: a randomized, crossover study. J Int Soc Sports Nutr 2021; 18:4. [PMID: 33413462 PMCID: PMC7791816 DOI: 10.1186/s12970-020-00401-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 12/10/2020] [Indexed: 02/07/2023] Open
Abstract
Background The effects of ingesting varying essential amino acid (EAA)/protein-containing food formats on protein kinetics during energy deficit are undetermined. Therefore, recommendations for EAA/protein food formats necessary to optimize both whole-body protein balance and muscle protein synthesis (MPS) during energy deficit are unknown. We measured protein kinetics after consuming iso-nitrogenous amounts of free-form essential amino acid-enriched whey (EAA + W; 34.7 g protein, 24 g EAA sourced from whey and free-form EAA), whey (WHEY; 34.7 g protein, 18.7 g EAA), or a mixed-macronutrient meal (MEAL; 34.7 g protein, 11.4 g EAA) after exercise during short-term energy deficit. Methods Ten adults (mean ± SD; 21 ± 4 y; 25.7 ± 1.7 kg/m2) completed a randomized, double-blind crossover study consisting of three, 5 d energy-deficit periods (− 30 ± 3% of total energy requirements), separated by 14 d. Whole-body protein synthesis (PS), breakdown (PB), and net balance (NET) were determined at rest and in response to combination exercise consisting of load carriage treadmill walking, deadlifts, and box step-ups at the end of each energy deficit using L-[2H5]-phenylalanine and L-[2H2]-tyrosine infusions. Treatments were ingested immediately post-exercise. Mixed-muscle protein synthesis (mixed-MPS) was measured during exercise through recovery. Results Change (Δ postabsorptive + exercise to postprandial + recovery [mean treatment difference (95%CI)]) in whole-body (g/180 min) PS was 15.8 (9.8, 21.9; P = 0.001) and 19.4 (14.8, 24.0; P = 0.001) greater for EAA + W than WHEY and MEAL, respectively, with no difference between WHEY and MEAL. ΔPB was − 6.3 (− 11.5, − 1.18; P = 0.02) greater for EAA + W than WHEY and − 7.7 (− 11.9, − 3.6; P = 0.002) greater for MEAL than WHEY, with no difference between EAA + W and MEAL. ΔNET was 22.1 (20.5, 23.8; P = 0.001) and 18.0 (16.5, 19.5; P = 0.00) greater for EAA + W than WHEY and MEAL, respectively, while ΔNET was 4.2 (2.7, 5.6; P = 0.001) greater for MEAL than WHEY. Mixed-MPS did not differ between treatments. Conclusions While mixed-MPS was similar across treatments, combining free-form EAA with whey promotes greater whole-body net protein balance during energy deficit compared to iso-nitrogenous amounts of whey or a mixed-macronutrient meal. Trial registration ClinicalTrials.gov, Identifier no. NCT04004715. Retrospectively registered 28 June 2019, first enrollment 6 June 2019
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Affiliation(s)
- Jess A Gwin
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg. 42, Natick, MA, 01760, USA.,Oak Ridge Institute for Science and Education, Belcamp, MD, USA
| | - David D Church
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Adrienne Hatch-McChesney
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg. 42, Natick, MA, 01760, USA
| | - Jillian T Allen
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg. 42, Natick, MA, 01760, USA.,Oak Ridge Institute for Science and Education, Belcamp, MD, USA
| | - Marques A Wilson
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg. 42, Natick, MA, 01760, USA
| | - Alyssa N Varanoske
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg. 42, Natick, MA, 01760, USA.,Oak Ridge Institute for Science and Education, Belcamp, MD, USA
| | - Christopher T Carrigan
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg. 42, Natick, MA, 01760, USA
| | - Nancy E Murphy
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg. 42, Natick, MA, 01760, USA
| | - Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg. 42, Natick, MA, 01760, USA
| | - John W Carbone
- School of Health Sciences, Eastern Michigan University, Ypsilanti, MI, USA
| | - Robert R Wolfe
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Arny A Ferrando
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg. 42, Natick, MA, 01760, USA.
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Howard EE, Margolis LM, Berryman CE, Lieberman HR, Karl JP, Young AJ, Montano MA, Evans WJ, Rodriguez NR, Johannsen NM, Gadde KM, Harris MN, Rood JC, Pasiakos SM. Testosterone supplementation upregulates androgen receptor expression and translational capacity during severe energy deficit. Am J Physiol Endocrinol Metab 2020; 319:E678-E688. [PMID: 32776828 PMCID: PMC7750513 DOI: 10.1152/ajpendo.00157.2020] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Testosterone supplementation during energy deficit promotes whole body lean mass accretion, but the mechanisms underlying that effect remain unclear. To elucidate those mechanisms, skeletal muscle molecular adaptations were assessed from muscle biopsies collected before, 1 h, and 6 h after exercise and a mixed meal (40 g protein, 1 h postexercise) following 14 days of weight maintenance (WM) and 28 days of an exercise- and diet-induced 55% energy deficit (ED) in 50 physically active nonobese men treated with 200 mg testosterone enanthate/wk (TEST) or placebo (PLA) during the ED. Participants (n = 10/group) exhibiting substantial increases in leg lean mass and total testosterone (TEST) were compared with those exhibiting decreases in both of these measures (PLA). Resting androgen receptor (AR) protein content was higher and fibroblast growth factor-inducible 14 (Fn14), IL-6 receptor (IL-6R), and muscle ring-finger protein-1 gene expression was lower in TEST vs. PLA during ED relative to WM (P < 0.05). Changes in inflammatory, myogenic, and proteolytic gene expression did not differ between groups after exercise and recovery feeding. Mechanistic target of rapamycin signaling (i.e., translational efficiency) was also similar between groups at rest and after exercise and the mixed meal. Muscle total RNA content (i.e., translational capacity) increased more during ED in TEST than PLA (P < 0.05). These findings indicate that attenuated proteolysis at rest, possibly downstream of AR, Fn14, and IL-6R signaling, and increased translational capacity, not efficiency, may drive lean mass accretion with testosterone administration during energy deficit.
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Affiliation(s)
- Emily E Howard
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee
- University of Connecticut, Storrs, Connecticut
| | - Lee M Margolis
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Claire E Berryman
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee
- Florida State University, Tallahassee, Florida
| | - Harris R Lieberman
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - J Philip Karl
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Andrew J Young
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee
| | - Monty A Montano
- MyoSyntax Corporation, Worcester, Massachusetts
- Harvard Medical School, Boston, Massachusetts
- Brigham and Women's Hospital, Boston, Massachusetts
| | - William J Evans
- University of California at Berkeley, Berkeley, California
- Duke University, Durham, North Carolina
| | | | - Neil M Johannsen
- Louisiana State University's Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Kishore M Gadde
- Louisiana State University's Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Melissa N Harris
- Louisiana State University's Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Jennifer C Rood
- Louisiana State University's Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Stefan M Pasiakos
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
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Varanoske AN, Margolis LM, Pasiakos SM. Effects of Testosterone on Serum Concentrations, Fat-free Mass, and Physical Performance by Population: A Meta-analysis. J Endocr Soc 2020; 4:bvaa090. [PMID: 32864543 DOI: 10.1210/jendso/bvaa090] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 06/29/2020] [Indexed: 11/19/2022] Open
Abstract
Testosterone (T) administration (TA) increases serum T and fat-free mass (FFM). Although TA-mediated increases in FFM may enhance physical performance, the data are largely equivocal, which may be due to differences in study populations, the magnitude of change in serum T and FFM, or the performance metrics. This meta-analysis explored effects of TA on serum T, FFM, and performance. Associations between increases in serum T and FFM were assessed, and whether changes in serum T or FFM, study population, or the performance metrics affected performance was determined. A systematic review of double-blind randomized trials comparing TA versus placebo on serum T, FFM, and performance was performed. Data were extracted from 20 manuscripts. Effect sizes (ESs) were assessed using Hedge's g and a random effects model. Data are presented as ES (95% confidence interval). No significant correlation between changes in serum T and FFM was observed (P = .167). Greater increases in serum T, but not FFM, resulted in larger effects on performance. Larger increases in testosterone (7.26 [0.76-13.75]) and FFM (0.80 [0.20-1.41]) were observed in young males, but performance only improved in diseased (0.16 [0.05-0.28]) and older males (0.19 [0.10-0.29]). TA increased lower body (0.12 [0.07-0.18]), upper body (0.26 [0.11-0.40]), and handgrip (0.13 [0.04-0.22]) strength, lower body muscular endurance (0.38 [0.09-0.68]), and functional performance (0.20 [0.00-0.41]), but not lower body power or aerobic endurance. TA elicits increases in serum T and FFM in younger, older, and diseased males; however, the performance-enhancing effects of TA across studies were small, observed mostly in muscular strength and endurance, and only in older and diseased males.
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Affiliation(s)
- Alyssa N Varanoske
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts.,Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee
| | - Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Stefan M Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
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Margolis LM, O’Hara JP, Griffiths A, Wolfe RW, Young AJ, Pasiakos SM. Isotope tracer assessment of exogenous glucose oxidation during aerobic exercise in hypoxia. Physiol Rep 2020; 8:e14594. [PMID: 32959522 PMCID: PMC7507501 DOI: 10.14814/phy2.14594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 08/19/2020] [Indexed: 11/24/2022] Open
Affiliation(s)
- Lee M. Margolis
- U.S. Army Research Institute of Environmental MedicineNatickMAUSA
| | | | | | - Robert W. Wolfe
- Department of GeriatricsCenter for Translational Research in Aging and LongevityDonald W. Reynolds Institute on AgingUniversity of Arkansas for Medical SciencesLittle RockARUSA
| | - Andrew J. Young
- U.S. Army Research Institute of Environmental MedicineNatickMAUSA
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Murphy NE, Carrigan CT, Margolis LM. High-Fat Ketogenic Diets and Physical Performance: A Systematic Review. Adv Nutr 2020; 12:223-233. [PMID: 32865567 PMCID: PMC7850028 DOI: 10.1093/advances/nmaa101] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/13/2020] [Accepted: 07/28/2020] [Indexed: 12/15/2022] Open
Abstract
Use of high-fat, ketogenic diets (KDs) to support physical performance has grown in popularity over recent years. While these diets enhance fat and reduce carbohydrate oxidation during exercise, the impact of a KD on physical performance remains controversial. The objective of this work was to assess the effect of KDs on physical performance compared with mixed macronutrient diets [control (CON)]. A systematic review of the literature was conducted using PubMed and Cochrane Library databases. Randomized and nonrandomized studies were included if participants were healthy (free of chronic disease), nonobese [BMI (kg/m2) <30], trained or untrained men or women consuming KD (<50 g carbohydrate/d or serum or whole-blood β-hydroxybutyrate >0.5 mmol/L) compared with CON (fat, 12-38% of total energy intake) diets for ≥14 d, followed by a physical performance test. Seventeen studies (10 parallel, 7 crossover) with 29 performance (13 endurance, 16 power or strength) outcomes were identified. Of the 13 endurance-type performance outcomes, 3 (1 time trial, 2 time-to-exhaustion) reported lower and 10 (4 time trials, 6 time-to-exhaustion) reported no difference in performance between the KD compared with CON. Of the 16 power or strength performance outcomes, 3 (1 power, 2 strength) reported lower, 11 (4 power, 7 strength) no difference, and 2 (power) enhanced performance in the KD compared with the CON. Risk of bias identified some concern of bias primarily due to studies allowing participants to self-select diet intervention groups and the inability to blind participants to the study intervention. Overall, the majority of null results across studies suggest that a KD does not have a positive or negative impact on physical performance compared with a CON diet. However, discordant results between studies may be due to multiple factors, such as the duration consuming study diets, training status, performance test, and sex differences, which will be discussed in this systematic review.
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Affiliation(s)
- Nancy E Murphy
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Christopher T Carrigan
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
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Hatch-McChesney A, Gwin JA, Church DD, Wolfe RR, Margolis LM, Ferrando AA, Pasiakos SM. Energy Deficit Attenuates Muscle Protein Synthetic Responses To Essential Amino Acids. Med Sci Sports Exerc 2020. [DOI: 10.1249/01.mss.0000679656.24140.cb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Gwin JA, Church DD, Hatch-McChesney A, Howard EE, Carrigan CT, Murphy NE, Wilson MA, Margolis LM, Carbone JW, Wolfe RR, Ferrando AA, Pasiakos SM. High And Standard Free-form EAA Intake Equally Stimulate Muscle Protein Synthesis During Moderate Energy Deficit. Med Sci Sports Exerc 2020. [DOI: 10.1249/01.mss.0000671168.51514.52] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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39
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Howard EE, Margolis LM, Berryman CE, Lieberman HR, Karl JP, Young AJ, Montano MA, Evans WJ, Rodriguez NR, Johannsen NM, Gadde KM, Harris MN, Rood JC, Pasiakos SM. Testosterone Supplementation Upregulates Myogenesis And Attenuates Proteolytic Gene Expression During Severe Energy Deficit. Med Sci Sports Exerc 2020. [DOI: 10.1249/01.mss.0000670164.42362.28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Margolis LM, Wilson MA, Whitney CC, Carrigan CT, Murphy NE, Radcliffe PN, Gwin JA, Church DD, Wolfe RR, Ferrando AA, Young AJ, Pasiakos SM. Acute Hypoxia Suppresses Exogenous Glucose Rate Of Appearance And Metabolic Clearance Rate During Steady-state Aerobic Exercise. Med Sci Sports Exerc 2020. [DOI: 10.1249/01.mss.0000680744.41183.d1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Varanoske AN, Margolis LM, Pasiakos SM. Effects Of Exogenous Testosterone Administration On Lean Body Mass And Physical Performance: A Meta-analysis. Med Sci Sports Exerc 2020. [DOI: 10.1249/01.mss.0000678880.36821.5d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Wilson M, Armstrong NJ, Barringer ND, Karis AJ, McClung JP, Pasiakos SM, Margolis LM. Characterization Of Energy Expenditure, Body Composition, And Androgen Status During Summer And Winter Marine Mountain Warfare Training. Med Sci Sports Exerc 2020. [DOI: 10.1249/01.mss.0000676920.51821.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Affiliation(s)
| | - Kevin S O'Fallon
- Soldier Performance Optimization Directorate, Combat Capabilities Development Command Soldier Center, Natick, MA, USA
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Margolis LM, Young AJ, Pasiakos SM. Re: "High Carbohydrate Ingestion in High Altitude" by Pesta et al. High Alt Med Biol 2020; 21:213-214. [PMID: 32239974 DOI: 10.1089/ham.2020.0007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine (USARIEM), Natick, Massachusetts, USA
| | - Andrew J Young
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine (USARIEM), Natick, Massachusetts, USA.,Oak Ridge Institute of Science and Education, Oak Ridge, Tennessee, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine (USARIEM), Natick, Massachusetts, USA
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Margolis LM, O'Fallon KS. Utility of Ketone Supplementation to Enhance Physical Performance: A Systematic Review. Adv Nutr 2020; 11:412-419. [PMID: 31586177 PMCID: PMC7442417 DOI: 10.1093/advances/nmz104] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/30/2019] [Accepted: 08/30/2019] [Indexed: 11/14/2022] Open
Abstract
Ingesting exogenous ketone bodies has been touted as producing ergogenic effects by altering substrate metabolism; however, research findings from recent studies appear inconsistent. This systematic review aimed to aggregate data from the current literature to examine the impact of consuming ketone supplements on enhancing physical performance. A systematic search was performed for randomized controlled trials that measured physical performance outcomes in response to ingesting exogenous ketone supplements compared with a control (nutritive or non-nutritive) in humans. A total of 161 articles were screened. Data were extracted from 10 eligible studies (112 participants; 109 men, 3 women ) containing 16 performance outcomes [lower-body power (n = 8) and endurance performance (n = 8)]. Ketone supplements were grouped as ketone esters (n = 8) or ketone salts/precursors (n = 8). Of the 16 performance outcomes identified by the systematic review, 3 reported positive, 10 reported null, and 3 reported negative effects of ketone supplementation on physical performance compared with controls. Heterogeneity was detected for lower-body power ( Q = 40, I2 = 83%, P < 0.01) and endurance performance (Q = 95, I2 = 93%, P < 0.01) between studies. Similarly high levels of heterogeneity were detected in studies providing ketone esters (Q = 111, I2 = 93%, P < 0.01), and to a lesser extent studies with ketone salts/precursors (Q = 25, I2 = 72%, P < 0.01). Heterogeneity across studies makes it difficult to conclude any benefit or detriment to consuming ketone supplements on physical performance. This systematic review discusses factors within individual studies that may contribute to discordant outcomes across investigations to elucidate if there is sufficient evidence to warrant recommendation of consuming exogenous ketone supplements to enhance physical performance.
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Affiliation(s)
- Lee M Margolis
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA,Address correspondence to LMM (e-mail: )
| | - Kevin S O'Fallon
- Soldier Performance Optimization Directorate, Combat Capabilities Development Command Soldier Center, Natick, MA, USA
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Margolis LM, Wilson MA, Whitney CC, Carrigan CT, Murphy NE, Radcliffe PN, Gwin JA, Church DD, Wolfe RR, Ferrando AA, Young AJ, Pasiakos SM. Acute hypoxia reduces exogenous glucose oxidation, glucose turnover, and metabolic clearance rate during steady-state aerobic exercise. Metabolism 2020; 103:154030. [PMID: 31778707 DOI: 10.1016/j.metabol.2019.154030] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 10/30/2019] [Accepted: 11/25/2019] [Indexed: 12/21/2022]
Abstract
BACKGROUND Exogenous carbohydrate oxidation is lower during steady-state aerobic exercise in native lowlanders sojourning at high altitude (HA) compared to sea level (SL). However, the underlying mechanism contributing to reduction in exogenous carbohydrate oxidation during steady-state aerobic exercise performed at HA has not been explored. OBJECTIVE To determine if alterations in glucose rate of appearance (Ra), disappearance (Rd) and metabolic clearance rate (MCR) at HA provide a mechanism for explaining the observation of lower exogenous carbohydrate oxidation compared to during metabolically-matched, steady-state exercise at SL. METHODS Using a randomized, crossover design, native lowlanders (n = 8 males, mean ± SD, age: 23 ± 2 yr, body mass: 87 ± 10 kg, and VO2peak: SL 4.3 ± 0.2 L/min and HA 2.9 ± 0.2 L/min) consumed 145 g (1.8 g/min) of glucose while performing 80-min of metabolically-matched (SL: 1.66 ± 0.14 V̇O2 L/min 329 ± 28 kcal, HA: 1.59 ± 0.10 V̇O2 L/min, 320 ± 19 kcal) treadmill exercise in SL (757 mmHg) and HA (460 mmHg) conditions after a 5-h exposure. Substrate oxidation rates (g/min) and glucose turnover (mg/kg/min) during exercise were determined using indirect calorimetry and dual tracer technique (13C-glucose oral ingestion and [6,6-2H2]-glucose primed, continuous infusion). RESULTS Total carbohydrate oxidation was higher (P < 0.05) at HA (2.15 ± 0.32) compared to SL (1.39 ± 0.14). Exogenous glucose oxidation rate was lower (P < 0.05) at HA (0.35 ± 0.07) than SL (0.44 ± 0.05). Muscle glycogen oxidation was higher at HA (1.67 ± 0.26) compared to SL (0.83 ± 0.13). Total glucose Ra was lower (P < 0.05) at HA (12.3 ± 1.5) compared to SL (13.8 ± 2.0). Exogenous glucose Ra was lower (P < 0.05) at HA (8.9 ± 1.3) compared to SL (10.9 ± 2.2). Glucose Rd was lower (P < 0.05) at HA (12.7 ± 1.7) compared to SL (14.3 ± 2.0). MCR was lower (P < 0.05) at HA (9.0 ± 1.8) compared to SL (12.1 ± 2.3). Circulating glucose and insulin concentrations were higher in response carbohydrate intake during exercise at HA compared to SL. CONCLUSION Novel results from this investigation suggest that reductions in exogenous carbohydrate oxidation at HA may be multifactorial; however, the apparent insensitivity of peripheral tissue to glucose uptake may be a primary determinate.
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Affiliation(s)
- Lee M Margolis
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America.
| | - Marques A Wilson
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Claire C Whitney
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Christopher T Carrigan
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Nancy E Murphy
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Patrick N Radcliffe
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America; Oak Ridge Institute of Science and Education, Oak Ridge, TN, United States of America
| | - Jess A Gwin
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America; Oak Ridge Institute of Science and Education, Oak Ridge, TN, United States of America
| | - David D Church
- Department of Geriatrics, Center for Translational Research in Aging and Longevity, Donald W. Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Robert R Wolfe
- Department of Geriatrics, Center for Translational Research in Aging and Longevity, Donald W. Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Arny A Ferrando
- Department of Geriatrics, Center for Translational Research in Aging and Longevity, Donald W. Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Andrew J Young
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America; Oak Ridge Institute of Science and Education, Oak Ridge, TN, United States of America
| | - Stefan M Pasiakos
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America
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Margolis LM, Wilson MA, Whitney CC, Carrigan CT, Murphy NE, Hatch AM, Montain SJ, Pasiakos SM. Exercising with low muscle glycogen content increases fat oxidation and decreases endogenous, but not exogenous carbohydrate oxidation. Metabolism 2019; 97:1-8. [PMID: 31095946 DOI: 10.1016/j.metabol.2019.05.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 05/01/2019] [Accepted: 05/10/2019] [Indexed: 01/05/2023]
Abstract
BACKGROUND Initiating aerobic exercise with low muscle glycogen content promotes greater fat and less endogenous carbohydrate oxidation during exercise. However, the extent exogenous carbohydrate oxidation increases when exercise is initiated with low muscle glycogen is unclear. PURPOSE Determine the effects of muscle glycogen content at the onset of exercise on whole-body and muscle substrate metabolism. METHODS Using a randomized, crossover design, 12 men (mean ± SD, age: 21 ± 4 y; body mass: 83 ± 11 kg; VO2peak: 44 ± 3 mL/kg/min) completed 2 cycle ergometry glycogen depletion trials separated by 7-d, followed by a 24-h refeeding to elicit low (LOW; 1.5 g/kg carbohydrate, 3.0 g/kg fat) or adequate (AD; 6.0 g/kg carbohydrate, 1.0 g/kg fat) glycogen stores. Participants then performed 80 min of steady-state cycle ergometry (64 ± 3% VO2peak) while consuming a carbohydrate drink (95 g glucose +51 g fructose; 1.8 g/min). Substrate oxidation (g/min) was determined by indirect calorimetry and 13C. Muscle glycogen (mmol/kg dry weight), pyruvate dehydrogenase (PDH) activity, and gene expression were assessed in muscle. RESULTS Initiating steady-state exercise with LOW (217 ± 103) or AD (396 ± 70; P < 0.05) muscle glycogen did not alter exogenous carbohydrate oxidation (LOW: 0.84 ± 0.14, AD: 0.87 ± 0.16; P > 0.05) during exercise. Endogenous carbohydrate oxidation was lower and fat oxidation was higher in LOW (0.75 ± 0.29 and 0.55 ± 0.10) than AD (1.17 ± 0.29 and 0.38 ± 0.13; all P < 0.05). Before and after exercise PDH activity was lower (P < 0.05) and transcriptional regulation of fat metabolism (FAT, FABP, CPT1a, HADHA) was higher (P < 0.05) in LOW than AD. CONCLUSION Initiating exercise with low muscle glycogen does not impair exogenous carbohydrate oxidative capacity, rather, to compensate for lower endogenous carbohydrate oxidation acute adaptations lead to increased whole-body and skeletal muscle fat oxidation.
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Affiliation(s)
- Lee M Margolis
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America; Oak Ridge Institute of Science and Education, Oak Ridge, TN, United States of America.
| | - Marques A Wilson
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Claire C Whitney
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Christopher T Carrigan
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Nancy E Murphy
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Adrienne M Hatch
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Scott J Montain
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Stefan M Pasiakos
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States of America
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Young AJ, Margolis LM, Pasiakos SM. Commentary on the effects of hypoxia on energy substrate use during exercise. J Int Soc Sports Nutr 2019; 16:28. [PMID: 31299980 PMCID: PMC6624974 DOI: 10.1186/s12970-019-0295-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 07/03/2019] [Indexed: 11/23/2022] Open
Abstract
A recently published meta-analysis in this journal analyzed findings from studies comparing substrate use during exercise at the same relative intensity (i.e., % V̇O2max) in normoxic and hypoxic conditions. The primary conclusion was that hypoxia had no consistent effects on the contribution of carbohydrate oxidation to total energy expenditure. However, findings from studies comparing exercise at the same absolute intensity in normoxic as hypoxic conditions were not considered in the meta-analysis. Assessment of substrate oxidation using matched absolute intensity leads to different conclusions regarding hypoxic effects on fuel use during exercise, and that experimental model, (i.e., comparing responses to exercise at matched absolute intensity) has more practical application for developing nutritional recommendations for high-altitude sojourners. This commentary will discuss those differences.
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Affiliation(s)
- Andrew J Young
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg 42, Natick, MA, 01760, USA. .,Oak Ridge Institute for Science and Education, Belcamp, MD, 21017, USA.
| | - Lee M Margolis
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg 42, Natick, MA, 01760, USA
| | - Stefan M Pasiakos
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg 42, Natick, MA, 01760, USA
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Pasiakos SM, Wilson MA, Whitney CC, Carrigan CT, Murphy NE, Hatch AM, Montain SJ, Margolis LM. Transcriptional Regulation Of Substrate Metabolism Following Carbohydrate Ingestion During Exercise Initiated With Different Glycogen Concentrations. Med Sci Sports Exerc 2019. [DOI: 10.1249/01.mss.0000562794.56072.dc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Margolis LM, Wilson MA, Whitney CC, Carrigan CT, Murphy NE, Hatch AM, Montain SJ, Pasiakos SM. Low Muscle Glycogen Content Does Not Alter Exogenous Carbohydrate Oxidation During Aerobic Exercise. Med Sci Sports Exerc 2019. [DOI: 10.1249/01.mss.0000562796.33201.88] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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