1
|
Zheng AC, He CS, Lu CC, Hung BL, Chou KM, Fang SH. The Cognitive Function and Taekwondo-Specific Kick Performance of Taekwondo Athletes at Different Hydration Statuses. Int J Sports Physiol Perform 2024; 19:637-644. [PMID: 38702046 DOI: 10.1123/ijspp.2023-0332] [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: 08/29/2023] [Revised: 02/03/2024] [Accepted: 03/05/2024] [Indexed: 05/06/2024]
Abstract
PURPOSE Successful participation in taekwondo (TKD) requires athletes to possess quick decision-making abilities and demonstrate technical proficiency during competition. Dehydration, occurring during both training and competition, is widely recognized to have various negative effects. METHODS This study investigated the impact of different levels of dehydration on cognitive function, as measured by the Vienna Test System, and the specific performance of kicking techniques among TKD athletes. Using a randomized crossover design, 12 participants were involved in the study. Before and after 1 hour of training at 80% of maximal heart rate, participants were weighed and provided urine samples. All participants were randomly assigned to 3 different hydration conditions: the euhydrated (EUH) group had unrestricted access to fluid consumption, while the hypohydrated (HYP) and severely HYP (S-HYP) groups experienced reductions of 2.0% and 4.0% of their initial body weight, respectively. RESULTS The EUH group exhibited better reaction speed in reaction-time test-form S1 than the HYP and S-HYP groups. Notably, the EUH group demonstrated a significantly higher success rate in the front-side kick (EUH 98%, HYP 90%, S-HYP 88%; P < .05). However, the success rates of back roundhouse kick and free head kick were similar among the 3 statuses. Furthermore, postexercise heart rates were found to be significantly higher in the HYP and S-HYP groups compared with the EUH group. CONCLUSIONS This study provides insight into the negative effects of dehydration on cognitive function and TKD-specific performance. It is recommended that TKD athletes maintain optimal hydration levels during training and competition to ensure optimal performance.
Collapse
Affiliation(s)
- Ai-Chi Zheng
- Department of Sport Performance, National Taiwan University of Sport, Taichung, Taiwan
| | - Cheng-Shiun He
- Department of Athletic Sports, National Chung Cheng University, Minxiong, Taiwan
| | - Chi-Cheng Lu
- Department of Sport Performance, National Taiwan University of Sport, Taichung, Taiwan
| | - Bao-Lien Hung
- Department of Sports Medicine, China Medical University, Taichung, Taiwan
| | - Kuei-Ming Chou
- Department of Combat Sports, National Taiwan University of Sport, Taichung, Taiwan
| | - Shih-Hua Fang
- Department of Sport Performance, National Taiwan University of Sport, Taichung, Taiwan
- Institute of Athletics, National Taiwan University of Sport, Taichung, Taiwan
| |
Collapse
|
2
|
Merrell LH, Perkin OJ, Bradshaw L, Collier-Bain HD, Collins AJ, Davies S, Eddy R, Hickman JA, Nicholas AP, Rees D, Spellanzon B, James LJ, McKay AKA, Smith HA, Turner JE, Koumanov F, Maher J, Thompson D, Gonzalez JT, Betts JA. Myths and Methodologies: Standardisation in human physiology research-should we control the controllables? Exp Physiol 2024. [PMID: 38763158 DOI: 10.1113/ep091557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 02/05/2024] [Indexed: 05/21/2024]
Abstract
The premise of research in human physiology is to explore a multifaceted system whilst identifying one or a few outcomes of interest. Therefore, the control of potentially confounding variables requires careful thought regarding the extent of control and complexity of standardisation. One common factor to control prior to testing is diet, as food and fluid provision may deviate from participants' habitual diets, yet a self-report and replication method can be flawed by under-reporting. Researchers may also need to consider standardisation of physical activity, whether it be through familiarisation trials, wash-out periods, or guidance on levels of physical activity to be achieved before trials. In terms of pharmacological agents, the ethical implications of standardisation require researchers to carefully consider how medications, caffeine consumption and oral contraceptive prescriptions may affect the study. For research in females, it should be considered whether standardisation between- or within-participants in regards to menstrual cycle phase is most relevant. The timing of measurements relative to various other daily events is relevant to all physiological research and so it can be important to standardise when measurements are made. This review summarises the areas of standardisation which we hope will be considered useful to anyone involved in human physiology research, including when and how one can apply standardisation to various contexts.
Collapse
Affiliation(s)
- Lucy H Merrell
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| | - Oliver J Perkin
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| | - Louise Bradshaw
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| | | | - Adam J Collins
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| | - Sophie Davies
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| | - Rachel Eddy
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| | - James A Hickman
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| | - Anna P Nicholas
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| | - Daniel Rees
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| | - Bruno Spellanzon
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| | - Lewis J James
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Alannah K A McKay
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia
| | - Harry A Smith
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| | - James E Turner
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Francoise Koumanov
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| | - Jennifer Maher
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| | - Dylan Thompson
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| | - Javier T Gonzalez
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| | - James A Betts
- Centre for Nutrition, Exercise and Metabolism, University of Bath, Bath, UK
| |
Collapse
|
3
|
Gavel EH, Hawke KV, Logan-Sprenger HM. The Effect of Menthol Mouth Rinsing and Fluid Temperature on Male Cycling Performance in Thermoneutral Conditions. Nutrients 2024; 16:1016. [PMID: 38613049 PMCID: PMC11013829 DOI: 10.3390/nu16071016] [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: 02/23/2024] [Revised: 03/26/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
PURPOSE The purpose of this study was to determine the effect of a menthol (MEN) mouth rinse (MR) on cycling time trial (TT) performance in thermoneutral conditions and to explore the impact of fluid temperature (cold water [CW] or thermoneutral water [TNW]) on MEN's effect on performance. METHODS Twelve trained male cyclists (VO2 peak, 61.4 ± 12.1 mL/kg/min) completed a cycling TT in thermoneutral conditions (21 ± 0.2 °C, 40 ± 0.6% relative humidity) with four different mouth rinses: (1) MEN + CW; (2) MEN + TNW; (3) CW; and (4) TNW. The time to complete the TT and the power output (W) were recorded. The ratings of perceived exertion (RPE, Borg 6-20), thermal sensation (TS), and thermal comfort (TC) were recorded prior to and throughout the TT. The core body temperature (Tc) and heart rate (HR) were recorded throughout. RESULTS The TT duration was not significantly different between trials (MEN + TNW: 38:11 ± 12:48, MEN + CW: 37:21 ± 13:00, CW: 38:12 ± 13:54, TNW: 36:06 ± 14:12 mins:secs, p < 0.05). The mean trial power output did not significantly differ between conditions (>0.05). The Tc, HR, RPE, TS, and TC were not significantly different between trials (p > 0.05). CONCLUSION The results suggest that a MEN MR with either CW or TNW does not significantly improve cycling TT performance in trained male cyclists compared to a CW or TNW MR in thermoneutral conditions.
Collapse
Affiliation(s)
- Erica H. Gavel
- Faculty of Science, Ontario Tech University, 2000 Simcoe St N, Oshawa, ON L1G 0C5, Canada;
- Departments of Family Medicine and Physical Medicine and Rehabilitation, University of Michigan, Ann Arbor, MI 48109, USA
- Tanenbaum Institute for Science in Sport, University of Toronto, Toronto, ON M5T 1R8, Canada
| | - Kierstyn V. Hawke
- Faculty of Health Science, Ontario Tech University, Oshawa, ON L1G 0C5, Canada;
| | - Heather M. Logan-Sprenger
- Faculty of Science, Ontario Tech University, 2000 Simcoe St N, Oshawa, ON L1G 0C5, Canada;
- Faculty of Health Science, Ontario Tech University, Oshawa, ON L1G 0C5, Canada;
| |
Collapse
|
4
|
Funnell MP, Moss J, Brown DR, Mears SA, James LJ. Perceived dehydration impairs endurance cycling performance in the heat in active males. Physiol Behav 2024; 276:114462. [PMID: 38215862 DOI: 10.1016/j.physbeh.2024.114462] [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: 10/17/2023] [Revised: 12/21/2023] [Accepted: 01/09/2024] [Indexed: 01/14/2024]
Abstract
Dehydration of >3 % body mass impairs endurance performance irrespective of the individual's knowledge of their hydration status, but whether knowledge of hydration status influences performance at lower levels of dehydration is unknown. This study examined whether perception of hydration status influenced endurance performance. After familiarisation, nine active males (age 25 ± 2 y, V̇O2peak 52.5 ± 9.1 mL kg min-1) completed two randomised trials at 34 °C. Trials involved an intermittent exercise preload (8 × 10 min cycling/5 min rest), followed by a 15 min all-out cycling performance test. During the preload in both trials, water was ingested orally every 10 min (0.3 mL kg body mass-1), with additional water infused into the stomach via gastric feeding tube to produce dehydration of ∼1.5 % body mass pre-performance test. Participants were told intra-gastric infusion was manipulated to produce euhydration (0 % dehydration; Perceived-EUH) or dehydration (2 % dehydration; Perceived-DEH) pre-performance test, which was told to them pre-preload and confirmed after body mass measurement pre-performance test. Body mass loss during the preload (Perceived-EUH 1.6 ± 0.2 %, Perceived-DEH 1.7 ± 0.2 %; P = 0.459), heart rate, gastrointestinal temperature and RPE (P ≥ 0.110) were not different between trials. Thirst was greater at the end of the preload and performance test in Perceived-DEH (P ≤ 0.040). Work completed during the performance test was 5.6 ± 6.1 % lower in Perceived-DEH (187.4 ± 37.0 kJ vs. 176.9 ± 36.0 kJ; P = 0.038). These results suggest that at lower levels of dehydration (<2 % body mass), an individual's perception of their hydration status could impair their performance, as well as their thirst perception.
Collapse
Affiliation(s)
- Mark P Funnell
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, LE11 3TU, UK
| | - Jodie Moss
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, LE11 3TU, UK
| | - Daniel R Brown
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, LE11 3TU, UK; Centre for Human Performance, Carnegie School of Sport, Leeds Beckett University, Leeds, LS6 3QT, UK
| | - Stephen A Mears
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, LE11 3TU, UK
| | - Lewis J James
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, LE11 3TU, UK.
| |
Collapse
|
5
|
Sempere-Ruiz N, Sarabia JM, Baladzhaeva S, Moya-Ramón M. Reliability and validity of a non-linear index of heart rate variability to determine intensity thresholds. Front Physiol 2024; 15:1329360. [PMID: 38375458 PMCID: PMC10875128 DOI: 10.3389/fphys.2024.1329360] [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: 10/28/2023] [Accepted: 01/18/2024] [Indexed: 02/21/2024] Open
Abstract
Exercise intensity distribution is crucial for exercise individualization, prescription, and monitoring. As traditional methods to determine intensity thresholds present limitations, heart rate variability (HRV) using DFA a1 has been proposed as a biomarker for exercise intensity distribution. This index has been associated with ventilatory and lactate thresholds in previous literature. This study aims to assess DFA a1's reliability and validity in determining intensity thresholds during an incremental cycling test in untrained healthy adults. Sixteen volunteers (13 males and 3 females) performed two identical incremental cycling stage tests at least 1 week apart. First and second ventilatory thresholds, lactate thresholds, and HRV thresholds (DFA a1 values of 0.75 and 0.5 for HRVT1 and HRVT2, respectively) were determined in heart rate (HR), relative oxygen uptake (VO2rel), and power output (PO) values for both tests. We used intraclass correlation coefficient (ICC), change in mean, and typical error for the reliability analysis, and paired t-tests, correlation coefficients, ICC, and Bland-Altman analysis to assess the agreement between methods. Regarding reliability, HRV thresholds showed the best ICCs when measured in PO (HRVT1: ICC = .87; HRVT2: ICC = .97), comparable to ventilatory and lactate methods. HRVT1 showed the strongest agreement with LA 2.5 in PO (p = 0.09, r = .93, ICC = .93, bias = 9.9 ± 21.1), while HRVT2 reported it with VT2 in PO (p = 0.367, r = .92, ICC = .92, bias = 5.3 ± 21.9). DFA a1 method using 0.75 and 0.5 values is reliable and valid to determine HRV thresholds in this population, especially in PO values.
Collapse
Affiliation(s)
- Noemí Sempere-Ruiz
- Department of Sport Sciences, Sport Research Centre, Miguel Hernandez University, Elche, Spain
- Alicante Institute for Health and Biomedical Research (ISABIAL), Alicante, Spain
| | - José Manuel Sarabia
- Department of Sport Sciences, Sport Research Centre, Miguel Hernandez University, Elche, Spain
- Alicante Institute for Health and Biomedical Research (ISABIAL), Alicante, Spain
| | - Sabina Baladzhaeva
- Department of Sport Sciences, Sport Research Centre, Miguel Hernandez University, Elche, Spain
- Alicante Institute for Health and Biomedical Research (ISABIAL), Alicante, Spain
| | - Manuel Moya-Ramón
- Department of Sport Sciences, Sport Research Centre, Miguel Hernandez University, Elche, Spain
- Alicante Institute for Health and Biomedical Research (ISABIAL), Alicante, Spain
| |
Collapse
|
6
|
Rivera-Brown AM, Pagán-Lassalle P. Hydration and Performance in Young Triathletes During a Competition in Tropical Climate. Pediatr Exerc Sci 2024; 36:8-14. [PMID: 37604485 DOI: 10.1123/pes.2022-0148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 04/26/2023] [Accepted: 05/25/2023] [Indexed: 08/23/2023]
Abstract
PURPOSE We examined fluid intake, the relation between body mass (BM) loss and performance, and core temperature in young triathletes during a competition in tropical climate. METHODS Fluid intake and pre and post BM were measured in 35 adolescent athletes, and core temperature was measured in one female and one male. RESULTS Mean urine specific gravity (1.024 [0.007]) indicated that athletes were in suboptimal state of hydration upon waking. Race time was 73.2 (8.0) minutes. BM decreased by 0.6 (0.3) kg (P < .05). Fluid intake (528.5 [221.6] mL) replaced 47% of the fluid loss (1184.9 [256.4] mL) and was higher during run (11.5 [6.6] mL·min-1) compared to bike (7.3 [3.1] mL·min-1), P < .01. Loss in BM was ≥1.0% in 66% and ≥1.5% in 29% of the athletes. Males showed a moderate association between percentage loss in BM and finishing time (r = -.52), higher sweat rates (1.0 [0.3] L·h-1), and faster times (69.4 [7.5] min; P < .05). Core temperature rose to 40.1 °C in the female and 39.6 °C in the male. CONCLUSION Young triathletes competing in a hot/humid climate became mildly to moderately dehydrated and hyperthermic even when water and sports drinks were available but did not show symptoms of heat illness.
Collapse
Affiliation(s)
- Anita M Rivera-Brown
- Center for Sports Health and Exercise Sciences, Department of Physical Medicine, Rehabilitation and Sports Medicine and Department of Physiology, University of Puerto Rico School of Medicine, San Juan,Puerto Rico
| | - Patricia Pagán-Lassalle
- Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC,USA
| |
Collapse
|
7
|
Strüven A, Brunner S, Weis G, Cohrdes Y, Lackermair S, Schlichtiger J, Kellnar A, Lackermair K. Impact of Preparticipation Hypohydration on Cognitive Performance and Concussion-like Symptoms in Recreational Athletes. Nutrients 2023; 15:4420. [PMID: 37892495 PMCID: PMC10609819 DOI: 10.3390/nu15204420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/16/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
BACKGROUND Sports-related concussion is a relevant risk of contact sports, with several million cases per year worldwide. Prompt identification is crucial to prevent complications and late effects but may be impeded by an overlap with dehydration-associated impairment of cognitive function. Researchers have extensively studied the effects of pronounced dehydration in endurance sports, especially in the heat. However, little is known about the effects of isolated and mild dehydration. METHODS Healthy recreational athletes underwent a standardized fluid deprivation test. Hypohydration was assessed by bioelectrical impedance analysis (BIA) and laboratory testing of electrolytes and retention parameters. Participants underwent cardiopulmonary exercise testing (CPET) with a cycle ramp protocol. Each participant served as their own control undergoing CPET in a hypohydrated [HYH] and a euhydrated [EUH] state. Effects were assessed using a shortened version of Sport Concussion Assessment Tool 3 (SCAT3). RESULTS Fluid deprivation caused a mild (2%) reduction in body water, resulting in a calculated body mass loss of 0.8% without alterations of electrolytes, serum-osmolality, or hematocrit. Athletes reported significantly more (1.8 ± 2.2 vs. 0.4 ± 0.7; p < 0.01) and more severe (4.4 ± 6.2 vs. 1.0 ± 1.9; p < 0.01) concussion-like symptoms in a hypohydrated state. Balance was worse in HYH by trend with a significant difference for tandem stance (1.1 ± 1.3 vs. 0.6 ± 1.1; p = 0.02). No relevant differences were presented for items of memory and concentration. CONCLUSIONS Mild dehydration caused relevant alterations of concussion-like symptoms and balance in healthy recreational athletes in the absence of endurance exercise or heat. Further research is needed to clarify the real-life relevance of these findings and to strengthen the differential diagnosis of concussion.
Collapse
Affiliation(s)
- Anna Strüven
- Department of Medicine I, University Hospital Munich, Ludwig Maximilian University, 81377 Munich, Germany
- Center for Sports Medicine, University Hospital Munich, Ludwig Maximilian University, 81377 Munich, Germany
| | - Stefan Brunner
- Department of Medicine I, University Hospital Munich, Ludwig Maximilian University, 81377 Munich, Germany
- Center for Sports Medicine, University Hospital Munich, Ludwig Maximilian University, 81377 Munich, Germany
| | - Georges Weis
- Department of Medicine I, University Hospital Munich, Ludwig Maximilian University, 81377 Munich, Germany
- Center for Sports Medicine, University Hospital Munich, Ludwig Maximilian University, 81377 Munich, Germany
| | - Yannick Cohrdes
- Department of Medicine I, University Hospital Munich, Ludwig Maximilian University, 81377 Munich, Germany
- Center for Sports Medicine, University Hospital Munich, Ludwig Maximilian University, 81377 Munich, Germany
| | - Stephan Lackermair
- Department of Neurosurgery, Krankenhaus Barmherzige Brüder Regensburg, 93049 Regensburg, Germany
| | - Jenny Schlichtiger
- Department of Medicine I, University Hospital Munich, Ludwig Maximilian University, 81377 Munich, Germany
- Center for Sports Medicine, University Hospital Munich, Ludwig Maximilian University, 81377 Munich, Germany
| | - Antonia Kellnar
- Department of Medicine I, University Hospital Munich, Ludwig Maximilian University, 81377 Munich, Germany
| | - Korbinian Lackermair
- Department of Medicine I, University Hospital Munich, Ludwig Maximilian University, 81377 Munich, Germany
- Center for Sports Medicine, University Hospital Munich, Ludwig Maximilian University, 81377 Munich, Germany
| |
Collapse
|
8
|
Webb KL, Gorman EK, Morkeberg OH, Klassen SA, Regimbal RJ, Wiggins CC, Joyner MJ, Hammer SM, Senefeld JW. The relationship between hemoglobin and [Formula: see text]: A systematic review and meta-analysis. PLoS One 2023; 18:e0292835. [PMID: 37824583 PMCID: PMC10569622 DOI: 10.1371/journal.pone.0292835] [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: 10/21/2022] [Accepted: 09/29/2023] [Indexed: 10/14/2023] Open
Abstract
OBJECTIVE There is widespread agreement about the key role of hemoglobin for oxygen transport. Both observational and interventional studies have examined the relationship between hemoglobin levels and maximal oxygen uptake ([Formula: see text]) in humans. However, there exists considerable variability in the scientific literature regarding the potential relationship between hemoglobin and [Formula: see text]. Thus, we aimed to provide a comprehensive analysis of the diverse literature and examine the relationship between hemoglobin levels (hemoglobin concentration and mass) and [Formula: see text] (absolute and relative [Formula: see text]) among both observational and interventional studies. METHODS A systematic search was performed on December 6th, 2021. The study procedures and reporting of findings followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Article selection and data abstraction were performed in duplicate by two independent reviewers. Primary outcomes were hemoglobin levels and [Formula: see text] values (absolute and relative). For observational studies, meta-regression models were performed to examine the relationship between hemoglobin levels and [Formula: see text] values. For interventional studies, meta-analysis models were performed to determine the change in [Formula: see text] values (standard paired difference) associated with interventions designed to modify hemoglobin levels or [Formula: see text]. Meta-regression models were then performed to determine the relationship between a change in hemoglobin levels and the change in [Formula: see text] values. RESULTS Data from 384 studies (226 observational studies and 158 interventional studies) were examined. For observational data, there was a positive association between absolute [Formula: see text] and hemoglobin levels (hemoglobin concentration, hemoglobin mass, and hematocrit (P<0.001 for all)). Prespecified subgroup analyses demonstrated no apparent sex-related differences among these relationships. For interventional data, there was a positive association between the change of absolute [Formula: see text] (standard paired difference) and the change in hemoglobin levels (hemoglobin concentration (P<0.0001) and hemoglobin mass (P = 0.006)). CONCLUSION These findings suggest that [Formula: see text] values are closely associated with hemoglobin levels among both observational and interventional studies. Although our findings suggest a lack of sex differences in these relationships, there were limited studies incorporating females or stratifying results by biological sex.
Collapse
Affiliation(s)
- Kevin L. Webb
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Ellen K. Gorman
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Olaf H. Morkeberg
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Stephen A. Klassen
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Riley J. Regimbal
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Chad C. Wiggins
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Michael J. Joyner
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Shane M. Hammer
- Department of Kinesiology, Applied Health, and Recreation, Oklahoma State University, Stillwater, Oklahoma, United States of America
| | - Jonathon W. Senefeld
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois
| |
Collapse
|
9
|
Strüven A, Brunner S, Weis G, Stremmel C, Teupser D, Schlichtiger J, Lackermair K. Impact of Preparticipating Hypohydration on Cardiopulmonary Exercise Capacity in Ambitious Recreational Athletes. Nutrients 2023; 15:3333. [PMID: 37571272 PMCID: PMC10421152 DOI: 10.3390/nu15153333] [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: 05/31/2023] [Revised: 07/24/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
BACKGROUND Heat induces a thermoregulatory strain that impairs cardiopulmonary exercise capacity. The aim of the current study is to elucidate the effect of isolated dehydration on cardiopulmonary exercise capacity in a model of preparticipating hypohydration. METHODS Healthy recreational athletes underwent a standardised fluid deprivation test. Hypohydration was assessed by bioelectrical impedance analysis (BIA) and laboratory testing of electrolytes and retention parameters in the blood and urine. The participants underwent cardiopulmonary exercise testing (CPET) with a cycle ramp protocol. Each participant served as their own control undergoing CPET in a hypohydrated [HYH] and euhydrated [EUH] state. RESULTS Fluid deprivation caused a mild (2%) but significant reduction of body water (38.6 [36.6; 40.7] vs. 39.4 [37.4; 41.5] %; p < 0.01) and an increase of urine osmolality (767 [694; 839] vs. 537 [445; 629] mosm/kg; p < 0.01). Hypohydration was without alterations of electrolytes, serum osmolality or hematocrit. The oxygen uptake was significantly lower after hypohydration (-4.8%; p = 0.02 at ventilatory threshold1; -2.0%; p < 0.01 at maximum power), with a corresponding decrease of minute ventilation (-4% at ventilatory threshold1; p = 0.01, -3.3% at maximum power; p < 0.01). The power output was lower in hypohydration (-6.8%; p < 0.01 at ventilatory threshold1; -2.2%; p = 0.01 at maximum power). CONCLUSION Isolated hypohydration causes impairment of workload as well as peak oxygen uptake in recreational athletes. Our findings might indicate an important role of hypohydration in the heat-induced reduction of exercise capacity.
Collapse
Affiliation(s)
- Anna Strüven
- Department of Medicine I, University Hospital Munich, Ludwig Maximilian University, Marchioninistr. 15, 81377 Munich, Germany
- Center for Sports Medicine, University Hospital Munich, Ludwig Maximilian University, Ziemssenstraße 5, 80336 Munich, Germany
| | - Stefan Brunner
- Department of Medicine I, University Hospital Munich, Ludwig Maximilian University, Marchioninistr. 15, 81377 Munich, Germany
- Center for Sports Medicine, University Hospital Munich, Ludwig Maximilian University, Ziemssenstraße 5, 80336 Munich, Germany
| | - Georges Weis
- Department of Medicine I, University Hospital Munich, Ludwig Maximilian University, Marchioninistr. 15, 81377 Munich, Germany
- Center for Sports Medicine, University Hospital Munich, Ludwig Maximilian University, Ziemssenstraße 5, 80336 Munich, Germany
| | - Christopher Stremmel
- Department of Medicine I, University Hospital Munich, Ludwig Maximilian University, Marchioninistr. 15, 81377 Munich, Germany
| | - Daniel Teupser
- Institute of Laboratory Medicine, University Hospital Ludwig Maximilian University, Marchioninistr. 15, 81377 Munich, Germany
| | - Jenny Schlichtiger
- Department of Medicine I, University Hospital Munich, Ludwig Maximilian University, Marchioninistr. 15, 81377 Munich, Germany
- Center for Sports Medicine, University Hospital Munich, Ludwig Maximilian University, Ziemssenstraße 5, 80336 Munich, Germany
| | - Korbinian Lackermair
- Department of Medicine I, University Hospital Munich, Ludwig Maximilian University, Marchioninistr. 15, 81377 Munich, Germany
- Center for Sports Medicine, University Hospital Munich, Ludwig Maximilian University, Ziemssenstraße 5, 80336 Munich, Germany
| |
Collapse
|
10
|
Rastmanesh R. Inadequate Hydration Status of Test Subjects Can Affect Bioavailability Studies. ACS Pharmacol Transl Sci 2023; 6:1104-1106. [PMID: 37470021 PMCID: PMC10353055 DOI: 10.1021/acsptsci.3c00089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Indexed: 07/21/2023]
Abstract
This Viewpoint identifies some of the pitfalls in the bioavailability of water-soluble drugs and introduces a novel bias we term the "hypohydration bias". We suggest that future bioavailability studies take some important neglected confounding factors into account, and we propose that, to avoid such a bias, some relevant variables such as serum and urine osmolality, dry weight adjustment, fluid balance, semi-nude body mass, saliva osmolality, saliva total protein concentration, and urine specific gravity should be controlled to increase the precision of the bioavailability measurements. We suggest that a new definition of hydration status is needed, and that systematic protocols of bioavailability studies should be revisited.
Collapse
Affiliation(s)
- Reza Rastmanesh
- American
Physical Society, College Park, Maryland 20740, USA
- The
Nutrition Society, London W6 7NJ, U.K.
- Independent
researcher, #6, Physicians
Building, Sarshar Alley, Vali-Asr, Tajrish, Tehran 1961835555, Iran
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
Steel C, Lees AM, Tarr G, Warner R, Dunshea F, Cowley F, McGilchrist P. The impact of weather on the incidence of dark cutting in Australian feedlot cattle. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2022; 66:263-274. [PMID: 34468837 DOI: 10.1007/s00484-021-02180-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 07/29/2021] [Accepted: 08/04/2021] [Indexed: 06/13/2023]
Abstract
This study conducted a retrospective analysis of historical Meat Standard Australia (MSA) carcass data in combination with Bureau of Meteorology (BOM) weather data, to evaluate the relationship between climatic conditions prior to feedlot departure on the incidence of dark cutting grain-fed beef. Data records for 2,795,754 carcasses from 17 commercial feedlots over a 6-year period were evaluated within this study. Carcasses were consigned to 16 abattoirs. Weather data from BOM were recorded at 30-min intervals and were obtained from weather stations with the closest proximity to each feedlot. These data were used to calculate the Temperature Humidity Index (THI). Climatic data were amalgamated into daily observations and a series of predictors including ambient temperature (TA, °C), relative humidity (RH, %), wind speed (WS, m/s), rainfall (mm) and THI. In addition, lag interactions from 24 h out to 28 days prior to exiting the feedlot were generated. The incidence of dark cutting was determined as percentage per cohort with an ultimate pH > 5.7. Data were analysed using three models: model 1 included feedlot, abattoir, hormone growth promotant status and sex as fixed effects. Model 2 incorporated the fixed effects within model 1 and minimum, maximum and standard deviation (SD) of TA and RH, daily range in TA, average WS and rainfall as random effects. Model 3 incorporated minimum, maximum, range and SD of THI, average WS and rainfall as random effects in addition to the fixed effects of model 1. The incidence of dark cutting within feedlot had a 10.1% range in estimated means with the lowest incidence was observed at feedlot 17 (0%) and highest incidence at feedlot 10 (10.1%). The inclusion of the climatic variables in model 2 and model 3 accounted for an additional 0.1 to 0.2% of the incidence of dark cutting carcasses. Higher maximum TA, RH and THI in the 3 to 28 days prior to consignment were all associated with an increased incidence of dark cutting (P < 0.05), but not in the 48 h preceding consignment (P > 0.05). Low minimum TA and low THI were also associated with an increase the incidence of dark cutting across all lag periods (P < 0.05). Increased variation in THI and TA in the 48 h prior to consignment increased dark cutting (P < 0.05) while increased standard deviation (SD) of temperature and THI range also increased dark cutting in the 14 and 28 day prior to feedlot exit (P < 0.05). Smaller minimum ranges in TA in the 28 days prior to consignment also reduced dark cutting (P < 0.05). Climatic conditions accounted for a further 0.1 to 0.2% of the incidence of dark cutting, whereas animal management factors, feedlot and abattoir were able to account for 21% of dark cutting. These data suggest that climatic conditions appear to have an inherent role in the incidence of dark cutting, albeit a small impact. Regardless, understanding the influence of climatic conditions on dark cutting allows for the implementation of management strategies within the supply chain to further reduce the impact of climatic conditions on grain-fed cattle.
Collapse
Affiliation(s)
- Cameron Steel
- School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia.
- University of New England, Armidale, NSW, 2350, Australia.
| | - A M Lees
- School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia
| | - G Tarr
- School of Mathematics and Statistics, The University of Sydney, Sydney, NSW, 2006, Australia
| | - R Warner
- Faculty of Veterinary and Agricultural Sciences, School of Agriculture and Food, The University of Melbourne, Melbourne, VIC, 3010, Australia
| | - F Dunshea
- Faculty of Veterinary and Agricultural Sciences, School of Agriculture and Food, The University of Melbourne, Melbourne, VIC, 3010, Australia
- Faculty of Biological Sciences, The University of Leeds, Leeds, LS2 9JT, UK
| | - F Cowley
- School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia
| | - P McGilchrist
- School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia
| |
Collapse
|
13
|
Kelly DJ, West SL, O'Keeffe N, Brown LE. A quasi-experimental examination of weight-reducing dehydration practices in collegiate male rowers. BMC Sports Sci Med Rehabil 2021; 13:115. [PMID: 34563254 PMCID: PMC8466389 DOI: 10.1186/s13102-021-00344-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 09/14/2021] [Indexed: 11/10/2022]
Abstract
Background Lightweight rowers commonly utilize weight loss techniques over 24-h before competition to achieve the qualifying weight for racing. The objective was to investigate, using a quasi-experimental design, whether changes in weight resulting from dehydration practices are related to changes in proxies of bodily systems involved in rowing and whether these relationships depend on the dehydration technique used. Methods Twelve elite male rowers performed a power test, an incremental VO2max test, and a visuomotor battery following: weight loss via thermal exposure, weight loss via fluid abstinence and then thermal exposure, and no weight loss. The total percent body mass change (%BMC), %BMC attributable to thermal exposure, and %BMC attributable to fluid abstinence were used to predict performance variables. Results Fluid abstinence but not thermal exposure was related to a lower total wattage produced on a incremental VO2max test (b = 4261.51 W/1%BMC, 95%CI = 1502.68–7020.34), lower wattages required to elicit 2 mmol/L (b = 27.84 W/1%BMC, 95%CI = 14.69–40.99) and 4 mmol/L blood lactate (b = 20.45 W/1%BMC, 95%CI = 8.91–31.99), and slower movement time on a visuomotor task (b = -38.06 ms/1%BMC, 95%CI = -62.09–-14.03). Conclusions Dehydration related weight changes are associated with reductions in some proxies of bodily systems involved in rowing but depend on the dehydration technique used. Supplementary Information The online version contains supplementary material available at 10.1186/s13102-021-00344-7.
Collapse
Affiliation(s)
- Dayton J Kelly
- Department of Biology, Trent University, Peterborough, Canada.,Department of Psychology, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada.,Northern Ontario School of Medicine, Sudbury, Canada
| | - Sarah L West
- Department of Biology, Trent University, Peterborough, Canada.,Trent University, Peterborough, Canada.,Trent/Fleming School of Nursing, Trent University, Peterborough, Canada
| | - Nathan O'Keeffe
- Department of Biology, Trent University, Peterborough, Canada
| | - Liana E Brown
- Department of Psychology, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada. .,Trent University, Peterborough, Canada.
| |
Collapse
|
14
|
Périard JD, Eijsvogels TMH, Daanen HAM. Exercise under heat stress: thermoregulation, hydration, performance implications, and mitigation strategies. Physiol Rev 2021; 101:1873-1979. [PMID: 33829868 DOI: 10.1152/physrev.00038.2020] [Citation(s) in RCA: 130] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A rise in body core temperature and loss of body water via sweating are natural consequences of prolonged exercise in the heat. This review provides a comprehensive and integrative overview of how the human body responds to exercise under heat stress and the countermeasures that can be adopted to enhance aerobic performance under such environmental conditions. The fundamental concepts and physiological processes associated with thermoregulation and fluid balance are initially described, followed by a summary of methods to determine thermal strain and hydration status. An outline is provided on how exercise-heat stress disrupts these homeostatic processes, leading to hyperthermia, hypohydration, sodium disturbances, and in some cases exertional heat illness. The impact of heat stress on human performance is also examined, including the underlying physiological mechanisms that mediate the impairment of exercise performance. Similarly, the influence of hydration status on performance in the heat and how systemic and peripheral hemodynamic adjustments contribute to fatigue development is elucidated. This review also discusses strategies to mitigate the effects of hyperthermia and hypohydration on exercise performance in the heat by examining the benefits of heat acclimation, cooling strategies, and hyperhydration. Finally, contemporary controversies are summarized and future research directions are provided.
Collapse
Affiliation(s)
- Julien D Périard
- University of Canberra Research Institute for Sport and Exercise, Bruce, Australia
| | - Thijs M H Eijsvogels
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hein A M Daanen
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
15
|
Wiśniewski D, Śliwicka E, Malik J, Durkalec-Michalski K. Evaluation of Fluid Loss and Customary Fluid Intake among a Selected Group of Young Swimmers: A Preliminary Field Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18063205. [PMID: 33808826 PMCID: PMC8003718 DOI: 10.3390/ijerph18063205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/15/2021] [Accepted: 03/16/2021] [Indexed: 11/26/2022]
Abstract
This study aimed to assess fluid loss (FL) and customary fluid intake (FI) during a training session, and the relationship between FL and total body water (TBW) content in a selected group of young swimmers. The study involved 17 (seven females, 10 males) individuals whose anthropometric and body composition analyses and FI during training units were carried out. The total average FI and total actual FL oscillated around 531 mL and −513 mL for the whole study group (469 mL and −284 mL for females, 574 mL and −674 mL for males). The dependent and independent sample t-tests, the Cohen’s d effect size and Pearson’s correlation coefficient were analysed. Significant differences were observed between pre-workout and post-workout body weights after training without FI in the whole group (66.5 kg vs. 66.0 kg, p < 0.001, d = 0.06), in females (61.2 kg vs. 60.9 kg, p = 0.015, d = 0.04) and males (70.3 kg vs. 69.6 kg, p < 0.001, d = 0.9). For the TBW content and fat-free mass (FFM) before and after training, significant differences were observed only in males (TBW: 43.8 L vs. 43.2 L, p = 0.002, d = 0.14; and 62.4% vs. 61.7%, p < 0.001, d = 0.36; FFM: 59.8 kg vs. 59.1 kg, p = 0.002, d = 0.12). Moreover, the relationship between the actual FL and TBW before training was observed in the whole (mL vs. %: r = −0.64, p = 0.006; mL vs. L: r = −0.84, p < 0.001) and the male group (mL vs. L: r = −0.73, p = 0.017). These results indicated FL in young swimmers during training and the relationship between FL and pre-training TBW content, which suggests that it is important to also pay special attention to effective hydration procedures before and during training in aquatic environments.
Collapse
Affiliation(s)
- Damian Wiśniewski
- Department of Sports Dietetics, Poznan University of Physical Education, 61-871 Poznań, Poland;
| | - Ewa Śliwicka
- Department of Physiology and Biochemistry, Poznan University of Physical Education, 61-871 Poznań, Poland;
| | - Jakub Malik
- Department of Physical Activity and Health Promotion Science, Poznan University of Physical Education, 61-871 Poznań, Poland;
| | - Krzysztof Durkalec-Michalski
- Department of Sports Dietetics, Poznan University of Physical Education, 61-871 Poznań, Poland;
- Department of Human Nutrition and Dietetics, Poznan University of Life Sciences, 61-871 Poznań, Poland
- Correspondence: ; Tel.: +48-61-835-52-87
| |
Collapse
|
16
|
Perez-Quintero M, Siquier-Coll J, Bartolomé I, Robles-Gil MC, Muñoz D, Maynar-Mariño M. Three weeks of passive and intervallic heat at high temperatures (100±2 °C) in a sauna improve acclimation to external heat (42±2 °C) in untrained males. J Therm Biol 2021; 96:102837. [PMID: 33627275 DOI: 10.1016/j.jtherbio.2021.102837] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 12/14/2020] [Accepted: 01/01/2021] [Indexed: 12/28/2022]
Abstract
Currently, the effect of passive heat acclimation on aerobic performance is still controversial. Therefore, this study aimed to observe the effect of passive and intervallic exposure to high temperatures (100 ± 2 °C) in untrained males. Forty healthy untrained men participated in this investigation. They were randomised into a Control Group (CG; n = 18) and an Experimental Group (EG; n = 22). Both groups performed maximum incremental tests until exhaustion in normothermia (GXT1; 22 ± 2 °C), and 48h afterwards, in hyperthermia (GXT2; 42 ± 2 °C). The EG performed 9 sessions of intervallic exposure to heat (100 ± 2 °C) over 3 weeks. Subsequently, both groups performed two maximal incremental trials in normothermia (GXT3; 22 ± 2 °C) and 48h later, in hyperthermia (GXT4; 42 ± 2 °C). In each test, the maximal ergospirometric parameters and the aerobic (VT1), anaerobic (VT2) and recovery ventilatory thresholds were recorded. The Wilcoxon Test was used for intra-group comparisons and the Mann-Whitney U for inter-group comparisons. There were improvements in absolute VO2max (p = 0.049), W (p = 0.005) and O2pulse (p = 0.006) in hyperthermia. In VT1 there was an increase in W (p = 0.046), in VO2 in absolute (p = 0.025) and relative (p = 0.013) values, O2pulse (p = 0.006) and VE (p = 0.028) in hyperthermia. While W increased in hyperthermia (p = 0.022) at VT2. The results suggest that passive and intervallic acclimation at high temperatures improves performance in hyperthermia. This protocol could be implemented in athletes when they have to compete in hot environments.
Collapse
Affiliation(s)
- M Perez-Quintero
- Department of Physiology. School of Sport Sciences, University of Extremadura, Spain
| | - J Siquier-Coll
- Department of Physiology. School of Sport Sciences, University of Extremadura, Spain; Movement, Brain and Health Research Group (MOBhE), Center of Higher Education Alberta Giménez (Comillas Pontifical University), Palma de Mallorca, Balearic Islands, Spain.
| | - I Bartolomé
- Department of Physiology. School of Sport Sciences, University of Extremadura, Spain
| | - M C Robles-Gil
- Department of Didactics of Musical, Plastic and Corporal Expression, School of Teacher Training, University of Extremadura, Spain
| | - D Muñoz
- Department of Physical Education and Sport. Sport Sciences Faculty. University of Extremadura, Cáceres, Spain
| | - M Maynar-Mariño
- Department of Physiology. School of Sport Sciences, University of Extremadura, Spain
| |
Collapse
|
17
|
Choi DH, Gonzales M, Kitchen GB, Phan DT, Searson PC. A Capacitive Sweat Rate Sensor for Continuous and Real-Time Monitoring of Sweat Loss. ACS Sens 2020; 5:3821-3826. [PMID: 33263987 DOI: 10.1021/acssensors.0c01219] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Individualized measurement of sweat loss under heat stress is important in assessing physical performance and preventing heat-related illness for athletes or individuals working in extreme environments. The objective of this work was to develop a low-cost and easy-to-fabricate wearable sensor that enables accurate real-time measurement of sweat rate. A capacitive-type sensor was fabricated from two conducting parallel plates, plastic insulating layers, and a central microfluidic channel formed by laser cutting a plastic film. The device has no microfabricated electrodes and is assembled using adhesive tape. Sensor accuracy was validated at different flow rates and confirmed using an equivalent circuit model of the device. On-body measurements demonstrate the feasibility of real-time measurements and show good agreement with values determined from a conventional sweat collection device.
Collapse
Affiliation(s)
- Dong-Hoon Choi
- Institute for Nanobiotechnology, John Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Mark Gonzales
- Institute for Nanobiotechnology, John Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Grant B. Kitchen
- Institute for Nanobiotechnology, John Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Dinh-Tuan Phan
- Institute for Nanobiotechnology, John Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Peter C. Searson
- Institute for Nanobiotechnology, John Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
- Department of Materials Science and Engineering, John Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| |
Collapse
|
18
|
Gandia Soriano A, Carpes FP, Rodríguez Fernández A, Priego-Quesada JI. Effect of cycling specialization on effort and physiological responses to uphill and flat cycling at similar intensity. Eur J Sport Sci 2020; 21:854-860. [PMID: 32672508 DOI: 10.1080/17461391.2020.1785016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Power output is considered one of the best tools to control external loads in cycling, but the relationship between a target power output and the physiological responses may suffer from the effects of road gradient, which is also affected by cyclist specialization. The objective was to determine the effects of cyclist specialization on effort perception and physiological response (heart rate and lactate concentration) while sustaining efforts at similar power output but riding on two different road gradients. Nineteen male competitive road cyclists performed two randomized trials of 10 min at 0% (velodrome) and 10 min at 6% road gradient (field uphill), at an intensity of 10% ± 3% below the individual's functional threshold power. Cadence was kept between 75 and 80 rpm in both trials and posture remained unchanged during the tests. Heart rate, speed, cadence, power output, blood lactate, and rate of perceived effort were measured for each trial. K-means cluster analyses differentiate uphill (n = 10) and flat specialists (n = 9) according to lactate responses. Flat specialists presented lower heart rate (p < 0.001 and ES = 0.2), perceived exertion (p < 0.01 and ES = 0.7), and blood lactate concentration (p < 0.001 and ES = 0.7) riding on the flat than uphill. Uphill specialists presented lower perceived exertion (p < 0.01 and ES = 0.8) and blood lactate concentration (p < 0.01 and ES = 0.5) riding uphill than on the flat. In conclusion, the combination of cyclist specialization and road gradient affects physiological and effort perception parameters in response to a similar power output demand. These factors deserve attention in training schedules and monitoring performance using power output data.
Collapse
Affiliation(s)
- Alexis Gandia Soriano
- Biophysics and Medical Physics Group, Department of Physiology, University of Valencia, Valencia, Spain
| | - Felipe P Carpes
- Applied Neuromechanics Group, Laboratory of Neuromechanics, Federal University of Pampa, Uruguaiana, Brazil
| | | | - Jose Ignacio Priego-Quesada
- Biophysics and Medical Physics Group, Department of Physiology, University of Valencia, Valencia, Spain.,Research Group in Sports Biomechanics (GIBD), Department of Physical Education and Sports, University of Valencia, Valencia, Spain
| |
Collapse
|
19
|
James LJ, Funnell MP, James RM, Mears SA. Does Hypohydration Really Impair Endurance Performance? Methodological Considerations for Interpreting Hydration Research. Sports Med 2020; 49:103-114. [PMID: 31696453 PMCID: PMC6901416 DOI: 10.1007/s40279-019-01188-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The impact of alterations in hydration status on human physiology and performance responses during exercise is one of the oldest research topics in sport and exercise nutrition. This body of work has mainly focussed on the impact of reduced body water stores (i.e. hypohydration) on these outcomes, on the whole demonstrating that hypohydration impairs endurance performance, likely via detrimental effects on a number of physiological functions. However, an important consideration, that has received little attention, is the methods that have traditionally been used to investigate how hypohydration affects exercise outcomes, as those used may confound the results of many studies. There are two main methodological limitations in much of the published literature that perhaps make the results of studies investigating performance outcomes difficult to interpret. First, subjects involved in studies are generally not blinded to the intervention taking place (i.e. they know what their hydration status is), which may introduce expectancy effects. Second, most of the methods used to induce hypohydration are both uncomfortable and unfamiliar to the subjects, meaning that alterations in performance may be caused by this discomfort, rather than hypohydration per se. This review discusses these methodological considerations and provides an overview of the small body of recent work that has attempted to correct some of these methodological issues. On balance, these recent blinded hydration studies suggest hypohydration equivalent to 2–3% body mass decreases endurance cycling performance in the heat, at least when no/little fluid is ingested.
Collapse
Affiliation(s)
- Lewis J James
- School of Sport, Exercise and Health Sciences, National Centre for Sport and Exercise Medicine, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK.
| | - Mark P Funnell
- School of Sport, Exercise and Health Sciences, National Centre for Sport and Exercise Medicine, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK
| | - Ruth M James
- Sport, Health and Performance Enhancement Research Centre, School of Science and Technology, Nottingham Trent University, Nottingham, UK
| | - Stephen A Mears
- School of Sport, Exercise and Health Sciences, National Centre for Sport and Exercise Medicine, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK
| |
Collapse
|
20
|
Rampazzo F, Tosi F, Tedeschi P, Gion C, Arcangeli G, Brandolini V, Giovanardi O, Maietti A, Berto D. Preliminary multi analytical approach to address geographic traceability at the intraspecific level in Scombridae family. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2020; 56:260-279. [PMID: 32216466 DOI: 10.1080/10256016.2020.1739671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 01/29/2020] [Indexed: 06/10/2023]
Abstract
Globalization of seafood product marketing caused the increase of request of an effective fish traceability that enhances the consumer confidence in food safety. In this study, an integrated multi analytical approach based on two different and independent analytical techniques (carbon and nitrogen stable isotopes and fatty acids analysis) was applied in order to identify different fish species and trace their geographical provenience. The investigation was focused on four species (Thunnus thynnus, Thunnus alalunga, Auxis rochei and Scomber scombrus) belonging to the Scombridae family. The DNA barcoding method confirmed genus and species for S. scombrus and A. rochei, but only genus for T. alalunga and T. thynnus. Carbon and nitrogen stable isotopes results evidenced different fish diets and trophic positions, whereas fatty acids analysis displayed that the unsaturated prevailed (∼60 %) over the saturated compounds with a variation among the species and the geographical area in particular for docosahexaenoic and eicosapentaenoic acids percentage. The principal component analysis applied to stable isotopes and fatty acids evidenced a good discrimination among species and their geographical catching area. This multi-disciplinary analytical approach could represent a promising tool to identify the commercial fish and trace their origin in order to guarantee the health of consumers.
Collapse
Affiliation(s)
- Federico Rampazzo
- Italian National Institute for Environmental Protection and Research (ISPRA), Chioggia (VE), Italy
| | - Federica Tosi
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro (PD), Italy
| | - Paola Tedeschi
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara (FE), Ferrara (FE), Italy
| | - Claudia Gion
- Italian National Institute for Environmental Protection and Research (ISPRA), Chioggia (VE), Italy
| | - Giuseppe Arcangeli
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro (PD), Italy
| | - Vincenzo Brandolini
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara (FE), Ferrara (FE), Italy
| | - Otello Giovanardi
- Italian National Institute for Environmental Protection and Research (ISPRA), Chioggia (VE), Italy
| | - Annalisa Maietti
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara (FE), Ferrara (FE), Italy
| | - Daniela Berto
- Italian National Institute for Environmental Protection and Research (ISPRA), Chioggia (VE), Italy
| |
Collapse
|
21
|
Ito H, Kabayma S, Goto K. Effects of electrolyzed hydrogen water ingestion during endurance exercise in a heated environment on body fluid balance and exercise performance. Temperature (Austin) 2020; 7:290-299. [PMID: 33117861 PMCID: PMC7575226 DOI: 10.1080/23328940.2020.1742056] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Electrolyzed hydrogen water (EHW) is generated at a cathode. It contains many hydrogen molecules with high alkaline properties. The physiological effects of ingesting EHW during endurance exercise are unclear. The purpose of this study was to determine the effects of ingesting EHW during endurance exercise in a heated environment on body fluid balance and exercise performance. Twelve triathletes (20.0 ± 1.3 years, 171 ± 6 cm, 60.6 ± 3.9 kg, V̇O2max 67.1 ± 3.8 mL/kg/min) performed pedaling exercise for 60 min at 65% of V̇O2max consuming either purified water (CON trial) or EHW (EHW trial) and then conducted an incremental pedaling test. Blood parameters, tissue temperature, and respiratory variables were determined during 60 min of exercise. The time to exhaustion (TTE) during the incremental pedaling test was also determined. Body weights were 1.1 ± 0.4 kg lower after exercise, with no significant differences between trials. Plasma volume and serum osmolality and blood sodium and potassium concentrations significantly changed with exercise, but no significant differences were observed between trials. The pH, blood lactate and bicarbonate concentrations, and changes in skin and muscle temperature did not significantly differ between the two trials. Energy expenditure during exercise was significantly (P = 0.04) lower in the EHW trial (13.2 ± 0.5 kcal/min) than in the CON trial (13.7 ± 0.4 kcal/min). TTE did not significantly differ between the trials. In conclusion, EHW ingestion during endurance exercise in a heated environment decreased energy expenditure but did not affect body fluid balance or exercise performance. Abbreviations: CON: control trial; CV: coefficient of variation; EHW: electrolyzed hydrogen water; HR: heart rate; RPE: rating of perceived exertion; SE: standard error; TP: total protein; TTE: time to exhaustion.
Collapse
Affiliation(s)
- Hiroto Ito
- Graduate School of Sport and Health Science, Ritsumeikan University, Shiga, Japan
| | | | - Kazushige Goto
- Graduate School of Sport and Health Science, Ritsumeikan University, Shiga, Japan
| |
Collapse
|
22
|
Abstract
People undertaking prolonged vigorous exercise experience substantial bodily fluid losses due to thermoregulatory sweating. If these fluid losses are not replaced, endurance capacity may be impaired in association with a myriad of alterations in physiological function, including hyperthermia, hyperventilation, cardiovascular strain with reductions in brain, skeletal muscle and skin blood perfusion, greater reliance on muscle glycogen and cellular metabolism, alterations in neural activity and, in some conditions, compromised muscle metabolism and aerobic capacity. The physiological strain accompanying progressive exercise-induced dehydration to a level of ~ 4% of body mass loss can be attenuated or even prevented by: (1) ingesting fluids during exercise, (2) exercising in cold environments, and/or (3) working at intensities that require a small fraction of the overall body functional capacity. The impact of dehydration upon physiological function therefore depends on the functional demand evoked by exercise and environmental stress, as cardiac output, limb blood perfusion and muscle metabolism are stable or increase during small muscle mass exercise or resting conditions, but are impaired during whole-body moderate to intense exercise. Progressive dehydration is also associated with an accelerated drop in perfusion and oxygen supply to the human brain during submaximal and maximal endurance exercise. Yet their consequences on aerobic metabolism are greater in the exercising muscles because of the much smaller functional oxygen extraction reserve. This review describes how dehydration differentially impacts physiological function during exercise requiring low compared to high functional demand, with an emphasis on the responses of the human brain, heart and skeletal muscles.
Collapse
|
23
|
The Effects of Dehydration on Metabolic and Neuromuscular Functionality During Cycling. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17041161. [PMID: 32059577 PMCID: PMC7068562 DOI: 10.3390/ijerph17041161] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/06/2020] [Accepted: 02/10/2020] [Indexed: 11/17/2022]
Abstract
This study aimed to determine the effects of dehydration on metabolic and neuromuscular functionality performance during a cycling exercise. Ten male subjects (age 23.4 ± 2.7 years; body weight 74.6 ± 10.4 kg; height 177.3 ± 4.6 cm) cycled at 65% VO2max for 60 min followed by a time-to-trial (TT) at 95% VO2max, in two different conditions: dehydration (DEH) and hydration (HYD). The bioelectrical impedance vector analysis (BIVA) and body weight measurements were performed to assess body fluid changes. Heart rate (HR), energy cost, minute ventilation, oxygen uptake, and metabolic power were evaluated during the experiments. In addition, neuromuscular activity of the vastus medialis and biceps femoris muscles were assessed by surface electromyography. After exercise induced dehydration, the bioimpedance vector significantly lengthens along the major axis of the BIVA graph, in conformity with the body weight change (-2%), that indicates a fluid loss. Metabolic and neuromuscular parameters significantly increased during TT at 95% VO2max with respect to constant workload at 65% of VO2max. Dehydration during a one-hour cycling test and subsequent TT caused a significant increase in HR, while neuromuscular function showed a lower muscle activation in dehydration conditions on both constant workload and on TT. Furthermore, a significant difference between HYD and DEH for TT duration was found.
Collapse
|
24
|
Hosick PA, Sheris A, Alencewicz JS, Matthews EL. Mild dehydration following voluntary water intake reduction does not affect anaerobic power performance. J Sports Med Phys Fitness 2020; 60:361-366. [PMID: 31958003 DOI: 10.23736/s0022-4707.19.10166-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Dehydration is common among athletes. The negative impact of dehydration on aerobic performance is well characterized. However, little is known about the effect of dehydration on anaerobic performance particularly when dehydration results from insufficient water intake, not water loss due to body temperature regulation. The purpose of this study was to examine the effect of dehydration on anaerobic performance following voluntary water intake reduction. METHODS Fifteen healthy adults completed two exercise sessions, euhydrated (EUD) and dehydrated (DEH). Sessions consisted of baseline anthropometric and blood lactate measurement followed by a 30-second Wingate test and three vertical jump trials to measure anaerobic performance. Additional blood lactate measurements were taken immediately and at 5, 10, and 15 minutes after taking the Wingate test. RESULTS The dehydration protocol resulted in a reduction in body mass (EUD 69.1±17.2 kg, DEH 68.1±16.6 kg, P=0.039). The 30-s Wingate peak power (EUD 971±302 W, DEH 960±316 W, P=0.578) was not different between conditions, nor was the vertical jump height (EUH 26.4±4.5 cm, DEH 26.6±3.6 cm, P=0.778). Blood lactate (P<0.001) was elevated immediately following the 30-s Wingate test which remained throughout the trial. There were no differences in blood lactate between conditions. CONCLUSIONS Acute anaerobic power and exercise performance is not negatively affected by voluntary dehydration.
Collapse
Affiliation(s)
- Peter A Hosick
- Department of Exercise Science and Physical Education, Montclair State University, Montclair, NJ, USA -
| | - Arielle Sheris
- Department of Exercise Science and Physical Education, Montclair State University, Montclair, NJ, USA
| | - Jacklyn S Alencewicz
- Department of Exercise Science and Physical Education, Montclair State University, Montclair, NJ, USA
| | - Evan L Matthews
- Department of Exercise Science and Physical Education, Montclair State University, Montclair, NJ, USA
| |
Collapse
|
25
|
Gonzalez-Rivas PA, Chauhan SS, Ha M, Fegan N, Dunshea FR, Warner RD. Effects of heat stress on animal physiology, metabolism, and meat quality: A review. Meat Sci 2019; 162:108025. [PMID: 31841730 DOI: 10.1016/j.meatsci.2019.108025] [Citation(s) in RCA: 185] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 10/15/2019] [Accepted: 11/26/2019] [Indexed: 12/22/2022]
Abstract
Heat stress is one of the most stressful events in the life of livestock with harmful consequences for animal health, productivity and product quality. Ruminants, pigs and poultry are susceptible to heat stress due to their rapid metabolic rate and growth, high level of production, and species-specific characteristics such as rumen fermentation, sweating impairment, and skin insulation. Acute heat stress immediately before slaughter stimulates muscle glycogenolysis and can result in pale, soft and exudative (PSE) meat characterized by low water holding capacity (WHC). By contrast, animals subjected to chronic heat stress, have reduced muscle glycogen stores resulting in dark, firm and dry (DFD) meat with high ultimate pH and high WHC. Furthermore, heat stress leads to oxidative stress, lipid and protein oxidation, and reduced shelf life and food safety due to bacterial growth and shedding. This review discusses the scientific evidence regarding the effects of heat stress on livestock physiology and metabolism, and their consequences for meat quality and safety.
Collapse
Affiliation(s)
- Paula A Gonzalez-Rivas
- School of Agriculture and Food, Faculty of Veterinary and Agricultural Science, The University of Melbourne, Parkville, VIC 3010, Australia.
| | - Surinder S Chauhan
- School of Agriculture and Food, Faculty of Veterinary and Agricultural Science, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Minh Ha
- School of Agriculture and Food, Faculty of Veterinary and Agricultural Science, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Narelle Fegan
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organization, 39 Kessels Road, Coopers Plains, QLD 4108, Australia
| | - Frank R Dunshea
- School of Agriculture and Food, Faculty of Veterinary and Agricultural Science, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Robyn D Warner
- School of Agriculture and Food, Faculty of Veterinary and Agricultural Science, The University of Melbourne, Parkville, VIC 3010, Australia
| |
Collapse
|
26
|
Impact of Pre-exercise Hypohydration on Aerobic Exercise Performance, Peak Oxygen Consumption and Oxygen Consumption at Lactate Threshold: A Systematic Review with Meta-analysis. Sports Med 2019; 50:581-596. [DOI: 10.1007/s40279-019-01223-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
27
|
Tan XR, Low ICC, Stephenson MC, Kok T, Nolte HW, Soong TW, Lee JKW. Altered brain structure with preserved cortical motor activity after exertional hypohydration: a MRI study. J Appl Physiol (1985) 2019; 127:157-167. [DOI: 10.1152/japplphysiol.00081.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypohydration exceeding 2% body mass can impair endurance capacity. It is postulated that the brain could be perturbed by hypohydration, leading to impaired motor performance. We investigated the neural effects of hypohydration with magnetic resonance imaging (MRI). Ten men were dehydrated to approximately −3% body mass by running on a treadmill at 65% maximal oxygen consumption (V̇o2max) before drinking to replace either 100% [euhydration (EU)] or 0% [hypohydration (HH)] of fluid losses. MRI was performed before start of trial (baseline) and after rehydration phase (post) to evaluate brain structure, cerebral perfusion, and functional activity. Endurance capacity assessed with a time-to-exhaustion run at 75% V̇o2max was reduced with hypohydration (EU: 45.2 ± 9.3 min, HH: 38.4 ± 10.7 min; P = 0.033). Mean heart rates were comparable between trials (EU: 162 ± 5 beats/min, HH: 162 ± 4 beats/min; P = 0.605), but the rate of rise in rectal temperature was higher in HH trials (EU: 0.06 ± 0.01°C/min, HH: 0.07 ± 0.02°C/min; P < 0.01). In HH trials, a reduction in total brain volume (EU: +0.7 ± 0.6%, HH: −0.7 ± 0.9%) with expansion of ventricles (EU: −2.7 ± 1.6%, HH: +3.7 ± 3.3%) was observed, and vice versa in EU trials. Global and regional cerebral perfusion remained unchanged between conditions. Functional activation in the primary motor cortex in left hemisphere during a plantar-flexion task was similar between conditions (EU: +0.10 ± 1.30%, HH: −0.11 ± 0.31%; P = 0.637). Our findings demonstrate that with exertional hypohydration, brain volumes were altered but the motor-related functional activity was unperturbed. NEW & NOTEWORTHY Dehydration occurs rapidly during prolonged or intensive physical activity, leading to hypohydration if fluid replenishment is insufficient to replace sweat losses. Altered hydration status poses an osmotic challenge for the brain, leading to transient fluctuations in brain tissue and ventricle volumes. Therefore, the amount of fluid ingestion during exercise plays a critical role in preserving the integrity of brain architecture. These structural changes, however, did not translate directly to motor functional deficits in a simple motor task.
Collapse
Affiliation(s)
- X. R. Tan
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- National University of Singapore Graduate School for Integrative Sciences and Engineering, Singapore, Singapore
| | - I. C. C. Low
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - M. C. Stephenson
- Clinical Imaging Research Centre, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - T. Kok
- Clinical Imaging Research Centre, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - H. W. Nolte
- Movement Physiology Research Laboratory, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand Medical School, Johannesburg, South Africa
| | - T. W. Soong
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- National University of Singapore Graduate School for Integrative Sciences and Engineering, Singapore, Singapore
| | - J. K. W. Lee
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Orthopaedic Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Global Asia Institute, National University of Singapore, Singapore, Singapore
- N.1 Institute for Health, National University of Singapore, Singapore, Singapore
| |
Collapse
|
28
|
Stroh MA, Winter MK, McCarson KE, Thyfault JP, Zhu H. NCB5OR Deficiency in the Cerebellum and Midbrain Leads to Dehydration and Alterations in Thirst Response, Fasted Feeding Behavior, and Voluntary Exercise in Mice. THE CEREBELLUM 2019; 17:152-164. [PMID: 28887630 DOI: 10.1007/s12311-017-0880-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cytosolic NADH-cytochrome-b5-oxidoreductase (NCB5OR) is ubiquitously expressed in animal tissues. We have previously reported that global ablation of NCB5OR in mice results in early-onset lean diabetes with decreased serum leptin levels and increased metabolic and feeding activities. The conditional deletion of NCB5OR in the mouse cerebellum and midbrain (conditional knock out, CKO mice) results in local iron dyshomeostasis and altered locomotor activity. It has been established that lesion to or removal of the cerebellum leads to changes in nutrient organization, visceral response, feeding behavior, and body weight. This study assessed whether loss of NCB5OR in the cerebellum and midbrain altered feeding or metabolic activity and had an effect on serum T3, cortisol, prolactin, and leptin levels. Metabolic cage data revealed that 16 week old male CKO mice had elevated respiratory quotients and decreased respiratory water expulsion, decreased voluntary exercise, and altered feeding and drinking behavior compared to wild-type littermate controls. Most notably, male CKO mice displayed higher consumption of food during refeeding after a 48-h fast. Echo MRI revealed normal body composition but decreased total water content and hydration ratios in CKO mice. Increased serum osmolality measurements confirmed the dehydration status of male CKO mice. Serum leptin levels were significantly elevated in male CKO mice while prolactin, T3, and cortisol levels remain unchanged relative to wild-type controls, consistent with elevated transcript levels for leptin receptors (short form) in the male CKO mouse cerebellum. Taken together, these findings suggest altered feeding response post starvation as a result of NCB5OR deficiency in the cerebellum.
Collapse
Affiliation(s)
- Matthew A Stroh
- Landon Center on Aging, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,Neuroscience Graduate Program, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,Department of Neurology, Washington University in St. Louis School of Medicine, St. Louis, MO, 63110, USA
| | - Michelle K Winter
- Kansas Intellectual and Developmental Disabilities Research Center, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Kenneth E McCarson
- Kansas Intellectual and Developmental Disabilities Research Center, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - John P Thyfault
- Department of Molecular Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,Research Service, Kansas City VA Medical Center, Kansas City, MO, 64128, USA
| | - Hao Zhu
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA. .,Neuroscience Graduate Program, University of Kansas Medical Center, Kansas City, KS, 66160, USA. .,Department of Clinical Laboratory Sciences, University of Kansas Medical Center, 3901 Rainbow Blvd., MSN 4048G-Eaton, Kansas City, KS, 66160, USA.
| |
Collapse
|
29
|
Performance Effects of Carbohydrate Ingestion Between Bouts of Intense Aerobic Interval Exercise. Int J Sports Physiol Perform 2019; 15:262-267. [PMID: 31188694 DOI: 10.1123/ijspp.2019-0239] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
PURPOSE This study tested whether CHO intake during a 2-h rest between exercise bouts improved performance in the subsequent bout. METHODS In a randomized, single-blinded, crossover design, 10 recreationally-active participants (23 ± 4 yr, 70.8 ± 6.6 kg, VO2peak:47.0 ± 5.4 mL O2·min-1·kg body mass-1) arrived at the lab post-prandial and completed 2 exercise bouts separated by 2-h rest. Bouts included 5 x 4-min intervals at ~80% VO2peak separated by 2-min at ~40% VO2peak and ended with an endurance trial (ET) to voluntary exhaustion at ~90% VO2peak. During intervals 1 and 4 in each bout expired gases were collected and O2 deficit was estimated. Immediately following bout-1, either a CHO (1.2 g CHO·kg body mass-1) or placebo (PL) solution was consumed. RESULTS ET duration decreased in bout-2 vs. 1 in both conditions (P<0.01) but was ~35% longer in bout-2 with CHO vs. PL (Interaction, P=0.03; post-hoc, P=0.03). VO2 increased during interval 4 vs. 1 in both bouts (P<0.01) but was unaffected by CHO (P≥0.58). O2 deficit was unaffected by CHO (P=0.93), bout or interval (P≥0.15). Perceived exertion was higher in bout-2 vs. 1 (P<0.001) and reduced in intervals 2 and 4 in CHO (P≤0.01). CONCLUSIONS When rest between training sessions is 2 hours, athletes may improve subsequent performance by consuming CHO during recovery. Supported by NSERC, Canada.
Collapse
|
30
|
Funnell MP, Mears SA, Bergin-Taylor K, James LJ. Blinded and unblinded hypohydration similarly impair cycling time trial performance in the heat in trained cyclists. J Appl Physiol (1985) 2019; 126:870-879. [DOI: 10.1152/japplphysiol.01026.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Knowledge of hydration status may contribute to hypohydration-induced exercise performance decrements; therefore, this study compared blinded and unblinded hypohydration on cycling performance. Fourteen trained, nonheat-acclimated cyclists (age: 25 ± 5 yr; V̇o2peak: 63.3 ± 4.7 ml·kg−1·min−1; cycling experience: 6 ± 3 yr) were pair matched to blinded (B) or unblinded (UB) groups. After familiarization, subjects completed euhydrated (B-EUH; UB-EUH) and hypohydrated (B-HYP; UB-HYP) trials in the heat (31°C); 120-min cycling preload (50% Wpeak) and a time trial (~15 min). During the preload of all trials, 0.2 ml water·kg body mass−1 was ingested every 10 min, with additional water provided during EUH trials to match sweat losses. To blind the B group, a nasogastric tube was inserted in both trials and used to provide water in B-EUH. The preload induced similar ( P = 0.895) changes in body mass between groups (B-EUH: −0.6 ± 0.5%; B-HYP: −3.0 ± 0.5%; UB-EUH: −0.5 ± 0.3%; UB-HYP −3.0 ± 0.3%). All variables responded similarly between B and UB groups ( P ≥ 0.558), except thirst ( P = 0.004). Changes typical of hypohydration (increased heart rate, rating of perceived exertion, gastrointestinal temperature, serum osmolality and thirst, and decreased plasma volume; P ≤ 0.017) were apparent in HYP by 120 min. Time trial performance was similar between groups ( P = 0.710) and slower ( P ≤ 0.013) with HYP for B (B-EUH: 903 ± 89 s; B-HYP: 1,008 ± 121 s; −11.4%) and UB (UB-EUH: 874 ± 108 s; UB-HYP: 967 ± 170 s; −10.1%). Hypohydration of ~3% body mass impairs time trial performance in the heat, regardless of knowledge of hydration status. NEW & NOTEWORTHY This study demonstrates, for the first time, that knowledge of hydration status does not exacerbate the negative performance consequences of hypohydration when hypohydration is equivalent to ~3% body mass. This is pivotal for the interpretation of the many previous studies that have not blinded subjects to their hydration status and suggests that these previous studies are not likely to be confounded by the overtness of the methods used to induce hypohydration.
Collapse
Affiliation(s)
- Mark P. Funnell
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, United Kingdom
| | - Stephen A. Mears
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, United Kingdom
| | - Kurt Bergin-Taylor
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, United Kingdom
| | - Lewis J. James
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, United Kingdom
| |
Collapse
|
31
|
Relationship Between Various Training-Load Measures in Elite Cyclists During Training, Road Races, and Time Trials. Int J Sports Physiol Perform 2019; 14:493-500. [DOI: 10.1123/ijspp.2017-0722] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Purpose: The relationship between various training-load (TL) measures in professional cycling is not well explored. This study investigated the relationship between mechanical energy spent (in kilojoules), session rating of perceived exertion (sRPE), Lucia training impulse (LuTRIMP), and training stress score (TSS) in training, races, and time trials (TT). Methods: For 4 consecutive years, field data were collected from 21 professional cyclists and categorized as being collected in training, racing, or TTs. Kilojoules (kJ) spent, sRPE, LuTRIMP, and TSS were calculated, and the correlations between the various TLs were made. Results: 11,655 sessions were collected, from which 7596 sessions had heart-rate data and 5445 sessions had an RPE score available. The r between the various TLs during training was almost perfect. The r between the various TLs during racing was almost perfect or very large. The r between the various TLs during TTs was almost perfect or very large. For all relationships between TSS and 1 of the other measurements of TL (kJ spent, sRPE, and LuTRIMP), a significant different slope was found. Conclusion: kJ spent, sRPE, LuTRIMP, and TSS all have a large or almost perfect relationship with each other during training, racing, and TTs, but during racing, both sRPE and LuTRIMP have a weaker relationship with kJ spent and TSS. Furthermore, the significant different slope of TSS vs the other measurements of TL during training and racing has the effect that TSS collected in training and road races differs by 120%, whereas the other measurements of TL (kJ spent, sRPE, and LuTRIMP) differ by only 73%, 67%, and 68%, respectively.
Collapse
|
32
|
Logan-Sprenger HM. Fluid balance and thermoregulatory responses of competitive triathletes. J Therm Biol 2019; 79:69-72. [PMID: 30612687 DOI: 10.1016/j.jtherbio.2018.12.003] [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] [Received: 09/24/2018] [Revised: 11/05/2018] [Accepted: 12/09/2018] [Indexed: 11/28/2022]
Abstract
As little as 2% total body mass (BM) loss from sweat has been shown to compromise physiological functioning during prolonged exercise in the heat, subsequently compromising endurance performance. PURPOSE This observational study aims to describe the fluid balance and thermoregulatory responses of competitive triathletes racing at a major international competition in a cool environment. METHODS Fluid balance and thermoregulatory responses was measured in six (3 male, 3 female) national-level triathletes competing at the ITU World Triathlon Grand Finale in ambient temperatures of 19-20 °C (relative humidity (RH) ~55%). Dry, nude BM was recorded before and immediately following the race. Fluid intake was monitored throughout the race. Pre-race urine samples were measured for specific gravity (USG). Each athlete ingested a core temperature (Tc) pill 5 h prior to the event and was monitored before and after the race. RESULTS Three of six triathletes arrived at the race mildly dehydrated (USG 1.021,1.024,1.030). One of these athletes (1F) subsequently withdrew from the race providing no further data. Another athlete (1M) ended the race vomiting providing invalid hydration data. The four remaining competitors' sweat loss was on average 2.15 L (range: 1.65-2.80 L), while fluid intake was 0.66 L (0.50-0.85 L). A mean loss of 3.3% (2.2-4.5%) BM was recorded. Tc increased by 2.0 °C (1.1-2.9 °C) and 4/5 athletes' (2 M, 2 F) Tc exceeded 39 °C by race-end. Both female athletes self-reported feelings of heat-related exhaustion at the completion of the race. CONCLUSIONS Despite cool environmental conditions, elite triathletes lost ~3.3% BM, replacing only 33% of sweat losses, and achieved a Tc > 39 °C by race-end.
Collapse
Affiliation(s)
- Heather M Logan-Sprenger
- University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, Canada L1H 7K4.
| |
Collapse
|
33
|
Scrivin R, Black K. Sports Drinks Consumed During Exercise, Which Affect Thermoregulation and/or Athletic Performance in the Heat: A Review. Strength Cond J 2018. [DOI: 10.1519/ssc.0000000000000394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
34
|
O’Connell SM, Woodman RJ, Brown IL, Vincent DJ, Binder HJ, Ramakrishna BS, Young GP. Comparison of a sports-hydration drink containing high amylose starch with usual hydration practice in Australian rules footballers during intense summer training. J Int Soc Sports Nutr 2018; 15:46. [PMID: 30241477 PMCID: PMC6150988 DOI: 10.1186/s12970-018-0253-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 09/14/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Fluid deficits exceeding 1.6% can lead to physical and cognitive impairment in athletes. Sport drinks used by athletes are often hyper-osmolar but this is known to be suboptimal for rehydration in medical settings and does not utilize colonic absorptive capacity. Colonic absorption can be enhanced by fermentative production of short chain fatty acids (SCFA) from substrates such as high amylose maize starch (HAMS). This study therefore compared, in elite Australian Football League (AFL) players at the height of outdoor summer training, a novel dual-action sports oral rehydration strategy that contained HAMS as well as glucose, to their usual rehydration practices (Control). The primary outcome markers of hydration were hematocrit and body weight. METHODS A randomized single-blind crossover study was undertaken in thirty-one AFL players; twenty-seven completed the study which was conducted on four days (two days in the Intervention arm and two in Control arm). The Intervention arm was comprised a 50-100 g evening preload of an acetylated HAMS (Ingredion Pty Ltd) followed by consumption of a specially formulated sports oral rehydration solution (SpORS) drink during intense training and recovery. Players followed their usual hydration routine in the Control arm. Quantitative assessments of body weight, hematocrit and urine specific gravity were made at three time-points on each day of training: pre-training, post-training (90 min), and at end of recovery (30-60 min later). GPS tracking monitored player exertion. RESULTS Across the three time-points, hematocrit was significantly lower and body weight significantly higher in Intervention compared to Control arms (p < 0.02 and p = 0.001 respectively, mixed effects model). Weights were significantly heavier at all three assessment points for Intervention compared to Control arms (Δ = 0.30 ± 0.13, p = 0.02 pre-training; Δ = 0.43 ± 0.14, p = 0.002 post training; and Δ = 0.68 ± 0.14, p < 0.001 for recovery). Between the pre-training and end-of-recovery assessments, the Control arm lost 0.80 kg overall compared with 0.12 kg in the Intervention arm, an 85% lower reduction of bodyweight across the assessment period. CONCLUSION The combination of the significantly lower hematocrit and increased body weight in the Intervention arm represents better hydration not only at the end of training as well as following a recovery period but also at its commencement. The magnitude of the benefit seems sufficient to have an impact on performance and further studies to test this possibility are now indicated. TRIAL REGISTRATION Trial is listed on the Australian New Zealand Clinical Trials Registry ( ACTRN 12613001373763 ).
Collapse
Affiliation(s)
| | - Richard John Woodman
- Flinders Centre for Epidemiology and Biostatistics, Flinders University, GPO Box 2100, 5001 Adelaide, Australia
| | - Ian Lewis Brown
- Flinders Centre for Innovation in Cancer, Flinders University, Adelaide, SA Australia
| | | | - Henry Joseph Binder
- Department of Internal Medicine, Yale School of Medicine, P.O. Box 208019, New Haven, CT 06520 USA
| | | | - Graeme Paul Young
- Flinders Centre for Innovation in Cancer, Flinders University, Adelaide, SA Australia
| |
Collapse
|
35
|
Ayotte D, Corcoran MP. Individualized hydration plans improve performance outcomes for collegiate athletes engaging in in-season training. J Int Soc Sports Nutr 2018; 15:27. [PMID: 29866199 PMCID: PMC5987390 DOI: 10.1186/s12970-018-0230-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 05/17/2018] [Indexed: 11/16/2022] Open
Abstract
Background Athletes commonly consume insufficient fluid and electrolytes just prior to, or during training and competition. Unlike non-athletes or athletes who do not engage in frequent rigorous and prolonged training sessions, “hard trainers” may require additional sodium and better benefit from a hydration plan tailored to their individual physiology. The purpose of this randomized cross-over study was to determine whether a hydration plan based off of an athlete’s sweat rate and sodium loss improves anaerobic and neurocognitive performance during a moderate to hard training session as well as heart rate recovery from this session. Methods Collegiate athletes who were injury free and could exercise at ≥ 75% of their maximum heart rate for a minimum of 45 min were recruited for this randomized, cross-over study. After completing a questionnaire assessing hydration habits, participants were randomized either to a prescription hydration plan (PHP), which considered sweat rate and sodium loss or instructed to follow their normal ad libitum hydration habits (NHP) during training. Attention and awareness, as well as lower body anaerobic power (standing long jump) were assessed immediately before and after a moderate to hard training session of ≥ 45 min. Heart rate recovery was also measured. After a washout period of 7 days, the PHP group repeated the training bout with their normal hydration routine, while the NHP group were provided with a PHP plan and were assessed as previously described. Results Fifteen athletes from three different sports, aged 20 ± 0.85 years, participated in this study. Most participants reported feeling somewhat or very dehydrated after a typical training session. Compared to their NHP, participants following a PHP jumped 4.53 ± 3.80 in. farther, tracked moving objects 0.36 ± 0.60 m/second faster, and exhibited a faster heart rate recovery following a moderate to hard training session of 45–120 min in duration. Conclusion A tailored hydration plan, based on an athlete’s fluid and sodium loss has the potential to improve anaerobic power, attention and awareness, and heart rate recovery time.
Collapse
Affiliation(s)
- David Ayotte
- Department of Health Sciences, Merrimack College, O'Reilly Hall, Room 414, 315 Turnpike Street, North Andover, MA, 01845, USA
| | - Michael P Corcoran
- Department of Health Sciences, Merrimack College, O'Reilly Hall, Room 414, 315 Turnpike Street, North Andover, MA, 01845, USA.
| |
Collapse
|
36
|
Buoite Stella A, Yardley J, Francescato MP, Morrison SA. Fluid Intake Habits in Type 1 Diabetes Individuals during Typical Training Bouts. ANNALS OF NUTRITION AND METABOLISM 2018; 73:10-18. [PMID: 29843124 DOI: 10.1159/000489823] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 04/30/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND/AIMS Hyperglycemia may influence the hydration status in diabetic individuals. During exercise, type 1 diabetes mellitus (T1DM) individuals may be challenged by a higher risk of dehydration due to a combination of fluid losses from sweat and increased urine output via glycosuria. So far, no study has characterised spontaneous fluid intake in T1DM individuals during active trainings. METHODS A validated questionnaire was used to assess T1DM participants' diabetes therapy, sports characteristics and fluid intake during training; results were then compared to an age- and sport-matched sample of non-diabetic individuals. RESULTS Ninety individuals completed the survey (n = 45 T1DM individuals, n = 45 matched controls). A proportion of T1DM -individuals reported blood glucose levels greater than 10.0 mmol at both the start (28.9%) and end (24.4%) of the exercise. The mean self-reported fluid intake was greater in T1DM (0.60 ± 0.47 L·h-1) compared to that of the control (0.37 ± 0.28 L·h-1, p < 0.05). In spite of drinking fluid volumes in line with international guidelines, 84.4% of those with T1DM reported that they were still feeling thirsty at the end of their training session. CONCLUSIONS T1DM individuals self-report spontaneously consuming fluid adequate volumes suggested by sport nutrition guidelines for non-diabetic athletes. Discrepancies in the T1DM subjectively reported feelings of thirst suggest that more education on hydration during exercise is needed for this population to adequately compensate for elevated blood glucose levels. It remains to be established whether fluid volumes suggested for healthy athletes are adequate for maintaining euhydration in T1DM patients due to their altered diuresis.
Collapse
Affiliation(s)
- Alex Buoite Stella
- Department of Medicine, University of Udine, Udine, Italy.,Department of Medicine, Surgery, and Health Sciences, University of Trieste, Trieste, Italy
| | - Jane Yardley
- Department of Social Sciences, Augustana Campus, University of Alberta, Edmonton, Alberta, Canada
| | | | | |
Collapse
|
37
|
de Melo-Marins D, Souza-Silva AA, da Silva-Santos GLL, Freire-Júnior FDA, Lee JKW, Laitano O. Personalized Hydration Strategy Attenuates the Rise in Heart Rate and in Skin Temperature Without Altering Cycling Capacity in the Heat. Front Nutr 2018; 5:22. [PMID: 29707541 PMCID: PMC5907529 DOI: 10.3389/fnut.2018.00022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 03/22/2018] [Indexed: 11/13/2022] Open
Abstract
The optimal hydration plan [i.e., drink to thirst, ad libitum (ADL), or personalized plan] to be adopted during exercise in recreational athletes has recently been a matter of debate and, due to conflicting results, consensus does not exist. In the present investigation, we tested whether a personalized hydration strategy based on sweat rate would affect cardiovascular and thermoregulatory responses and exercise capacity in the heat. Eleven recreational male cyclists underwent two familiarization cycling sessions in the heat (34°C, 40% RH) where sweat rate was also determined. A fan was used to enhance sweat evaporation. Participants then performed three randomized time-to-exhaustion (TTE) trials in the heat with different hydration strategies: personalized volume (PVO), where water was consumed, based on individual sweat rate, every 10 min; ADL, where free access to water was allowed; and a control (CON) trial with no fluids. Blood osmolality and urine-specific gravity were measured before each trial. Heart rate (HR), rectal, and skin temperatures were monitored throughout trials. Time to exhaustion at 70% of maximal workload was used to define exercise capacity in the heat, which was similar in all trials (p = 0.801). Body mass decreased after ADL (p = 0.008) and CON (p < 0.001) and was maintained in PVO trials (p = 0.171). Participants consumed 0 ml in CON, 166 ± 167 ml in ADL, and 1,080 ± 166 ml in PVO trials. The increase in mean body temperature was similar among trials despite a lower increase in skin temperature during PVO trial in comparison with CON (2.1 ± 0.6 vs. 2.9 ± 0.5°C, p = 0.0038). HR was lower toward the end of TTE in PVO (162 ± 8 bpm) in comparison with ADL (168 ± 12 bpm) and CON (167 ± 10 bpm), p < 0.001. In conclusion, a personalized hydration strategy can reduce HR during a moderate to high intensity exercise session in the heat and halt the increase in skin temperature. Despite these advantages, cycling capacity in the heat remained unchanged.
Collapse
Affiliation(s)
- Denise de Melo-Marins
- College of Physical Education, Federal University of Vale do São Francisco (UNIVASF), Petrolina, Brazil
| | - Ana Angélica Souza-Silva
- College of Physical Education, Federal University of Vale do São Francisco (UNIVASF), Petrolina, Brazil
| | | | | | - Jason Kai Wei Lee
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Orlando Laitano
- College of Physical Education, Federal University of Vale do São Francisco (UNIVASF), Petrolina, Brazil
| |
Collapse
|
38
|
James LJ, Moss J, Henry J, Papadopoulou C, Mears SA. Hypohydration impairs endurance performance: a blinded study. Physiol Rep 2018. [PMID: 28637708 PMCID: PMC5492205 DOI: 10.14814/phy2.13315] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The general scientific consensus is that starting exercise with hypohydration >2% body mass impairs endurance performance/capacity, but most previous studies might be confounded by a lack of subject blinding. This study examined the effect of hypohydration in a single blind manner using combined oral and intragastric rehydration to manipulate hydration status. After familiarization, seven active males (mean ± SD: age 25 ± 2 years, height 1.79 ± 0.07, body mass 78.6 ± 6.2, VO2peak 48 ± 7 mL·kg·min-1) completed two randomized trials at 34°C. Trials involved an intermittent exercise preload (8 × 15 min exercise/5 min rest), followed by a 15-min all-out performance test on a cycle ergometer. During the preload, water was ingested orally every 10 min (0.2 mL·kg body mass-1). Additional water was infused into the stomach via a gastric feeding tube to replace sweat loss (EU) or induce hypohydration of ~2.5% body mass (HYP). Blood samples were drawn and thirst sensation rated before, during, and after exercise. Body mass loss during the preload was greater (2.4 ± 0.2% vs. 0.1 ± 0.1%; P < 0.001), while work completed during the performance test was lower (152 ± 24 kJ vs. 165 ± 22 kJ; P < 0.05) during HYP At the end of the preload, heart rate, RPE, serum osmolality, and thirst were greater and plasma volume lower during HYP (P < 0.05). These results provide novel data demonstrating that exercise performance in the heat is impaired by hypohydration, even when subjects are blinded to the intervention.
Collapse
Affiliation(s)
- Lewis J James
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, LE11 3TU, United Kingdom
| | - Jodie Moss
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, LE11 3TU, United Kingdom
| | - Joshua Henry
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, LE11 3TU, United Kingdom
| | - Charikleia Papadopoulou
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, LE11 3TU, United Kingdom
| | - Stephen A Mears
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, LE11 3TU, United Kingdom
| |
Collapse
|
39
|
Kanter M. High-Quality Carbohydrates and Physical Performance: Expert Panel Report. NUTRITION TODAY 2018; 53:35-39. [PMID: 29449746 PMCID: PMC5794245 DOI: 10.1097/nt.0000000000000238] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
While all experts agreed that protein needs for performance are likely greater than believed in past generations, particularly for strength training athletes, and that dietary fat could sustain an active person through lower-intensity training bouts, current research still points to carbohydrate as an indispensable energy source for high-intensity performance.
Collapse
Affiliation(s)
- Mitch Kanter
- is the chief science officer with FoodMinds, a division of Padilla, in Chicago IL. He leads nutrition research and scientific projects and programming for FoodMinds clients. He also leads the FoodMinds Global Expert Bench , a group of nutrition scientists and technical communications experts from around the world who provide strategic counsel to FoodMinds clients on various international projects. During his 25-plus years in the food industry, he has served in various technical leadership roles for a number of multinational companies
| |
Collapse
|
40
|
Green JM, Miller B, Simpson J, Dubroc D, Keyes A, Neal K, Gann J, Andre T. Effects of 2% Dehydration on Lactate Concentration During Constant-Load Cycling. J Strength Cond Res 2017; 32:2066-2071. [PMID: 29239983 DOI: 10.1519/jsc.0000000000002293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Green, JM, Miller, B, Simpson, J, Dubroc, D, Keyes, A, Neal, K, Gann, J, and Andre, T. Effects of 2% dehydration on lactate concentration during constant-load cycling. J Strength Cond Res 32(7): 2066-2071, 2018-The lactate [La] threshold (LT) can predict endurance performance potential. Dehydration may alter LT. This study examined effects of dehydration on [La] response during constant-load cycling. Recreationally fit (V[Combining Dot Above]O2peak = 48.7 ± 5.2 ml·kg·min) male participants (n = 9) completed 2 × 40-minute constant-load cycling trials; euhydrated (HYD) and after previous evening passive (water bath) dehydration (2% body weight, DEH) (HYD and DEH counterbalanced). Lactate, heart rate (HR), 10-point Omni ratings of perceived exertion (RPE), and rectal temperature (Trec) were measured after warm-up (WU) and at 10, 20, 30, and 40 minutes. Before cycling, urine specific gravity (USG) was measured and participants estimated perceived recovery status (PRS). Urine specific gravity DEH (1.027 ± 0.004) was significantly greater than HYD (1.013 ± 0.007). After WU, [La] was significantly greater (all time points) for DEH (∼4.1 mmol·L) vs. HYD (∼3.5 mmol·L) with similar results for HR (DEH: ∼167, HYD: ∼158 b·min). For DEH, RPE was significantly greater (∼1 unit) at 20, 30, and 40 minutes, and Trec was significantly greater at 30 and 40 minutes (∼0.4° C). DEH (vs. HYD) also resulted in significantly different resting HR (93 ± 6, vs. 85 ± 7 b·min), significantly greater session RPE (7.7 ± 1.1 vs. 5.3 ± 1.1), and significantly lower subjective feelings of recovery (PRS = 6.4 ± 2.9, vs. 9.0 ± 1.5). Current results indicate systematic changes in [La] and associated physiological responses result from previous day dehydration. Hydration status should be a concern in paradigms where [La] assessment is used.
Collapse
Affiliation(s)
- James M Green
- Department of HPER, University of North Alabama, Florence, Alabama.,School of Kinesiology, Recreation and Sport, Western Kentucky University, Bowling Green, Kentucky
| | - Brandon Miller
- Department of Kinesiology, Mississippi State University, Starkville, Mississippi
| | - Jeffrey Simpson
- Department of Kinesiology, Mississippi State University, Starkville, Mississippi
| | - Danielle Dubroc
- Department of HPER, University of North Alabama, Florence, Alabama
| | - Anthony Keyes
- Department of HPER, University of North Alabama, Florence, Alabama
| | - Kailee Neal
- Department of HPER, University of North Alabama, Florence, Alabama
| | - Josh Gann
- Department of Kinesiology, University of Louisiana-Monroe, Monroe, Louisiana
| | - Tom Andre
- Department of Health and Fitness Management, Clayton State University, Morrow, Georgia
| |
Collapse
|
41
|
Heat adaptation from regular hot water immersion decreases proinflammatory responses, HSP70 expression, and physical heat stress. J Therm Biol 2017; 69:95-103. [DOI: 10.1016/j.jtherbio.2017.06.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 06/09/2017] [Accepted: 06/30/2017] [Indexed: 01/13/2023]
|
42
|
Barrington JH, Chrismas BCR, Gibson OR, Tuttle J, Pegrum J, Govilkar S, Kabir C, Giannakakis N, Rayan F, Okasheh Z, Sanaullah A, Ng Man Sun S, Pearce O, Taylor L. Hypoxic Air Inhalation and Ischemia Interventions Both Elicit Preconditioning Which Attenuate Subsequent Cellular Stress In vivo Following Blood Flow Occlusion and Reperfusion. Front Physiol 2017; 8:560. [PMID: 28824456 PMCID: PMC5539087 DOI: 10.3389/fphys.2017.00560] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 07/18/2017] [Indexed: 12/17/2022] Open
Abstract
Ischemic preconditioning (IPC) is valid technique which elicits reductions in femoral blood flow occlusion mediated reperfusion stress (oxidative stress, Hsp gene transcripts) within the systemic blood circulation and/or skeletal muscle. It is unknown whether systemic hypoxia, evoked by hypoxic preconditioning (HPC) has efficacy in priming the heat shock protein (Hsp) system thus reducing reperfusion stress following blood flow occlusion, in the same manner as IPC. The comparison between IPC and HPC being relevant as a preconditioning strategy prior to orthopedic surgery. In an independent group design, 18 healthy men were exposed to 40 min of (1) passive whole-body HPC (FiO2 = 0.143; no ischemia. N = 6), (2) IPC (FiO2 = 0.209; four bouts of 5 min ischemia and 5 min reperfusion. n = 6), or (3) rest (FiO2 = 0.209; no ischemia. n = 6). The interventions were administered 1 h prior to 30 min of tourniquet derived femoral blood flow occlusion and were followed by 2 h subsequent reperfusion. Systemic blood samples were taken pre- and post-intervention. Systemic blood and gastrocnemius skeletal muscle samples were obtained pre-, 15 min post- (15PoT) and 120 min (120PoT) post-tourniquet deflation. To determine the cellular stress response gastrocnemius and leukocyte Hsp72 mRNA and Hsp32 mRNA gene transcripts were determined by RT-qPCR. The plasma oxidative stress response (protein carbonyl, reduced glutathione/oxidized glutathione ratio) was measured utilizing commercially available kits. In comparison to control, at 15PoT a significant difference in gastrocnemius Hsp72 mRNA was seen in HPC (−1.93-fold; p = 0.007) and IPC (−1.97-fold; p = 0.006). No significant differences were observed in gastrocnemius Hsp32 and Hsp72 mRNA, leukocyte Hsp72 and Hsp32 mRNA, or oxidative stress markers (p > 0.05) between HPC and IPC. HPC provided near identical amelioration of blood flow occlusion mediated gastrocnemius stress response (Hsp72 mRNA), compared to an established IPC protocol. This was seen independent of changes in systemic oxidative stress, which likely explains the absence of change in Hsp32 mRNA transcripts within leukocytes and the gastrocnemius. Both the established IPC and novel HPC interventions facilitate a priming of the skeletal muscle, but not leukocyte, Hsp system prior to femoral blood flow occlusion. This response demonstrates a localized tissue specific adaptation which may ameliorate reperfusion stress.
Collapse
Affiliation(s)
- James H Barrington
- Institute of Sport and Physical Activity Research, University of BedfordshireLuton, United Kingdom
| | - Bryna C R Chrismas
- Sport Science Program, College of Arts and Sciences, Qatar UniversityDoha, Qatar
| | - Oliver R Gibson
- Division of Sport, Health and Exercise Sciences, Department of Life Sciences, Centre for Human Performance, Exercise and Rehabilitation, Brunel University LondonUxbridge, United Kingdom
| | - James Tuttle
- Institute of Sport and Physical Activity Research, University of BedfordshireLuton, United Kingdom
| | - J Pegrum
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - S Govilkar
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - Chindu Kabir
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - N Giannakakis
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - F Rayan
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - Z Okasheh
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - A Sanaullah
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - S Ng Man Sun
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - Oliver Pearce
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - Lee Taylor
- ASPETAR, Athlete Health and Performance Research Centre, Qatar Orthopedic and Sports Medicine HospitalDoha, Qatar.,School of Sport, Exercise and Health Sciences. Loughborough UniversityLoughborough, United Kingdom
| |
Collapse
|
43
|
Gibson OR, Tuttle JA, Watt PW, Maxwell NS, Taylor L. Hsp72 and Hsp90α mRNA transcription is characterised by large, sustained changes in core temperature during heat acclimation. Cell Stress Chaperones 2016; 21:1021-1035. [PMID: 27511024 PMCID: PMC5083671 DOI: 10.1007/s12192-016-0726-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/15/2016] [Accepted: 07/19/2016] [Indexed: 12/19/2022] Open
Abstract
Increased intracellular heat shock protein-72 (Hsp72) and heat shock protein-90α (Hsp90α) have been implicated as important components of acquired thermotolerance, providing cytoprotection during stress. This experiment determined the physiological responses characterising increases in Hsp72 and Hsp90α mRNA on the first and tenth day of 90-min heat acclimation (in 40.2 °C, 41.0 % relative humidity (RH)) or equivalent normothermic training (in 20 °C, 29 % RH). Pearson's product-moment correlation and stepwise multiple regression were performed to determine relationships between physiological [e.g. (Trec, sweat rate (SR) and heart rate (HR)] and training variables (exercise duration, exercise intensity, work done), and the leukocyte Hsp72 and Hsp90α mRNA responses via reverse transcription quantitative polymerase chain reaction (RT-QPCR) (n = 15). Significant (p < 0.05) correlations existed between increased Hsp72 and Hsp90α mRNA (r = 0.879). Increased core temperature was the most important criteria for gene transcription with ΔTrec (r = 0.714), SR (r = 0.709), Trecfinal45 (r = 0.682), area under the curve where Trec ≥ 38.5 °C (AUC38.5 °C; r = 0.678), peak Trec (r = 0.661), duration Trec ≥ 38.5 °C (r = 0.650) and ΔHR (r = 0.511) each demonstrating a significant (p < 0.05) correlation with the increase in Hsp72 mRNA. The Trec AUC38.5 °C (r = 0.729), ΔTrec (r = 0.691), peak Trec (r = 0.680), Trecfinal45 (r = 0.678), SR (r = 0.660), duration Trec ≥ 38.5 °C (r = 0.629), the rate of change in Trec (r = 0.600) and ΔHR (r = 0.531) were the strongest correlate with the increase in Hsp90α mRNA. Multiple regression improved the model for Hsp90α mRNA only, when Trec AUC38.5 °C and SR were combined. Training variables showed insignificant (p > 0.05) weak (r < 0.300) relationships with Hsp72 and Hsp90α mRNA. Hsp72 and Hsp90α mRNA correlates were comparable on the first and tenth day. When transcription of the related Hsp72 and Hsp90α mRNA is important, protocols should rapidly induce large, prolonged changes in core temperature.
Collapse
Affiliation(s)
- Oliver R Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, Uxbridge, UK.
- Centre for Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, Welkin Human Performance Laboratories, University of Brighton, Denton Road, Eastbourne, UK.
| | - James A Tuttle
- Muscle Cellular and Molecular Physiology (MCMP) and Applied Sport and Exercise Science (ASEP) Research Groups, Institute of Sport and Physical Activity Research (ISPAR), University of Bedfordshire, Bedford, UK
| | - Peter W Watt
- Centre for Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, Welkin Human Performance Laboratories, University of Brighton, Denton Road, Eastbourne, UK
| | - Neil S Maxwell
- Centre for Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, Welkin Human Performance Laboratories, University of Brighton, Denton Road, Eastbourne, UK
| | - Lee Taylor
- Athlete Health and Performance Research Centre, ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| |
Collapse
|
44
|
Kuhlenhoelter AM, Kim K, Neff D, Nie Y, Blaize AN, Wong BJ, Kuang S, Stout J, Song Q, Gavin TP, Roseguini BT. Heat therapy promotes the expression of angiogenic regulators in human skeletal muscle. Am J Physiol Regul Integr Comp Physiol 2016; 311:R377-91. [PMID: 27357800 DOI: 10.1152/ajpregu.00134.2016] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 06/12/2016] [Indexed: 01/08/2023]
Abstract
Heat therapy has been shown to promote capillary growth in skeletal muscle and in the heart in several animal models, but the effects of this therapy on angiogenic signaling in humans are unknown. We evaluated the acute effect of lower body heating (LBH) and unilateral thigh heating (TH) on the expression of angiogenic regulators and heat shock proteins (HSPs) in healthy young individuals. Exposure to LBH (n = 18) increased core temperature (Tc) from 36.9 ± 0.1 to 37.4 ± 0.1°C (P < 0.01) and average leg skin temperature (Tleg) from 33.1 ± 0.1 to 39.6 ± 0.1°C (P < 0.01), but did not alter the levels of circulating angiogenic cytokines and bone marrow-derived proangiogenic cells (CD34(+)CD133(+)). In skeletal muscle, the change in mRNA expression from baseline of vascular endothelial growth factor (VEGF), angiopoietin 2 (ANGPT2), chemokines CCL2 and CX3CL1, platelet factor-4 (PF4), and several members of the HSP family was higher 30 min after the intervention in the individuals exposed to LBH (n = 11) compared with the control group (n = 12). LBH also reduced the expression of transcription factor FOXO1 (P = 0.03). Exposure to TH (n = 14) increased Tleg from 32.8 ± 0.2 to 40.3 ± 0.1°C (P < 0.05) but Tc remained unaltered (36.8 ± 0.1°C at baseline and 36.9 ± 0.1°C at 90 min). This intervention upregulated the expression of VEGF, ANGPT1, ANGPT2, CCL2, and HSPs in skeletal muscle but did not affect the levels of CX3CL1, FOXO-1, and PF4. These findings suggest that both LBH and TH increase the expression of factors associated with capillary growth in human skeletal muscle.
Collapse
Affiliation(s)
| | - Kyoungrae Kim
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana
| | - Dustin Neff
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana
| | - Yaohui Nie
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana; Department of Animal Sciences, Purdue University, West Lafayette, Indiana
| | - A Nicole Blaize
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana
| | - Brett J Wong
- Department of Kinesiology and Health, Georgia State University, Atlanta, Georgia
| | - Shihuan Kuang
- Department of Animal Sciences, Purdue University, West Lafayette, Indiana
| | - Julianne Stout
- Indiana University School of Medicine-Lafayette, West Lafayette, Indiana; and
| | - Qifan Song
- Department of Statistics, Purdue University, West Lafayette, Indiana
| | - Timothy P Gavin
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana
| | - Bruno T Roseguini
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana;
| |
Collapse
|