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Brown HA, Chalmers S, Topham TH, Clark B, Jowett A, Meyer T, Jay O, Périard JD. Efficacy of the FIFA cooling break heat policy during an intermittent treadmill football simulation in hot conditions in trained males. Br J Sports Med 2024:bjsports-2024-108131. [PMID: 39029949 DOI: 10.1136/bjsports-2024-108131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2024] [Indexed: 07/21/2024]
Abstract
OBJECTIVE To evaluate the efficacy of the Fédération Internationale de Football Association (FIFA) cooling break policy against alternative cooling configurations in attenuating thermal strain during simulated football in the heat. METHODS 12 males (age: 27±6 years, V̇O2peak: 61±7 mL/kg/min) completed five 90 min intermittent treadmill football match simulations in 40°C and 41% relative humidity (32°C wet-bulb globe temperature) with different cooling configurations: regular match without cooling breaks (REG), 3 min breaks without cooling (BRKno-cool), 3 min breaks with cooling (BRKcool: current FIFA policy; chilled fluid ingestion and ice towel across neck and shoulders), 5 min extended half-time without cooling breaks (ExtHTonly) and 3 min cooling breaks with 5 min ExtHT (ExtHTcool). Rectal temperature (Tre), heart rate, whole-body sweat rate (WBSR) and rating of perceived exertion (RPE) were recorded. Data are presented as mean (95% CIs). RESULTS Final Tre was lower in BRKno-cool (0.20°C (0.01, 0.39), p=0.038), BRKcool (0.39°C (0.21, 0.57), p<0.001) and ExtHTcool (0.40°C (0.22, 0.58), p<0.001) than REG (39.1°C (38.8, 39.3)). Mean Tre was lower in ExtHTcool (38.2°C (38.0, 38.4)) than BRKcool (38.3°C (38.1, 38.5), p=0.018), BRKno-cool and ExtHTonly (38.4°C (38.2, 38.6), p<0.001) and REG (38.5°C (38.3, 38.7), p<0.001). Mean heart rate was lower during BRKcool (6 beats/min (4, 7), p<0.001) and ExtHTcool (7 beats/min (6, 8), p<0.001) compared with REG. WBSR was comparable across trials (p≥0.07) and RPE was attenuated during BRKcool (0.4 (0.1, 0.7), p=0.004) and ExtHTcool (0.5 (0.2, 0.7), p=0.002), compared with REG. CONCLUSION BRKcool and ExtHTcool attenuated thermal, cardiovascular and perceptual strain during a simulated football match in the heat. Additional strategies may be required in field settings or under harsher conditions.
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Affiliation(s)
- Harry A Brown
- University of Canberra Research Institute for Sport and Exercise, Bruce, Australian Capital Territory, Australia
| | | | - Thomas H Topham
- University of Canberra Research Institute for Sport and Exercise, Bruce, Australian Capital Territory, Australia
| | - Brad Clark
- University of Canberra Research Institute for Sport and Exercise, Bruce, Australian Capital Territory, Australia
| | - Andrew Jowett
- Football Federation Victoria, Melbourne, Victoria, Australia
- Olympic Park Sports Medicine Centre, Melbourne, Victoria, Australia
| | - Tim Meyer
- Institute of Sports and Preventive Medicine, Saarland University, Saarbrucken, Germany
| | - Ollie Jay
- Heat and Health Research Incubator, The University of Sydney Faculty of Medicine and Health, Camperdown, New South Wales, Australia
| | - Julien D Périard
- University of Canberra Research Institute for Sport and Exercise, Bruce, Australian Capital Territory, Australia
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Yang H, Ding H, Wei W, Li X, Duan X, Zhuang C, Liu W, Chen S, Wang X. Skin-interfaced microfluidic sweat collection devices for personalized hydration management through thermal feedback. LAB ON A CHIP 2024; 24:356-366. [PMID: 38108440 DOI: 10.1039/d3lc00791j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Non-electronic wearables that utilize skin-interfaced microfluidic technology have revolutionized the collection and analysis of human sweat, providing valuable biochemical information and indicating body hydration status. However, existing microfluidic devices often require constant monitoring of data during sweat assessment, thereby impeding the user experience and potentially missing anomalous physiological events, such as excessive sweating. Moreover, the complex manufacturing process hampers the scalability and large-scale production of such devices. Herein, we present a self-feedback microfluidic device with a unique dehydration reminder through a cost-effective "CAD-to-3D device" approach. It incorporates two independent systems for sweat collection and thermal feedback, including serpentine microchannels, reservoirs, petal-like bursting valves and heating chambers. The device operates by sequentially collecting sweat in the channels and reservoirs, and then activating thermal stimulators in the heating chambers through breaking the valves, initiating a chemical exothermic reaction. Human trials validate that the devices effectively alert users to potential dehydration by inducing skin thermal sensations triggered by sweat sampling. The proposed device offers facile scalability and customizable fabrication, and holds promise for managing hydration strategies in real-world scenarios, benefiting individuals engaged in sporting activities or exposed to high-temperature settings.
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Affiliation(s)
- Hanlin Yang
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, China.
| | - Hongyan Ding
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, China.
| | - Wenkui Wei
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, China.
| | - Xiaofeng Li
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, China.
| | - Xiaojun Duan
- Respiratory medicine department, Hunan Children's Hospital, Changsha, Hunan 410007, China
| | - Changgen Zhuang
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, China.
| | - Weiyi Liu
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, China.
| | - Shangda Chen
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, China.
| | - Xiufeng Wang
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, China.
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3
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Dean TM, Knight SN, Robinson MJ, Bowling LR, Russell AR, O'Neal EK, Davis BA. 24 h Hydration profile of collegiate soccer players training once versus twice per day in the heat. Physiol Behav 2023; 269:114273. [PMID: 37331456 DOI: 10.1016/j.physbeh.2023.114273] [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: 05/12/2023] [Accepted: 06/15/2023] [Indexed: 06/20/2023]
Abstract
This study examined 24-h hydration parameters among collegiate, male soccer players (n = 17) during twice (X2) and once (X1) per day practice schedules in the heat. Urine specific gravity (USG) and body mass were measured before morning practices, afternoon practice (X2)/team meeting (X1), and the next morning practices. Fluid intake, sweat losses, and urinary losses were assessed during each 24-h window. Pre-practice body mass or USG did not differ among the timepoints. Sweat losses differed among all practices (p < 0.05) and averaged approximately 2.181±0.693 (X2AM) 1.710±0.474 (X2PM), and 3.361±0.956 L (X1AM), but players averaged replacing >50% of sweat losses with fluid intake every practice. Fluid intake during and between practices from practice 1 to the afternoon practice for X2 resulted in a positive fluid balance for X2 (+0.446±0.916 L). However, higher sweat loss during the initial morning practice and lower relative fluid intake prior to the afternoon team meeting the following morning resulted in a negative fluid balance (-0.304±0.675 L; p < 0.05: Cohen's d = 0.94) over the same time period for X1. By the start of the next morning practice sessions, both X1 (+0.664±1.051 L) and X2 (+0.446±0.916 L) were in positive fluid balance, respectively. Ample fluid consumption opportunities, scaled down practice intensities during X2, and potentially intentional greater relative fluid intake during X2 training resulted in no difference in fluid shift versus an X1 schedule before the start of practices. The majority of players maintained fluid balance drinking ad libitum regardless of practice schedule.
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Affiliation(s)
- Tate M Dean
- Auburn University at Montgomery, Department of Kinesiology, Montgomery, United States of America
| | - Savanna N Knight
- University of North Alabama, Department of Kinesiology, Florence, United States of America
| | - Marcus J Robinson
- Auburn University at Montgomery, Department of Kinesiology, Montgomery, United States of America
| | - Lynnsey R Bowling
- University of North Alabama, Department of Kinesiology, Florence, United States of America.
| | - Angela R Russell
- Auburn University at Montgomery, Department of Kinesiology, Montgomery, United States of America
| | - Eric K O'Neal
- University of North Alabama, Department of Kinesiology, Florence, United States of America
| | - Brett A Davis
- Auburn University at Montgomery, Department of Kinesiology, Montgomery, United States of America
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4
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Turner O, Mitchell N, Ruddock A, Purvis A, Ranchordas MK. Fluid Balance, Sodium Losses and Hydration Practices of Elite Squash Players during Training. Nutrients 2023; 15:nu15071749. [PMID: 37049589 PMCID: PMC10096645 DOI: 10.3390/nu15071749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 03/30/2023] [Accepted: 04/01/2023] [Indexed: 04/07/2023] Open
Abstract
Elite squash players are reported to train indoors at high volumes and intensities throughout a microcycle. This may increase hydration demands, with hypohydration potentially impairing many key performance indicators which characterise elite squash performance. Consequently, the main aim of this study was to quantify the sweat rates and sweat [Na+] of elite squash players throughout a training session, alongside their hydration practices. Fourteen (males = seven; females = seven) elite or world class squash player’s fluid balance, sweat [Na+] and hydration practices were calculated throughout a training session in moderate environmental conditions (20 ± 0.4 °C; 40.6 ± 1% RH). Rehydration practices were also quantified post-session until the players’ next training session, with some training the same day and some training the following day. Players had a mean fluid balance of −1.22 ± 1.22% throughout the session. Players had a mean sweat rate of 1.11 ± 0.56 L·h−1, with there being a significant difference between male and female players (p < 0.05), and a mean sweat (Na+) of 46 ± 12 mmol·L−1. Players training the following day were able to replace fluid and sodium losses, whereas players training again on the same day were not. These data suggest the variability in players hydration demands and highlight the need to individualise hydration strategies, as well as training prescription, to ensure players with high hydration demands have ample time to optimally rehydrate.
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Affiliation(s)
- Ollie Turner
- Academy of Sport & Physical Activity, Sheffield Hallam University, Sheffield S10 2BP, UK
- English Institute of Sport, Manchester M11 3BS, UK
| | | | - Alan Ruddock
- Academy of Sport & Physical Activity, Sheffield Hallam University, Sheffield S10 2BP, UK
| | - Alison Purvis
- Academy of Sport & Physical Activity, Sheffield Hallam University, Sheffield S10 2BP, UK
| | - Mayur K. Ranchordas
- Academy of Sport & Physical Activity, Sheffield Hallam University, Sheffield S10 2BP, UK
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Heatherly AJ, Caputo JL, Johnson SL, Fuller DK. Heat Acclimation Knowledge among Recreational Runners. Sports (Basel) 2023; 11:sports11020049. [PMID: 36828334 PMCID: PMC9965591 DOI: 10.3390/sports11020049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/10/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023] Open
Abstract
Heat acclimation (HA) is the foremost method of preventing exertional heat illness during exercise in hot and humid environments. However, the prevalence of HA training and its associated knowledge is not currently known in recreational running populations. The purpose of this study was to determine the knowledge of recreational runners toward HA. A survey consisting of 38 questions that required approximately 10-15 min to complete was disseminated to running clubs throughout the Southeastern United States. Questions were designed to collect data on participant demographics, yearly training habits, and HA knowledge. Recreational runners (N = 125) demonstrated a lack of knowledge toward proper HA training and its associated benefits. Participants largely received HA advice from their peers (31.2%) and reported no professional guidance in their training (79.2%). Finally, participants' beliefs toward proper HA training differed among training groups with moderate and high groups perceiving greater frequency, miles/wk, and min/wk as appropriate for HA compared to the low group (p ≤ 0.05). Due to the warmer temperatures and higher relative humidity experienced in the southeastern, southwestern, and mid-Atlantic locations of the United States and throughout certain regions of the European Union, governing bodies in sport and exercise science should develop more educational initiatives to convey the importance and advantages of HA, especially when runners are training for major marathons that are typically held in the late spring and early fall seasons.
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Affiliation(s)
| | - Jennifer L. Caputo
- Department of Health and Human Performance, Middle Tennessee State University, Murfreesboro, TN 37132, USA
| | - Samantha L. Johnson
- Department of Health and Human Performance, Middle Tennessee State University, Murfreesboro, TN 37132, USA
| | - Dana K. Fuller
- Department of Psychology, Middle Tennessee State University, Murfreesboro, TN 37132, USA
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6
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Benjamin CL, Dobbins LW, Sullivan SG, Rogers RR, Williams TD, Marshall MR, Ballmann CG. The Effect of Fluid Availability on Consumption and Perceptual Measures during Aerobic Exercise. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:1310. [PMID: 36674064 PMCID: PMC9858706 DOI: 10.3390/ijerph20021310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/05/2023] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
Fluid availability may alter drinking behavior; however, it is currently unknown if the availability of fluid impacts behavior and gastrointestinal issues (GI) that are often associated with increased fluid intake. The purpose of this study was to determine if ad libitum (AL) versus periodic (PER) fluid intake influences fluid consumption and GI distress during exercise in trained athletes. Male and female Division I NCAA Cross Country athletes (n = 11; age = 20 ± 1 years) participated in this counterbalanced crossover study. Each participant completed a moderate intensity 10 km run on two separate occasions. In one trial, participants had unlimited availability to fluid to consume AL. In the other trial, participants consumed PER fluid at stations placed every 3.2 km. Assurance of euhydration prior to each trial was confirmed via urine specific gravity (USG) and urine color. Subjective perceptions of thirst and gastric fullness were assessed pre- and post-exercise via Likert questioning and a visual analog scale, respectively. Participants started each trial euhydrated (AL = 1.009 USG ± 0.009; PER = 1.009 USG ± 0.009; urine color AL, 3 ± 1; urine color PER, 2 ± 1). Fluid volume consumption was significantly higher during the AL condition compared to PER (p = 0.050). Thirst significantly increased from pre- to post-run regardless of treatment (p < 0.001); however, there was no significant difference between the groups (p = 0.492). Feelings of fullness did not change pre-post trial (p = 0.304) or between trials (p = 0.958). Increased fluid availability allows for increased fluid consumption without the negative experience of GI discomfort.
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Affiliation(s)
| | - Luke W. Dobbins
- Department of Kinesiology, Samford University, Birmingham, AL 35226, USA
| | | | - Rebecca R. Rogers
- Department of Kinesiology, Samford University, Birmingham, AL 35226, USA
- SHP Research Collaborative, University of Alabama at Birmingham, Birmingham, AL 35226, USA
| | - Tyler D. Williams
- Department of Kinesiology, Samford University, Birmingham, AL 35226, USA
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7
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Fernandes H. Hydration analysis and recommendations for elite soccer players. Sci Sports 2022. [DOI: 10.1016/j.scispo.2021.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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8
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Body Composition Assessment and Mediterranean Diet Adherence in U12 Spanish Male Professional Soccer Players: Cross-Sectional Study. Nutrients 2021; 13:nu13114045. [PMID: 34836297 PMCID: PMC8623059 DOI: 10.3390/nu13114045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 11/08/2021] [Accepted: 11/10/2021] [Indexed: 01/10/2023] Open
Abstract
Soccer is the most practiced team sport in the world. Due to the importance of nutrition in soccer performance, controlling the body composition and dietary guidelines of players takes place starting from lower categories. The objective of this study was to evaluate body composition and adherence to the Mediterranean diet of U12 players from a professional soccer team and to identify their dietary weak points. Seventy-one U12 male soccer players participated in the study. Weight, height, percentiles, skinfolds, and body fat were measured by a certified anthropometrist following the procedures recommended by the International Society for the Advancement of Kinanthropometry. The Mediterranean diet adherence test (KIDMED) was the questionnaire used to evaluate eating habits. In addition, a comparison was made among field positions. The results showed percentiles and body fat percentages appropriate for their age. Furthermore, the average score on the KIDMED test showed that the players generally adhered well to the Mediterranean diet, although they should improve their consumption of fruits and vegetables, as well as avoid skipping breakfast. Moreover, goalkeepers and defenders had a higher percentile BMI and percentage of fat than midfielders and forwards. In addition, these players had lower KIDMED values than midfielders and forwards. Although U12 soccer players have an appropriate body composition and adherence to the Mediterranean diet, there are differences between the different field positions that should be assessed by coaches, doctors, and nutritionists/dietitians.
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Abreu R, Figueiredo P, Beckert P, Marques JP, Amorim S, Caetano C, Carvalho P, Sá C, Cotovio R, Cruz J, Dias T, Fernandes G, Gonçalves E, Leão C, Leitão A, Lopes J, Machado E, Neves M, Oliveira A, Pereira AI, Pereira B, Ribeiro F, Silva LM, Sousa F, Tinoco T, Teixeira VH, Sousa M, Brito J. Portuguese Football Federation consensus statement 2020: nutrition and performance in football. BMJ Open Sport Exerc Med 2021; 7:e001082. [PMID: 34527279 PMCID: PMC8395276 DOI: 10.1136/bmjsem-2021-001082] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2021] [Indexed: 11/04/2022] Open
Abstract
Nutrition is an undeniable part of promoting health and performance among football (soccer) players. Nevertheless, nutritional strategies adopted in elite football can vary significantly depending on culture, habit and practical constraints and might not always be supported by scientific evidence. Therefore, a group of 28 Portuguese experts on sports nutrition, sports science and sports medicine sought to discuss current practices in the elite football landscape and review the existing evidence on nutritional strategies to be applied when supporting football players. Starting from understanding football's physical and physiological demands, five different moments were identified: preparing to play, match-day, recovery after matches, between matches and during injury or rehabilitation periods. When applicable, specificities of nutritional support to young athletes and female players were also addressed. The result is a set of practical recommendations that gathered consensus among involved experts, highlighting carbohydrates periodisation, hydration and conscious use of dietary supplements.
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Affiliation(s)
- Rodrigo Abreu
- Portugal Football School, Portuguese Football Federation, Cruz Quebrada, Portugal.,Universidade do Porto Faculdade de Ciências da Nutrição e Alimentação, Porto, Portugal
| | - Pedro Figueiredo
- Portugal Football School, Portuguese Football Federation, Cruz Quebrada, Portugal.,Research Center in Sports Sciences, Health Sciences and Human Development, CIDESD, University Institute of Maia, ISMAI, Maia, Portugal
| | - Paulo Beckert
- Portugal Football School, Portuguese Football Federation, Cruz Quebrada, Portugal
| | - José P Marques
- Portugal Football School, Portuguese Football Federation, Cruz Quebrada, Portugal
| | | | | | - Pedro Carvalho
- Universidade Catolica Portuguesa Escola Superior de Biotecnologia, Porto, Portugal
| | - Carla Sá
- ISMAI, Castelo da Maia, Porto, Portugal.,Polytechnic Institute of Bragança, Braganca, Portugal
| | | | - Joana Cruz
- Portimonense Futebol SAD, Portimao, Portugal
| | - Tiago Dias
- Clube Desportivo Santa Clara, Ponta Delgada, Portugal
| | | | | | - César Leão
- Instituto Politecnico de Viana do Castelo Escola Superior de Desporto e Lazer, Melgaco, Viana do Castelo, Portugal.,FC Paços de Ferreira, Paços de Ferreira, Portugal
| | | | - João Lopes
- Sporting Clube de Portugal, SAD, Lisboa, Portugal
| | | | - Mónica Neves
- Vitória Futebol Clube, Setúbal, Portugal.,Universidade do Algarve, Faro, Portugal
| | | | | | - Bruno Pereira
- Sports Medicine Control Training Unit, Instituto Portugues do Desporto e Juventude, Lisboa, Portugal
| | - Fernando Ribeiro
- Universidade do Porto Faculdade de Ciências da Nutrição e Alimentação, Porto, Portugal.,Moreirense FC, Moreira, Portugal
| | - Luis M Silva
- Centro de Medicina Desportiva do Porto, Porto, Portugal
| | - Filipe Sousa
- Futebol Clube de Vizela, Vizela, Portugal.,Futbolniy Klub Shakhtar, Shakhtar, Ukraine
| | | | - Vitor H Teixeira
- Universidade do Porto Faculdade de Ciências da Nutrição e Alimentação, Porto, Portugal.,Futebol Clube do Porto SAD, Porto, Portugal
| | - Monica Sousa
- Nutrition and Metabolism, Universidade Nova de Lisboa Faculdade de Ciências Médicas de Lisboa, Lisboa, Portugal.,NOVA Medical School, CINTESIS, Porto, Portugal
| | - João Brito
- Portugal Football School, Portuguese Football Federation, Cruz Quebrada, Portugal
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Estimated Sweat Loss, Fluid and Carbohydrate Intake, and Sodium Balance of Male Major Junior, AHL, and NHL Players During On-Ice Practices. Int J Sport Nutr Exerc Metab 2021; 29:612-619. [PMID: 31141409 DOI: 10.1123/ijsnem.2019-0029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/11/2019] [Accepted: 04/20/2019] [Indexed: 11/18/2022]
Abstract
Several previous studies have reported performance decrements in team sport athletes who dehydrated approximately 1.5-2% of their body mass (BM) through sweating. This study measured on-ice sweat loss, fluid intake, sodium balance, and carbohydrate (CHO) intake of 77 major junior (JR; 19 ± 1 years), 60 American Hockey League (AHL; 24 ± 4 years), and 77 National Hockey League (NHL; 27 ± 5 years) players. Sweat loss was calculated from pre- to post-exercise BM plus fluid intake minus urine loss. AHL (2.03 ± 0.62 L/hr) and NHL (2.02 ± 0.74 L/hr) players had higher sweat rates (p < .05) than JR players (1.63 ± 0.58 L/hr). AHL (1.23 ± 0.69%; p = .006) and NHL (1.29% ± 0.63%; p < .001) players had ∼30% greater BM losses than JR players (0.89% ± 0.57%). There was no difference in fluid intake between groups (p > .05). Sodium deficits (sodium loss - intake) were greater (p < .05) in AHL (1.68 ± 0.74 g/hr) and NHL (1.56 ± 0.84 g/hr) players compared with JR players (1.01 ± 0.50 g/hr). CHO intake was similar between groups (14-20 g CHO/hr), with 29%, 32%, and 40% of JR, AHL, and NHL players consuming no CHO, respectively. In summary, sweat rates were high in all players, but the majority of players (74/77, 54/60, and 68/77 of JR, AHL, and NHL, respectively) avoided mild dehydration (>2% BM) during 60 min of practice. However, ∼15%, 41%, and 48% of the JR, AHL, and NHL players, respectively, may have reached mild dehydration and increased risk of performance decrements in a 90-min practice.
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11
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The Validity of Ultrasound Technology in Providing an Indirect Estimate of Muscle Glycogen Concentrations Is Equivocal. Nutrients 2021; 13:nu13072371. [PMID: 34371881 PMCID: PMC8308826 DOI: 10.3390/nu13072371] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/02/2021] [Accepted: 07/07/2021] [Indexed: 12/04/2022] Open
Abstract
Researchers and practitioners in sports nutrition would greatly benefit from a rapid, portable, and non-invasive technique to measure muscle glycogen, both in the laboratory and field. This explains the interest in MuscleSound®, the first commercial system to use high-frequency ultrasound technology and image analysis from patented cloud-based software to estimate muscle glycogen content from the echogenicity of the ultrasound image. This technique is based largely on muscle water content, which is presumed to act as a proxy for glycogen. Despite the promise of early validation studies, newer studies from independent groups reported discrepant results, with MuscleSound® scores failing to correlate with the glycogen content of biopsy-derived mixed muscle samples or to show the expected changes in muscle glycogen associated with various diet and exercise strategies. The explanation of issues related to the site of assessment do not account for these discrepancies, and there are substantial problems with the premise that the ratio of glycogen to water in the muscle is constant. Although further studies investigating this technique are warranted, current evidence that MuscleSound® technology can provide valid and actionable information around muscle glycogen stores is at best equivocal.
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12
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Venugopal V, Latha PK, Shanmugam R, Krishnamoorthy M, Omprashanth R, Lennqvist R, Johnson P. Epidemiological evidence from south Indian working population-the heat exposures and health linkage. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2021; 31:177-186. [PMID: 32892212 DOI: 10.1038/s41370-020-00261-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 08/05/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
Changing climate and rising temperatures are predicted to affect millions of workers due to heat stress risks, especially in tropical settings. We used a cross-sectional study design to profile the heat exposures of ~1500 workers from eight-industrial sectors using a QuesTemp wet bulb globe temperature (WBGT) monitor, quantified the heat-strain indicators viz., rise in Core Body Temperature (CBT), Sweat Rate (SwR), and Urine Specific Gravity (USG) by standard methods and evaluated the health impacts of heat stress using a structured questionnaire. Heat exposures (Avg.WBGT: 28.4 ± 2.6 °C) exceeded the Threshold Limit Value (TLV) for 70% of workers and was significantly associated with the rise in CBT >1 °C in 11.3% and elevated USG >1.020 in 10.5% of the workers. The heat-exposed workers had 2.3 times higher odds of reporting adverse health outcomes (84%) compared to the unexposed workers (95% CI: 1.74-3.19; p value ≤ 0.0001). Mild reduction in kidney function observed in 49% of salt - pan workers, and a high prevalence of kidney stones (33%) among the 91 steelworkers subjected to kidney ultrasound had a significant association with chronic high WBGT exposure above the TLV (p value < 0.034). Further, in-depth assessments are warranted to develop strategies for interventions and protective labor policies to avert adverse occupational health and productivity consequences for millions of workers globally, especially in the rising temperature scenario.
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Affiliation(s)
- Vidhya Venugopal
- Faculty of Public Health, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India.
| | - P K Latha
- Faculty of Public Health, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
| | - Rekha Shanmugam
- Faculty of Public Health, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
| | - Manikandan Krishnamoorthy
- Faculty of Public Health, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
| | - R Omprashanth
- Faculty of Public Health, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
| | - Robin Lennqvist
- Department of Public Health and Community Medicine/Section of Occupational and Environmental Medicine, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden
| | - Priscilla Johnson
- Department of Physiology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
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Rollo I, Randell RK, Baker L, Leyes JY, Medina Leal D, Lizarraga A, Mesalles J, Jeukendrup AE, James LJ, Carter JM. Fluid Balance, Sweat Na + Losses, and Carbohydrate Intake of Elite Male Soccer Players in Response to Low and High Training Intensities in Cool and Hot Environments. Nutrients 2021; 13:nu13020401. [PMID: 33513989 PMCID: PMC7912570 DOI: 10.3390/nu13020401] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 11/21/2022] Open
Abstract
Hypohydration increases physiological strain and reduces physical and technical soccer performance, but there are limited data on how fluid balance responses change between different types of sessions in professional players. This study investigated sweat and fluid/carbohydrate intake responses in elite male professional soccer players training at low and high intensities in cool and hot environments. Fluid/sodium (Na+) losses and ad-libitum carbohydrate/fluid intake of fourteen elite male soccer players were measured on four occasions: cool (wet bulb globe temperature (WBGT): 15 ± 7 °C, 66 ± 6% relative humidity (RH)) low intensity (rating of perceived exertion (RPE) 2–4, m·min−1 40–46) (CL); cool high intensity (RPE 6–8, m·min−1 82–86) (CH); hot (29 ± 1 °C, 52 ± 7% RH) low intensity (HL); hot high intensity (HH). Exercise involved 65 ± 5 min of soccer-specific training. Before and after exercise, players were weighed in minimal clothing. During training, players had ad libitum access to carbohydrate beverages and water. Sweat [Na+] (mmol·L−1), which was measured by absorbent patches positioned on the thigh, was no different between conditions, CL: 35 ± 9, CH: 38 ± 8, HL: 34 ± 70.17, HH: 38 ± 8 (p = 0.475). Exercise intensity and environmental condition significantly influenced sweat rates (L·h−1), CL: 0.55 ± 0.20, CH: 0.98 ± 0.21, HL: 0.81 ± 0.17, HH: 1.43 ± 0.23 (p =0.001), and percentage dehydration (p < 0.001). Fluid intake was significantly associated with sweat rate (p = 0.019), with no players experiencing hypohydration > 2% of pre-exercise body mass. Carbohydrate intake varied between players (range 0–38 g·h−1), with no difference between conditions. These descriptive data gathered on elite professional players highlight the variation in the hydration status, sweat rate, sweat Na+ losses, and carbohydrate intake in response to training in cool and hot environments and at low and high exercise intensities.
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Affiliation(s)
- Ian Rollo
- Gatorade Sports Science Institute, PepsiCo Life Sciences, Global R&D, Leicestershire LE4 1ET, UK; (R.K.R.); (L.B.); (J.M.C.)
- School of Sports Exercise and Health Sciences, Loughborough University, Leicestershire LE11 3TU, UK; (A.E.J.); (L.J.J.)
- Correspondence: ; Tel.: +116-2348846
| | - Rebecca K. Randell
- Gatorade Sports Science Institute, PepsiCo Life Sciences, Global R&D, Leicestershire LE4 1ET, UK; (R.K.R.); (L.B.); (J.M.C.)
- School of Sports Exercise and Health Sciences, Loughborough University, Leicestershire LE11 3TU, UK; (A.E.J.); (L.J.J.)
| | - Lindsay Baker
- Gatorade Sports Science Institute, PepsiCo Life Sciences, Global R&D, Leicestershire LE4 1ET, UK; (R.K.R.); (L.B.); (J.M.C.)
| | - Javier Yanguas Leyes
- FC Barcelona Medical Department, FC, 08014 Barcelona, Spain; (J.Y.L.); (D.M.L.); (A.L.); (J.M.)
| | - Daniel Medina Leal
- FC Barcelona Medical Department, FC, 08014 Barcelona, Spain; (J.Y.L.); (D.M.L.); (A.L.); (J.M.)
| | - Antonia Lizarraga
- FC Barcelona Medical Department, FC, 08014 Barcelona, Spain; (J.Y.L.); (D.M.L.); (A.L.); (J.M.)
| | - Jordi Mesalles
- FC Barcelona Medical Department, FC, 08014 Barcelona, Spain; (J.Y.L.); (D.M.L.); (A.L.); (J.M.)
| | - Asker E. Jeukendrup
- School of Sports Exercise and Health Sciences, Loughborough University, Leicestershire LE11 3TU, UK; (A.E.J.); (L.J.J.)
| | - Lewis J. James
- School of Sports Exercise and Health Sciences, Loughborough University, Leicestershire LE11 3TU, UK; (A.E.J.); (L.J.J.)
| | - James M. Carter
- Gatorade Sports Science Institute, PepsiCo Life Sciences, Global R&D, Leicestershire LE4 1ET, UK; (R.K.R.); (L.B.); (J.M.C.)
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14
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Horn M, de Waal S, Kraak W. In-match penalty kick analysis of the 2009/10 to 2018/19 English Premier League competition. INT J PERF ANAL SPOR 2020. [DOI: 10.1080/24748668.2020.1855052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
| | | | - Wilbur Kraak
- Department of Sport Science, Faculty of Medicine and Health Science, Stellenbosch University, Matieland, Republic of South Africa
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15
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Sun FH, Cooper SB, Chak-Fung Tse F. Effects of different solutions consumed during exercise on cognitive function of male college soccer players. J Exerc Sci Fit 2020; 18:155-161. [PMID: 32636892 PMCID: PMC7330616 DOI: 10.1016/j.jesf.2020.06.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 12/20/2022] Open
Abstract
Background/Objectives: The present study aimed to investigate the effects of three solutions, i.e. carbohydrate-electrolyte-solution (CES), carbohydrate-electrolyte-protein-solution (CEPS), and placebo (PLA), on cognitive function of college soccer players. Methods Sixteen male college soccer players completed three main trials in a randomized cross-over study design. In each main trial, participants completed 90 min Loughborough Intermittent Shuttle Test (LIST) protocol and consumed one of three solutions. The cognitive function tests were performed; blood glucose and lactate concentrations, and several subjective measurements were also recorded in each trial. Results Compared with pre-exercise level, the accuracy of Rapid Visual Information Processing test (RVIPT) and the response time in Visual Search Test (VST, complex level) after LIST improved in CES and CEPS trials, but not in PLA trial. However, the accuracy of VST (complex level) decreased in both CES and CEPS trials, compared with PLA trial. CEPS consumption improved accuracy in VST (simple level), compared with CES consumption. Blood glucose concentrations were well maintained in CEPS trial, but not in CES and PLA trials. Conclusion It seems that both CES and CEPS consumption show certain benefits on some aspects of cognitive function in male college soccer players in Hong Kong. However, these effects may be specific to the cognitive domain tested.
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Key Words
- 5-HT, 5-hydroxytryptophan
- AD, Abdominal discomfort
- BCAA, Branched chain amino acids
- BM, Body mass
- CEPS, Carbohydrate-electrolyte-protein solution
- CES, Carbohydrate-electrolyte solution
- Carbohydrate
- Dehydration
- HR, Heart rate
- LIST, Loughborough Intermittent Shuttle Test
- Loughborough intermittent shuttle test
- PT, Perceived thirst
- Performance
- Protein
- RPE, Rating of perceived exertion
- RVIPT, Rapid visual information processing test
- ST, Stroop test
- Sports drink
- VST, Visual search test
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Affiliation(s)
- Feng-Hua Sun
- Department of Health and Physical Education, The Education University of Hong Kong, Hong Kong SAR, China
| | - Simon B Cooper
- Department of Sport Science, Sport Health and Performance Enhancement (SHAPE) Research Centre, School of Science and Technology, Nottingham Trent University, Nottingham, UK
| | - Frank Chak-Fung Tse
- Department of Health and Physical Education, The Education University of Hong Kong, Hong Kong SAR, China
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16
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Chapelle L, Tassignon B, Rommers N, Mertens E, Mullie P, Clarys P. Pre-exercise hypohydration prevalence in soccer players: A quantitative systematic review. Eur J Sport Sci 2019; 20:744-755. [PMID: 31526234 DOI: 10.1080/17461391.2019.1669716] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Pre-exercise hypohydration can impair soccer performance and has been extensively studied in different soccer populations. Therefore, the aim of this systematic review was to report hypohydration prevalence, measured by blood or urine samples, in different soccer populations based on sex (males and females), performance level (professional and recreational players) and context (training sessions and games). The Pubmed, Web of Science and SPORTDiscus databases were systematically searched until November 2018. Data were pooled to compare hypohydration prevalence between the different subgroups. Following the systematic search selection process, 24 studies were included. The results indicated that overall pre-exercise hypohydration prevalence was 63.3%, 37.4% and 58.8% for urine specific gravity (USG), urine osmolality (U Osm) and urine colour, respectively. Furthermore, no study implemented blood samples to examine hypohydration prevalence in soccer players. The subgroup analyses using USG data indicated that pre-exercise hypohydration prevalence was significantly higher amongst males (66.0%; p = 0.001), professional soccer players (66.2%; p = 0.020) and before a training session (79.6%; p < 0.001). Pre-exercise hypohydration prevalence was 46.8% among female soccer players, 55.6% in recreational soccer players and 41,3% before a game. The subgroup analyses using U Osm data indicated that hypohydration prevalence was significantly higher before a training session (52.6%; p = 0.023). Based on these results, it can be concluded that hypohydration prevalence in soccer players is of major concern. Future research should explore how pre-exercise hydration status can be improved in a sustainable way.
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Affiliation(s)
- L Chapelle
- Faculty of Physical Education and Physiotherapy, Department of Movement and Sports Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - B Tassignon
- Faculty of Physical Education and Physiotherapy, Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
| | - N Rommers
- Faculty of Physical Education and Physiotherapy, Department of Movement and Sports Sciences, Vrije Universiteit Brussel, Brussels, Belgium.,Department of Movement and Sports Sciences, Ghent University, Ghent, Belgium.,Research Foundation Flanders (FWO), Belgium
| | - E Mertens
- Faculty of Physical Education and Physiotherapy, Department of Movement and Sports Sciences, Vrije Universiteit Brussel, Brussels, Belgium.,Erasmus University College, Brussels, Belgium
| | - P Mullie
- Faculty of Physical Education and Physiotherapy, Department of Movement and Sports Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - P Clarys
- Faculty of Physical Education and Physiotherapy, Department of Movement and Sports Sciences, Vrije Universiteit Brussel, Brussels, Belgium
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17
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Garrett DC, Rae N, Fletcher JR, Zarnke S, Thorson S, Hogan DB, Fear EC. Engineering Approaches to Assessing Hydration Status. IEEE Rev Biomed Eng 2017; 11:233-248. [PMID: 29990109 DOI: 10.1109/rbme.2017.2776041] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Dehydration is a common condition characterized by a decrease in total body water. Acute dehydration can cause physical and cognitive impairment, heat stroke and exhaustion, and, if severe and uncorrected, even death. The health effects of chronic mild dehydration are less well studied with urolithiasis (kidney stones) the only condition consistently associated with it. Aside from infants and those with particular medical conditions, athletes, military personnel, manual workers, and older adults are at particular risk of dehydration due to their physical activity, environmental exposure, and/or challenges in maintaining fluid homeostasis. This review describes the different approaches that have been explored for hydration assessment in adults. These include clinical indicators perceived by the patient or detected by a practitioner and routine laboratory analyses of blood and urine. These techniques have variable accuracy and practicality outside of controlled environments, creating a need for simple, portable, and rapid hydration monitoring devices. We review the wide array of devices proposed for hydration assessment based on optical, electromagnetic, chemical, and acoustical properties of tissue and bodily fluids. However, none of these approaches has yet emerged as a reliable indicator in diverse populations across various settings, motivating efforts to develop new methods of hydration assessment.
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18
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Tucker MA, Butts CL, Satterfield AZ, Six A, Johnson EC, Ganio MS. Spot Sample Urine Specific Gravity Does Not Accurately Represent Small Decreases in Plasma Volume in Resting Healthy Males. J Am Coll Nutr 2017; 37:17-23. [PMID: 28985131 DOI: 10.1080/07315724.2017.1323692] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Urine specific gravity (USG) is often used to assess hydration status, particularly around athletic competition, but it is unknown whether high USG is indicative of plasma volume (PV) reduction (i.e., hypohydration). We tested the hypothesis that if high USG is reflective of reduced PV, subsequent fluid ingestion would increase PV. PURPOSE The purpose of this study was to examine 24-hour changes in USG and PV in individuals presenting with high and low spot USG. METHODS Nineteen healthy males were provided food and water over 24 hours with a total water volume of 35 ml·kg-1 body mass. Absolute PV and blood volume (BV), measured using the CO-rebreathe technique, along with USG were measured before and after a 24-hour intervention period. Based on a preintervention morning spot USG, subjects were post hoc assigned to groups according to USG (≤1.020 or >1.020; low and high USG, respectively). RESULTS Despite presenting with an elevated spot USG (1.026 ± 0.004), subsequent fluid ingestion over 24 hours did not lead to changes (∆) in PV (-75 ± 234 ml) or BV (-156 ± 370 ml) in the high USG group (p > 0.05). However, a spot USG after the 24-hour intervention in this group decreased (p = 0.018) to a level indicating improved hydration status (1.017 ± 0.007). In the low USG group, there were no changes in PV (-39 ± 274 ml), BV (-82 ± 396 ml), or USG (0.003 ± 0.007) over the 24-hour fluid intervention (all p > 0.05). CONCLUSIONS Despite a high preintervention USG and subsequent decrease after 24-hour fluid intake, measures of PV and BV were not indicative of this seemingly improved hydration status. This suggests that a highly concentrated spot sample USG and subsequent changes are not accurately representative of PV or BV.
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Affiliation(s)
- Matthew A Tucker
- a Department of Health , Human Performance, and Recreation, University of Arkansas , Fayetteville , Arkansas , USA.,b Georgia Prevention Institute, Augusta University , Augusta , Georgia , USA
| | - Cory L Butts
- a Department of Health , Human Performance, and Recreation, University of Arkansas , Fayetteville , Arkansas , USA
| | - Alf Z Satterfield
- a Department of Health , Human Performance, and Recreation, University of Arkansas , Fayetteville , Arkansas , USA
| | - Ashley Six
- a Department of Health , Human Performance, and Recreation, University of Arkansas , Fayetteville , Arkansas , USA
| | - Evan C Johnson
- a Department of Health , Human Performance, and Recreation, University of Arkansas , Fayetteville , Arkansas , USA.,c Division of Kinesiology and Health , University of Wyoming , Laramie , Wyoming , USA
| | - Matthew S Ganio
- a Department of Health , Human Performance, and Recreation, University of Arkansas , Fayetteville , Arkansas , USA
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19
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Nuccio RP, Barnes KA, Carter JM, Baker LB. Fluid Balance in Team Sport Athletes and the Effect of Hypohydration on Cognitive, Technical, and Physical Performance. Sports Med 2017; 47:1951-1982. [PMID: 28508338 PMCID: PMC5603646 DOI: 10.1007/s40279-017-0738-7] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Sweat losses in team sports can be significant due to repeated bursts of high-intensity activity, as well as the large body size of athletes, equipment and uniform requirements, and environmental heat stress often present during training and competition. In this paper we aimed to: (1) describe sweat losses and fluid balance changes reported in team sport athletes, (2) review the literature assessing the impact of hypohydration on cognitive, technical, and physical performance in sports-specific studies, (3) briefly review the potential mechanisms by which hypohydration may impact team sport performance, and (4) discuss considerations for future directions. Significant hypohydration (mean body mass loss (BML) >2%) has been reported most consistently in soccer. Although American Football, rugby, basketball, tennis, and ice hockey have reported high sweating rates, fluid balance disturbances have generally been mild (mean BML <2%), suggesting that drinking opportunities were sufficient for most athletes to offset significant fluid losses. The effect of hydration status on team sport performance has been studied mostly in soccer, basketball, cricket, and baseball, with mixed results. Hypohydration typically impaired performance at higher levels of BML (3-4%) and when the method of dehydration involved heat stress. Increased subjective ratings of fatigue and perceived exertion consistently accompanied hypohydration and could explain, in part, the performance impairments reported in some studies. More research is needed to develop valid, reliable, and sensitive sport-specific protocols and should be used in future studies to determine the effects of hypohydration and modifying factors (e.g., age, sex, athlete caliber) on team sport performance.
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Affiliation(s)
- Ryan P Nuccio
- Gatorade Sports Science Institute, 617 W. Main St., Barrington, IL, 60010, USA.
| | - Kelly A Barnes
- Gatorade Sports Science Institute, 617 W. Main St., Barrington, IL, 60010, USA
| | - James M Carter
- Gatorade Sports Science Institute, 617 W. Main St., Barrington, IL, 60010, USA
| | - Lindsay B Baker
- Gatorade Sports Science Institute, 617 W. Main St., Barrington, IL, 60010, USA
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20
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Oliveira CC, Ferreira D, Caetano C, Granja D, Pinto R, Mendes B, Sousa M. Nutrition and Supplementation in Soccer. Sports (Basel) 2017; 5:sports5020028. [PMID: 29910389 PMCID: PMC5968974 DOI: 10.3390/sports5020028] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 04/25/2017] [Accepted: 05/03/2017] [Indexed: 12/26/2022] Open
Abstract
Contemporary elite soccer features increased physical demands during match-play, as well as a larger number of matches per season. Now more than ever, aspects related to performance optimization are highly regarded by both players and soccer coaches. Here, nutrition takes a special role as most elite teams try to provide an adequate diet to guarantee maximum performance while ensuring a faster recovery from matches and training exertions. It is currently known that manipulation and periodization of macronutrients, as well as sound hydration practices, have the potential to interfere with training adaptation and recovery. A careful monitoring of micronutrient status is also relevant to prevent undue fatigue and immune impairment secondary to a deficiency status. Furthermore, the sensible use of evidence-based dietary supplements may also play a role in soccer performance optimization. In this sense, several nutritional recommendations have been issued. This detailed and comprehensive review addresses the most relevant and up-to-date nutritional recommendations for elite soccer players, covering from macro and micronutrients to hydration and selected supplements in different contexts (daily requirements, pre, peri and post training/match and competition).
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Affiliation(s)
- César Chaves Oliveira
- Instituto Politécnico de Viana do Castelo - Escola Superior de Desporto e Lazer, Viana do Castelo 4960-320, Portugal.
| | - Diogo Ferreira
- Benfica LAB, Sport Lisboa e Benfica, Lisbon 1500-313, Portugal.
| | - Carlos Caetano
- Benfica LAB, Sport Lisboa e Benfica, Lisbon 1500-313, Portugal.
| | - Diana Granja
- Benfica LAB, Sport Lisboa e Benfica, Lisbon 1500-313, Portugal.
| | - Ricardo Pinto
- Benfica LAB, Sport Lisboa e Benfica, Lisbon 1500-313, Portugal.
| | - Bruno Mendes
- Benfica LAB, Sport Lisboa e Benfica, Lisbon 1500-313, Portugal.
| | - Mónica Sousa
- Instituto Politécnico de Leiria - Escola Superior de Saúde, Leiria 2411-901, Portugal.
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21
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Venugopal V, Rekha S, Manikandan K, Latha PK, Vennila V, Ganesan N, Kumaravel P, Chinnadurai SJ. Heat stress and inadequate sanitary facilities at workplaces - an occupational health concern for women? Glob Health Action 2016; 9:31945. [PMID: 27633034 PMCID: PMC5025522 DOI: 10.3402/gha.v9.31945] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 07/11/2016] [Accepted: 07/12/2016] [Indexed: 11/14/2022] Open
Abstract
Background Health concerns unique to women are growing with the large number of women venturing into different trades that expose them to hot working environments and inadequate sanitation facilities, common in many Indian workplaces. Objective The study was carried out to investigate the health implications of exposures to hot work environments and inadequate sanitation facilities at their workplaces for women workers. Design A cross-sectional study was conducted with 312 women workers in three occupational sectors in 2014–2015. Quantitative data on heat exposures and physiological heat strain indicators such as core body temperature (CBT), sweat rate (SwR), and urine specific gravity (USG) were collected. A structured questionnaire captured workers perceptions about health impacts of heat stress and inadequate sanitary facilities at the workplace. Results Workplace heat exposures exceeded the threshold limit value for safe manual work for 71% women (Avg. wet bulb globe temperature=30°C±2.3°C) during the study period. Eighty-seven percent of the 200 women who had inadequate/no toilets at their workplaces reported experiencing genitourinary problems periodically. Above normal CBT, SwR, and USG in about 10% women workers indicated heat strain and moderate dehydration that corroborated well with their perceptions. Observed significant associations between high-heat exposures and SwR (t=−2.3879, p=0.0192), inadequate toilet facilities and self-reported adverse heat-related health symptoms (χ2=4.03, p=0.0444), and prevalence of genitourinary issues (χ2=42.92, p=0.0005×10−7) reemphasize that heat is a risk and lack of sanitation facilities is a major health concern for women workers. Conclusions The preliminary evidence suggests that health of women workers is at risk due to occupational heat exposures and inadequate sanitation facilities at many Indian workplaces. Intervention through strong labor policies with gender sensitivity is the need of the hour to empower women, avert further health risks, and also enhance productivity for the few million women workers who contribute largely to the country's economy.
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Affiliation(s)
- Vidhya Venugopal
- Department of Environmental Health Engineering, Sri Ramachandra University, Chennai, India;
| | - Shanmugam Rekha
- Department of Environmental Health Engineering, Sri Ramachandra University, Chennai, India
| | | | | | - Viswanathan Vennila
- Department of Environmental Health Engineering, Sri Ramachandra University, Chennai, India
| | - Nalini Ganesan
- Department of Biochemistry, Sri Ramachandra University, Chennai, India
| | - Perumal Kumaravel
- Department of Environmental Health Engineering, Sri Ramachandra University, Chennai, India
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22
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Castro-Sepulveda M, Johannsen N, Astudillo S, Jorquera C, Álvarez C, Zbinden-Foncea H, Ramírez-Campillo R. Effects of Beer, Non-Alcoholic Beer and Water Consumption before Exercise on Fluid and Electrolyte Homeostasis in Athletes. Nutrients 2016; 8:nu8060345. [PMID: 27338452 PMCID: PMC4924186 DOI: 10.3390/nu8060345] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 05/25/2016] [Accepted: 05/31/2016] [Indexed: 12/03/2022] Open
Abstract
Fluid and electrolyte status have a significant impact on physical performance and health. Pre-exercise recommendations cite the possibility of consuming beverages with high amounts of sodium. In this sense, non-alcoholic beer can be considered an effective pre-exercise hydration beverage. This double-blind, randomized study aimed to compare the effect of beer, non-alcoholic beer and water consumption before exercise on fluid and electrolyte homeostasis. Seven male soccer players performed 45 min of treadmill running at 65% of the maximal heart rate, 45 min after ingesting 0.7 L of water (W), beer (AB) or non-alcoholic beer (NAB). Body mass, plasma Na+ and K+ concentrations and urine specific gravity (USG) were assessed before fluid consumption and after exercise. After exercise, body mass decreased (p < 0.05) in W (−1.1%), AB (−1.0%) and NAB (−1.0%). In the last minutes of exercise, plasma Na+ was reduced (p < 0.05) in W (−3.9%) and AB (−3.7%), plasma K+ was increased (p < 0.05) in AB (8.5%), and USG was reduced in W (−0.9%) and NAB (−1.0%). Collectively, these results suggest that non-alcoholic beer before exercise could help maintain electrolyte homeostasis during exercise. Alcoholic beer intake reduced plasma Na+ and increased plasma K+ during exercise, which may negatively affect health and physical performance, and finally, the consumption of water before exercise could induce decreases of Na+ in plasma during exercise.
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Affiliation(s)
- Mauricio Castro-Sepulveda
- Exercise Science Laboratory, Faculty of Medicine, Universidad Finis Terrae, Av. Pedro de Valdivia 1509, Providencia, Santiago 7500000, Chile.
| | - Neil Johannsen
- Department of Preventive Medicine, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
- School of Kinesiology, Louisiana State University, Baton Rouge, LA 70803, USA.
| | - Sebastián Astudillo
- Family Health Center, El Peral s/n Sector La Pirca, Panquehue 2210000, Chile.
| | - Carlos Jorquera
- Nutrition and Exercise Laboratory, Faculty of Medicine, Universidad Mayor, Santiago 8320000, Chile.
| | | | - Hermann Zbinden-Foncea
- Exercise Science Laboratory, Faculty of Medicine, Universidad Finis Terrae, Av. Pedro de Valdivia 1509, Providencia, Santiago 7500000, Chile.
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23
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Castro-Sepulveda M, Astudillo J, Letelier P, Zbinden-Foncea H. Prevalence of Dehydration Before Training Sessions, Friendly and Official Matches in Elite Female Soccer Players. J Hum Kinet 2016; 50:79-84. [PMID: 28149344 PMCID: PMC5260643 DOI: 10.1515/hukin-2015-0145] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2016] [Indexed: 11/29/2022] Open
Abstract
This study aimed to evaluate and compare the hydration states prior to different sporting events (training sessions, friendly and official matches) in elite female soccer players and relate that to the importance that the player attached to the hydration state as a determinant of sports performance. The hydration state of 17 female elite soccer players (age: 21.5 ± 3 years; body mass: 62 ± 6 kg; body height: 165 ± 9 cm) was determined by measuring their urine specific gravity (USG) prior to three different sports events: training sessions (PT), friendly (PF) and official (PO) matches. The importance that each player attached to the hydration state as a determinant of sports performance was evaluated through a simple questionnaire. An average of 47.05% of the soccer players were severely dehydrated (USG > 1.030), 33.33% were significantly dehydrated (USG > 1.020), 17.64% were mildly dehydrated (USG > 1.010) and 1.96% were euhydrated (USG < 1.010). The average USG was 1.027 ± 0.007 (PT = 1.029 ± 0.009; PF = 1.023 ± 0.010 and PO = 1.030 ± 0.006). Differences were found between urine specific gravity prior to a friendly and an official match (p = 0.03). No relationship was found between urine specific gravity and the importance each player attached to the hydration state as a determinant of sports performance. The results show that dehydration is the most prevalent hydration state of elite soccer players before training sessions, friendly and official matches. Players were most dehydrated prior to official matches, which was unlinked to the players’ perceived importance of hydration for sports performance.
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Affiliation(s)
| | - Javier Astudillo
- Exercise Science Laboratory, Faculty of Medicine, Universidad Finis Terrae, Santiago, Chile
| | - Pablo Letelier
- Exercise Science Laboratory, Faculty of Medicine, Universidad Finis Terrae, Santiago, Chile
| | - Hermann Zbinden-Foncea
- Exercise Science Laboratory, Faculty of Medicine, Universidad Finis Terrae, Santiago, Chile
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Gordon RE, Kassier SM, Biggs C. Hydration status and fluid intake of urban, underprivileged South African male adolescent soccer players during training. J Int Soc Sports Nutr 2015; 12:21. [PMID: 26038679 PMCID: PMC4451871 DOI: 10.1186/s12970-015-0080-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 04/06/2015] [Indexed: 11/10/2022] Open
Abstract
Background Poor hydration compromises performance and heightens the risk of heat stress which adolescents are particularly susceptible to as they produce comparatively larger amount of metabolic heat during exercise. This study determined the hydration status and fluid intake of socio-economically disadvantaged, male adolescent soccer players during training. Methods A pilot study was conducted among 79 soccer players (mean age 15.9 ± 0.8 years; mean BMI 20.2 ± 2.1 kg/m2). Hydration status was determined before and after two training sessions, using both urine specific gravity and percent loss of body weight. The type and amount of fluid consumed was assessed during training. A self-administered questionnaire was used to determine the players’ knowledge regarding fluid and carbohydrate requirements for soccer training. Results Players were at risk of developing heat illness during six of the 14 training sessions (60 - 90 minutes in length). Although on average players were slightly dehydrated (1.023 ± 0.006 g/ml) before and after (1.024 ± 0.007 g/ml) training, some were extremely dehydrated before (24%) and after (27%) training. Conversely some were extremely hyperhydrated before (3%) and after training (6%). The mean percent loss of body weight was 0.7 ± 0.7%. The majority did not consume fluid during the first (57.0%) and second (70.9%) training sessions. An average of 216.0 ± 140.0 ml of fluid was consumed during both training sessions. The majority (41.8%) consumed water, while a few (5.1%) consumed pure fruit juice. More than 90% stated that water was the most appropriate fluid to consume before, during and after training. Very few (5.0%) correctly stated that carbohydrate should be consumed before, during and after training. Conclusions Approximately a quarter were severely dehydrated. Many did not drink or drank insufficient amounts. The players’ beliefs regarding the importance of fluid and carbohydrate consumption did not correspond with their practices. A nutrition education programme is needed to educate players on the importance of fluid and carbohydrate to prevent dehydration and ensure appropriate carbohydrate intake.
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Affiliation(s)
- Reno Eron Gordon
- Discipline of Dietetics and Human Nutrition, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209 South Africa
| | - Susanna Maria Kassier
- Discipline of Dietetics and Human Nutrition, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209 South Africa
| | - Chara Biggs
- Discipline of Dietetics and Human Nutrition, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209 South Africa
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Yeargin SW, Finn ME, Eberman LE, Gage MJ, McDermott BP, Niemann A. Ad libitum fluid consumption via self- or external administration. J Athl Train 2014; 50:51-8. [PMID: 25389698 DOI: 10.4085/1062-6050-49.3.76] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT During team athletic events, athletic trainers commonly provide fluids with water bottles. When a limited number of water bottles exist, various techniques are used to deliver fluids. OBJECTIVE To determine whether fluid delivered via water-bottle administration influenced fluid consumption and hydration status. DESIGN Crossover study. SETTING Outdoor field (22.2°C ± 3.5°C). PATIENTS OR OTHER PARTICIPANTS Nineteen participants (14 men, 5 women, age = 30 ± 10 years, height = 176 ± 8 cm, mass = 72.5 ± 10 kg) were recruited from the university and local running clubs. INTERVENTION(S) The independent variable was fluid delivery with 3 levels: self-administration with mouth-to-bottle direct contact (SA-DC), self-administration with no contact between mouth and bottle (SA-NC), and external administration with no contact between the mouth and the bottle (EA-NC). Participants warmed up for 10 minutes before completing 5 exercise stations, after which an ad libitum fluid break was given, for a total of 6 breaks. MAIN OUTCOME MEASURE(S) We measured the fluid variables of total volume consumed, total number of squirts, and average volume per squirt. Hydration status via urine osmolality and body-mass loss, and perceptual variables for thirst and fullness were recorded. We calculated repeated-measures analyses of variance to assess hydration status, fluid variables, and perceptual measures to analyze conditions across time. RESULTS The total volume consumed for EA-NC was lower than for SA-DC (P = .001) and SA-NC (P = .001). The total number of squirts for SA-DC was lower than for SA-NC (P = .009). The average volume per squirt for EA-NC was lower than for SA-DC (P = .020) and SA-NC (P = .009). Participants arrived (601.0 ± 21.3 mOsm/L) and remained (622.3 ± 38.3 mOsm/L) hydrated, with no difference between conditions (P = .544); however, the EA-NC condition lost more body mass than did the SA-DC condition (P = .001). There was no main effect for condition on thirst (P = .147) or fullness (P = .475). CONCLUSIONS External administration of fluid decreased total volume consumed via a decreased average volume per squirt. The SA-DC method requires fewer squirts within a specific time frame. Fluid breaks every 15 minutes resulted in maintenance of euhydration; however, loss of body mass was influenced by fluid administration. Athletic trainers should avoid external administration to promote positive hydration behaviors. When fluid is self-administered, individual bottles may be the best clinical practice because more volume can be consumed per squirt.
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Affiliation(s)
- Susan W Yeargin
- Department of Physical Education and Athletic Training, University of South Carolina, Columbia
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Flores-Salamanca R, Aragón-Vargas LF. Postexercise rehydration with beer impairs fluid retention, reaction time, and balance. Appl Physiol Nutr Metab 2014; 39:1175-81. [PMID: 25041559 DOI: 10.1139/apnm-2013-0576] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Beer is promoted by popular media as a good choice for rehydration, but there is limited support for the claim. To assess the effect of beer alcohol on rehydration and motor control, 11 young (24.4 ± 3.7 years old) males of legal drinking age were dehydrated to 2.12% ± 0.20% body mass (mean ± SD) by exercising in a climatic chamber (31.7 ± 1.6 °C, 55.0% ± 8.3% relative humidity) on 3 different days, 1 week apart, and rehydrated with 100% of their sweat loss using water (WATER), 4.6% alcohol beer (BEER), or low-alcohol beer (LAB), in random order. Urine output, blood alcohol content (BAC), reaction time (RT), and balance (as measured by center of pressure velocity (VCoP)) were measured every 30 min over 3 h and compared via 2-way, repeated-measures analyses of variance (ANOVAs). After consuming ≈1.6 L in 1 h, urine output was greater for BEER (1218 ± 279 mL) than for LAB (745 ± 313 mL, p = 0.007) and WATER (774 ± 304 mL, p = 0.043). BAC remained at 0 with WATER and LAB; with BEER, BAC reached 0.857 g/L (95% confidence intervals [0.752, 0.963]) immediately postrehydration. RT was longer for BEER (0.314 ± 0.039 s) than for LAB (0.294 ± 0.034 s, p = 0.009), but was no different from WATER (0.293 ± 0.049 s, p = 0.077). VCoPx was significantly higher for BEER (0.0284 ± 0.0020 m/s) compared with LAB (0.0233 ± 0.0010 m/s) or WATER (0.0238 ± 0.0010 m/s) (p = 0.022), but VCoPy was not different among beverages. In conclusion, rehydration with BEER resulted in higher diuresis, slower RT, and impaired VCoP than rehydration with LAB or WATER.
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Influence of Hydration Status on Changes in Plasma Cortisol, Leukocytes, and Antigen-Stimulated Cytokine Production by Whole Blood Culture following Prolonged Exercise. ISRN NUTRITION 2014; 2014:561401. [PMID: 24967270 PMCID: PMC4045312 DOI: 10.1155/2014/561401] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 02/11/2014] [Indexed: 12/29/2022]
Abstract
Elevated antigen-stimulated anti-inflammatory cytokine production appears to be a risk factor for upper respiratory tract illness in athletes. The purpose of this study was to determine the effects of prolonged exercise and hydration on antigen-stimulated cytokine production. Twelve healthy males cycled for 120 min at 60% V˙O2max on two occasions, either euhydrated or moderately hypohydrated (induced by fluid restriction for 24 h). Blood samples were collected before and after exercise and following 2 h recovery for determination of cell counts, plasma cortisol, and in vitro antigen-stimulated cytokine production by whole blood culture. Fluid restriction resulted in mean body mass loss of 1.3% and 3.9% before and after exercise, respectively. Exercise elicited a significant leukocytosis and elevated plasma cortisol, with no differences between trials. IL-6 production was significantly reduced 2 h postexercise (P < 0.05), while IL-10 production was elevated postexercise (P < 0.05). IFN-γ and IL-2 production tended to decrease postexercise. No significant effect of hydration status was observed for the measured variables. Prolonged exercise appears to result in augmented anti-inflammatory cytokine release in response to antigen challenge, possibly coupled with acute suppression of proinflammatory cytokine production, corresponding with studies using mitogen or endotoxin as stimulant. Moderate hypohydration does not appear to influence these changes.
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Da Silva RP, Mündel T, Natali AJ, Bara Filho MG, Alfenas RCG, Lima JRP, Belfort FG, Lopes PRNR, Marins JCB. Pre-game hydration status, sweat loss, and fluid intake in elite Brazilian young male soccer players during competition. J Sports Sci 2012; 30:37-42. [DOI: 10.1080/02640414.2011.623711] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Hydration Status of Male Football Players Across a Week of Training and Competition. ACTA ACUST UNITED AC 2011. [DOI: 10.2478/v10036-011-0021-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Silva RP, Mündel T, Natali AJ, Bara Filho MG, Lima JRP, Alfenas RCG, Lopes PRNR, Belfort FG, Marins JCB. Fluid balance of elite Brazilian youth soccer players during consecutive days of training. J Sports Sci 2011; 29:725-32. [DOI: 10.1080/02640414.2011.552189] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Maughan RJ, Shirreffs SM, Ozgünen KT, Kurdak SS, Ersöz G, Binnet MS, Dvorak J. Living, training and playing in the heat: challenges to the football player and strategies for coping with environmental extremes. Scand J Med Sci Sports 2011; 20 Suppl 3:117-24. [PMID: 21029198 DOI: 10.1111/j.1600-0838.2010.01221.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dehydration and hyperthermia both, if sufficiently severe, will impair exercise performance. Dehydration can also impair performance of tasks requiring cognition and skill. Body temperature may exceed 40 °C in competitive games played in hot weather, but limited data are available. Football played in the heat, therefore, poses a challenge, and effects on some aspects of performance become apparent as environmental temperature increases above about 12-15 °C. Prior acclimatization will reduce the impact of high environmental temperatures but provides limited protection when humidity is also high. Ingestion of fluids is effective in limiting the detrimental effects on performance: drinks with added carbohydrate and electrolytes are generally more effective than plain water and drinks may be more effective if taken cold than if taken at ambient temperature. Pre-exercise lowering of body temperature may aid some aspects of performance, but the efficacy has not been demonstrated in football.
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Affiliation(s)
- R J Maughan
- School of Sport and Health Exercise Sciences, Loughborough University, Loughborough, UK.
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