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Talarico Neto T, Magraner JM, Hahns Júnior HC, Ferreira L, Martinelli Júnior CE, Tourinho Filho H. Biphasic Kinetics of IGF-I and IGFBP-3 in Response to Military Field Training in Brazilian Air Force Recruits. Mil Med 2024; 189:e1417-e1422. [PMID: 38687564 PMCID: PMC11221556 DOI: 10.1093/milmed/usae097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 10/10/2023] [Accepted: 03/14/2024] [Indexed: 05/02/2024] Open
Abstract
INTRODUCTION Insulin-like growth factor type I (IGF-I) has gained considerable notoriety in military training, primarily because it is responsible for energy deficits and sensitive to an inadequate protein intake, which are situations that are commonly experienced in specific military operations. Therefore, this study aimed to assess the kinetics of IGF-I and insulin-like growth factor binding protein type 3 (IGFBP-3) in a 4-day military field training exercise. MATERIALS AND METHODS The sample comprised 12 male soldiers (21.71 ± 1.64 years). Changes were assessed at 3 times: time 1-basal (control week); time 2-after specific military field training; and time 3-1 week after the specific training (control week). Changes in body composition and serum levels of IGF-I and IGFBP-3 were observed. RESULTS The main finding of this study was it verified the biphasic kinetics of both IGF-I and IGFBP-3 at the 3 times observed, that is, a significant drop from time 1 (basal-IGF-I: 189 ng/mL and IGFBP-3: 4.71 mg/L) to time 2 (immediately after military training-IGF-I: 162 ng/mL and IGFBP-3: 4.08 mg/L) and a subsequent recovery of these markers, with a significant increase from time 2 (immediately after military training) to time 3 (a week after military training-IGF-I: 199 ng/mL and IGFBP-3: 4.96 mg/L). CONCLUSIONS It can be concluded that IGF-I and IGFBP-3 levels respond quickly to the stimuli caused by military training, especially after specific field training. However, the same markers quickly return to their basal values after this type of training finishes, simply by following the daily routine of the battalion in the control weeks, with no specific intervention being necessary.
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Affiliation(s)
- Thomaz Talarico Neto
- School of Physical Education and Sport of Ribeirao Preto-EEFERP/USP, University of Sao Paulo-USP; 3900 Bandeirantes Avenue-Campus da USP, Ribeirão Preto, SP 14049-900, Brazil
| | - José Maurício Magraner
- Brazilian Air Force Academy-AFA, Pirassununga, SP 13643-000, Brazil
- School of Physical Education-FEF/UNICAMP, State University of Campinas; Cidade Universitária Zeferino Vaz-Barão Geraldo, Campinas, SP 13083-970, Brazil
| | - Higino Carlos Hahns Júnior
- School of Physical Education and Sport of Ribeirao Preto-EEFERP/USP, University of Sao Paulo-USP; 3900 Bandeirantes Avenue-Campus da USP, Ribeirão Preto, SP 14049-900, Brazil
| | | | - Carlos Eduardo Martinelli Júnior
- Faculty of Medicine of Ribeirão Preto, University of Sao Paulo-USP; 3900 Bandeirantes Avenue-Campus da USP, Ribeirão Preto, SP 14049-900, Brazil
| | - Hugo Tourinho Filho
- School of Physical Education and Sport of Ribeirao Preto-EEFERP/USP, University of Sao Paulo-USP; 3900 Bandeirantes Avenue-Campus da USP, Ribeirão Preto, SP 14049-900, Brazil
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Drole K, Pori P, Jerin A, Kren A, Paravlic AH. Anabolic/Catabolic Hormone Imbalance but Still Jumping Further? Negative Association of Free Testosterone With Jumping Performance in Elite Handball Players Following a Preparatory Period. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 2024:1-7. [PMID: 38941621 DOI: 10.1080/02701367.2024.2353715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 05/05/2024] [Indexed: 06/30/2024]
Abstract
Purpose: The present study investigated the effects of a 10-week preparatory training period on biomarkers and jumping performance and associations of changes in biomarkers, load, and jumping performance from the beginning (PRE) to the end of the preparatory period (POST) in elite handball players. Methods: Seventeen elite handball players competing in the first Slovenian men's League were recruited. Training, competition and academic loads were reported weekly, while biomarkers and jumping performance were assessed at PRE and POST. Results: At POST, decreased levels of free testosterone (large effect size [ES] = -1.69, p < .001) and free testosterone to cortisol ratio [FTCR] (large ES = -.95, p = .004) were observed; whereas, better performance on the single leg lateral hop test [SLLH] (large ES = .85, p = .007) and single leg triple hop test [SLTH] (large ES = 1.05, p = .002) were observed compared to PRE. Furthermore, changes in FTCR correlated with changes in cortisol (high r = -.751, p = .001), SLLH (moderate r = -.603, p = .022), and SLTH (moderate r = -.643, p = .013), while changes in free testosterone correlated with SLTH (moderate r = -.645, p = .013). Conclusions: High intensity trainings with a saturated competition schedule can result in disturbed anabolic/catabolic hormone ratio observed through FTCR decrease, which could indicate either an optimal state or early exhaustiveness. It seems that SLLH and SLTH are more sensitive to changes in biomarkers than a single leg hop test. Sport professionals may use the results for individualized monitoring of an athlete's health and performance, specifically, as an aid for adjusting training loads accordingly to prevent performance declines and potential injury/illness events.
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Affiliation(s)
| | | | - Aleš Jerin
- University of Ljubljana
- University Medical Centre Ljubljana
| | | | - Armin H Paravlic
- University of Ljubljana
- Masaryk University
- Science and Research Centre Koper, Institute for Kinesiology Research
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Anderson RE, Casperson SL, Kho H, Flack KD. The Role of Dietary Protein in Body Weight Regulation among Active-Duty Military Personnel during Energy Deficit: A Systematic Review. Nutrients 2023; 15:3948. [PMID: 37764730 PMCID: PMC10536394 DOI: 10.3390/nu15183948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 09/06/2023] [Accepted: 09/09/2023] [Indexed: 09/29/2023] Open
Abstract
Active-duty military personnel are subjected to sustained periods of energy deficit during combat and training, leaving them susceptible to detrimental reductions in body weight. The importance of adequate dietary protein intake during periods of intense physical training is well established, where previous research has primarily focused on muscle protein synthesis, muscle recovery, and physical performance. Research on how protein intake may influence body weight regulation in this population is lacking; therefore, the objective of this review was to evaluate the role of dietary protein in body weight regulation among active-duty military during an energy deficit. A literature search based on fixed inclusion and exclusion criteria was performed. English language peer-reviewed journal articles from inception to 3 June 2023 were selected for extraction and quality assessment. Eight studies were identified with outcomes described narratively. The study duration ranged from eight days to six months. Protein was directly provided to participants in all studies except for one. Three studies supplied additional protein via supplementation. The Downs and Black Checklist was used to assess study quality. Five studies were classified as good, two as fair, and one as excellent. All studies reported mean weight loss following energy deficit: the most severe was 4.0 kg. Protein dose during energy deficit varied from 0.5 g/kg/day to 2.4 g/kg/day. Six studies reported mean reductions in fat mass, with the largest being 4.5 kg. Four studies reported mean reductions in fat-free mass, while two studies reported an increase. Results support the recommendation that greater than 0.8 g/kg/day is necessary to mitigate the impact of energy deficit on a decline in lean body mass, while intakes up to 1.6 g/kg/day may be preferred. However, exact recommendations cannot be inferred as the severity and duration of energy deficit varied across studies. Longer and larger investigations are needed to elucidate protein's role during energy deficit in active-duty military.
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Affiliation(s)
- Robert E. Anderson
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27517, USA
| | - Shanon L. Casperson
- Grand Forks Human Nutrition Research Center, Agricultural Research Service, U.S. Department of Agriculture, Grand Forks, ND 58203, USA
| | - Hannah Kho
- Department of Dietetics and Human Nutrition, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40506, USA
| | - Kyle D. Flack
- Department of Dietetics and Human Nutrition, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40506, USA
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Stellingwerff T, Mountjoy M, McCluskey WT, Ackerman KE, Verhagen E, Heikura IA. Review of the scientific rationale, development and validation of the International Olympic Committee Relative Energy Deficiency in Sport Clinical Assessment Tool: V.2 (IOC REDs CAT2)-by a subgroup of the IOC consensus on REDs. Br J Sports Med 2023; 57:1109-1118. [PMID: 37752002 DOI: 10.1136/bjsports-2023-106914] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/14/2023] [Indexed: 09/28/2023]
Abstract
Relative Energy Deficiency in Sport (REDs) has various different risk factors, numerous signs and symptoms and is heavily influenced by one's environment. Accordingly, there is no singular validated diagnostic test. This 2023 International Olympic Committee's REDs Clinical Assessment Tool-V.2 (IOC REDs CAT2) implements a three-step process of: (1) initial screening; (2) severity/risk stratification based on any identified REDs signs/symptoms (primary and secondary indicators) and (3) a physician-led final diagnosis and treatment plan developed with the athlete, coach and their entire health and performance team. The CAT2 also introduces a more clinically nuanced four-level traffic-light (green, yellow, orange and red) severity/risk stratification with associated sport participation guidelines. Various REDs primary and secondary indicators have been identified and 'weighted' in terms of scientific support, clinical severity/risk and methodological validity and usability, allowing for objective scoring of athletes based on the presence or absence of each indicator. Early draft versions of the CAT2 were developed with associated athlete-testing, feedback and refinement, followed by REDs expert validation via voting statements (ie, online questionnaire to assess agreement on each indicator). Physician and practitioner validity and usability assessments were also implemented. The aim of the IOC REDs CAT2 is to assist qualified clinical professionals in the early and accurate diagnosis of REDs, with an appropriate clinical severity and risk assessment, in order to protect athlete health and prevent prolonged and irreversible outcomes of REDs.
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Affiliation(s)
- Trent Stellingwerff
- Canadian Sport Institute Pacific, Victoria, British Columbia, Canada
- Exercise Science, Physical & Health Education, University of Victoria, Victoria, British Columbia, Canada
| | - Margo Mountjoy
- Association for Summer Olympic International Federations (ASOIF), Lausanne, Switzerland
- Department of Family Medicine, McMaster University, Hamilton, Ontario, Canada
| | | | - Kathryn E Ackerman
- Wu Tsai Female Athlete Program, Division of Sports Medicine, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Evert Verhagen
- Amsterdam Collaboration on Health and Safety in Sports and Department of Public and Occupational Health, VU University Medical Centre Amsterdam, Amsterdam, The Netherlands
| | - Ida A Heikura
- Canadian Sport Institute Pacific, Victoria, British Columbia, Canada
- Exercise Science, Physical & Health Education, University of Victoria, Victoria, British Columbia, Canada
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Berryman CE, McClung HL, Sepowitz JJ, Gaffney‐Stomberg E, Ferrando AA, McClung JP, Pasiakos SM. Testosterone status following short-term, severe energy deficit is associated with fat-free mass loss in U.S. Marines. Physiol Rep 2022; 10:e15461. [PMID: 36117330 PMCID: PMC9483439 DOI: 10.14814/phy2.15461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 08/19/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023] Open
Abstract
The objective of this study was to determine metabolic and physiological differences between males with low testosterone (LT) versus those with normal testosterone (NT) following a period of severe energy deficit. In this secondary analysis, 68 male US Marines (mean ± SD, 24.6 ± 2.4 y) were dichotomized by testosterone concentration (< or ≥ 10.5 nmol/L as determined from a single blood sample collected between 0600-0630 after an 8-10 h overnight fast by automated immunoassay) following 7 days of near complete starvation (~300 kcal consumed/d, ~85% energy deficit) during Survival, Evasion, Resistance, and Escape (SERE) training. Dietary intake was assessed before (PRE) SERE. Body composition (dual-energy x-ray absorptiometry and peripheral quantitative computed tomography) and whole-body protein turnover (15 N alanine) were assessed before (PRE) and after (POST) SERE. Mean testosterone concentrations decreased PRE (17.5 ± 4.7 nmol/L) to POST (9.8 ± 4.0 nmol/L, p < 0.0001). When volunteers were dichotomized by POST testosterone concentrations [NT (n = 24) 14.1 ± 3.4 vs. LT (n = 44): 7.5 ± 1.8 nmol/L, p < 0.0001], PRE BMI, total fat mass, trunk fat mass, and testosterone were greater and the diet quality score and total carbohydrate intake were lower in NT compared to LT (p ≤ 0.05). LT lost more fat-free mass and less fat mass, particularly in the trunk region, compared to NT following SERE (p-interaction≤0.044). Whole-body protein synthesis, net balance, and flux decreased and whole-body protein breakdown increased from PRE to POST in both groups (p-time ≤0.025). Following short-term, severe energy deficit, Marines who exhibited low testosterone had greater fat-free mass loss than those who maintained normal testosterone concentrations. Altering body composition and dietary strategies prior to physical training that elicits severe energy deficit may provide an opportunity to attenuate post-training decrements in testosterone and its associated effects (e.g., loss of lean mass, performance declines, fatigue).
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Affiliation(s)
- Claire E. Berryman
- Military Nutrition DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
- Oak Ridge Institute for Science and EducationBelcampMarylandUSA
- Department of Nutrition and Integrative PhysiologyFlorida State UniversityTallahasseeFloridaUSA
| | - Holly L. McClung
- Military Nutrition DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - John J. Sepowitz
- Military Nutrition DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Erin Gaffney‐Stomberg
- Military Performance DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Arny A. Ferrando
- Department of Geriatrics, The Center for Translational Research in Aging & LongevityDonald W. Reynolds Institute of Aging, University of Arkansas for Medical SciencesLittle RockArkansasUSA
| | - James P. McClung
- Military Nutrition DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Stefan M. Pasiakos
- Military Performance DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
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E Silva FB, Vaisman M, Ponce T, de Barros TR, E Silva CB, Salerno VP, Mainenti MRM. A systematic review of hormone levels, biomarkers of cellular injury and oxidative stress in multi-stressor military field training exercises. ARCHIVES OF ENDOCRINOLOGY AND METABOLISM 2022; 66:2359-3997000000443. [PMID: 35289515 PMCID: PMC9832854 DOI: 10.20945/2359-3997000000443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 11/05/2021] [Indexed: 11/23/2022]
Abstract
The fundamental objective of military field training exercises (FTX) is to prepare military personnel for real-life operations through simulated scenarios. These training sessions often require extreme physical efforts with prolonged, high-intensity exercises that can be combined with food restrictions and partial, or total, sleep deprivation. Such conditions can compromise an individual's physical performance and cause tissue damage, thus affecting their health. This study aimed to perform a systematic review of the literature to identify studies that measured the changes in hormone levels and biomarkers of cellular injury and oxidative stress resulting from FTX with high levels of energy expenditure combined with food and sleep restrictions. PubMed and the Scopus database were searched for articles that combined physical effort/food restriction/sleep deprivation with military training. The initial database search identified 158 articles that were reduced to 18 after confirmation. Significant reductions were reported in thyroid hormones, T3, T4, and anabolic hormones such as testosterone, insulin and androstenedione. An exception for GH was found, which increased throughout FTX. Less distinct responses to FTX were observed with cortisol, TSH and LH. The presence of biomarkers for cellular damage (myoglobin, TNF, and CRP) and increased immune response activities were also described. The scarcity of information on oxidative stress, analyses of cellular injury and biomarkers of inflammatory responses warrants the future study of these topics, which could be helpful in facilitating the safe and effective physical preparations of the members of the armed forces.
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Affiliation(s)
| | - Mario Vaisman
- Departamento de Medicina Interna - Endocrinologia, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil
| | - Thalita Ponce
- Departamento de Medicina Interna - Endocrinologia, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil
- Escola de Educação Física e Desportos, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil
| | - Thiago Ramos de Barros
- Escola de Educação Física e Desportos, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil
- Academia de Bombeiro Militar Dom Pedro II, Rio de Janeiro, RJ, Brasil
| | - Camila Brasil E Silva
- Companhia de Comando da 4ª Brigada de Infantaria Leve de Montanha - Exército Brasileiro, Juiz de Fora, MG, Brasil
| | - Verônica Pinto Salerno
- Escola de Educação Física e Desportos, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil
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McAdam JS, Lyons KD, Beck DT, Haun CT, Romero MA, Mumford PW, Roberson PA, Young KC, Lohse KR, Roberts MD, Sefton JM. Whey Protein Supplementation Effects on Body Composition, Performance, and Blood Biomarkers During Army Initial Entry Training. Front Nutr 2022; 9:807928. [PMID: 35330708 PMCID: PMC8940516 DOI: 10.3389/fnut.2022.807928] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/25/2022] [Indexed: 11/26/2022] Open
Abstract
This study assesses if a lower dose of whey protein can provide similar benefits to those shown in previous work supplementing Army Initial Entry Training (IET) Soldiers with two servings of whey protein (WP) per day. Eighty-one soldiers consumed one WP or a calorie matched carbohydrate (CHO) serving/day during IET (WP: n = 39, height = 173 ± 8 cm, body mass = 76.8 ± 12.8 kg, age = 21 ± 3 years; CHO: n = 42, 175 ± 8 cm, 77.8 ± 15.3 kg, 23 ± 4 years). Physical performance (push-ups, sit-ups, and a two-mile run) was assessed during weeks two and eight. All other measures (dietary intake, body composition, blood biomarkers) at weeks one and nine. There was a significant group difference for fat mass (p = 0.044) as WP lost 2.1 ± 2.9 kg and had a moderate effect size (Cohen's d: −0.24), whereas the CHO group lost 0.9 ± 2.5 kg and had only a small effect size (d: −0.1). There was no significant group-by-time interaction on fat-free mass (p = 0.069). WP gained 1.2 ± 2.4 (d: 0.1) and CHO gained 0.1 ± 3 (d: 0) kg of FFM on average. There was a significant group by week 1-fat free mass interaction (p = 0.003) indicating individuals with higher initial fat-free mass benefitted more from WP. There were no group differences for push-up (p = 0.514), sit-up (p = 0.429) or run (p = 0.313) performance. For all biomarkers there was a significant effect of time as testosterone (p < 0.01), testosterone to cortisol ratio (p = 0.39), and IGF-1 (p < 0.01) increased across training and cortisol (p = 0.04) and IL-6 (p < 0.01) decreased. There were no differences in groups across IET for any of the biomarkers. We conclude one WP serving is beneficial for FM and for FFM in soldiers with high baseline FFM but may not significantly alter biomarker response or physical performance of IET soldiers who have high relative dietary protein intakes.
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Affiliation(s)
- Jeremy S. McAdam
- School of Kinesiology, Warrior Research Center, Auburn University, Auburn, AL, United States
- Healthspan, Resilience, and Performance Research, Florida Institute for Human and Machine Cognition, Pensacola, FL, United States
| | - Kaitlin D. Lyons
- School of Kinesiology, Warrior Research Center, Auburn University, Auburn, AL, United States
| | - Darren T. Beck
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL, United States
- Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine (Auburn Campus), Auburn, AL, United States
| | - Cody T. Haun
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL, United States
- Fitomics, LLC, Pelham, AL, United States
| | - Matthew A. Romero
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL, United States
| | - Petey W. Mumford
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL, United States
| | - Paul A. Roberson
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL, United States
| | - Kaelin C. Young
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL, United States
- Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine (Auburn Campus), Auburn, AL, United States
| | - Keith R. Lohse
- Neurorehabilitation Informatics Lab, Department of Health, Kinesiology, and Recreation, University of Utah, Salt Lake City, UT, United States
| | - Michael D. Roberts
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL, United States
- Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine (Auburn Campus), Auburn, AL, United States
| | - JoEllen M. Sefton
- School of Kinesiology, Warrior Research Center, Auburn University, Auburn, AL, United States
- *Correspondence: JoEllen M. Sefton
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Smith SJ, Teo SYM, Lopresti AL, Heritage B, Fairchild TJ. Examining the effects of calorie restriction on testosterone concentrations in men: a systematic review and meta-analysis. Nutr Rev 2021; 80:1222-1236. [PMID: 34613412 DOI: 10.1093/nutrit/nuab072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
CONTEXT Testosterone concentrations decline with age, and lower testosterone concentrations are associated with several morbidities, including sexual dysfunction, obesity, type 2 diabetes mellitus (T2DM), and metabolic syndrome. OBJECTIVE Because dietary habits play a critical role in weight regulation and T2DM management, the aim of this systematic review and meta-analysis was to summarize and critically evaluate the evidence from randomized controlled trials to determine the effects of calorie restriction (CR) on testosterone concentrations in men. DATA SOURCES A literature search was conducted across 4 databases, from their inception until March 2020. DATA EXTRACTION The screening and data extraction were completed by 2 authors independently, and in a blinded manner, according to a priori inclusion and exclusion criteria. DATA ANALYSIS Of the 4198 studies identified from the initial search, 7 randomized controlled trials were included for data extraction. Significant increases in total testosterone concentrations were reported in 3 of 4 studies in which CR was examined with overweight or obese men, compared with the control groups. Significant decreases in total testosterone concentrations were reported in 2 of 3 studies in which the effects of CR were examined with normal-weight, healthy men, compared with the control groups. In all 4 studies that examined the effect of CR on sex hormone-binding globulin concentrations, the intervention significantly increased sex hormone-binding globulin concentrations compared with that of the control groups irrespective of body composition. CONCLUSION This systematic review and meta-analysis provide some evidence that CR affects testosterone concentrations in men and this effect depends on their body mass index. PROSPERO registration no. CRD42020173102.
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Affiliation(s)
- Stephen J Smith
- S.J. Smith and A.L. Lopresti are with Clinical Research Australia, Perth, Western Australia, Australia. S.J. Smith, S.Y.M. Teo, A.L. Lopresti, B. Heritage, and T.J. Fairchild are with the College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia, Australia
| | - Shaun Y M Teo
- S.J. Smith and A.L. Lopresti are with Clinical Research Australia, Perth, Western Australia, Australia. S.J. Smith, S.Y.M. Teo, A.L. Lopresti, B. Heritage, and T.J. Fairchild are with the College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia, Australia
| | - Adrian L Lopresti
- S.J. Smith and A.L. Lopresti are with Clinical Research Australia, Perth, Western Australia, Australia. S.J. Smith, S.Y.M. Teo, A.L. Lopresti, B. Heritage, and T.J. Fairchild are with the College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia, Australia
| | - Brody Heritage
- S.J. Smith and A.L. Lopresti are with Clinical Research Australia, Perth, Western Australia, Australia. S.J. Smith, S.Y.M. Teo, A.L. Lopresti, B. Heritage, and T.J. Fairchild are with the College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia, Australia
| | - Timothy J Fairchild
- S.J. Smith and A.L. Lopresti are with Clinical Research Australia, Perth, Western Australia, Australia. S.J. Smith, S.Y.M. Teo, A.L. Lopresti, B. Heritage, and T.J. Fairchild are with the College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia, Australia
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Michael SW, Siddall AG, O'Leary TJ, Groeller H, Sampson JA, Blacker SD, Drain JR. Monitoring work and training load in military settings - what's in the toolbox? Eur J Sport Sci 2021; 22:58-71. [PMID: 34463198 DOI: 10.1080/17461391.2021.1971774] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Military personnel are required to complete physically demanding tasks when performing work and training, which may be quantified through the physical stress imposed (external load) or the resultant physiological strain (internal load). The aim of this narrative review is to provide an overview of the techniques used to monitor work and training load in military settings, summarise key findings, and discuss important practical, analytical, and conceptual considerations. Most investigations have focused upon measuring external and internal load in military training environments; however, limited data exist in operational settings. Accelerometry has been the primary tool used to estimate external load, with heart rate commonly used to quantify internal load. Supplemental to heart rate, psychophysiological and biochemical measures have also been investigated to elucidate aspects of internal load. Broadly, investigations have revealed that military training requires personnel to perform relatively large volumes of physical activity (e.g. averaging ∼15,000 steps·day-1) of typically low-moderate intensity activity (<6 MET), although considerable temporal and inter-individual variability is observed from these gross mean estimates. There are limitations associated with these measures and, at best, estimates of external and internal load can only be inferred. These limitations are particularly pertinent for military tasks such as load carriage and manual material handling, which often involve complex activities performed individually or in teams, in a range of operational environments, with multiple layers of protection, over a protracted duration. Comprehensively quantifying external and internal loads during these functional activities poses substantial practical and analytical challenges.
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Affiliation(s)
- Scott W Michael
- Centre of Medical and Exercise Physiology, University of Wollongong, Wollongong, Australia
| | - Andrew G Siddall
- Occupational Performance Research Group, Institute of Sport, University of Chichester, Chichester, UK
| | - Thomas J O'Leary
- Army Health and Performance Research, Army Headquarters, Andover, UK
| | - Herbert Groeller
- Centre of Medical and Exercise Physiology, University of Wollongong, Wollongong, Australia
| | - John A Sampson
- Centre of Medical and Exercise Physiology, University of Wollongong, Wollongong, Australia
| | - Sam D Blacker
- Occupational Performance Research Group, Institute of Sport, University of Chichester, Chichester, UK
| | - Jace R Drain
- Land Division, Defence Science and Technology Group, Melbourne, Australia
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10
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Negative energy balance during military training: The role of contextual limitations. Appetite 2021; 164:105263. [PMID: 33862189 DOI: 10.1016/j.appet.2021.105263] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 02/09/2021] [Accepted: 04/09/2021] [Indexed: 12/25/2022]
Abstract
During multiday training exercises, soldiers almost systematically face a moderate-to-large energy deficit, affecting their body mass and composition and potentially their physical and cognitive performance. Such energy deficits are explained by their inability to increase their energy intake during these highly demanding periods. With the exception of certain scenarios in which rations are voluntarily undersized to maximize the constraints, the energy content of the rations are often sufficient to maintain a neutral energy balance, suggesting that other limitations are responsible for such voluntary and/or spontaneous underconsumption. In this review, the overall aim was to present an overview of the impact of military training on energy balance, a context that stands out by its summation of specific limitations that interfere with energy intake. We first explore the impact of military training on the various components of energy balance (intake and expenditure) and body mass loss. Then, the role of the dimensioning of the rations (total energy content above or below energy expenditure) on energy deficits are addressed. Finally, the potential limitations inherent to military training (training characteristics, food characteristics, timing and context of eating, and the soldiers' attitude) are discussed to identify potential strategies to spontaneously increase energy intake and thus limit the energy deficit.
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Coker MS, Ladd K, Murphy CJ, Ruby BC, Shriver TC, Schoeller DA, Newcomer BR, Bateman T, Bartlett L, Coker RH. Alaska backcountry expeditionary hunting promotes rapid improvements in metabolic biomarkers in healthy males and females. Physiol Rep 2021; 9:e14682. [PMID: 33369890 PMCID: PMC7769173 DOI: 10.14814/phy2.14682] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 09/23/2020] [Accepted: 11/14/2020] [Indexed: 12/16/2022] Open
Abstract
We have previously reported negative energy balance and health benefits during an Alaska backcountry expeditionary hunting (ABEH) immersion in two males. The purpose of our present study was to increase the number of participants, include females, and evaluate macronutrient intake and serum lipids. Four men (age: 46 ± 6 year, BMI: 26 ± 1 kg/m2 ) and three women (age: 46 ± 11 year, BMI: 25 ± 3 kg/m2 ) were recruited. Doubly labeled water methodology and dietary recall were utilized to assess energy expenditure and energy intake, respectively. Data were collected during pre- and post-ABEH visits. Body composition was measured using dual-energy x-ray absorptiometry and the cross-sectional area of skeletal muscle in the upper leg (XT), and intrahepatic lipid (IHL) was determined using magnetic resonance imaging and/or spectroscopy (MRI/MRS). Blood parameters were measured by LabCorp. Paired T-tests were used for statistical analysis. Data are reported as mean ± SD and considered significant at p < 0.05. Total energy intake was 7.7 ± 3.4 MJ/day and total energy expenditure was 17.4 ± 2.6 MJ/day, resulting in a negative energy balance of -9.7 ± 3.4 MJ/day. Protein intake(grams)/body weight(kilograms)/day was 1.0 ± 0.4. There were reductions in body weight (Δ-1.5 ± 0.7 kg), BMI (Δ-0.3 ± 0.2 kg/m2 ), fat mass (Δ-1.7 ± 0.9 kg), and IHL (Δ-0.3 ± 0.3% water peak). There were no changes in lean tissue mass (Δ0.6 ± 1.4 kg) or XT (Δ-1.3 ± 3.3 cm2 ). There were significant reductions in total cholesterol (Δ-44 ± 35 mg/dl), LDL-cholesterol (Δ-25 ± 14 mg/dl), VLDL-cholesterol (Δ-7 ± 7 mg/dl), and triglycerides (Δ-35 ± 33 mg/dl). The ABEH immersion resulted in considerable negative energy balance and provided comprehensive benefits in metabolic health without any reduction in skeletal muscle.
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Affiliation(s)
- Melynda S. Coker
- Department of Natural Resources and EnvironmentUniversity of Alaska FairbanksFairbanksAKUSA
| | - Kaylee Ladd
- Department of Biology and WildlifeUniversity of Alaska FairbanksFairbanksAKUSA
| | - Carl J. Murphy
- Institute of Arctic BiologyUniversity of Alaska FairbanksFairbanksAKUSA
| | - Brent C. Ruby
- Montana Center for Work Physiology and Exercise MetabolismUniversity of MontanaMissoulaMTUSA
| | - Timothy C. Shriver
- Isotope Ratio Core LaboratoryUniversity of Wisconsin‐MadisonMadisonWIUSA
| | - Dale A. Schoeller
- Isotope Ratio Core LaboratoryUniversity of Wisconsin‐MadisonMadisonWIUSA
| | - Bradley R. Newcomer
- Department of Physics and Honors CollegeJames Madison UniversityHarrisonburgVAUSA
| | | | | | - Robert H. Coker
- Department of Biology and WildlifeUniversity of Alaska FairbanksFairbanksAKUSA
- Institute of Arctic BiologyUniversity of Alaska FairbanksFairbanksAKUSA
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12
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Effects of Task-Specific and Strength Training on Simulated Military Task Performance in Soldiers. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17218000. [PMID: 33143178 PMCID: PMC7662950 DOI: 10.3390/ijerph17218000] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/26/2020] [Accepted: 10/29/2020] [Indexed: 11/18/2022]
Abstract
A soldier’s occupational physical task requirements are diverse and varied. However, the type of physical training that most effectively improves soldiers’ occupational task requirements has not been studied previously. The purpose of this study was to determine the important strength characteristics for soldiers during a repeated simulated military task course, and the type of training that may be effective to improve these abilities during a specialized military training period. Forty-two (n = 42) soldiers participated in the study. They were divided into three training groups; a soldier task-specific training group (TSG, n = 17), a strength training group (STG, n = 15), and a control group (CON, n = 10). Participants were measured before (PRE), middle (MID) and after (POST) the 12-week training intervention for strength performance and simulated military task test. Simulated military task performance improved significantly in TSG and STG between the PRE and MID measurements (from 9.4 to 15.7%). TSG and STG improved in various spilt times, especially in strength tasks; casualty drag (from 8.3 to 13.6%) and kettlebell carry (from 13.2 to 22.4%) between the PRE and MID measurements. The present study showed that both the training of TSG and STG were more effective than the training of CON (control group) in terms of improving the performance in the repeated simulated military task course. The present study showed that training of TSG was as effective as STG to improve repeated simulated military task course time. Therefore, an optimal training combination should include high-intensity simulated military task field training and strength training programmed with consideration of the military training phase and environmental possibilities.
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13
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Hinde KL, O'Leary TJ, Greeves JP, Wardle SL. Measuring Protein Turnover in the Field: Implications for Military Research. Adv Nutr 2020; 12:887-896. [PMID: 33079983 PMCID: PMC8166569 DOI: 10.1093/advances/nmaa123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/04/2020] [Accepted: 09/08/2020] [Indexed: 11/15/2022] Open
Abstract
Protein turnover reflects the continual synthesis and breakdown of body proteins, and can be measured at a whole-body (i.e. aggregated across all body proteins) or tissue (e.g. skeletal muscle only) level using stable isotope methods. Evaluating protein turnover in free-living environments, such as military training, can help inform protein requirements. We undertook a narrative review of published literature with the aim of reviewing the suitability of, and advancements in, stable isotope methods for measuring protein turnover in field research. The 2 primary approaches for measuring protein turnover are based on precursor- and end-product methods. The precursor method is the gold-standard for measuring acute (over several hours) skeletal muscle protein turnover, whereas the end-product method measures chronic (over several weeks) skeletal muscle protein turnover and provides the opportunity to monitor free-living activities. Both methods require invasive procedures such as the infusion of amino acid tracers and muscle biopsies to assess the uptake of the tracer into tissue. However, the end-product method can also be used to measure acute (over 9-24 h) whole-body protein turnover noninvasively by ingesting 15N-glycine, or equivalent isotope tracers, and collecting urine samples. The end-product method using 15N-glycine is a practical method for measuring whole-body protein turnover in the field over short (24 h) time frames and has been used effectively in recent military field research. Application of this method may improve our understanding of protein kinetics during conditions of high physiological stress in free-living environments such as military training.
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Affiliation(s)
- Katrina L Hinde
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom
| | - Thomas J O'Leary
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom,Division of Surgery & Interventional Science, University College London, London, United Kingdom
| | - Julie P Greeves
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom,Division of Surgery & Interventional Science, University College London, London, United Kingdom,Norwich Medical School, University of East Anglia, Norwich, United Kingdom
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14
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Chapman S, Rawcliffe AJ, Smith L, Izard R, Roberts J. Evaluation of the current methods used for assessing dietary intake in military research settings: a scoping review. BMJ Mil Health 2020; 167:126-130. [PMID: 32859652 DOI: 10.1136/bmjmilitary-2020-001436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 07/21/2020] [Accepted: 07/21/2020] [Indexed: 11/03/2022]
Abstract
INTRODUCTION It is important to collate the literature that has assessed dietary intake within military settings to establish which methods are commonly used and which are valid so that accurate nutrition recommendations can be made. This scoping review aims to identify which methods are typically used to assess dietary intake in military settings and which of these have been validated. This review also aims to provide a recommendation as to which method(s) should be used in military settings. METHODS This scoping review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. Searches were conducted in PubMed, Web of Science and SPORTDiscus with the most recent search executed on 12th June 2020. Eligible studies had to report original data, assess and quantify dietary intake and have been published in peer-reviewed academic journals. The reporting bias was calculated for each study where possible. RESULTS Twenty-eight studies used a single method to assess dietary intake and seven studies used a combination of methods. The most commonly used methods were the gold standard food intake/waste method, Food Frequency Questionnaire (FFQ) or a food diary (FD). The only method to date that has been validated in military settings is weighed food records (WFR). CONCLUSIONS The food intake/waste method or WFR should be used where feasible. Where this is not practical the FFQ or FD should be considered with control measures applied. There is currently not sufficient evidence to state that using multiple methods together improves validity.
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Affiliation(s)
- Shaun Chapman
- HQ Army Recruiting and Initial Training Command, UK Ministry of Defence, Upavon, UK
- Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University, Cambridge, UK
| | - A J Rawcliffe
- HQ Army Recruiting and Initial Training Command, UK Ministry of Defence, Upavon, UK
| | - L Smith
- Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University, Cambridge, UK
| | - R Izard
- Defence Science and Technology, Porton Down, UK Ministry of Defence, Salisbury, Wiltshire, UK
| | - J Roberts
- Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University, Cambridge, UK
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15
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O'Leary TJ, Wardle SL, Greeves JP. Energy Deficiency in Soldiers: The Risk of the Athlete Triad and Relative Energy Deficiency in Sport Syndromes in the Military. Front Nutr 2020; 7:142. [PMID: 32984399 PMCID: PMC7477333 DOI: 10.3389/fnut.2020.00142] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/21/2020] [Indexed: 12/15/2022] Open
Abstract
Military personnel experience energy deficit (total energy expenditure higher than energy intake), particularly during combat training and field exercises where exercising energy expenditures are high and energy intake is reduced. Low energy availability (energy intake minus exercising energy expenditure expressed relative to fat free mass) impairs endocrine function and bone health, as recognized in female athletes as the Female Athlete Triad syndrome. More recently, the Relative Energy Deficiency in Sport (RED-S) syndrome encompasses broader health outcomes, physical and cognitive performance, non-athletes, and men. This review summarizes the evidence for the effect of low energy availability and energy deficiency in military training and operations on health and performance outcomes. Energy availability is difficult to measure in free-living individuals but doubly labeled water studies demonstrate high total energy expenditures during military training; studies that have concurrently measured energy intake, or measured body composition changes with DXA, suggest severe and/or prolonged energy deficits. Military training in energy deficit disturbs endocrine and metabolic function, menstrual function, bone health, immune function, gastrointestinal health, iron status, mood, and physical and cognitive performance. There are more data for men than women, and little evidence on the chronic effects of repeated exposures to energy deficit. Military training impairs indices of health and performance, indicative of the Triad and RED-S, but the multi-stressor environment makes it difficult to isolate the independent effects of energy deficiency. Studies supplementing with energy to attenuate the energy deficit suggest an independent effect of energy deficiency in the disturbances to metabolic, endocrine and immune function, and physical performance, but randomized controlled trials are lacking.
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Affiliation(s)
- Thomas J O'Leary
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom.,Division of Surgery and Interventional Science, UCL, London, United Kingdom
| | - Sophie L Wardle
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom.,Division of Surgery and Interventional Science, UCL, London, United Kingdom
| | - Julie P Greeves
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom.,Division of Surgery and Interventional Science, UCL, London, United Kingdom.,Norwich Medical School, University of East Anglia, Norwich, United Kingdom
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16
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Ojanen T, Kyröläinen H, Kozharskaya E, Häkkinen K. Changes in strength and power performance and serum hormone concentrations during 12 weeks of task-specific or strength training in conscripts. Physiol Rep 2020; 8:e14422. [PMID: 32378340 PMCID: PMC7202986 DOI: 10.14814/phy2.14422] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/19/2020] [Accepted: 03/23/2020] [Indexed: 11/24/2022] Open
Abstract
The purpose of this study was to investigate the effects of two different training programs on strength and power performance and serum hormone concentrations. A total of 104 male soldiers volunteered and took part in the 12-week training period with baseline, mid-, and post-measurements of body composition, muscle strength, lower and upper body power, and blood samples to determine serum hormone concentrations. The mean (±SD) age of subjects was 20 ± 1 years, height 180 ± 6 cm and body mass 72.4 ± 8.8 kg. The subjects were divided into three different training groups: soldier task-specific training (TS), strength training (ST), and control (CON). Each group had a total of 18 training sessions during the 12-week study. In the muscle strength tests, most improvements could be observed in the TS and ST groups, especially, during the first weeks of the training period. Maximal isometric leg extension force increased significantly by 7.9 ± 12.2% (p < .05) in the TS and 7.1 ± 12.6% (p < .05) in the ST groups between the PRE and MID, as well as between the PRE and POST measurements by 8.1 ± 12.4% (p < .05) in TS and 12.3 ± 15.3% (p < .01) in ST. Serum TES concentration increased significantly in TS between the PRE and MID (16.8 ± 33.9%) and PRE and POST (11.2 ± 16.7%) measurements. Serum COR concentrations decreased in TS between the MID and POST (-7.8 ± 10.9%) and PRE and POST (-11.0 ± 14.3%) measurements. Although the differences observed were rather minor in magnitude, training in the TS and ST groups led to greater improvements in muscle strength and power performance compared to the training in the CON group. The development of strength and/or power of the lower and upper body was greater in the TS and ST groups, which is crucial for warfighter's performance. Therefore, it is important to have a structured resistance-training program during military training to optimize the strength, power, and military-specific performance.
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Affiliation(s)
- Tommi Ojanen
- Finnish Defence Research AgencyFinnish Defence ForcesJärvenpääFinland
| | - Heikki Kyröläinen
- Biology of Physical ActivityUniversity of JyväskyläJyväskyläFinland
- National Defence UniversityHelsinkiFinland
| | | | - Keijo Häkkinen
- Biology of Physical ActivityUniversity of JyväskyläJyväskyläFinland
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17
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Karl JP, Berryman CE, Harris MN, Lieberman HR, Gadde KM, Rood JC, Pasiakos SM. Effects of Testosterone Supplementation on Ghrelin and Appetite During and After Severe Energy Deficit in Healthy Men. J Endocr Soc 2020; 4:bvaa024. [PMID: 32258956 DOI: 10.1210/jendso/bvaa024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 02/26/2020] [Indexed: 12/17/2022] Open
Abstract
Background Severe energy deficits cause interrelated reductions in testosterone and fat free mass. Testosterone supplementation may mitigate those decrements, but could also reduce circulating concentrations of the orexigenic hormone ghrelin, thereby exacerbating energy deficit by suppressing appetite. Objective To determine whether testosterone supplementation during severe energy deficit influences fasting and postprandial ghrelin concentrations and appetite. Design and methods Secondary analysis of a randomized, double-blind trial that determined the effects of testosterone supplementation on body composition changes during and following severe energy deficit in nonobese, eugonadal men. Phase 1 (PRE-ED): 14-day run-in; phase 2: 28 days, 55% energy deficit with 200 mg testosterone enanthate weekly (TEST; n = 24) or placebo (PLA; n = 26); phase 3: free-living until body mass recovered (end-of-study; EOS). Fasting and postprandial acyl ghrelin and des-acyl ghrelin concentrations and appetite were secondary outcomes measured during the final week of each phase. Results Fasting acyl ghrelin concentrations, and postprandial acyl and des-acyl ghrelin concentrations increased in PLA during energy deficit then returned to PRE-ED values by EOS, but did not change in TEST (phase-by-group, P < 0.05). Correlations between changes in free testosterone and changes in fasting acyl ghrelin concentrations during energy deficit (ρ = -0.42, P = 0.003) and body mass recovery (ρ = -0.38; P = 0.01) were not mediated by changes in body mass or body composition. Transient increases in appetite during energy deficit were not affected by testosterone treatment. Conclusions Testosterone supplementation during short-term, severe energy deficit in healthy men prevents deficit-induced increases in circulating ghrelin without blunting concomitant increases in appetite. Clinical Trials Registration www.clinicaltrials.gov NCT02734238 (registered 12 April 2016).
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Affiliation(s)
- J Philip Karl
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Claire E Berryman
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute for Science and Education, Belcamp, MD, USA.,Department of Nutrition, Food, and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| | - Melissa N Harris
- Louisiana State University's Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Harris R Lieberman
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Kishore M Gadde
- Louisiana State University's Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Jennifer C Rood
- Louisiana State University's Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
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18
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Wright CS, Li J, Campbell WW. Effects of Dietary Protein Quantity on Bone Quantity following Weight Loss: A Systematic Review and Meta-analysis. Adv Nutr 2019; 10:1089-1107. [PMID: 31301138 PMCID: PMC6855958 DOI: 10.1093/advances/nmz058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/09/2019] [Accepted: 05/17/2019] [Indexed: 01/02/2023] Open
Abstract
Research supports the hypothesis that higher total protein intake during weight loss promotes retention of lean soft tissue, but the effect of dietary protein quantity on bone mass, a lean hard tissue, is inconsistent. The purpose of this systematic review and meta-analysis was to assess the effect of dietary protein quantity [higher protein (HP): ≥25% of energy from protein or ≥1.0 g · kg body wt-1 · d-1; normal protein (NP): <25% of energy from protein or <1.0 g · kg body wt-1 · d-1] on changes in bone mineral density (BMD) and content (BMC; total body, lumbar spine, total hip, femoral neck) following a prescribed energy restriction. We hypothesized that an HP diet would attenuate the loss of BMD/BMC following weight loss in comparison to an NP diet. Two researchers systematically and independently screened 2366 publications from PubMed, Cochrane, Scopus, CINAHL, and Web of Science Core Collection and extracted data from 34 qualified publications. Inclusion criteria included the following: 1) healthy subjects ≥19 y; 2) a prescribed energy restriction; 3) measurements of total protein intake, BMD, and BMC; and 4) an intervention duration of ≥3 mo. Data from 10 of the 34 publications with 2 groups of different total protein intakes were extracted and used to conduct a random-effects model meta-analysis. A majority of publications (59%) showed a decrease in bone quantity following active weight loss, regardless of total protein intake. Statistically, the loss of total BMD (P = 0.016; weighted mean difference: +0.006 g/cm2; 95% CI: 0, 0.011 g/cm2) and lumbar spine BMD (P = 0.019; weighted mean difference: +0.017 g/cm2; 95% CI: 0.001, 0.033 g/cm2) was attenuated with an HP versus an NP weight-loss diet. However, the clinical significance is questionable given the modest weighted mean difference and study duration. Higher total protein intake does not exacerbate but may attenuate the loss of bone quantity following weight loss.
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Affiliation(s)
- Christian S Wright
- Department of Nutrition Science, Purdue University, West Lafayette, IN, USA
| | - Jia Li
- Department of Nutrition Science, Purdue University, West Lafayette, IN, USA
| | - Wayne W Campbell
- Department of Nutrition Science, Purdue University, West Lafayette, IN, USA
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19
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Dwyer AA, Chavan NR, Lewkowitz-Shpuntoff H, Plummer L, Hayes FJ, Seminara SB, Crowley WF, Pitteloud N, Balasubramanian R. Functional Hypogonadotropic Hypogonadism in Men: Underlying Neuroendocrine Mechanisms and Natural History. J Clin Endocrinol Metab 2019; 104:3403-3414. [PMID: 31220265 PMCID: PMC6594303 DOI: 10.1210/jc.2018-02697] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 03/05/2019] [Indexed: 11/19/2022]
Abstract
CONTEXT After completion of puberty a subset of men experience functional hypogonadotropic hypogonadism (FHH) secondary to excessive exercise or weight loss. This phenomenon is akin to hypothalamic amenorrhea (HA) in women, yet little is known about FHH in men. OBJECTIVE To investigate the neuroendocrine mechanisms, genetics, and natural history underlying FHH. DESIGN Retrospective study in an academic medical center. PARTICIPANTS Healthy postpubertal men presenting with symptoms of hypogonadism in the setting of excessive exercise (>10 hours/week) or weight loss (>10% of body weight). Healthy age-matched men served as controls. INTERVENTIONS Clinical assessment, biochemical and neuroendocrine profiling, body composition, semen analysis, and genetic evaluation of genes known to cause isolated GnRH deficiency. MAIN OUTCOME MEASURES Reproductive hormone levels, endogenous GnRH-induced LH pulse patterns, and rare genetic variants. RESULTS Ten men with FHH were compared with 18 age-matched controls. Patients had significantly lower body mass index, testosterone, LH, and mean LH pulse amplitudes yet normal LH pulse frequency, serum FSH, and sperm counts. Some patients exhibited nocturnal, sleep-entrained LH pulses characteristic of early puberty, and one FHH subject showed a completely apulsatile LH secretion. After decreased exercise and weight gain, five men with men had normalized serum testosterone levels, and symptoms resolved. Rare missense variants in NSMF (n = 1) and CHD7 (n = 1) were identified in two men with FHH. CONCLUSIONS FHH is a rare, reversible form of male GnRH deficiency. LH pulse patterns in male FHH are similar to those observed in women with HA. This study expands the spectrum of GnRH deficiency disorders in men.
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Affiliation(s)
- Andrew A Dwyer
- Boston College William F. Connell School of Nursing, Chestnut Hill, Massachusetts
- Harvard Reproductive Endocrine Sciences Center and Reproductive Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Niraj R Chavan
- Department of Obstetrics and Gynecology, University of Kentucky College of Medicine, Lexington, Kentucky
| | - Hilana Lewkowitz-Shpuntoff
- Harvard Reproductive Endocrine Sciences Center and Reproductive Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts
- Department of Anesthesiology, Columbia University Medical Center, New York, New York
| | - Lacey Plummer
- Harvard Reproductive Endocrine Sciences Center and Reproductive Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Frances J Hayes
- Harvard Reproductive Endocrine Sciences Center and Reproductive Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Stephanie B Seminara
- Harvard Reproductive Endocrine Sciences Center and Reproductive Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - William F Crowley
- Harvard Reproductive Endocrine Sciences Center and Reproductive Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Nelly Pitteloud
- Endocrinology, Diabetes, and Metabolism Service, University Hospital of Lausanne, Lausanne, Switzerland
| | - Ravikumar Balasubramanian
- Harvard Reproductive Endocrine Sciences Center and Reproductive Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts
- Correspondence and Reprint Requests: Ravikumar Balasubramanian, MD, PhD, Harvard Reproductive Endocrine Sciences Center, Massachusetts General Hospital, Bartlett Hall Extension, 5th Floor, 55 Fruit Street, Boston, Massachusetts 02114. E-mail:
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Ojanen T, Häkkinen K, Vasankari T, Kyröläinen H. Changes in Physical Performance During 21 d of Military Field Training in Warfighters. Mil Med 2019; 183:e174-e181. [PMID: 29420780 DOI: 10.1093/milmed/usx049] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Accepted: 11/06/2017] [Indexed: 11/12/2022] Open
Abstract
Introduction Few studies have reported the amount of physical activity (PA) and its associations to physical performance of warfighters during military field training (MFT). The purpose of this study was to investigate changes in neuromuscular performance and PA among male Finnish Army conscripts during a 21-d MFT and to evaluate their recovery during 4 d after MFT. Methods Body composition and physical performance were measured four times during the study (before MFT (PRE), after 12 d (MID), post training (POST) and after 4 d of recovery (RECO)). PA was measured throughout MFT in a group of healthy young male conscripts (n=49) by using a tri-axial accelerometer. The study was approved by the Finnish Defence Forces and was granted ethics approval by the Ethics Committee of the University of Jyväskylä. Results Body mass declined significantly from 73.5 ± 8.7 to 71.6 ± 8.2 kg, but it recovered close to the PRE values (73.0 ± 8.3 kg). The same trend was also found in skeletal muscle mass and fat mass. The change in body mass and in skeletal muscle mass correlated negatively with the change in vigorous physical activity (r = -0.374, p = 0.016, and r = -0.337, p = 0.031, respectively). Muscular endurance decreased significantly (p < 0.001) in sit-ups from the PRE (46 ± 9 reps/min) values compared with MID (40 ± 8 reps/min), POST (42 ± 8 reps/min), and RECO (34 ± 11 reps/min) values. Also in push-ups, the declines in the POST (34 ± 10 reps/min) and RECO (34 ± 13 reps/min) values (p < 0.001) from the PRE (40 ± 13 reps/min) and MID (39 ± 12 reps/min) values were observed. There was a significant decrease in a standing long jump in all measurement points MID (220 ± 20 cm), POST (216 ± 20 cm), and RECO (213 ± 20 cm) as compared with the PRE values (229 ± 23 cm, p < 0.001). There was no change in 3.2 km loaded march time between the PRE (23:57 ± 4:12 min:s) and POST (23:44 ± 5:02 min:s) measurement time points. In PA, the total number of steps per day was significantly (p < 0.001) greater during ST (13,722 ± 2,379 steps) and MFT (13,937 ± 2,276 steps) than during garrison days (9,550 ± 2,569 steps). In POST, there was significantly (p < 0.001) more light (1.5-3.0 metabolic equivalent) (2:34:38 ± 0:22:53 h:min:s in ST and 3:03:27 ± 0:23:24 h:min:s in MFT) and moderate (3.0-6.0 metabolic equivalent) (2:12:15 ± 0:23:14 h:min:s in ST and 2:47:59 ± 0:27:23 h:min:s in MFT) PA than in the PRE measurements. Conclusion This study demonstrated slight decrements in warfighter physical performance during the 21-d MFT. The conscripts were overloaded during MFT, but 4 d of recovery seemed not to be enough to obtain the PRE measurement values in physical performance. This study also showed changes in the muscular endurance levels and PA during the 21-d MFT. It is important for warfighters to have a good physical fitness level PRE training or combat. As the prolonged MFT may have adverse effects in warfighters muscular endurance and PA levels, it is important to have sufficient recovery time after long MFT to regain combat readiness.
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Affiliation(s)
- Tommi Ojanen
- Finnish Defence Research Agency, Finnish Defence Forces, P.O. Box 5, 04401 Järvenpää, Finland
| | - Keijo Häkkinen
- Biology of Physical Activity, Faculty of Sport and Health Sciences, University of Jyväskylä, P.O. Box 35, 40014 Jyväskylä, Finland
| | - Tommi Vasankari
- The UKK Institute for Health Promotion Research, P.O. Box 30, 33501 Tampere, Finland
| | - Heikki Kyröläinen
- Biology of Physical Activity, Faculty of Sport and Health Sciences, University of Jyväskylä, P.O. Box 35, 40014 Jyväskylä, Finland.,National Defence University, P.O. Box 7, 00861 Helsinki, Finland
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21
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Substantial fat mass loss reduces low-grade inflammation and induces positive alteration in cardiometabolic factors in normal-weight individuals. Sci Rep 2019; 9:3450. [PMID: 30837600 PMCID: PMC6400952 DOI: 10.1038/s41598-019-40107-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 02/08/2019] [Indexed: 12/29/2022] Open
Abstract
The accumulation of fat, especially in visceral sites, is a significant risk factor for several chronic diseases with altered cardiometabolic homeostasis. We studied how intensive long-term weight loss and subsequent weight regain affect physiological changes, by longitudinally interrogating the lipid metabolism and white blood cell transcriptomic markers in healthy, normal-weight individuals. The current study examined 42 healthy, young (age: 27.5 ± 4.0 years), normal-weight (body mass index, BMI: 23.4 ± 1.7 kg/m2) female athletes, of which 25 belong to the weight loss and regain group (diet group), and 17 to the control group. Participants were evaluated, and fasting blood samples were drawn at three time points: at baseline (PRE); at the end of the weight loss period (MID: 21.1 ± 3.1 weeks after PRE); and at the end of the weight regain period (POST: 18.4 ± 2.9 weeks after MID). Following the weight loss period, the diet group experienced a ~73% reduction (~0.69 kg) in visceral fat mass (false discovery rate, FDR < 2.0 × 10-16), accompanied by anti-atherogenic effects on transcriptomic markers, decreased low-grade inflammation (e.g., as α1-acid glycoprotein (FDR = 3.08 × 10-13) and hs-CRP (FDR = 2.44 × 10-3)), and an increase in functionally important anti-atherogenic high-density lipoprotein -associated metabolites (FDR < 0.05). This occurred even though these values were already at favorable levels in these participants, who follow a fitness-lifestyle compared to age- and BMI-matched females from the general population (n = 58). Following the weight regain period, most of the observed beneficial changes in visceral fat mass, and metabolomic and transcriptomic profiles dissipated. Overall, the beneficial anti-atherogenic effects of weight loss can be observed even in previously healthy, normal-weight individuals.
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Hooper DR, Tenforde AS, Hackney AC. Treating exercise-associated low testosterone and its related symptoms. PHYSICIAN SPORTSMED 2018; 46:427-434. [PMID: 30063407 DOI: 10.1080/00913847.2018.1507234] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The Exercise-Hypogonadal Male Condition (EHMC) has been described to occur in athletes who experience low serum testosterone and associated symptoms. While high volumes of endurance exercise can lead to reduced testosterone concentrations in men, similar changes may occur in other sports including anerobic and power sports such as American football, and weight class sports such as wrestling. A reduced testosterone concentration alone does not necessarily warrant treatment, but when it is accompanied by symptoms of hypogonadism, such as fatigue, sexual dysfunction, and/or low bone mineral density (BMD), an athlete's performance and/or health may suffer. While pharmacological treatments such as testosterone or clomiphene citrate have been shown to be effective in treating hypogonadism, these options are not available to athletes competing in sports governed by the World Anti-Doping Agency. We recommend treatment of EHMC in athletes should include nutritional intervention and modification of training. Recognizing EHMC's existence in male athletes is important to optimize their health.
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Affiliation(s)
- David R Hooper
- a Department of Kinesiology , Jacksonville University , Jacksonville , FL , USA
| | - Adam S Tenforde
- b Department of Physical Medicine and Rehabilitation , Harvard Medical School , Cambridge , MA , USA
| | - Anthony C Hackney
- c Department of Exercise & Sport Science and Department of Nutrition , Gillings School of Global Public Health, University of North Carolina , Chapel Hill , NC , USA
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23
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Chronic heat stress increases insulin-like growth factor-1(IGF-1) but does not affect IGF-binding proteins in growing pigs. J Therm Biol 2018; 77:122-130. [DOI: 10.1016/j.jtherbio.2018.08.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 07/08/2018] [Accepted: 08/17/2018] [Indexed: 12/19/2022]
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24
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Ojanen T, Jalanko P, Kyröläinen H. Physical fitness, hormonal, and immunological responses during prolonged military field training. Physiol Rep 2018; 6:e13850. [PMID: 30187684 PMCID: PMC6125608 DOI: 10.14814/phy2.13850] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/06/2018] [Accepted: 08/10/2018] [Indexed: 11/24/2022] Open
Abstract
Physical fitness is crucial to warfighters' performance in the battlefield. Previous studies have shown negative changes in their hormonal and neuromuscular responses induced by military field training (MFT). The purpose of this study was to investigate the changes in hormonal and immunological values and body composition during a prolonged MFT and to find out how warfighters' physical condition influences these changes. Conscripts (n = 49, age 20 ± 1 years, height 179 ± 9 cm, body mass 73.8 ± 7.8 kg, fat 12.6 ± 3.7% and BMI 23 kg/m²) were measured before, during, after MFT, and after a 4-day recovery period. Serum insulin-like growth factor-1 (IGF-1), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6) concentrations, creatine kinase (CK) activity and leptin concentration were analyzed as well as body composition throughout MFT. Neuromuscular performance was assessed via lower and upper body muscle endurance at the beginning of the study. During MFT, there was a significant decrease (P < 0.05) in body mass (2.3%), fat mass (7.7%) and in muscle mass (2.2%), but all of these values recovered to PRE-levels after the recovery period. Serum IGF-1 (22%) and leptin decreased (66%) while CK increased (88%) significantly (P < 0.05) during MFT but recovered at the end of MFT. Upper body dynamic and trunk isometric muscular endurance had a positive correlation (r = 0.37. P < 0.05) with the change in IGF-1 during MFT and a negative correlation with the changes in CK (-0.34, P < 0.05). The results show that there were negative changes in conscript's body composition and hormonal and immunological values during the prolonged MFT. These changes suggest that the physiological stress was high during MFT. High levels of upper body and trunk muscular strength were negatively correlated with warfighters' physiological effects and should therefore be developed prior to actual deployment to reduce the physical decline experienced during prolonged MFTs.
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Affiliation(s)
- Tommi Ojanen
- Finnish Defence Research AgencyFinnish Defence ForcesJärvenpääFinland
| | - Petri Jalanko
- Biology of Physical ActivityUniversity of JyväskyläJyväskyläFinland
| | - Heikki Kyröläinen
- Biology of Physical ActivityUniversity of JyväskyläJyväskyläFinland
- National Defence UniversityHelsinkiFinland
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25
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Salonen M, Huovinen J, Kyröläinen H, Piirainen JM, Vaara JP. Neuromuscular Performance and Hormonal Profile During Military Training and Subsequent Recovery Period. Mil Med 2018; 184:e113-e119. [DOI: 10.1093/milmed/usy176] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 06/15/2018] [Indexed: 11/14/2022] Open
Affiliation(s)
- Mika Salonen
- Department of Leadership and Military Pedagogy, National Defense University, Santahamina, Helsinki, Finland
| | - Jukka Huovinen
- Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Rautpohjankatu 8, Jyväskylä, Finland
| | - Heikki Kyröläinen
- Department of Leadership and Military Pedagogy, National Defense University, Santahamina, Helsinki, Finland
- Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Rautpohjankatu 8, Jyväskylä, Finland
| | - Jarmo M Piirainen
- Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Rautpohjankatu 8, Jyväskylä, Finland
| | - Jani P Vaara
- Department of Leadership and Military Pedagogy, National Defense University, Santahamina, Helsinki, Finland
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26
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Threshold of Energy Deficit and Lower-Body Performance Declines in Military Personnel: A Meta-Regression. Sports Med 2018; 48:2169-2178. [DOI: 10.1007/s40279-018-0945-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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27
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Ojanen T, Kyröläinen H, Igendia M, Häkkinen K. Effect of Prolonged Military Field Training on Neuromuscular and Hormonal Responses and Shooting Performance in Warfighters. Mil Med 2018; 183:e705-e712. [DOI: 10.1093/milmed/usy122] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Indexed: 11/13/2022] Open
Affiliation(s)
- Tommi Ojanen
- Finnish Defence Research Agency, Finnish Defence Forces, Järvenpää, Finland
| | - Heikki Kyröläinen
- Biology of Physical Activity, Faculty of Sport and Health Sciences, University of Jyväskylä., Jyväskylä, Finland
- National Defence University, Helsinki, Finland
| | - Mikael Igendia
- Biology of Physical Activity, Faculty of Sport and Health Sciences, University of Jyväskylä., Jyväskylä, Finland
| | - Keijo Häkkinen
- Biology of Physical Activity, Faculty of Sport and Health Sciences, University of Jyväskylä., Jyväskylä, Finland
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28
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Karl JP, Margolis LM, Murphy NE, Carrigan CT, Castellani JW, Madslien EH, Teien HK, Martini S, Montain SJ, Pasiakos SM. Military training elicits marked increases in plasma metabolomic signatures of energy metabolism, lipolysis, fatty acid oxidation, and ketogenesis. Physiol Rep 2017; 5:e13407. [PMID: 28899914 PMCID: PMC5599865 DOI: 10.14814/phy2.13407] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 08/06/2017] [Accepted: 08/10/2017] [Indexed: 01/08/2023] Open
Abstract
Military training studies provide unique insight into metabolic responses to extreme physiologic stress induced by multiple stressor environments, and the impacts of nutrition in mediating these responses. Advances in metabolomics have provided new approaches for extending current understanding of factors modulating dynamic metabolic responses in these environments. In this study, whole-body metabolic responses to strenuous military training were explored in relation to energy balance and macronutrient intake by performing nontargeted global metabolite profiling on plasma collected from 25 male soldiers before and after completing a 4-day, 51-km cross-country ski march that produced high total daily energy expenditures (25.4 MJ/day [SD 2.3]) and severe energy deficits (13.6 MJ/day [SD 2.5]). Of 737 identified metabolites, 478 changed during the training. Increases in 88% of the free fatty acids and 91% of the acylcarnitines, and decreases in 88% of the mono- and diacylglycerols detected within lipid metabolism pathways were observed. Smaller increases in 75% of the tricarboxylic acid cycle intermediates, and 50% of the branched-chain amino acid metabolites detected were also observed. Changes in multiple metabolites related to lipid metabolism were correlated with body mass loss and energy balance, but not with energy and macronutrient intakes or energy expenditure. These findings are consistent with an increase in energy metabolism, lipolysis, fatty acid oxidation, ketogenesis, and branched-chain amino acid catabolism during strenuous military training. The magnitude of the energy deficit induced by undereating relative to high energy expenditure, rather than macronutrient intake, appeared to drive these changes, particularly within lipid metabolism pathways.
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Affiliation(s)
- J Philip Karl
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee
| | - Nancy E Murphy
- 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
| | - John W Castellani
- Thermal and Mountain Medicine Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | | | | | - Svein Martini
- Norwegian Defense Research Establishment, Kjeller, Norway
| | - Scott J Montain
- 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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29
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Hooper DR, Kraemer WJ, Saenz C, Schill KE, Focht BC, Volek JS, Maresh CM. The presence of symptoms of testosterone deficiency in the exercise-hypogonadal male condition and the role of nutrition. Eur J Appl Physiol 2017; 117:1349-1357. [PMID: 28470410 DOI: 10.1007/s00421-017-3623-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 04/24/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE High volumes of aerobic exercise have been associated with reduced testosterone (T), known as the exercise-hypogonadal male condition (EHMC). Although the presence of low T has been identified, few studies have assessed the presence of androgen-deficient symptoms. The purpose of this investigation is to assess men exhibiting EHMC and evaluate their hypothalamic-pituitary-gonadal axis, the presence of hypogonadal symptoms, and also investigate a possible contribution of inadequate nutrition to the condition. METHODS A cross-sectional design compared 9 long-distance runners exhibiting EHMC to 8 non-active controls. Comparisons included serum T, luteinizing hormone (LH), follicle-stimulating hormone, and cortisol, the Aging Male Symptoms (AMS) questionnaire score, bone mineral density (BMD), and a food frequency questionnaire. RESULTS Mean T was significantly reduced in the EHMC group (EHMC 9.2 nmol L-1 vs. CONT 16.2 nmol L-1). The EHMC group demonstrated significantly higher AMS scores (EHMC 27.1 ± 7.3 vs. CONT 19.7 ± 2.5). There were no differences in bone density, although 3 cases of osteopenia were noted for EHMC in the lumbar spine, 1 in the right femur, and 1 in the radius. Energy availability was significantly reduced in EHMC (EHMC 27.2 ± 12.7 vs. CONT 45.4 ± 18.2 kcal d FFM-1). CONCLUSIONS Men exhibiting EHMC do appear to present with symptoms associated with androgen deficiency. For the most part, these symptoms are limited to those reported on the AMS questionnaire, although there are also some cases of clinically low BMD. It is possible that inadequate energy intake is contributing to this condition.
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Affiliation(s)
- David R Hooper
- Department of Health Sciences, Armstrong State University, Savannah, GA, USA.,Department of Human Sciences, The Ohio State University, A054 PAES Building, 305 Annie and John Glenn Avenue, Columbus, OH, 43210, USA
| | - William J Kraemer
- Department of Human Sciences, The Ohio State University, A054 PAES Building, 305 Annie and John Glenn Avenue, Columbus, OH, 43210, USA.
| | - Catherine Saenz
- Department of Human Sciences, The Ohio State University, A054 PAES Building, 305 Annie and John Glenn Avenue, Columbus, OH, 43210, USA
| | - Kevin E Schill
- Department of Human Sciences, The Ohio State University, A054 PAES Building, 305 Annie and John Glenn Avenue, Columbus, OH, 43210, USA
| | - Brian C Focht
- Department of Human Sciences, The Ohio State University, A054 PAES Building, 305 Annie and John Glenn Avenue, Columbus, OH, 43210, USA
| | - Jeff S Volek
- Department of Human Sciences, The Ohio State University, A054 PAES Building, 305 Annie and John Glenn Avenue, Columbus, OH, 43210, USA
| | - Carl M Maresh
- Department of Human Sciences, The Ohio State University, A054 PAES Building, 305 Annie and John Glenn Avenue, Columbus, OH, 43210, USA
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Body weight and body composition changes during military training and deployment involving the use of combat rations: a systematic literature review. Br J Nutr 2017; 117:897-910. [DOI: 10.1017/s0007114517000630] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
AbstractDismounted military personnel operate in physically and psychologically demanding environments, with energy intake from combat rations often falling short of their requirements, leading to reductions in body weight and changes in body composition, which can impact both their health and performance. This review systematically investigated the effects of the continual use of combat rations for periods of 3–40 d on body weight and/or body composition in military personnel engaged in training or deployment. In all, ten databases were searched from their inception until October 2016. Outcome data were described narratively, with studies assessed for quality and risk of bias. A total of thirty studies undertaken over 3–34 d were included. Studies were rated positive, neutral or negative in quality according to the Academy of Nutrition and Dietetics Quality Checklist, with many at risk of bias. Reductions in mean body weight varied, from a negligible decrease of 0·1 % during 8 d of combat training to a substantial decrease of approximately 8·3 % during 12 d of energy restriction during a US Army Ranger course. Decreases in fat mass, fat-free mass and percentage body fat were also reported. There is thus evidence that the continual use of combat rations for periods of 3–34 d results in reductions in body weight and body composition changes which, in some scenarios, may impact on the performance of troops. Body weight and composition should be routinely monitored before and after field activities, and at more regular intervals depending on the length, intensity and type of activity being undertaken.
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31
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Negative energy balance and loss of body mass and fat-free mass in military personnel subsisting on combat rations during training and combat operations: a comment on Tassone and Baker. Br J Nutr 2017; 117:894-896. [DOI: 10.1017/s0007114517000605] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Does soy protein affect circulating levels of unbound IGF-1? Eur J Nutr 2017; 57:423-432. [PMID: 28434035 DOI: 10.1007/s00394-017-1459-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 04/13/2017] [Indexed: 01/26/2023]
Abstract
INTRODUCTION Despite the enormous amount of research that has been conducted on the role of soyfoods in the prevention and treatment of chronic disease, the mechanisms by which soy exerts its physiological effects are not fully understood. The clinical data show that neither soyfoods nor soy protein nor isoflavones affect circulating levels of reproductive hormones in men or women. However, some research suggests that soy protein, but not isoflavones, affects insulin-like growth factor I (IGF-1). METHODS Since IGF-1 may have wide-ranging physiological effects, we sought to determine the effect of soy protein on IGF-1 and its major binding protein insulin-like growth factor-binding protein (IGFBP-3). Six clinical studies were identified that compared soy protein with a control protein, albeit only two studies measured IGFBP-3 in addition to IGF-1. RESULTS Although the data are difficult to interpret because of the different experimental designs employed, there is some evidence that large amounts of soy protein (>25 g/day) modestly increase IGF-1 levels above levels observed with the control protein. CONCLUSION The clinical data suggest that a decision to incorporate soy into the diet should not be based on its possible effects on IGF-1.
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Hulmi JJ, Isola V, Suonpää M, Järvinen NJ, Kokkonen M, Wennerström A, Nyman K, Perola M, Ahtiainen JP, Häkkinen K. The Effects of Intensive Weight Reduction on Body Composition and Serum Hormones in Female Fitness Competitors. Front Physiol 2017; 7:689. [PMID: 28119632 PMCID: PMC5222856 DOI: 10.3389/fphys.2016.00689] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 12/23/2016] [Indexed: 11/13/2022] Open
Abstract
Worries about the potential negative consequences of popular fat loss regimens for aesthetic purposes in normal weight females have been surfacing in the media. However, longitudinal studies investigating these kinds of diets are lacking. The purpose of the present study was to investigate the effects of a 4-month fat-loss diet in normal weight females competing in fitness-sport. In total 50 participants finished the study with 27 females (27.2 ± 4.1 years) dieting for a competition and 23 (27.7 ± 3.7 years) acting as weight-stable controls. The energy deficit of the diet group was achieved by reducing carbohydrate intake and increasing aerobic exercise while maintaining a high level of protein intake and resistance training in addition to moderate fat intake. The diet led to a ~12% decrease in body weight (P < 0.001) and a ~35-50% decrease in fat mass (DXA, bioimpedance, skinfolds, P < 0.001) whereas the control group maintained their body and fat mass (diet × group interaction P < 0.001). A small decrease in lean mass (bioimpedance and skinfolds) and in vastus lateralis muscle cross-sectional area (ultrasound) were observed in diet (P < 0.05), whereas other results were unaltered (DXA: lean mass, ultrasound: triceps brachii thickness). The hormonal system was altered during the diet with decreased serum concentrations of leptin, triiodothyronine (T3), testosterone (P < 0.001), and estradiol (P < 0.01) coinciding with an increased incidence of menstrual irregularities (P < 0.05). Body weight and all hormones except T3 and testosterone returned to baseline during a 3-4 month recovery period including increased energy intake and decreased levels aerobic exercise. This study shows for the first time that most of the hormonal changes after a 35-50% decrease in body fat in previously normal-weight females can recover within 3-4 months of increased energy intake.
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Affiliation(s)
- Juha J Hulmi
- Department of Biology of Physical Activity, Neuromuscular Research Center, University of JyväskyläJyväskylä, Finland; Department of Physiology, Faculty of Medicine, University of HelsinkiHelsinki, Finland
| | - Ville Isola
- Department of Biology of Physical Activity, Neuromuscular Research Center, University of Jyväskylä Jyväskylä, Finland
| | - Marianna Suonpää
- Department of Health Sciences, University of Jyväskylä Jyväskylä, Finland
| | - Neea J Järvinen
- Department of Biology of Physical Activity, Neuromuscular Research Center, University of Jyväskylä Jyväskylä, Finland
| | - Marja Kokkonen
- Department of Physical Education, University of Jyväskylä Jyväskylä, Finland
| | - Annika Wennerström
- Genomics and Biomarkers Unit, Department of Health, National Institute for Health and WelfareHelsinki, Finland; Institute for Molecular Medicine Finland and Diabetes and Obesity Research Program, University of HelsinkiHelsinki, Finland
| | - Kai Nyman
- Central Hospital of Central Finland Jyväskylä, Finland
| | - Markus Perola
- Genomics and Biomarkers Unit, Department of Health, National Institute for Health and WelfareHelsinki, Finland; Institute for Molecular Medicine Finland and Diabetes and Obesity Research Program, University of HelsinkiHelsinki, Finland; The Estonian Genome Center of the University of TartuTartu, Estonia
| | - Juha P Ahtiainen
- Department of Biology of Physical Activity, Neuromuscular Research Center, University of Jyväskylä Jyväskylä, Finland
| | - Keijo Häkkinen
- Department of Biology of Physical Activity, Neuromuscular Research Center, University of Jyväskylä Jyväskylä, Finland
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Joro R, Uusitalo A, DeRuisseau KC, Atalay M. Changes in cytokines, leptin, and IGF-1 levels in overtrained athletes during a prolonged recovery phase: A case-control study. J Sports Sci 2016; 35:2342-2349. [PMID: 27966392 DOI: 10.1080/02640414.2016.1266379] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
We investigated how cytokines are implicated with overtraining syndrome (OTS) in athletes during a prolonged period of recovery. Plasma IL-6, IL-10, TNF-α, IL-1β, adipokine leptin, and insulin like growth factor-1 (IGF-1) concentrations were measured in overtrained (OA: 5 men, 2 women) and healthy control athletes (CA: 5 men, 5 women) before and after exercise to volitional exhaustion. Measurements were conducted at baseline and after 6 and 12 months. Inflammatory cytokines did not differ between groups at rest. However, resting leptin concentration was lower in OA than CA at every measurement (P < 0.050) but was not affected by acute exercise. Although IL-6 and TNF-α concentrations increased with exercise in both groups (P < 0.050), pro-inflammatory IL-1β concentration increased only in OA (P < 0.050) and anti-inflammatory IL-10 was greater in CA (P < 0.001). In OA, exercise-related IL-6 and TNF-α induction was enhanced during the follow-up (P < 0.050). IGF-1 decreased with exercise in OA (P < 0.050); however, no differences in resting IGF-1 were observed. In conclusion, low leptin level at rest and a pro-inflammatory cytokine response to acute exercise may reflect a chronic maladaptation state in overtrained athletes. In contrast, the accentuation of IL-6 and TNF-α responses to acute exercise seemed to associate with the progression of recovery from overtraining.
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Affiliation(s)
- Raimo Joro
- a Institute of Biomedicine, Physiology , University of Eastern Finland , Kuopio , Finland
| | - Arja Uusitalo
- b HUS Medical Imaging Center, Clinical Physiology and Nuclear Medicine , University of Helsinki and Helsinki University Hospital , Helsinki , Finland
| | - Keith C DeRuisseau
- a Institute of Biomedicine, Physiology , University of Eastern Finland , Kuopio , Finland.,c Department of Exercise Science , Syracuse University , Syracuse , NY , USA
| | - Mustafa Atalay
- a Institute of Biomedicine, Physiology , University of Eastern Finland , Kuopio , Finland
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Austin KG, Price LL, McGraw SM, McLellan TM, Lieberman HR. Longitudinal trends in use of dietary supplements by U.S. Army personnel differ from those of civilians. Appl Physiol Nutr Metab 2016; 41:1217-1224. [DOI: 10.1139/apnm-2016-0296] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Prevalence and patterns of dietary supplement (DS) use by U.S. Army soldiers differ from the civilian population. Longitudinal trends in use of DSs by civilians have been examined, but are unavailable in subpopulations such as military service members. The present study examined longitudinal changes in DS use by soldiers. A standardized questionnaire on DS use was administered in 2006–2007 (N = 989) and 2010–2011 (N = 1196) to convenience samples of active duty soldiers. Data were weighted for total population demographics of age, sex, and rank. Regular use of DSs by soldiers increased significantly (56% ± 1.6% vs. 64% ± 1.7%; p ≤ 0.001) over the 4 years primarily because of an increase of DS use among the youngest 18- to 24-year-old soldiers (43.0% ± 2.5% vs 62.3% ± 2.4%; p ≤ 0.01). Protein (22% ± 1.4% vs. 26% ± 1.5%; p ≤ 0.001) and combination (10.0% ± 1.0% vs. 24% ± 1.4%; p ≤ 0.001) product consumption also increased over the 4 years. Individual vitamin and mineral use — including iron, magnesium, selenium, and vitamins A, B6, B12, and D — significantly increased as well (p ≤ 0.05). In addition, expenditures on DSs by soldiers increased over time (p < 0.01). Reasons reported by soldiers for DS use suggest use increased to meet the occupational demands of military service. Educational interventions to minimize inappropriate use of DSs by soldiers are necessary to reduce adverse events resulting from unnecessary use of DSs and the financial burden associated with their use.
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Affiliation(s)
- Krista G. Austin
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, USA
- Henry Jackson Foundation, 6720A Rockledge Drive #100, Bethesda, MD 20817, USA
| | - Lori Lyn Price
- Tufts Medical Center, 800 Washington Street, Tufts University, Boston, MA 02111, USA
| | - Susan M. McGraw
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, USA
| | - Tom M. McLellan
- TM McLellan Research Inc., 25 Dorman Drive, Stouffville, ON L4A 8A7, Canada
| | - Harris R. Lieberman
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, USA
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Cognitive function, stress hormones, heart rate and nutritional status during simulated captivity in military survival training. Physiol Behav 2016; 165:86-97. [DOI: 10.1016/j.physbeh.2016.06.037] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 06/23/2016] [Accepted: 06/30/2016] [Indexed: 12/25/2022]
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Longland TM, Oikawa SY, Mitchell CJ, Devries MC, Phillips SM. Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial. Am J Clin Nutr 2016; 103:738-46. [PMID: 26817506 DOI: 10.3945/ajcn.115.119339] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 12/16/2015] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND A dietary protein intake higher than the Recommended Dietary Allowance during an energy deficit helps to preserve lean body mass (LBM), particularly when combined with exercise. OBJECTIVE The purpose of this study was to conduct a proof-of-principle trial to test whether manipulation of dietary protein intake during a marked energy deficit in addition to intense exercise training would affect changes in body composition. DESIGN We used a single-blind, randomized, parallel-group prospective trial. During a 4-wk period, we provided hypoenergetic (~40% reduction compared with requirements) diets providing 33 ± 1 kcal/kg LBM to young men who were randomly assigned (n = 20/group) to consume either a lower-protein (1.2 g · kg(-1) · d(-1)) control diet (CON) or a higher-protein (2.4 g · kg(-1) · d(-1)) diet (PRO). All subjects performed resistance exercise training combined with high-intensity interval training for 6 d/wk. A 4-compartment model assessment of body composition was made pre- and postintervention. RESULTS As a result of the intervention, LBM increased (P < 0.05) in the PRO group (1.2 ± 1.0 kg) and to a greater extent (P < 0.05) compared with the CON group (0.1 ± 1.0 kg). The PRO group had a greater loss of fat mass than did the CON group (PRO: -4.8 ± 1.6 kg; CON: -3.5 ± 1.4kg; P < 0.05). All measures of exercise performance improved similarly in the PRO and CON groups as a result of the intervention with no effect of protein supplementation. Changes in serum cortisol during the intervention were associated with changes in body fat (r = 0.39, P = 0.01) and LBM (r = -0.34, P = 0.03). CONCLUSIONS Our results showed that, during a marked energy deficit, consumption of a diet containing 2.4 g protein · kg(-1) · d(-1) was more effective than consumption of a diet containing 1.2 g protein · kg(-1) · d(-1) in promoting increases in LBM and losses of fat mass when combined with a high volume of resistance and anaerobic exercise. Changes in serum cortisol were associated with changes in body fat and LBM, but did not explain much variance in either measure. This trial was registered at clinicaltrials.gov as NCT01776359.
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Affiliation(s)
- Thomas M Longland
- Department of Kinesiology, Exercise Metabolism Research Group, McMaster University, Hamilton, Canada
| | - Sara Y Oikawa
- Department of Kinesiology, Exercise Metabolism Research Group, McMaster University, Hamilton, Canada
| | - Cameron J Mitchell
- Department of Kinesiology, Exercise Metabolism Research Group, McMaster University, Hamilton, Canada
| | - Michaela C Devries
- Department of Kinesiology, Exercise Metabolism Research Group, McMaster University, Hamilton, Canada
| | - Stuart M Phillips
- Department of Kinesiology, Exercise Metabolism Research Group, McMaster University, Hamilton, Canada
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Koehler K, Hoerner NR, Gibbs JC, Zinner C, Braun H, De Souza MJ, Schaenzer W. Low energy availability in exercising men is associated with reduced leptin and insulin but not with changes in other metabolic hormones. J Sports Sci 2016; 34:1921-9. [PMID: 26852783 DOI: 10.1080/02640414.2016.1142109] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Low energy availability, defined as low caloric intake relative to exercise energy expenditure, has been linked to endocrine alterations frequently observed in chronically energy-deficient exercising women. Our goal was to determine the endocrine effects of low energy availability in exercising men. Six exercising men (VO2peak: 49.3 ± 2.4 ml · kg(-1) · min(-1)) underwent two conditions of low energy availability (15 kcal · kg(-1) fat-free mass [FFM] · day(-1)) and two energy-balanced conditions (40 kcal · kg(-1) FFM · day(-1)) in randomised order. During one low energy availability and one balanced condition, participants exercised to expend 15 kcal · kg(-1) FFM · day(-1); no exercise was conducted during the other two conditions. Metabolic hormones were assessed before and after each 4-day period. Following both low energy availability conditions, leptin (-53% to -56%) and insulin (-34% to -38%) were reduced (P < 0.05). Reductions in leptin and insulin were independent of whether low energy availability was attained with or without exercise (P > 0.80). Low energy availability did not significantly impact ghrelin, triiodothyronine, testosterone and IGF-1 (all P > 0.05). The observed reductions in leptin and insulin were in the same magnitude as changes previously reported in sedentary women. Further research is needed to understand why other metabolic hormones are more robust against low energy availability in exercising men than those in sedentary and exercising women.
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Affiliation(s)
- Karsten Koehler
- a Institute of Biochemistry , German Sport University , Cologne , Germany.,b Department of Kinesiology , Pennsylvania State University , University Park , PA , USA.,c Department of Nutrition and Health Sciences , University of Nebraska-Lincoln , Lincoln , NE , USA
| | - Neele R Hoerner
- a Institute of Biochemistry , German Sport University , Cologne , Germany
| | - Jenna C Gibbs
- b Department of Kinesiology , Pennsylvania State University , University Park , PA , USA.,d Department of Kinesiology , University of Waterloo , Waterloo , Canada
| | - Christoph Zinner
- e Department of Sport Science , University of Würzburg , Würzburg , Germany
| | - Hans Braun
- a Institute of Biochemistry , German Sport University , Cologne , Germany
| | - Mary Jane De Souza
- b Department of Kinesiology , Pennsylvania State University , University Park , PA , USA
| | - Wilhelm Schaenzer
- a Institute of Biochemistry , German Sport University , Cologne , Germany
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Vaara JP, Kalliomaa R, Hynninen P, Kyröläinen H. Physical Fitness and Hormonal Profile During an 11-Week Paratroop Training Period. J Strength Cond Res 2015; 29 Suppl 11:S163-7. [PMID: 26506182 DOI: 10.1519/jsc.0000000000001033] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Physical fitness and serum hormone concentrations have been shown to change during military training. The purpose was to examine these chronic changes in paratroopers (n = 52 male conscripts) during an 11-week training period, including acute changes induced by strenuous 5-day military field training. Hormonal profiles, body mass, maximal strength, muscle endurance, and 12-minute running test were assessed at several time points during paratrooper training. In the latter part of the training period, conscripts were involved in strenuous military field training (5 days). At week 7, during specialized military training period, aerobic performance decreased (3,146 ± 163 m) but recovered back to a baseline level (3,226 ± 190 m) at the end of the study period (p < 0.001). Standing long jump decreased at week 7 (242 ± 13 cm) (p < 0.001) from the baseline value (248 ± 13 cm), whereas push-up (52 ± 11, 60 ± 13 repetitions per minute) and sit-up (54 ± 6, 56 ± 7 repetitions per minute) performances increased (p < 0.001). No changes were observed in maximal strength and body composition, neither mostly in hormone concentrations, although cortisol decreased but increased back to baseline value at the end of the study period (p ≤ 0.05). Acute responses after the 5-day military field training included decreased maximal strength of the lower extremities and body mass, as well as changes in androgen hormone concentrations ([INCREMENT]testosterone: -46%, [INCREMENT]insulin-like growth factor-1: -28%, [INCREMENT]sex hormone-binding globulin: +25%) compared with all other measurements (p ≤ 0.05). The first 4 weeks of parachute military training decreased maximal aerobic capacity and neuromuscular performance of the lower body, whereas muscular endurance increased. Moreover, 5-day military field training resulted in dramatic changes in hormone concentrations. These findings highlight the importance of periodizing paratrooper training and underline the need for sufficient recovery immediately after military field training.
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Affiliation(s)
- Jani P Vaara
- 1Department of Leadership and Military Pedagogy, National Defence University, Helsinki, Finland; 2Utti Jaeger Regiman, Utti, Finland; and 3Department of Biology of Physical Activity, University of Jyväskylä, Jyväskylä, Finland
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Arnarson A, Gudny Geirsdottir O, Ramel A, Jonsson PV, Thorsdottir I. Insulin-Like Growth Factor-1 and Resistance Exercise in Community Dwelling Old Adults. J Nutr Health Aging 2015; 19:856-60. [PMID: 26412290 DOI: 10.1007/s12603-015-0547-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND Insulin-like growth factor-1 (IGF-1) is related to the preservation of lean body mass. Its decline during ageing is thought to make old adults more susceptible to sarcopenia and functional dependency. The aim of the present study was to investigate circulating total IGF-1 in old adults who engaged in a 12-weeks of progressive resistance training. DESIGN Intervention study. SETTING Community. PARTICIPANTS Old Icelandic adults (N = 235, 73.7 ± 5.7 years, 58.2% female). INTERVENTION Twelve-week resistance exercise program (3 times/week; 3 sets, 6-8 repetitions at 75-80% of the 1-repetition maximum) designed to increase strength and muscle mass of major muscle groups. MEASUREMENTS IGF-1. RESULTS At baseline IGF-1 was significantly associated with lean body mass and appendicular muscle mass (also when corrected for age, gender and various covariates). After the training IGF-1 decreased significantly from 112.1 ± 35.6 to 106.1 ± 35.2 µg/L during the course of the study. On and individual level, IGF-1 decreased in 59% and increased in 39% of the participants. Changes in IGF-1 were inversely related to changes in lean body mass (rho = -0.176, P = 0.013 ) and appendicular muscle mass (rho = -0.162, P = 0.019) also when corrected for protein intake, age, gender, and other covariates. CONCLUSION Serum total IGF-1 decreases after 12 weeks of resistance exercise in community dwelling old adults. When looked at IGF-1 changes for participants individually it becomes clear that IGF-1 response to resistances exercise is highly variable. Changes in IGF-1 are negatively related to changes in lean body mass during training, which supports the hypothesis that IGF-1 is redistributed from circulation into tissue during periods of active muscle building.
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Affiliation(s)
- A Arnarson
- Alfons Ramel, Unit for Nutrition Research, National University Hospital of Iceland, Eiriksgata 29, 101 Reykjavik, Iceland,Telephone: +354-543-8410, Fax: +354-543-4824,
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Woods DR, Delves SK, Britland SE, Shaw A, Brown PE, Bentley C, Hornby S, Burnett A, Lanham-New SA, Fallowfield JL. Nutritional status and the gonadotrophic response to a polar expedition. Appl Physiol Nutr Metab 2015; 40:292-7. [DOI: 10.1139/apnm-2014-0418] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Polar expeditions have been associated with changes in the hypothalamic–pituitary–testicular axis consistent with central hypogonadism (i.e., decreased testosterone, luteinising hormone (LH), and follicle stimulating hormone (FSH)). These changes are typically associated with body mass loss. Our aim was to evaluate whether maintenance of body mass during a polar expedition could mitigate against the development of central hypogonadism. Male participants (n = 22) from a 42-day expedition (British Services Antarctic Expedition 2012) volunteered to take part in the study. Body mass, body composition, and strength data were recorded pre- and postexpedition in addition to assessment of serum testosterone, LH, FSH, thyroid hormones, insulin-like growth factor 1 (IGF-1), and trace elements. Energy provision and energy expenditure were assessed at mid- and end-expedition. Daily energy provision was 6335 ± 149 kcal·day−1. Estimated energy expenditure midexpedition was 5783 ± 1690 kcal·day−1. Body mass and percentage body fat did not change between pre- and postexpedition. Total testosterone (nmol·L−1) (14.0 ± 4.9 vs. 17.3 ± 4.0, p = 0.006), calculated free testosterone (pmol·L−1) (288 ± 82 vs. 350 ± 70, p = 0.003), and sex hormone binding globulin (nmol·L−1) (33 ± 12 vs. 36 ± 11, p = 0.023) concentrations increased. LH and FSH remained unchanged. Thyroid stimulating hormone (TSH; IU·L−1) (2.1 ± 0.8 vs. 4.1 ± 2.1, p < 0.001) and free triiodothyronine (FT3; IU·L−1) (5.4 ± 0.4 vs. 6.1 ± 0.8, p < 0.001) increased while free thyroxine, IGF-1, and trace elements remained unchanged. Hand-grip strength was reduced postexpedition but static lift strength was maintained. Maintenance of body mass and nutritional status appeared to negate the central hypogonadism previously reported from polar expeditions. The elevated TSH and free FT3 were consistent with a previously reported “polar T3 syndrome”.
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Affiliation(s)
- David R. Woods
- Royal Victoria Infirmary and Newcastle University, Queen Victoria Road, Newcastle-upon-Tyne, NE1 4LP, UK
- Carnegie Research Institute, Leeds Metropolitan University, Leeds, LS6 3QS, UK
| | - Simon K. Delves
- Institute of Naval Medicine, Crescent Road, Alverstoke, PO12 2DL, UK
| | | | - Anneliese Shaw
- Institute of Naval Medicine, Crescent Road, Alverstoke, PO12 2DL, UK
| | - Piete E. Brown
- Institute of Naval Medicine, Crescent Road, Alverstoke, PO12 2DL, UK
| | - Conor Bentley
- NIHR SRMRC, Trauma Research, Room 36, 4th Floor, East Block Queen Elizabeth Hospital Research and Development, University Hospitals Birmingham NHS Foundation Trust Queen Elizabeth Hospital, Queen Elizabeth Medical Centre, Birmingham, B15 2TH, UK
| | | | - Anne Burnett
- Department of Clinical Biochemistry, Royal Victoria Infirmary, Queen Victoria Road, Newcastle-upon-Tyne, NE1 4LP, UK
| | - Sue A. Lanham-New
- Nutritional Sciences Department, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, UK
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Hill NE, Woods DR, Delves SK, Murphy KG, Davison AS, Brett SJ, Quinton R, Turner S, Stacey M, Allsopp AJ, Fallowfield JL. The gonadotrophic response of Royal Marines during an operational deployment in Afghanistan. Andrology 2015; 3:293-7. [DOI: 10.1111/andr.308] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Revised: 09/26/2014] [Accepted: 10/31/2014] [Indexed: 01/21/2023]
Affiliation(s)
- N. E. Hill
- Royal Centre for Defence Medicine; Birmingham UK
- Imperial College London; London UK
| | - D. R. Woods
- Consultant Physician in Endocrinology and Diabetes; Northumbria and Newcastle NHS Trusts; Newcastle, UK
- University of Newcastle upon Tyne; Newcastle UK
- Carnegie Research Institute; Leeds Metropolitan University; Leeds UK
| | | | | | - A. S. Davison
- Department of Clinical Biochemistry; Newcastle Hospitals NHS Trust; Newcastle UK
| | | | - R. Quinton
- Institute of Genetic Medicine; University of Newcastle upon Tyne; Newcastle UK
- Department of Endocrinology; Royal Victoria Infirmary; Newcastle upon Tyne UK
| | - S. Turner
- Department of Clinical Biochemistry; Newcastle Hospitals NHS Trust; Newcastle UK
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Pasiakos SM, Margolis LM, Orr JS. Optimized dietary strategies to protect skeletal muscle mass during periods of unavoidable energy deficit. FASEB J 2014; 29:1136-42. [DOI: 10.1096/fj.14-266890] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 12/01/2014] [Indexed: 12/14/2022]
Affiliation(s)
- Stefan M. Pasiakos
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Lee M. Margolis
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Jeb S. Orr
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
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Ritsche K, Nindl BC, Wideman L. Exercise-Induced growth hormone during acute sleep deprivation. Physiol Rep 2014; 2:2/10/e12166. [PMID: 25281616 PMCID: PMC4254093 DOI: 10.14814/phy2.12166] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The effect of acute (24‐h) sleep deprivation on exercise‐induced growth hormone (GH) and insulin‐like growth factor‐1 (IGF‐1) was examined. Ten men (20.6 ± 1.4 years) completed two randomized 24‐h sessions including a brief, high‐intensity exercise bout following either a night of sleep (SLEEP) or (24‐h) sleep deprivation (SLD). Anaerobic performance (mean power [MP], peak power [PP], minimum power [MinP], time to peak power [TTPP], fatigue index, [FI]) and total work per sprint [TWPS]) was determined from four maximal 30‐sec Wingate sprints on a cycle ergometer. Self‐reported sleep 7 days prior to each session was similar between SLEEP and SLD sessions (7.92 ± 0.33 vs. 7.98 ± 0.39 h, P =0.656, respectively) and during the actual SLEEP session in the lab, the total amount of sleep was similar to the 7 days leading up to the lab session (7.72 ± 0.14 h vs. 7.92 ± 0.33 h, respectively) (P =0.166). No differences existed in MP, PP, MinP, TTPP, FI, TWPS, resting GH concentrations, time to reach exercise‐induced peak GH concentration (TTP), or free IGF‐1 between sessions. GH area under the curve (AUC) (825.0 ± 199.8 vs. 2212.9 ± 441.9 μg/L*min, P <0.01), exercise‐induced peak GH concentration (17.8 ± 3.7 vs. 39.6 ± 7.1 μg/L, P <0.01) and ΔGH (peak GH – resting GH) (17.2 ± 3.7 vs. 38.2 ± 7.3 μg/L, P <0.01) were significantly lower during the SLEEP versus SLD session. Our results indicate that the exercise‐induced GH response was significantly augmented in sleep‐deprived individuals. Human growth hormone release is heavily influenced by sleep and exercise. Our study shows that sleep deprivation dramatically augments the exercise‐induced human growth hormone response.
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Affiliation(s)
- Kevin Ritsche
- Department of Kinesiology, University of North Carolina-Greensboro, Greensboro, North Carolina, USA Department of Exercise Physiology, Winston-Salem State University, Winston-Salem, North Carolina, USA
| | - Bradly C Nindl
- US Army Institute of Public Health, US Army Public Health Command, Aberdeen, Proving Ground, Aberdeen, Maryland, USA
| | - Laurie Wideman
- Department of Kinesiology, University of North Carolina-Greensboro, Greensboro, North Carolina, USA
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Henning PC, Margolis LM, McClung JP, Young AJ, Pasiakos SM. High protein diets do not attenuate decrements in testosterone and IGF-I during energy deficit. Metabolism 2014; 63:628-32. [PMID: 24641883 DOI: 10.1016/j.metabol.2014.02.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 02/10/2014] [Accepted: 02/11/2014] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Energy deficit (ED) diminishes fat-free mass (FFM) with concomitant reductions in anabolic hormone secretion. A modest increase in protein to recommended dietary allowance (RDA) levels during ED minimally attenuates decrements in insulin-like growth factor-I (IGF-I). The impact of dietary protein above the RDA on circulating anabolic hormones and their relationships with FFM in response to ED are not well described. MATERIALS/METHODS Thirty-three adults were assigned diets providing protein at 0.8 (RDA), 1.6 (2×-RDA), and 2.4 (3×-RDA) g/kg/d for 31days. Testosterone, sex-hormone binding globulin (SHBG) and IGF-I system components were assessed after a 10-day period of weight-maintenance (WM) and after a 21-day period of ED (40%) achieved by an increase in energy expenditure and decreased energy intake. Associations between the change in FFM and anabolic hormone levels were determined. RESULTS As compared to WM and regardless of dietary protein intake, total and free testosterone, total IGF-I, and acid-labile subunit decreased (P<0.05), whereas SHBG and IGF binding proteins-1, -2, and -3 increased (P<0.05) during ED. There were no energy-by-protein interactions on any hormones or IGF-I system components measured. Changes in FFM in response to ED were negatively associated with acid-labile subunit (ALS) (r=-0.62, P<0.05) in 2×-RDA; however, no other relationships were observed. CONCLUSION Consuming a high protein diet does not impact the androgenic and IGF-I system response to ED. These data suggest that the protective effects of high protein diets on FFM during ED are likely not influenced by anabolic hormone concentrations.
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Affiliation(s)
- Paul C Henning
- Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - James P McClung
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Andrew J Young
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA.
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Henning PC, Scofield DE, Spiering BA, Staab JS, Matheny RW, Smith MA, Bhasin S, Nindl BC. Recovery of endocrine and inflammatory mediators following an extended energy deficit. J Clin Endocrinol Metab 2014; 99:956-64. [PMID: 24423293 DOI: 10.1210/jc.2013-3046] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Due to current operational requirements, elite soldiers deploy quickly after completing arduous training courses. Therefore, it is imperative that endocrine and inflammatory mediators have fully recovered. OBJECTIVE Our objective was to determine whether a short-term (2-6 wk) recovery period was sufficient to restore endocrine and inflammatory homeostasis after sustained energy deficit. DESIGN Before and immediately after the course, serum concentrations of inflammatory and endocrine markers were taken along with anthropometric measures prior to and immediately after the Army Ranger course. In addition, nine soldiers were assessed between 2 and 6 weeks after the course. SETTING This research occurred in a field setting during an intensive 8-week military training course characterized by high-energy expenditure, energy restriction, and sleep deprivation (U.S. Army Ranger School). PARTICIPANTS Twenty-three male soldiers (23.0 ± 2.8 y; 177.6 ± 7.9 cm; 81.0 ± 9.6 kg, 16.8 ± 3.9% body fat) participated in this study. INTERVENTIONS There were no interventions used in this research. OUTCOME MEASURES AND RESULTS Significant changes occurred in circulating total testosterone (-70%), brain-derived neurotrophic factor (-33%), total IGF-1 (-38.7%), free IGF-1 (-41%), IGF binding protein (IGFBP-6; -23.4%), sex-hormone binding globulin (+46%), thyroid stimulating hormone (+85%), IGFBP-1 (+534.4%), IGFBP-2 (+98.3%), IGFBP-3 (+14.7%), IL-4 (+135%), IL-6 (+217%), and IL-8 (+101%). Significant changes in body mass (-8%), bicep (-14%), forearm (-5%), thigh (-7%), and calf (-2%) circumferences, sum of skinfolds (-52%), and percentage body fat (-54%). All anthropometric, inflammatory, and hormonal values, except T3, were restored to baseline levels within 2-6 weeks after the course. CONCLUSIONS Endocrine markers and anthropometric measures were degraded, and inflammatory mediators increased after an extended energy deficit. A short-term recovery of 2-6 weeks was sufficient to restore these mediators.
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Affiliation(s)
- Paul C Henning
- Military Performance Division (P.C.H., D.E.S., B.A.S., J.S.S., R.W.M., B.C.N.), U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts 01760; Madigan Healthcare System (M.A.S.), Joint Base Lewis-McChord, Washington 98431; and Sections of Endocrinology (S.B.), Diabetes, and Nutrition, Boston University School of Medicine, Boston University, Boston, Massachusetts 02118; and Army Institute of Public Health Army Public Health Command (B.C.N.), Aberdeen Proving Ground, Maryland 21010
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Archakov A, Zgoda V, Kopylov A, Naryzhny S, Chernobrovkin A, Ponomarenko E, Lisitsa A. Chromosome-centric approach to overcoming bottlenecks in the Human Proteome Project. Expert Rev Proteomics 2013; 9:667-76. [PMID: 23256676 DOI: 10.1586/epr.12.54] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The international Human Proteome Project (HPP), a logical continuation of the Human Genome Project, was launched on 23 September 2010 in Sydney, Australia. In accordance with the gene-centric approach, the goals of the HPP are to prepare an inventory of all human proteins and decipher the network of cellular protein interactions. The greater complexity of the proteome in comparison to the genome gives rise to three bottlenecks in the implementation of the HPP. The main bottleneck is the insufficient sensitivity of proteomic technologies, hampering the detection of proteins with low- and ultra-low copy numbers. The second bottleneck is related to poor reproducibility of proteomic methods and the lack of a so-called 'gold' standard. The last bottleneck is the dynamic nature of the proteome: its instability over time. The authors here discuss approaches to overcome these bottlenecks in order to improve the success of the HPP.
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Affiliation(s)
- Alexander Archakov
- Orekhovich Institute of Biomedical Chemistry, Russian Academy of Medical Sciences, 119121, Pogodinskaya Street 10, Moscow, Russia.
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Henning PC, Scofield DE, Rarick KR, Pierce JR, Staab JS, Lieberman HR, Nindl BC. Effects of acute caloric restriction compared to caloric balance on the temporal response of the IGF-I system. Metabolism 2013; 62:179-87. [PMID: 22906764 DOI: 10.1016/j.metabol.2012.07.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 07/11/2012] [Accepted: 07/11/2012] [Indexed: 01/03/2023]
Abstract
OBJECTIVE Insulin-like growth factor-I (IGF-I) is a key regulator of metabolism during altered energy states. The IGF-I system components respond to prolonged caloric restriction but it is not clear if this system responds similarly to acute caloric restriction. The purpose of this study was to characterize the IGF-I system response to acute caloric restriction with a secondary purpose of determining if two isocaloric diets with different ratios of carbohydrate to fat alter the IGF-I system under conditions of caloric balance. MATERIALS/METHODS A double-blind, placebo-controlled crossover design was used in which 27 subjects underwent three, 48-h experimental treatments: 1) caloric restriction 2) carbohydrate and 3) carbohydrate/fat. Blood was sampled periodically (6 time points total) for IGF-I (total and free), IGFBPs1-4, insulin and glucose. ANOVAs were used with significance set at P<0.05. RESULTS Total IGF-I decreased 7% during CR (P=0.051) and remained stable during CHO and CHO/F. Free IGF-I decreased 43% during CR (P<0.05) and remained stable during CHO and CHO/F. IGFBP-1 increased by 445% during CR (P<0.05) compared to CHO and CHO/F with no changes for IGFBP-2, IGFBP-3 and IGFBP-4. There was no change in glucose or insulin during CR over the course of the study. Insulin and glucose increased (P<0.05) after a meal in both the CHO and CHO/F groups with no difference between these two groups. CONCLUSION Our findings indicate that free IGF-I decreases and IGFBP-1 increases during caloric restriction, but they are not altered with diets differing in carbohydrate and fat content. Changes in free IGF-I and IGFBP-1 are sensitive to caloric restriction, and their measurement may be valuable in monitoring the physiological response to refeeding in those consuming suboptimal calories.
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Affiliation(s)
- Paul C Henning
- Military Performance Division, US Army Research Institute of Environmental Medicine, Natick, MA 01760, USA.
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Tanskanen MM, Westerterp KR, Uusitalo AL, Atalay M, Häkkinen K, Kinnunen HO, Kyröläinen H. Effects of easy-to-use protein-rich energy bar on energy balance, physical activity and performance during 8 days of sustained physical exertion. PLoS One 2012; 7:e47771. [PMID: 23094083 PMCID: PMC3475712 DOI: 10.1371/journal.pone.0047771] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 09/17/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Previous military studies have shown an energy deficit during a strenuous field training course (TC). This study aimed to determine the effects of energy bar supplementation on energy balance, physical activity (PA), physical performance and well-being and to evaluate ad libitum fluid intake during wintertime 8-day strenuous TC. METHODS Twenty-six men (age 20±1 yr.) were randomly divided into two groups: The control group (n = 12) had traditional field rations and the experimental (Ebar) group (n = 14) field rations plus energy bars of 4.1 MJ•day(-1). Energy (EI) and water intake was recorded. Fat-free mass and water loss were measured with deuterium dilution and elimination, respectively. The energy expenditure was calculated using the intake/balance method and energy availability as (EI/estimated basal metabolic rate). PA was monitored using an accelerometer. Physical performance was measured and questionnaires of upper respiratory tract infections (URTI), hunger and mood state were recorded before, during and after TC. RESULTS Ebar had a higher EI and energy availability than the controls. However, decreases in body mass and fat mass were similar in both groups representing an energy deficit. No differences were observed between the groups in PA, water balance, URTI symptoms and changes in physical performance and fat-free mass. Ebar felt less hunger after TC than the controls and they had improved positive mood state during the latter part of TC while controls did not. Water deficit associated to higher PA. Furthermore, URTI symptoms and negative mood state associated negatively with energy availability and PA. CONCLUSION An easy-to-use protein-rich energy bars did not prevent energy deficit nor influence PA during an 8-day TC. The high content of protein in the bars might have induced satiation decreasing energy intake from field rations. PA and energy intake seems to be primarily affected by other factors than energy supplementation such as mood state.
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Affiliation(s)
- Minna M Tanskanen
- Department of Biology of Physical Activity, University of Jyväskylä, Jyväskylä, Finland.
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Mukaetova-Ladinska EB, Purshouse K, Andrade J, Krishnan M, Jagger C, Kalaria RN. Can healthy lifestyle modify risk factors for dementia? Findings from a pilot community-based survey in Chennai (India) and Newcastle (UK). Neuroepidemiology 2012; 39:163-70. [PMID: 22948094 DOI: 10.1159/000338674] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 03/30/2012] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Currently there are no effective treatments available for dementia. Attention has turned to defining preventive strategies and identifying modifying effects of lifestyle, including physical activity, diet, alcohol intake and smoking, in reducing cognitive decline and overt memory problems in the elderly. METHODS In this study, we addressed the modifying aspects of various components of lifestyle in two ageing samples and explored the possible effects that exercise, diet and spiritual and religious beliefs have upon physical and mental health. A total of 251 subjects (128 in Chennai, India, and 123 in Newcastle, UK) filled in a questionnaire regarding their lifestyle habits. Data were analysed with χ² analysis. RESULTS Our findings highlight that spiritual and religious beliefs promoted good physical and mental health and were negatively associated with risk factors for dementia, such as high blood pressure, high cholesterol level and diabetes. Lifelong diet and physical activity also contributed to better overall well-being in both samples. CONCLUSIONS Our study suggests substantial lifestyle variations between two urban populations in Chennai, India, and Newcastle-upon-Tyne, UK. Further detailed work is required to identify the lifestyle components that have the greatest impact on modifying the known risk factors for dementia.
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