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DiMarco KG, Chapman CL, Weiser NE, Matsell ER, Lucernoni KM, Chacon S, Grivette MMB, Halliwill JR, Lovering AT, Minson CT. Acute exposure to carbon monoxide inhalation and/or hot water immersion transiently increases erythropoietin in females but not in males. Exp Physiol 2024; 109:1782-1795. [PMID: 39143855 PMCID: PMC11442759 DOI: 10.1113/ep091923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 07/24/2024] [Indexed: 08/16/2024]
Abstract
The use of acute carbon monoxide inhalation (COi) and hot water immersion (HWI) are of growing interest as interventions to stimulate erythropoietin (EPO) production. However, whether EPO production is further augmented when combining these stressors and whether there are sex differences in this response are poorly understood. Therefore, we measured circulating EPO concentration in response to acute COi and HWI independently and in combination and determined whether the responses were altered by sex. Participants completed three study visits-COi, HWI, and combined COi and HWI-separated by 1 week in a randomized, balanced, crossover design. Renal blood velocity was measured during all interventions, and carboxyhaemoglobin was measured during and after COi. Serum samples were analysed every hour for 6 h post-intervention for EPO concentration. HWI decreased renal blood velocity (46.2 cm/s to 36.2 cm/s) (P < 0.0001), and COi increased carboxyhaemoglobin (1.5%-12.8%) (P < 0.0001) without changing renal blood velocity (46.4-45.2 cm/s) (P = 0.4456). All three interventions increased peak EPO concentration from baseline (COi: 6.02-9.74 mIU/mL; HWI: 6.80-11.10 mIU/mL; COi + HWI: 6.71-10.91 mIU/mL) (P = 0.0048) and to the same extent (P = 0.3505). On average, females increased EPO while males did not in response to COi (females: 6.17 mIU/mL; males: 1.27 mIU/mL) (P = 0.0010), HWI (females: 6.47 mIU/mL; males: 2.14 mIU/mL) (P = 0.0104), and COi and HWI (females: 6.65 mIU/mL; males: 1.76 mIU/mL) (P = 0.0256). These data emphasize that combining these interventions does not augment EPO secretion and that these interventions may work better in females.
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Affiliation(s)
- Kaitlyn G DiMarco
- Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | | | - Natasha E Weiser
- Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Emma R Matsell
- Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | | | - Samantha Chacon
- Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | | | - John R Halliwill
- Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Andrew T Lovering
- Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
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Webb KL, González-Alonso J. Heat and carbon monoxide exposure: Is two better than one? Exp Physiol 2024; 109:1627-1628. [PMID: 39173128 PMCID: PMC11442776 DOI: 10.1113/ep092198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2024] [Accepted: 08/08/2024] [Indexed: 08/24/2024]
Affiliation(s)
- Kevin L Webb
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - José González-Alonso
- Sport, Health and Exercise Sciences, Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, UK
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Thompson KMA, Pethick WA, Clarke J, Winegarden A, Johnson E, Coates AM, Stellingwerff T, Burr JF. Blood Flow-Restricted Training and Time Trial Performance: A Cohort Study of World-Class Rowers. Med Sci Sports Exerc 2024; 56:1606-1614. [PMID: 38619968 DOI: 10.1249/mss.0000000000003459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
INTRODUCTION This study aimed to explore the potential impact of incorporating blood flow restriction (BFR) training within a training block characterized by minimal high-intensity work on 2000-m rowing ergometer time trial (TT) performance in elite/world-class rowers. Physiological markers often associated with endurance performance (maximal aerobic capacity, V̇O 2max ; blood lactate thresholds and hemoglobin mass, Hb mass ) were measured to determine whether changes are related to an improvement in performance. METHODS Using a quasi-experimental, observational study design (no control group), 2000-m TT performance, V̇O 2max , submaximal work rates eliciting blood lactate concentrations of ~2 and ~4 mmol·L -1 , and Hb mass were measured before and after 4 wk of noncompetitive season training, which included BFR rowing. BFR training consisted of 11 sessions of 2 × 10 min of BFR rowing at a workload equating to blood lactate concentrations of ~2 mmol·L -1 . Paired t -tests were used to compare pre-/postvalues, and Pearson correlation was used to examine whether physiological changes were associated with changes to TT performance. RESULTS TT performance improved in both female (1.09% ± 1.2%, ~4.6 ± 5.2 s; P < 0.01) and male (1.17% ± 0.48%, ~4.5 ± 1.9 s; P < 0.001) athletes. V̇O 2max increased in female rowers only ( P < 0.01), but both sexes had an increase in work rates eliciting blood lactate concentrations of 2 mmol·L -1 (female: 184 ± 16 to 195 ± 15 W, P < 0.01; male: 288 ± 23 to 317 ± 26 W, P = 0.04) and 4 mmol·L -1 (female: 217 ± 13 to 227 ± 14 W, P = 0.02; male: 339 ± 43 to 364 ± 39 W, P < 0.01). No changes in Hb mass (both sexes, P = 0.8) were observed. Improvements in TT performance were not related to physiological changes (all correlations P ≥ 0.2). CONCLUSIONS After 4 wk of training with BFR, the improvement in TT performance was greater than what is typical for this population. Physiological variables improved during this training block but did not explain improved TT performance.
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Affiliation(s)
- Kyle M A Thompson
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, CANADA
| | - Wendy A Pethick
- Canadian Sport Institute-Pacific, Victoria, British Columbia, CANADA
| | - Jordan Clarke
- Rowing Canada Aviron National Training Centre, North Cowichan, British Columbia, CANADA
| | - Anneke Winegarden
- Canadian Sport Institute-Pacific, Victoria, British Columbia, CANADA
| | - Elizabeth Johnson
- Canadian Sport Institute-Pacific, Victoria, British Columbia, CANADA
| | - Alexandra M Coates
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, CANADA
| | | | - Jamie F Burr
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, CANADA
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Mirto M, Filipas L, Altini M, Codella R, Meloni A. Heart Rate Variability in Professional and Semiprofessional Soccer: A Scoping Review. Scand J Med Sci Sports 2024; 34:e14673. [PMID: 38859758 DOI: 10.1111/sms.14673] [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: 11/23/2023] [Revised: 05/18/2024] [Accepted: 05/20/2024] [Indexed: 06/12/2024]
Abstract
In modern soccer, fitness and fatigue monitoring tools tend to be focused on noninvasive, time-efficient and player-friendly measures. Heart rate variability (HRV) has been suggested as an effective method for monitoring training response and readiness to perform. However, there is still a lack of consensus on HRV monitoring when it comes to soccer. Thus, this scoping review aims to map existing evidence on HRV in professional and semiprofessional soccer settings, and to identify knowledge gaps to inform future research directions. A search of databases (PubMed, Scopus, Web of Science, Google Scholar) according to the PRISMA-ScR statement was employed. Studies were screened for eligibility on inclusion criteria: (1) HRV was among the topics discussed in the article; (2) adult professional or semiprofessional soccer players were involved in the study; (3) both male and female participants; (4) no geographical area exclusion; (5) articles published in English; and (6) article full text available. The search of the selected databases revealed 8456 records. The titles and abstracts of all articles were retrieved for screening of eligibility, leaving 30 articles for further consideration. Following screening against set criteria, a total of 25 studies were included in this review, the sample size of which ranged from 6 to 124 participants. The participants in the included studies were professional and semiprofessional soccer players, interviewed clubs staff, and practitioners. Along with other monitoring strategies, morning vagally mediated HRV analysis via (ultra)short-term orthostatic measurements may be an efficient way to assess training adaptations and readiness to perform in professional and semiprofessional soccer players. Further research is required to make definitive recommendations.
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Affiliation(s)
- Mauro Mirto
- Department of Biomedical Sciences for Health, Università Degli Studi di Milano, Milan, Italy
| | - Luca Filipas
- Department of Biomedical Sciences for Health, Università Degli Studi di Milano, Milan, Italy
| | - Marco Altini
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Roberto Codella
- Department of Biomedical Sciences for Health, Università Degli Studi di Milano, Milan, Italy
| | - Andrea Meloni
- Department of Biomedical Sciences for Health, Università Degli Studi di Milano, Milan, Italy
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Francisco R, Jesus F, Nunes CL, Santos P, Alvim M, Campa F, Schoeller DA, Lukaski H, Mendonca GV, Sardinha LFCB, Silva AMLDA. H2OAthletes study protocol: effects of hydration changes on neuromuscular function in athletes. Br J Nutr 2024; 131:1579-1590. [PMID: 38299306 DOI: 10.1017/s0007114524000308] [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] [Indexed: 02/02/2024]
Abstract
We aim to understand the effects of hydration changes on athletes' neuromuscular performance, on body water compartments, fat-free mass hydration and hydration biomarkers and to test the effects of the intervention on the response of acute dehydration in the hydration indexes. The H2OAthletes study (clinicaltrials.gov ID: NCT05380089) is a randomised controlled trial in thirty-eight national/international athletes of both sexes with low total water intake (WI) (i.e. < 35·0 ml/kg/d). In the intervention, participants will be randomly assigned to the control (CG, n 19) or experimental group (EG, n 19). During the 4-day intervention, WI will be maintained in the CG and increased in the EG (i.e. > 45·0 ml/kg/d). Exercise-induced dehydration protocols with thermal stress will be performed before and after the intervention. Neuromuscular performance (knee extension/flexion with electromyography and handgrip), hydration indexes (serum, urine and saliva osmolality), body water compartments and water flux (dilution techniques, body composition (four-compartment model) and biochemical parameters (vasopressin and Na) will be evaluated. This trial will provide novel evidence about the effects of hydration changes on neuromuscular function and hydration status in athletes with low WI, providing useful information for athletes and sports-related professionals aiming to improve athletic performance.
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Affiliation(s)
- Rúben Francisco
- Exercise and Health Laboratory, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, 1499-002 Cruz-Quebrada, Lisbon, Portugal
| | - Filipe Jesus
- Exercise and Health Laboratory, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, 1499-002 Cruz-Quebrada, Lisbon, Portugal
| | - Catarina L Nunes
- Exercise and Health Laboratory, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, 1499-002 Cruz-Quebrada, Lisbon, Portugal
| | - Paulo Santos
- Neuromuscular Research Lab, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal
| | - Marta Alvim
- National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - Francesco Campa
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Dale A Schoeller
- Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Henry Lukaski
- Department of Kinesiology and Public Health Education, Hyslop Sports Center, University of North Dakota, Grand Forks, ND, USA
| | - Goncalo V Mendonca
- Neuromuscular Research Lab, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal
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Dunn RA, Fry LA, Sekiguchi Y, Benjamin CL, Manning CN, Huggins RA, Stearns RL, Casa DJ. Effect of Heat Acclimatization, Heat Acclimation, and Intermittent Heat Training on Maximal Oxygen Uptake. Sports Health 2024:19417381241249470. [PMID: 38708678 DOI: 10.1177/19417381241249470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2024] Open
Abstract
BACKGROUND Maximal oxygen uptake (VO2max) is an important determinant of endurance performance. Heat acclimation/acclimatization (HA/HAz) elicits improvements in endurance performance. Upon heat exposure reduction, intermittent heat training (IHT) may alleviate HA/HAz adaptation decay; however, corresponding VO2max responses are unknown. HYPOTHESIS VO2max is maintained after HAz/HA; IHT mitigates decrements in aerobic power after HAz/HA. STUDY DESIGN Interventional study. LEVEL OF EVIDENCE Level 3. METHODS A total of 27 male endurance runners (mean ± SD; age, 36 ± 12 years; body mass, 73.03 ± 8.97 kg; height, 178.81 ± 6.39 cm) completed VO2max testing at 5 timepoints; baseline, post-HAz, post-HA, and weeks 4 and 8 of IHT (IHT4, IHT8). After baseline testing, participants completed HAz, preceded by 5 days of HA involving exercise to induce hyperthermia for 60 minutes in the heat (ambient temperature, 39.13 ± 1.37°C; relative humidity, 51.08 ± 8.42%). Participants were assigned randomly to 1 of 3 IHT groups: once-weekly, twice-weekly, or no IHT. Differences in VO2max, velocity at VO2max (vVO2), and maximal heart rate (HRmax) at all 5 timepoints were analyzed using repeated-measure analyses of variance with Bonferroni corrections post hoc. RESULTS No significant VO2max or vVO2 differences were observed between baseline, post-HAz, or post-HA (P = 0.36 and P = 0.09, respectively). No significant group or time effects were identified for VO2max or vVO2 at post-HA, IHT4, and IHT8 (P = 0.67 and P = 0.21, respectively). Significant HRmax differences were observed between baseline and post-HA tests (P < 0.01). No significant group or time HRmax differences shown for post-HA, IHT4, and IHT8 (P = 0.59). CONCLUSION VO2max was not reduced among endurance runners after HA/HAz and IHT potentially due to participants' similar aerobic training status and high aerobic fitness levels. CLINICAL RELEVANCE HAz/HA and IHT maintain aerobic power in endurance runners, with HAz/HA procuring reductions in HRmax.
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Affiliation(s)
- Ryan A Dunn
- Sports Performance Laboratory, Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, Texas
| | - Lauren A Fry
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, Connecticut
| | - Yasuki Sekiguchi
- Sports Performance Laboratory, Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, Texas and Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, Connecticut
| | - Courteney L Benjamin
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, Connecticut and Department of Kinesiology, Samford University, Birmingham, Alabama
| | - Ciara N Manning
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, Connecticut
| | - Robert A Huggins
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, Connecticut
| | - Rebecca L Stearns
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, Connecticut
| | - Douglas J Casa
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, Connecticut
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Girard O, Peeling P, Racinais S, Périard JD. Combining Heat and Altitude Training to Enhance Temperate, Sea-Level Performance. Int J Sports Physiol Perform 2024; 19:322-327. [PMID: 38237571 DOI: 10.1123/ijspp.2023-0250] [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: 06/28/2023] [Revised: 11/29/2023] [Accepted: 12/18/2023] [Indexed: 03/01/2024]
Abstract
BACKGROUND Repeated exposure to heat (ie, plasma volume expansion) or altitude (ie, increase in total hemoglobin mass), in conjunction with exercise, induces hematological adaptations that enhance endurance performance in each respective environment. Recently, combining heat and altitude training has become increasingly common for athletes preparing to compete in temperate, sea-level conditions. PURPOSE To review the physiological adaptations to training interventions combining thermal and hypoxic stimuli and summarize the implications for temperate, sea-level performance. Current Evidence: To date, research on combining heat and hypoxia has employed 2 main approaches: simultaneously combining the stressors during training or concurrently training in the heat and sleeping at altitude, sometimes with additional training in hypoxia. When environmental stimuli are combined in a training session, improvements in aerobic fitness and time-trial performance in temperate, sea-level conditions are generally similar in magnitude to those observed with heat, or altitude, training alone. Similarly, training in the heat and sleeping at altitude does not appear to provide any additional hematological or nonhematological benefits for temperate; sea-level performance relative to training in hot, hypoxic, or control conditions. CONCLUSIONS Current research regarding combined heat and altitude interventions does not seem to indicate that it enhances temperate, sea-level performance to a greater extent than "traditional" (heat or hypoxia alone) training approaches. A major challenge in implementing combined-stressor approaches lies in the uncertainty surrounding the prescription of dosing regimens (ie, exercise and environmental stress). The potential benefits of conducting heat and altitude exposure sequentially (ie, one after the other) warrants further investigation.
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Affiliation(s)
- Olivier Girard
- School of Human Sciences (Exercise and Sport Science), University of Western Australia, Perth, WA, Australia
| | - Peter Peeling
- School of Human Sciences (Exercise and Sport Science), University of Western Australia, Perth, WA, Australia
- Western Australian Institute of Sport, Mt Claremont, WA, Australia
| | - Sébastien Racinais
- Environmental Stress Unit, CREPS Montpellier-Font Romeu, Montpellier, France
| | - Julien D Périard
- Research Institute for Sport and Exercise, University of Canberra, Canberra, ACT, Australia
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Krumm B, Lundby C, Hansen J, Bejder J, Sørensen H, Equey T, Saugy J, Botrè F, Faiss R. Yearly intrasubject variability of hematological biomarkers in elite athletes for the Athlete Biological Passport. Drug Test Anal 2024. [PMID: 38291831 DOI: 10.1002/dta.3645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/18/2023] [Accepted: 01/03/2024] [Indexed: 02/01/2024]
Abstract
Confounding factors including exercise and environments challenge the interpretation of individual Athlete Biological Passports (ABPs). This study aimed to investigate the natural variability of hematological ABP parameters over 1 year in elite athletes compared with healthy control subjects and the validity of a multiparametric model estimating plasma volume (PV) shifts to correct individual ABP thresholds. Blood samples were collected monthly with full blood counts performed by flow cytometry (Sysmex XN analyzers) in 20 elite xc-skiers (ELITE) and 20 moderately trained controls. Individual ABP profiles were generated through Anti-Doping Administration & Management System Training, a standalone version of the ABP's adaptive model developed by the World Anti-Doping Agency. Additionally, eight serum parameters were computed as volume-sensitive biomarkers to run a multiparametric model to estimate PV. Variability in ELITE compared with controls was significantly higher for the Abnormal Blood Profile Scores (P = 0.003). Among 12 Atypical Passport Findings (ATPF) initially reported, six could be removed after correction of PV shifts with the multiparametric modeling. However, several ATPF were additionally generated (n = 19). Our study outlines a larger intraindividual variability in elite athletes, likely explained by more frequent exposure to extrinsic factors altering hematological biomarkers. PV correction for individual ABP thresholds allowed to explain most of the atypical findings while generating multiple new ATPF occurrences in the elite population. Overall, accounting for PV shifts in elite athletes was shown to be paramount in this study outlining the opportunity to consider PV variations with novel approaches when interpreting individual ABP profiles.
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Affiliation(s)
- Bastien Krumm
- REDs, Research & Expertise in antiDoping Sciences, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Carsten Lundby
- Section for Health and Exercise Physiology, Inland University of Applied Sciences, Lillehammer, Norway
- Department of Nutrition, Exercise and Sport, University of Copenhagen, Copenhagen, Denmark
| | - Joar Hansen
- Section for Health and Exercise Physiology, Inland University of Applied Sciences, Lillehammer, Norway
| | - Jacob Bejder
- Department of Nutrition, Exercise and Sport, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Sørensen
- Department of Nutrition, Exercise and Sport, University of Copenhagen, Copenhagen, Denmark
| | - Tristan Equey
- Athlete Biological Passport, Science Department, WADA, World Anti-Doping Agency, Montréal, Quebec, Canada
| | - Jonas Saugy
- REDs, Research & Expertise in antiDoping Sciences, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Francesco Botrè
- REDs, Research & Expertise in antiDoping Sciences, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
- Laboratorio Antidoping, Federazione Medico Sportiva Italiana, Rome, Italy
| | - Raphael Faiss
- REDs, Research & Expertise in antiDoping Sciences, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
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Thompson KMA, Gamble ASD, Kontro H, Lee JB, Burr JF. Low- and high-volume blood-flow restriction treadmill walking both improve maximal aerobic capacity independently of blood volume. Scand J Med Sci Sports 2024; 34:e14534. [PMID: 37961932 DOI: 10.1111/sms.14534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 10/22/2023] [Accepted: 10/26/2023] [Indexed: 11/15/2023]
Abstract
AIM Assess the effect of low- and high-volume blood flow restriction training (BFR) on maximal aerobic capacity (VO2 max) and determine if alteration in VO2 max is mediated through changes in hemoglobin mass (Hbmass) and blood volume. METHODS Participants' Hbmass (CO-rebreathe), single, and double-leg VO2 max and blood volume regulating hormonal responses (renin and copeptin) were measured before and after BFR training. Training consisted of treadmill walking either (1) twice-daily for 4week (CON and BFRHV ) or (2) twice-weekly for 6week (BFRLV ). Each session consisted of five intervals (3 min, 5% incline, 5 km/h, 100% of lowest occlusion pressure), with 1 min of standing rest between sets. RESULTS VO2 max increased using both training exposures, in as quickly as 2-weeks (BFRLV baseline to 4week: +315 ± 241 mL (8.7%), p = 0.02; BFRHV baseline to 2week: +360 ± 261 mL (7.9%), p < 0.01), for the BFRLV and BFRHV groups, with no change in CON. Single- and double-leg VO2 max improved proportionately (single/double-leg VO2 max ratio: BFRLV 78 ± 4.9-78 ± 5.8%, BFRHV 79 ± 6.5-77 ± 6.5%), suggesting that the mechanism for increased VO2 max is not solely limited to central or peripheral adaptations. Hbmass remained unchanged across groups (CON: +10.2 ± 34 g, BFRLV : +6.6 ± 42 g, BFRHV : +3.2 ± 44 g; p = 0.9), despite a significant release of blood volume regulating hormones after initial BFR exposure (renin +20.8 ± 21.9 ng/L, p < 0.01; copeptin +22.0 ± 23.8 pmol/L, p < 0.01), which was blunted following BFRHV training (renin: +13.4 ± 12.4 ng/L, p = 0.09; copeptin: +1.9 ± 1.7 pmol/L, p = 0.98). CONCLUSION BFR treadmill walking increases VO2 max irrespective of changes in Hbmass or blood volume despite a large release of blood volume regulating hormones in response to BFR treadmill walking.
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Affiliation(s)
- K M A Thompson
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - A S D Gamble
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - H Kontro
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - J B Lee
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - J F Burr
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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Nybo L, Rønnestad B, Lundby C. High or hot-Perspectives on altitude camps and heat-acclimation training as preparation for prolonged stage races. Scand J Med Sci Sports 2024; 34:e14268. [PMID: 36350277 DOI: 10.1111/sms.14268] [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: 09/02/2022] [Revised: 10/19/2022] [Accepted: 10/19/2022] [Indexed: 11/11/2022]
Abstract
Adaptation to heat stress and hypoxia are relevant for athletes participating in Tour de France or similar cycling races taking place during the summertime in landscapes with varying altitude. Both to minimize detrimental performance effects associated with arterial desaturation occurring at moderate altitudes in elite athletes, respectively, reduce the risk of hyperthermia on hot days, but also as a pre-competition acclimatization strategy to boost blood volume in already highly adapted athletes. The hematological adaptations require weeks of exposure to manifest, but are attractive as an augmented hemoglobin mass may improve arterial oxygen delivery and hence benefit prolonged performances. Altitude training camps have in this context a long history in exercise physiology and are still common practice in elite cycling. However, heat-acclimation training provides an attractive alternative for some athletes either as a stand-alone approach or in combination with altitude. The present paper provides an update and practical perspectives on the potential to utilize hypoxia and heat exposure to optimize hematological adaptations. Furthermore, we will consider temporal aspects both in terms of onset and decay of the adaptations relevant for improved thermoregulatory capacity and respiratory adaptations to abate arterial desaturation during altitude exposure. From focus on involved physiological mechanisms, time course, and responsiveness in elite athletes, we will provide guidance based on our experience from practical implementation in cyclists preparing for prolonged stage races such as the Tour de France.
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Affiliation(s)
- Lars Nybo
- Department of Nutrition, Exercise and Sport, University of Copenhagen, Copenhagen, Denmark
| | - Bent Rønnestad
- Inland Norway University of Applied Sciences, Lillehammer, Norway
| | - Carsten Lundby
- Inland Norway University of Applied Sciences, Lillehammer, Norway
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Corbett J, Young JS, Tipton MJ, Costello JT, Williams TB, Walker EF, Lee BJ, Stevens CE. Molecular biomarkers for assessing the heat-adapted phenotype: a narrative scoping review. J Physiol Sci 2023; 73:26. [PMID: 37848829 DOI: 10.1186/s12576-023-00882-4] [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: 06/13/2023] [Accepted: 10/03/2023] [Indexed: 10/19/2023]
Abstract
Heat acclimation/acclimatisation (HA) mitigates heat-related decrements in physical capacity and heat-illness risk and is a widely advocated countermeasure for individuals operating in hot environments. The efficacy of HA is typically quantified by assessing the thermo-physiological responses to a standard heat acclimation state test (i.e. physiological biomarkers), but this can be logistically challenging, time consuming, and expensive. A valid molecular biomarker of HA would enable evaluation of the heat-adapted state through the sampling and assessment of a biological medium. This narrative review examines candidate molecular biomarkers of HA, highlighting the poor sensitivity and specificity of these candidates and identifying the current lack of a single 'standout' biomarker. It concludes by considering the potential of multivariable approaches that provide information about a range of physiological systems, identifying a number of challenges that must be overcome to develop a valid molecular biomarker of the heat-adapted state, and highlighting future research opportunities.
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Affiliation(s)
- J Corbett
- Extreme Environments Laboratory, School of Sport Health and Exercise Sciences, University of Portsmouth, Portsmouth, UK.
| | - J S Young
- National Horizons Centre, Teesside University, Darlington, UK
| | - M J Tipton
- Extreme Environments Laboratory, School of Sport Health and Exercise Sciences, University of Portsmouth, Portsmouth, UK
| | - J T Costello
- Extreme Environments Laboratory, School of Sport Health and Exercise Sciences, University of Portsmouth, Portsmouth, UK
| | - T B Williams
- Extreme Environments Laboratory, School of Sport Health and Exercise Sciences, University of Portsmouth, Portsmouth, UK
| | - E F Walker
- Defence Science and Technology Laboratory, Porton Down, Salisbury, UK
| | - B J Lee
- Occupational and Environmental Physiology Group, Centre for Sport, Exercise and Life Sciences, Faculty of Health and Life Sciences, Coventry University, Coventry, UK
| | - C E Stevens
- Extreme Environments Laboratory, School of Sport Health and Exercise Sciences, University of Portsmouth, Portsmouth, UK
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12
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Tebeck ST, Buckley JD, Stanley J. Longitudinal haematological responses to training load and heat acclimation preceding a male team pursuit cycling world record. Eur J Sport Sci 2023; 23:1859-1867. [PMID: 36404735 DOI: 10.1080/17461391.2022.2150896] [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] [Indexed: 11/22/2022]
Abstract
This study evaluated relationships between changes in training load, haematological responses, and endurance exercise performance during temperate and heat acclimation (HA) training preceding a male team cycling pursuit world record (WR). Haemoglobin mass (Hbmass) and concentration ([Hb]), plasma volume (PV) and blood volume (BV) were assessed in nine male track endurance cyclists (∼3 occasions per month) training in temperate conditions (247-142 days prior to the WR) to establish responses to differing acute (ATL) and chronic (CTL) training loads. Testing was performed again pre- and post-HA (22-28 days prior to the WR). Endurance performance (V̇O₂max, 4MMP, lactate threshold 1 and 2) was assessed on three occasions (238-231, 189-182 and 133-126 days prior to the WR). In temperate conditions, CTL was associated with Hbmass (B = 0.62, P = 0.02), PV (B = 4.49, P = 0.01) and BV (B = 6.51, P = 0.04) but not [Hb] (B = -0.01, P = 0.17). ATL was associated with PV (B = 2.28, P < 0.01), BV (B = 2.63, P = 0.04) and [Hb] (B = -0.01, P = 0.04) but not Hbmass (B = 0.10, P = 0.41). During HA, PV increased 8.2% (P < 0.01), while Hbmass, CTL and ATL were unchanged. Hbmass and [Hb] were associated with all performance outcomes (P < 0.05), except V̇O2max. PV and BV were not associated with performance outcomes. During temperate training, changes in Hbmass were most strongly associated with changes in CTL. Both CTL and ATL were associated with changes in PV, but HA was associated with increased PV and maintenance of Hbmass without increasing ATL or CTL. In practical terms, maintaining high CTL and high Hbmass might be beneficial for improving endurance performance.HIGHLIGHTSChanges in haemoglobin mass were associated with endurance exercise performance and changes in chronic training load in temperate conditions.Heat acclimation increased plasma volume and maintained haemoglobin mass independently of chronic training load.Chronic training loads and haemoglobin mass should be increased to improve endurance exercise performance.Heat acclimation may optimise haematological adaptations when training load is reduced.
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Affiliation(s)
- Samuel T Tebeck
- Department of Sports Science, South Australian Sports Institute, Adelaide, Australia
- Alliance for Research in Exercise, Nutrition and Activity (ARENA), UniSA Allied Health & Human Performance, University of South Australia, Adelaide, Australia
| | - Jonathan D Buckley
- Alliance for Research in Exercise, Nutrition and Activity (ARENA), UniSA Allied Health & Human Performance, University of South Australia, Adelaide, Australia
| | - Jamie Stanley
- Department of Sports Science, South Australian Sports Institute, Adelaide, Australia
- Alliance for Research in Exercise, Nutrition and Activity (ARENA), UniSA Allied Health & Human Performance, University of South Australia, Adelaide, Australia
- Australian Cycling Team, Cycling Australia, Adelaide, Australia
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13
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Périard JD, Girard O, Townsend N, Bourdon P, Cocking S, Ihsan M, Lacome M, Nichols D, Travers G, Wilson MG, Piscione J, Racinais S. Hematological Adaptations Following a Training Camp in Hot and/or Hypoxic Conditions in Elite Rugby Union Players. Int J Sports Physiol Perform 2023; 18:1053-1061. [PMID: 37553108 DOI: 10.1123/ijspp.2023-0166] [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: 04/26/2023] [Revised: 06/30/2023] [Accepted: 07/08/2023] [Indexed: 08/10/2023]
Abstract
PURPOSE To investigate the effects of a training camp with heat and/or hypoxia sessions on hematological and thermoregulatory adaptations. METHODS Fifty-six elite male rugby players completed a 2-week training camp with 5 endurance and 5 repeated-sprint sessions, rugby practice, and resistance training. Players were separated into 4 groups: CAMP trained in temperate conditions at sea level, HEAT performed the endurance sessions in the heat, ALTI slept and performed the repeated sprints at altitude, and H + A was a combination of the heat and altitude groups. RESULTS Blood volume across all groups increased by 140 mL (95%CI, 42-237; P = .006) and plasma volume by 97 mL (95%CI 28-167; P = .007) following the training camp. Plasma volume was 6.3% (0.3% to 12.4%) higher in HEAT than ALTI (P = .034) and slightly higher in HEAT than H + A (5.6% [-0.3% to 11.7%]; P = .076). Changes in hemoglobin mass were not significant (P = .176), despite a ∼1.2% increase in ALTI and H + A and a ∼0.7% decrease in CAMP and HEAT. Peak rectal temperature was lower during a postcamp heat-response test in HEAT (0.3 °C [0.1-0.5]; P = .010) and H + A (0.3 °C [0.1-0.6]; P = .005). Oxygen saturation upon waking was lower in ALTI (3% [2% to 5%]; P < .001) and H + A (4% [3% to 6%]; P < .001) than CAMP and HEAT. CONCLUSION Although blood and plasma volume increased following the camp, sleeping at altitude impeded the increase when training in the heat and only marginally increased hemoglobin mass. Heat training induced adaptations commensurate with partial heat acclimation; however, combining heat training and altitude training and confinement during a training camp did not confer concomitant hematological adaptations.
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Affiliation(s)
- Julien D Périard
- Research Institute for Sport and Exercise, University of Canberra, Canberra, ACT,Australia
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
| | - Olivier Girard
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
- School of Human Sciences (Exercise and Sport Science), University of Western Australia, Crawley, WA,Australia
| | - Nathan Townsend
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha,Qatar
| | - Pitre Bourdon
- Department of Sport Science, ASPIRE, Academy for Sports Excellence, Doha,Qatar
- Alliance for Research in Exercise, Nutrition and Activity (ARENA), University of South Australia, Adelaide, SA,Australia
| | - Scott Cocking
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
- Department of Sport Science, ASPIRE, Academy for Sports Excellence, Doha,Qatar
| | - Mohammed Ihsan
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
| | - Mathieu Lacome
- Department of Research, Sport Laboratory, Expertise and Performance, French Institute of Sports (INSEP), Paris,France
- Department of Performance and Analytics, Parma Calcio, Parma,Italy
| | - David Nichols
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
| | - Gavin Travers
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
- Space Medicine Team, European Astronaut Center, Köln,Germany
| | - Mathew G Wilson
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
- Institute of Sport, Exercise and Health, University College London, London,United Kingdom
| | - Julien Piscione
- Department of Research, Sport Laboratory, Expertise and Performance, French Institute of Sports (INSEP), Paris,France
| | - Sebastien Racinais
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
- Department of Research, Sport Laboratory, Expertise and Performance, French Institute of Sports (INSEP), Paris,France
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14
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Breenfeldt Andersen A, Baungaard SB, Bejder J, Graae J, Hristovska AM, Agerskov M, Holm-Sørensen H, Foss NB. A semi-automated device rapidly determine circulating blood volume in healthy males and carbon monoxide uptake kinetics of arterial and venous blood. J Clin Monit Comput 2023; 37:437-447. [PMID: 36201093 DOI: 10.1007/s10877-022-00921-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 09/18/2022] [Indexed: 11/30/2022]
Abstract
We examined whether a semi-automated carbon monoxide (CO) rebreathing method accurately detect changes in blood volume (BV) and total hemoglobin mass (tHb). Furthermore, we investigated whether a supine position with legs raised reduced systemic CO dilution time, potentially allowing a shorter rebreathing period. Nineteen young healthy males participated. BV and tHb was quantified by a 10-min CO-rebreathing period in a supine position with legs raised before and immediately after a 900 ml phlebotomy and before and after a 900 ml autologous blood reinfusion on the same day in 16 subjects. During the first CO-rebreathing, arterial and venous blood samples were drawn every 2 min during the procedure to determine systemic CO equilibrium in all subjects. Phlebotomy decreased (P < 0.001) tHb and BV by 166 ± 24 g and 931 ± 247 ml, respectively, while reinfusion increased (P < 0.001) tHb and BV by 143 ± 21 g and 862 ± 250 ml compared to before reinfusion. After reinfusion BV did not differ from baseline levels while tHb was decreased (P < 0.001) by 36 ± 21 g. Complete CO mixing was achieved within 6 min in venous and arterial blood, respectively, when compared to the 10-min sample. On an individual level, the relative accuracy after donation for tHb and BV was 102-169% and 55-165%, respectively. The applied CO-rebreathing procedure precisely detect acute BV changes with a clinically insignificant margin of error. The 10-min CO-procedure may be reduced to 6 min with no clinical effects on BV and tHb calculation. Notwithstanding, individual differences may be of concern and should be investigated further.
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Affiliation(s)
- Andreas Breenfeldt Andersen
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark.
- Department of Public Health, Section of Sport Science, Aarhus University, Aarhus C, Denmark.
| | - Søren Brouw Baungaard
- Department of Anesthesiology, Hvidovre Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Jacob Bejder
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Jonathan Graae
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Ana-Marija Hristovska
- Department of Anesthesiology, Hvidovre Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Marianne Agerskov
- Department of Anesthesiology, Hvidovre Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Holm-Sørensen
- Department of Anesthesiology, Abdominal Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Nicolai Bang Foss
- Department of Anesthesiology, Hvidovre Hospital, University of Copenhagen, Copenhagen, Denmark
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15
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Peel J, John K, Page J, Scott G, Jeffries O, Heffernan S, Tallent J, Waldron M. Factors contributing to the change in thermoneutral maximal oxygen consumption after iso-intensity heat acclimation programmes. Eur J Sport Sci 2023:1-10. [PMID: 36533403 DOI: 10.1080/17461391.2022.2160278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The factors explaining variance in thermoneutral maximal oxygen uptake (V˙O2max) adaptation to heat acclimation (HA) were evaluated, with consideration of HA programme parameters, biophysical variables and thermo-physiological responses. Seventy-one participants consented to perform iso-intensity training (range: 45%-55% V˙O2max) in the heat (range: 30°C-38°C; 20%-60% relative humidity) on consecutive days (range: 5-days-14-days) for between 50-min and-90 min. The participants were evaluated for their thermoneutral V˙O2max change pre-to-post HA. Participants' whole-body sweat rate, heart rate, core temperature, perceived exertion and thermal sensation and plasma volume were measured, and changes in these responses across the programme determined. Partial least squares regression was used to explain variance in the change in V˙O2max across the programme using 24 variables. Sixty-three percent of the participants increased V˙O2max more than the test error, with a mean ± SD improvement of 2.6 ± 7.9%. A two-component model minimised the root mean squared error and explained the greatest variance (R2; 65%) in V˙O2max change. Eight variables positively contributed (P < 0.05) to the model: exercise intensity (%V˙O2max), ambient temperature, HA training days, total exposure time, baseline body mass, thermal sensation, whole-body mass losses and the number of days between the final day of HA and the post-testing day. Within the ranges evaluated, iso-intensity HA improved V˙O2max 63% of the time, with intensity - and volume-based parameters, alongside sufficient delays in post-testing being important considerations for V˙O2max maximisation. Monitoring of thermal sensation and body mass losses during the programme offers an accessible way to gauge the degree of potential adaptation.
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Affiliation(s)
- Jenny Peel
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK
| | - Kevin John
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK
| | - Joe Page
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK
| | - Georgia Scott
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK
| | - Owen Jeffries
- School of Biomedical, Nutritional and Sport Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - Shane Heffernan
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK
| | - Jamie Tallent
- School of Sport, Rehabilitation, and Exercise Sciences, University of Essex, Colchester, UK.,Department of Physiotherapy, Faculty of Medicine, Nursing and Health Sciences, School of Primary and Allied Health Care, Monash University, Melbourne, Australia
| | - Mark Waldron
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK.,Welsh Institute of Performance Science, Swansea University, Swansea, UK.,School of Health and Behavioural Sciences, University of the Sunshine Coast, Queensland, Australia
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16
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Sitkowski D, Cisoń T, Szygula Z, Surała O, Starczewski M, Sadowska D, Malczewska-Lenczowska J. Hematological Adaptations to Post-Exercise Sauna Bathing With No Fluid Intake: A Randomized Cross-Over Study. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 2022; 93:795-803. [PMID: 34727008 DOI: 10.1080/02701367.2021.1921684] [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: 04/08/2020] [Accepted: 04/21/2021] [Indexed: 06/13/2023]
Abstract
Purpose: Sauna bathing is recommended to improve the sports training process, yet empirical evidence confirming its effectiveness is still inconclusive. We examined the effects of post-exercise sauna bathing on hematological adaptations and exercise capacity in healthy men. Methods: Thirteen physical education students participated in randomized cross-over study: two, 4-week interventions, with 10-week washout. The interventions involved 3 times per week 60-min stationary cycling either with 30-min of post-exercise sauna bathing (89 ± 3°C, 10 ± 2% RH) or without; no fluid was ingested during both exercise and sauna sessions. Before and after both interventions, participants were tested for total hemoglobin mass (tHb-mass), intravascular volumes, erythropoietin, ferritin, red blood cell parameters with reticulocyte fractions, along with maximal/peak and submaximal variables in a graded exercise test (GXT). Results: Regardless of intervention type, tHb-mass increased (p = .014) whereas ferritin concentration decreased (p = .027); however, changes in tHb-mass were within the range of typical error (<1.8%). Absolute and relative values of maximal power and power at gas exchange threshold, as well as peak oxygen uptake (all p < .010), also increased irrespective of intervention type. Conclusions: The use of post-exercise sauna bathing with fluid intake restrictions does not provide any additional benefits in tested variables over endurance training alone. Thus, further evidence is required before recommendations to utilize this post-exercise conditioning strategy are deemed valid.
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Affiliation(s)
| | - Tomasz Cisoń
- State University of Applied Sciences in Nowy Sącz
| | | | - Olga Surała
- Institute of Sport - National Research Institute
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17
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Kellenberger K, Steiner T, Wehrlin JP. Comparison of the automatised and the optimised carbon monoxide rebreathing methods. Scandinavian Journal of Clinical and Laboratory Investigation 2022; 82:474-480. [PMID: 36129418 DOI: 10.1080/00365513.2022.2122078] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Recently, a new automated carbon monoxide (CO) rebreathing method (aCO) to estimate haemoglobin mass (Hbmass) was introduced. The aCO method uses the same CO dilution principle as the widely used optimised CO rebreathing method (oCO). The two methods differ in terms of CO administration, body position, and rebreathing time. Whereas with aCO, CO is administered automatically by the system in a supine position of the subject, with oCO, CO is administered manually by an experienced operator with the subject sitting. Therefore, the aim of this study was to quantify possible differences in Hbmass estimated with the two methods. Hbmass was estimated in 18 subjects (9 females, 9 males) with oCO using capillary blood samples (oCOc) and aCO taking simultaneously venous blood samples (aCOv) and capillary blood samples (aCOc). Overall, Hbmass was different between the three measurement procedures (F = 57.55, p < .001). Hbmass was lower (p < .001) for oCOc (737 g ± 179 g) than for both aCOv (825 g ± 189 g, -9.3%) and aCOc (835 g ± 189 g, -10.6%). There was no difference in Hbmass estimated with aCOv and aCOc procedures (p = .12). Three factors can likely explain the 10% difference in Hbmass: differences in calculations (including a factor for myoglobin flux), body position (distribution of CO in blood circulation) during rebreathing, and time of blood sampling. Moreover, the determination of Hbmass with aCO is possible with capillary blood sampling instead of venous blood sampling.
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Affiliation(s)
- Katja Kellenberger
- Section for Elite Sport, Swiss Federal Institute of Sport, Magglingen, Switzerland
| | - Thomas Steiner
- Section for Elite Sport, Swiss Federal Institute of Sport, Magglingen, Switzerland
| | - Jon Peter Wehrlin
- Section for Elite Sport, Swiss Federal Institute of Sport, Magglingen, Switzerland
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18
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RØNNESTAD BENTR, URIANSTAD TOMAS, HAMARSLAND HÅVARD, HANSEN JOAR, NYGAARD HÅVARD, ELLEFSEN STIAN, HAMMARSTRÖM DANIEL, LUNDBY CARSTEN. Heat Training Efficiently Increases and Maintains Hemoglobin Mass and Temperate Endurance Performance in Elite Cyclists. Med Sci Sports Exerc 2022; 54:1515-1526. [DOI: 10.1249/mss.0000000000002928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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19
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Rønnestad BR, Lid OM, Hansen J, Hamarsland H, Mølmen KS, Nygaard H, Ellefsen S, Hammarström D, Lundby C. Heat suit training increases hemoglobin mass in elite cross-country skiers. Scand J Med Sci Sports 2022; 32:1089-1098. [PMID: 35305278 PMCID: PMC9544462 DOI: 10.1111/sms.14156] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/18/2022] [Accepted: 03/08/2022] [Indexed: 01/29/2023]
Abstract
Purpose The primary purpose was to test the effect of heat suit training on hemoglobin mass (Hbmass) in elite cross‐country (XC) skiers. Methods Twenty‐five male XC‐skiers were divided into a group that added 5 × 50 min weekly heat suit training sessions to their regular training (HEAT; n = 13, 23 ± 5 years, 73.9 ± 5.2 kg, 180 ± 6 cm, 76.8 ± 4.6 ml·min−1·kg−1) or to a control group matched for training volume and intensity distribution (CON; n = 12, 23 ± 4 years, 78.4 ± 5.8 kg, 184 ± 4 cm, 75.2 ± 3.4 ml·min−1·kg−1) during the five‐week intervention period. Hbmass, endurance performance and factors determining endurance performance were assessed before and after the intervention. Results HEAT led to 30 g greater Hbmass (95% CI: [8.5, 51.7], p = 0.009) and 157 ml greater red blood cell volume ([29, 285], p = 0.018) post‐intervention, compared to CON when adjusted for baseline values. In contrast, no group differences were observed for changes in work economy, running velocity, and fractional utilization of maximal oxygen uptake (V̇O2max) at 4 mmol·L−1 blood lactate, V̇O2max or 15‐min running distance performance trial during the intervention. Conclusion HEAT induced a larger increase in Hbmass and red blood cell volume after five weeks with five weekly heat suit training sessions than CON, but with no detectable group differences on physiological determinants of endurance performance or actual endurance performance in elite CX skiers.
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Affiliation(s)
| | - Ole Martin Lid
- Inland University of Applied Sciences, Lillehammer, Norway
| | - Joar Hansen
- Inland University of Applied Sciences, Lillehammer, Norway
| | | | | | - Håvard Nygaard
- Inland University of Applied Sciences, Lillehammer, Norway
| | - Stian Ellefsen
- Inland University of Applied Sciences, Lillehammer, Norway
| | | | - Carsten Lundby
- Inland University of Applied Sciences, Lillehammer, Norway
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20
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Wearable Sensors and Machine Learning for Hypovolemia Problems in Occupational, Military and Sports Medicine: Physiological Basis, Hardware and Algorithms. SENSORS 2022; 22:s22020442. [PMID: 35062401 PMCID: PMC8781307 DOI: 10.3390/s22020442] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/14/2021] [Accepted: 12/30/2021] [Indexed: 11/16/2022]
Abstract
Hypovolemia is a physiological state of reduced blood volume that can exist as either (1) absolute hypovolemia because of a lower circulating blood (plasma) volume for a given vascular space (dehydration, hemorrhage) or (2) relative hypovolemia resulting from an expanded vascular space (vasodilation) for a given circulating blood volume (e.g., heat stress, hypoxia, sepsis). This paper examines the physiology of hypovolemia and its association with health and performance problems common to occupational, military and sports medicine. We discuss the maturation of individual-specific compensatory reserve or decompensation measures for future wearable sensor systems to effectively manage these hypovolemia problems. The paper then presents areas of future work to allow such technologies to translate from lab settings to use as decision aids for managing hypovolemia. We envision a future that incorporates elements of the compensatory reserve measure with advances in sensing technology and multiple modalities of cardiovascular sensing, additional contextual measures, and advanced noise reduction algorithms into a fully wearable system, creating a robust and physiologically sound approach to manage physical work, fatigue, safety and health issues associated with hypovolemia for workers, warfighters and athletes in austere conditions.
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21
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Krumm B, Faiss R. Factors Confounding the Athlete Biological Passport: A Systematic Narrative Review. SPORTS MEDICINE - OPEN 2021; 7:65. [PMID: 34524567 PMCID: PMC8443715 DOI: 10.1186/s40798-021-00356-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 08/28/2021] [Indexed: 11/10/2022]
Abstract
BACKGROUND Through longitudinal, individual and adaptive monitoring of blood biomarkers, the haematological module of the athlete biological passport (ABP) has become a valuable tool in anti-doping efforts. The composition of blood as a vector of oxygen in the human body varies in athletes with the influence of multiple intrinsic (genetic) or extrinsic (training or environmental conditions) factors. In this context, it is fundamental to establish a comprehensive understanding of the various causes that may affect blood variables and thereby alter a fair interpretation of ABP profiles. METHODS This literature review described the potential factors confounding the ABP to outline influencing factors altering haematological profiles acutely or chronically. RESULTS Our investigation confirmed that natural variations in ABP variables appear relatively small, likely-at least in part-because of strong human homeostasis. Furthermore, the significant effects on haematological variations of environmental conditions (e.g. exposure to heat or hypoxia) remain debatable. The current ABP paradigm seems rather robust in view of the existing literature that aims to delineate adaptive individual limits. Nevertheless, its objective sensitivity may be further improved. CONCLUSIONS This narrative review contributes to disentangling the numerous confounding factors of the ABP to gather the available scientific evidence and help interpret individual athlete profiles.
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Affiliation(s)
- Bastien Krumm
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Raphael Faiss
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland.
- Center of Research and Expertise in Anti-Doping Sciences - REDs, University of Lausanne, Lausanne, Switzerland.
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22
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Bartolomé I, Siquier-Coll J, Pérez-Quintero M, Robles-Gil MC, Grijota FJ, Muñoz D, Maynar-Mariño M. 3-Week passive acclimation to extreme environmental heat (100± 3 °C) in dry sauna increases physical and physiological performance among young semi-professional football players. J Therm Biol 2021; 100:103048. [PMID: 34503795 DOI: 10.1016/j.jtherbio.2021.103048] [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: 01/06/2021] [Revised: 05/10/2021] [Accepted: 06/26/2021] [Indexed: 10/21/2022]
Abstract
This manuscript aims to evaluate the influence of a novel passive heat acclimation program among human participants in the physical performance, as well as in several physiological parameters. 36 male football players were acclimated using a dry sauna bath to extreme hot (100 ± 3 °C), performing a total of nine sauna sessions with a weekly frequency of three sessions. The players were randomly into the sauna group (SG; n = 18; age: 20.69 ± 2.09 years) and the control group (CG; n = 18; age: 20.23 ± 1.98 years). All participants performed maximal effort test until exhaustion as well as hamstring flexibility test before and after the acclimation program. Anthropometric, respiratory, circulatory, hematological and physiological variables were evaluated at the beginning and at the end of the survey. Statistical analysis consisted of a Mann-Whitney U test to determine differences between groups at the beginning and at the end of the survey and a Wilcoxon test for paired samples to compare the differences for each group separately. Additionally, size effects of the pre-post acclimation changes were calculated. After the acclimation program SG participants experienced a diminution in body weight (p < 0.01), body mass index (p < 0.01), body fat (p < 0.05) and fat percentage (p < 0.05) decreased. Hamstring flexibility (p < 0.05) and work capacity (p < 0.05) increased. External basal temperature decreased (p < 0.05) as well as post-exercise systolic and diastolic blood pressures (p < 0.05). Finally, maximal oxygen uptake (ml Kg-1 min-1) (p < 0.05), maximal minute ventilation (p < 0.05) and maximal breath frequency (p < 0.05) increased at the end of the intervention. There were no significant changes in the CG in any variable. Favorable adaptations have been observed in this survey, suggesting a beneficial effect of extreme heat acclimation on physical performance. Several of the observed responses seem interesting for sport performance and health promotion as well. However, this is a novel, extreme protocol which requires further research.
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Affiliation(s)
- I Bartolomé
- Sport Sciences Faculty, University of Extremadura, Avenida de la Universidad s/n, 10003, Cáceres, Spain
| | - J Siquier-Coll
- Movement, Brain and Health Research Group (MOBhE), Center of Higher Education Alberta Giménez (Comillas Pontifical University), Palma de Mallorca, Balearic Islands, Spain.
| | - M Pérez-Quintero
- Sport Sciences Faculty, University of Extremadura, Avenida de la Universidad s/n, 10003, Cáceres, Spain
| | - M C Robles-Gil
- Sport Sciences Faculty, University of Extremadura, Avenida de la Universidad s/n, 10003, Cáceres, Spain
| | - F J Grijota
- Faculty of Language and Education, University of Nebrija, Campus La Berzosa, Calle del Hostal, 28248, Hoyo de Manzanares, Madrid, Spain
| | - D Muñoz
- Sport Sciences Faculty, University of Extremadura, Avenida de la Universidad s/n, 10003, Cáceres, Spain
| | - M Maynar-Mariño
- Sport Sciences Faculty, University of Extremadura, Avenida de la Universidad s/n, 10003, Cáceres, Spain
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23
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Piil JF, Kingma B, Morris NB, Christiansen L, Ioannou LG, Flouris AD, Nybo L. Proposed framework for forecasting heat-effects on motor-cognitive performance in the Summer Olympics. Temperature (Austin) 2021; 8:262-283. [PMID: 34485620 PMCID: PMC8409751 DOI: 10.1080/23328940.2021.1957367] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Heat strain impairs performance across a broad spectrum of sport disciplines. The impeding effects of hyperthermia and dehydration are often ascribed to compromised cardiovascular and muscular functioning, but expert performance also depends on appropriately tuned sensory, motor and cognitive processes. Considering that hyperthermia has implications for central nervous system (CNS) function and fatigue, it is highly relevant to analyze how heat stress forecasted for the upcoming Olympics may influence athletes. This paper proposes and demonstrates the use of a framework combining expected weather conditions with a heat strain and motor-cognitive model to analyze the impact of heat and associated factors on discipline- and scenario-specific performances during the Tokyo 2021 games. We pinpoint that hyperthermia-induced central fatigue may affect prolonged performances and analyze how hyperthermia may impair complex motor-cognitive performance, especially when accompanied by either moderate dehydration or exposure to severe solar radiation. Interestingly, several short explosive performances may benefit from faster cross-bridge contraction velocities at higher muscle temperatures in sport disciplines with little or no negative heat-effect on CNS fatigue or motor-cognitive performance. In the analyses of scenarios and Olympic sport disciplines, we consider thermal impacts on “motor-cognitive factors” such as decision-making, maximal and fine motor-activation as well as the influence on central fatigue and pacing. From this platform, we also provide perspectives on how athletes and coaches can identify risks for their event and potentially mitigate negative motor-cognitive effects for and optimize performance in the environmental settings projected.
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Affiliation(s)
- Jacob Feder Piil
- Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, University of Copenhagen, Copenhagen N, Copenhagen, Denmark
| | - Boris Kingma
- Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.,TNO, the Netherlands Organization for Applied Scientific Research, Unit Defense, Safety & Security, Soesterberg, The Netherlands
| | - Nathan B Morris
- Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, University of Copenhagen, Copenhagen N, Copenhagen, Denmark
| | - Lasse Christiansen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark
| | - Leonidas G Ioannou
- FAME Laboratory, School of Exercise Science, University of Thessaly, Thessaly, Greece
| | - Andreas D Flouris
- FAME Laboratory, School of Exercise Science, University of Thessaly, Thessaly, Greece
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, University of Copenhagen, Copenhagen N, Copenhagen, Denmark
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24
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Lundby C, Svendsen IS, Urianstad T, Hansen J, Rønnestad BR. Training wearing thermal clothing and training in hot ambient conditions are equally effective methods of heat acclimation. J Sci Med Sport 2021; 24:763-767. [DOI: 10.1016/j.jsams.2021.06.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 05/27/2021] [Accepted: 06/07/2021] [Indexed: 10/21/2022]
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25
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Case Report: Heat Suit Training May Increase Hemoglobin Mass in Elite Athletes. Int J Sports Physiol Perform 2021; 17:115-119. [PMID: 34271548 DOI: 10.1123/ijspp.2021-0033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/13/2021] [Accepted: 04/13/2021] [Indexed: 11/18/2022]
Abstract
PURPOSE The present case report aimed to investigate the effects of exercise training in temperate ambient conditions while wearing a heat suit on hemoglobin mass (Hbmass). METHODS As part of their training regimens, 5 national-team members of endurance sports (3 males) performed ∼5 weekly heat suit exercise training sessions each lasting 50 minutes for a duration of ∼8 weeks. Two other male athletes acted as controls. After the initial 8-week period, 3 of the athletes continued for 2 to 4 months with ∼3 weekly heat sessions in an attempt to maintain acquired adaptations at a lower cost. Hbmass was assessed in duplicate before and after intervention and maintenance period based on automated carbon monoxide rebreathing. RESULTS Heat suit exercise training increased rectal temperature to a median value of 38.7°C (range 38.6°C-39.0°C), and during the initial ∼8 weeks of heat suit training, there was a median increase of 5% (range 1.4%-12.9%) in Hbmass, while the changes in the 2 control athletes were a decrease of 1.7% and an increase of 3.2%, respectively. Furthermore, during the maintenance period, the 3 athletes who continued with a reduced number of heat suit sessions experienced a change of 0.7%, 2.8%, and -1.1%, indicating that it is possible to maintain initial increases in Hbmass despite reducing the weekly number of heat suit sessions. CONCLUSIONS The present case report illustrates that heat suit exercise training acutely raises rectal temperature and that following 8 weeks of such training Hbmass may increase in elite endurance athletes.
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26
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Corbett J, Massey HC, Costello JT, Tipton MJ, Neal RA. The effect of medium-term heat acclimation on endurance performance in a temperate environment. Eur J Sport Sci 2021; 22:190-199. [PMID: 33241974 DOI: 10.1080/17461391.2020.1856935] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
We investigated whether an 11-day heat acclimation programme (HA) enhanced endurance performance in a temperate environment, and the mechanisms underpinning any ergogenic effect. Twenty-four males (V̇O2max: 56.7 ± 7.5 mL·kg-1·min-1) completed either: (i) HA consisting of 11 consecutive daily exercise sessions (60-90 min·day-1; n = 16) in a hot environment (40°C, 50% RH) or; (ii) duration and exertion matched exercise in cool conditions (CON; n = 8 [11°C, 60% RH]). Before and after each programme power at lactate threshold, mechanical efficiency, VO2max, peak power output (PPO) and work done during a 30-minute cycle trial (T30) were determined under temperate conditions (22°C, 50% RH). HA reduced resting (-0.34 ± 0.30°C) and exercising (-0.43 ± 0.30°C) rectal temperature, and increased whole-body sweating (+0.37 ± 0.31 L·hr-1) (all P≤0.001), with no change in CON. Plasma volume increased in HA (10.1 ± 7.2%, P < 0.001) and CON (7.2 ± 6.3%, P = 0.015) with no between-groups difference, whereas exercise heart rate reduced in both groups, but to a greater extent in HA (-20 ± 11 b·min-1) than CON (-6 ± 4 b·min-1). VO2max, lactate threshold and mechanical efficiency were unaffected by HA. PPO increased in both groups (+14 ± 18W), but this was not related to alterations in any of the performance or thermal variables, and T30 performance was unchanged in either group (HA: Pre = 417 ± 90 vs. Post = 427 ± 83 kJ; CON: Pre = 418 ± 63 vs. Post = 423 ± 56 kJ). In conclusion, 11-days HA induces thermophysiological adaptations, but does not alter the key determinants of endurance performance. In trained males, the effect of HA on endurance performance in temperate conditions is no greater than that elicited by exertion and duration matched exercise training in cool conditions.
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Affiliation(s)
- Jo Corbett
- Extreme Environments Laboratory, School of Sport, Health and Exercise Science, University of Portsmouth, Portsmouth, UK
| | - Heather C Massey
- Extreme Environments Laboratory, School of Sport, Health and Exercise Science, University of Portsmouth, Portsmouth, UK
| | - Joseph T Costello
- Extreme Environments Laboratory, School of Sport, Health and Exercise Science, University of Portsmouth, Portsmouth, UK
| | - Michael J Tipton
- Extreme Environments Laboratory, School of Sport, Health and Exercise Science, University of Portsmouth, Portsmouth, UK
| | - Rebecca A Neal
- Department of Rehabilitation and Sport Sciences, Bournemouth University, Poole, UK
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27
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Baranauskas MN, Constantini K, Paris HL, Wiggins CC, Schlader ZJ, Chapman RF. Heat Versus Altitude Training for Endurance Performance at Sea Level. Exerc Sport Sci Rev 2021; 49:50-58. [PMID: 33044330 DOI: 10.1249/jes.0000000000000238] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Environmental stressors, such as heat or altitude, elicit dissimilar physiological adaptations to endurance training programs. Whether these differences (i.e., increased hemoglobin mass vs plasma volume) differentially influence performance is debated. We review data in support of our novel hypothesis, which proposes altitude as the preferred environmental training stimulus for elite endurance athletes preparing to compete in temperate, sea-level climates (5°C-18°C).
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Affiliation(s)
- Marissa N Baranauskas
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, IN
| | - Keren Constantini
- School of Public Health, Sackler Faculty of Medicine and Sylvan Adams Sports Institute, Tel Aviv University, Tel Aviv, Israel
| | - Hunter L Paris
- Division of Natural Sciences, Pepperdine University, Malibu, CA
| | - Chad C Wiggins
- Department of Anaesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN
| | - Zachary J Schlader
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, IN
| | - Robert F Chapman
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, IN
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28
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Four-month operational heat acclimatization positively affects the level of heat tolerance 6 months later. Sci Rep 2020; 10:20260. [PMID: 33219295 PMCID: PMC7680124 DOI: 10.1038/s41598-020-77358-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 10/30/2020] [Indexed: 12/02/2022] Open
Abstract
Benefits obtained after heat acclimation/acclimatization should be completely lost after an estimated period of 6 weeks. However, this estimate is still hypothetical. We evaluate the long-term effects of heat acclimatization on the level of heat tolerance. Physiological and subjective markers of heat tolerance were assessed during a heat stress test (HST: 3 × 8-min runs outdoors [~ 40 °C and 20% RH] at 50% of their estimated speed at VO2max) performed on the 2nd day upon arrival to the desert military base in the United Arab Emirates after a first day of mostly passive exposure to heat. Among the 50 male French soldiers, 25 partook in a 4-month military mission in countries characterized by a hot environment ~ 6 months prior to the study (HA). The other 25 participants were never heat acclimatized (CT). Rectal temperature (p = 0.023), heart rate (p = 0.033), and perceived exertion (p = 0.043) were lower in the HA than CT group at the end of HST. Soldiers who experienced a former 4-month period of natural heat acclimatization very likely had a higher level of heat tolerance during exercise in the heat, even 6 months after returning from the previous desert mission, than that of their non-acclimatized counterparts.
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29
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Travers G, González-Alonso J, Riding N, Nichols D, Shaw A, Périard JD. Exercise heat acclimation has minimal effects on left ventricular volumes, function and systemic hemodynamics in euhydrated and dehydrated trained humans. Am J Physiol Heart Circ Physiol 2020; 319:H965-H979. [DOI: 10.1152/ajpheart.00466.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This study demonstrates that 10 days of exercise heat acclimation has minimal effects on left ventricular volumes, intrinsic cardiac function, and systemic hemodynamics during prolonged, repeated semirecumbent exercise in moderate heat, where heart rate and blood volume are similar to preacclimation levels. However, progressive dehydration is consistently associated with similar degrees of hyperthermia and tachycardia and reductions in blood volume, diastolic filling of the left ventricle, stroke volume, and cardiac output, regardless of acclimation state.
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Affiliation(s)
- Gavin Travers
- Athlete Health and Performance Research Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
- Centre for Human Performance, Exercise and Rehabilitation, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, United Kingdom
- Division of Sport, Health and Exercise Sciences, Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - José González-Alonso
- Centre for Human Performance, Exercise and Rehabilitation, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, United Kingdom
- Division of Sport, Health and Exercise Sciences, Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Nathan Riding
- Athlete Health and Performance Research Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
| | - David Nichols
- Sport Development Centre, Loughborough University, Loughborough, United Kingdom
| | - Anthony Shaw
- Athlete Health and Performance Research Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
| | - Julien D. Périard
- Athlete Health and Performance Research Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
- University of Canberra Research Institute for Sport and Exercise, University of Canberra, Bruce, Australia
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30
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Oberholzer L, Bonne TC, Breenfeldt Andersen A, Bejder J, Højgaard Christensen R, Baastrup Nordsborg N, Lundby C. Reproducibility of the CO rebreathing technique with a lower CO dose and a shorter rebreathing duration at sea level and at 2320 m of altitude. Scandinavian Journal of Clinical and Laboratory Investigation 2020; 80:590-599. [PMID: 32955368 DOI: 10.1080/00365513.2020.1818282] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Total hemoglobin mass (Hbmass) is routinely assessed in studies by the carbon monoxide (CO) rebreathing. Its clinical application is often hindered due to the consequent rise in carboxyhemoglobin (%HbCO) and the concern of CO toxicity. We tested the reproducibility of the CO rebreathing with a CO dose of 0.5 mL/kg body mass (CO0.5) compared to 1.5 mL/kg (CO1.5) and when shortening the CO rebreathing protocol. Therefore, CO rebreathing was performed 1×/day in eight healthy individuals on four consecutive days. On each day, either CO0.5 (CO0.5-1 and CO0.5-2) or CO1.5 (CO1.5-1 and CO1.5-2) was administered. Venous blood samples to determine %HbCO and quantify Hbmass were obtained prior to, and at 6 (T6), 8 (T8) and 10 min (T10) of CO rebreathing. This protocol was tested at sea level and at 2320 m to investigate the altitude-related measurement error. At sea level, the mean difference (95% limits of agreement) in Hbmass between CO0.5-1 and CO0.5-2 was 26 g (-26; 79 g) and between CO1.5-1 and CO1.5-2, it was 17 g (-18; 52 g). The respective typical error (TE) corresponded to 2.4% (CO0.5) and 1.5% (CO1.5), while it was 6.5% and 3.0% at 2320 m. With CO0.5, shortening the CO rebreathing resulted in a TE for Hbmass of 4.4% (T8 vs. T10) and 14.1% (T6 vs T10) and with CO1.5, TE was 1.6% and 5.8%. In conclusion, the CO dose and rebreathing time for the CO rebreathing procedure can be decreased at the cost of a measurement error ranging from 1.5-14.1%.
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Affiliation(s)
- Laura Oberholzer
- Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Christian Bonne
- Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Jacob Bejder
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Carsten Lundby
- Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Innland University of Applied Sciences, Lillehammer, Norway
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31
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Rønnestad BR, Hamarsland H, Hansen J, Holen E, Montero D, Whist JE, Lundby C. Five weeks of heat training increases haemoglobin mass in elite cyclists. Exp Physiol 2020; 106:316-327. [DOI: 10.1113/ep088544] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 05/18/2020] [Indexed: 11/08/2022]
Affiliation(s)
| | | | - Joar Hansen
- Innland University of Applied Sciences Lillehammer Norway
| | - Espen Holen
- Innland University of Applied Sciences Lillehammer Norway
| | - David Montero
- Faculty of Kinesiology Cumming School of Medicine University of Calgary Calgary Canada
| | | | - Carsten Lundby
- Innland University of Applied Sciences Lillehammer Norway
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32
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Mikkelsen CJ, Junge N, Piil JF, Morris NB, Oberholzer L, Siebenmann C, Lundby C, Nybo L. Prolonged Heat Acclimation and Aerobic Performance in Endurance Trained Athletes. Front Physiol 2019; 10:1372. [PMID: 31749712 PMCID: PMC6843002 DOI: 10.3389/fphys.2019.01372] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 10/16/2019] [Indexed: 11/17/2022] Open
Abstract
Heat acclimation (HA) involves physiological adaptations that directly promote exercise performance in hot environments. However, for endurance-athletes it is unclear if adaptations also improve aerobic capacity and performance in cool conditions, partly because previous randomized controlled trial (RCT) studies have been restricted to short intervention periods. Prolonged HA was therefore deployed in the present RCT study including 21 cyclists [38 ± 2 years, 184 ± 1 cm, 80.4 ± 1.7 kg, and maximal oxygen uptake (VO2max) of 58.1 ± 1.2 mL/min/kg; mean ± SE] allocated to either 5½ weeks of training in the heat [HEAT (n = 12)] or cool control [CON (n = 9)]. Training registration, familiarization to test procedures, determination of VO2max, blood volume and 15 km time trial (TT) performance were assessed in cool conditions (14°C) during a 2-week lead-in period, as well as immediately pre and post the intervention. Participants were instructed to maintain total training volume and complete habitual high intensity intervals in normal settings; but HEAT substituted part of cool training with 28 ± 2 sessions in the heat (1 h at 60% VO2max in 40°C; eliciting core temperatures above 39°C in all sessions), while CON completed all training in cool conditions. Acclimation for HEAT was verified by lower sweat sodium [Na+], reduced steady-state heart rate and improved submaximal exercise endurance in the heat. However, when tested in cool conditions both peak power output and VO2max remained unchanged for HEAT (pre 60.0 ± 1.5 vs. 59.8 ± 1.3 mL O2/min/kg). TT performance tested in 14°C was improved for HEAT and average power output increased from 298 ± 6 to 315 ± 6 W (P < 0.05), but a similar improvement was observed for CON (from 294 ± 11 to 311 ± 10 W). Based on the present findings, we conclude that training in the heat was not superior compared to normal (control) training for improving aerobic power or TT performance in cool conditions.
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Affiliation(s)
- C. Jacob Mikkelsen
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Nicklas Junge
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Jacob F. Piil
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Nathan B. Morris
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Laura Oberholzer
- Centre for Physical Activity Research, Copenhagen University Hospital, Copenhagen, Denmark
| | - Christoph Siebenmann
- Centre for Physical Activity Research, Copenhagen University Hospital, Copenhagen, Denmark
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Carsten Lundby
- Centre for Physical Activity Research, Copenhagen University Hospital, Copenhagen, Denmark
- Innland Norway University of Applied Sciences, Lillehammer, Norway
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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