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Morishima T, Yamaguchi K, Goto K. Impact of moderate-intensity aerobic exercise in combined hypoxic and hot conditions on endothelial function. Clin Physiol Funct Imaging 2024. [PMID: 38922727 DOI: 10.1111/cpf.12894] [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: 03/12/2024] [Revised: 05/19/2024] [Accepted: 05/31/2024] [Indexed: 06/28/2024]
Abstract
There is no study that has investigated the impact of exercise in a combined hypoxic and hot environment on endothelial function. Therefore, we tested whether aerobic exercise in a combined hypoxic and hot conditions induces further enhancement of endothelial function. Twelve healthy males cycled at a constant workload (50% of their maximal oxygen uptake under normoxic/thermoneutral conditions) for 30 min in four different environments: exercise under normoxic condition (NOR: fraction of inspiratory oxygen or FiO2 = 20.9%, 20°C), exercise under hypoxic condition (HYP: FiO2 = 14.5%, 20°C), exercise under hot condition (HOT: FiO2 = 20.9%, 30°C), and exercise under combined hypoxia and hot conditions (HH: FiO2 = 14.5%, 30°C). Before, during, and after exercise, cardiovascular variables (e.g., heart rate, blood flow, and shear rate), blood variables, and endothelial function evaluated by flow-mediated dilation (FMD) were assessed. Heart rates were significantly higher throughout the HH trial's experimental period than the other trials (p < 0.05). However, in the HH trial, brachial artery blood flow and shear rate did not differ from those in other trials after exercise. Plasma catecholamines (epinephrine, norepinephrine, and dopamine) elevations in response to exercise were significantly higher in the HH trial than in the other three trials (p < 0.05). No considerable differences were observed in FMD responses among trials before and after the exercise. In conclusion, aerobic exercise in a combined hot and hypoxic environment further activated sympathetic nervous activity but did not considerably enhance blood flow, shear rate, or endothelial function.
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Affiliation(s)
- Takuma Morishima
- Faculty of Liberal Arts and Sciences, Chukyo University, Aichi, Japan
| | - Keiichi Yamaguchi
- Graduate School of Sport and Health Science, Ritsumeikan University, Shiga, Japan
| | - Kazushige Goto
- Graduate School of Sport and Health Science, Ritsumeikan University, Shiga, Japan
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2
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Mornas A, Brocherie F, Hollville E, Derouck T, Racinais S, Guilhem G. Running 40 Minutes under Temperate or Hot Environment Does Not Affect Operating Fascicle Length. Med Sci Sports Exerc 2024; 56:1140-1150. [PMID: 38233977 DOI: 10.1249/mss.0000000000003387] [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: 01/19/2024]
Abstract
PURPOSE Muscle mechanics is paramount in our understanding of motor performance. However, little is known regarding the sensitivity of fascicle dynamics and connective tissues stiffness to exercise duration and ambient temperature during running, both increasing muscle temperature. This study aimed to determine gastrocnemius medialis (GM) fascicle dynamics in vivo during running in temperate and hot conditions, as well as muscle-tendon unit responses. METHODS Using ultrafast ultrasound, 15 participants (8 men, 7 women; 26 ± 3 yr) were tested before, during (2 and 40 min), and after a running task (40 min at 10 km·h -1 ) in temperate (TEMP; ~23°C) and hot (HOT: ~38°C) conditions. RESULTS Although core, skin temperatures, and heart rate increased from the beginning to the end of the exercise and in a larger extent in HOT than TEMP ( P < 0.001), the physiological stress elicited did not alter running temporal parameters and GM fascicle operating lengths, with similar behavior of the fascicles on their force-length relationship, over time (2 vs 40 min) or across condition (TEMP vs HOT; P ≥ 0.248). Maximal voluntary force production did not reported statistical changes after exercise ( P = 0.060), and the connective tissues stiffness measured (i.e., passive muscle and stiffness of the series-elastic elements) did not show neither time ( P ≥ 0.281), condition ( P ≥ 0.256) nor time-condition interaction ( P ≥ 0.465) effect. CONCLUSIONS This study revealed that prolonged running exercise does not alter muscle-tendon unit properties and interplay, which are not influenced by ambient temperature. These findings may rule out potential detrimental effects of heat on muscle properties and encourage further investigations on longer and more intense running exercise.
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Affiliation(s)
| | - Franck Brocherie
- French Institute of Sport (INSEP), Laboratory Sport, Expertise and Performance (EA 7370), Paris, FRANCE
| | - Enzo Hollville
- French Institute of Sport (INSEP), Laboratory Sport, Expertise and Performance (EA 7370), Paris, FRANCE
| | | | | | - GaËL Guilhem
- French Institute of Sport (INSEP), Laboratory Sport, Expertise and Performance (EA 7370), Paris, FRANCE
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3
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Oberholzer L, Aamaas NS, Hallén J. Changes in cycling economy and fractional utilization of V̇O 2peak during a 40-min maximal effort exercise test with acute hypobaric hypoxia corresponding to 2800 m of altitude. Scand J Med Sci Sports 2024; 34:e14511. [PMID: 37828810 DOI: 10.1111/sms.14511] [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: 06/29/2023] [Revised: 09/16/2023] [Accepted: 09/25/2023] [Indexed: 10/14/2023]
Abstract
INTRODUCTION Peak oxygen uptake (V̇O2peak ) declines by ~7% per 1000 m of increasing altitude, whereas exercise performance seems reduced to a lesser extent. For example, 800-10 000 m track and field performances are decreased by 0.4%-2.4% above 1000 m as compared to below and some studies show similar drops in cycling performance. A greater decline in V̇O2peak than in endurance performance with altitude suggests a higher fractional utilization of V̇O2peak (%V̇O2peak ). Therefore, we hypothesized that the %V̇O2peak is higher with acute hypoxic exposure than near sea level. METHODS Sixteen lowlanders (8 women, age: 31 ± 7 years [mean ± SD], body mass: 68 ± 8 kg, V̇O2peak : 60 ± 8 mL min-1 kg-1 ) underwent cycling testing in a hypobaric hypoxic chamber on 6 test days, three conducted at 300 m and three at 2800 m of acute altitude. At both altitudes, V̇O2peak was determined, and during a 40-min all out maximal effort time trial (TT), mean power output (MPO) and mean V̇O2 (%V̇O2peak ) were assessed. RESULTS V̇O2peak decreased by 11.2 ± 3.0% (p < 0.001), while MPO during the TT declined by 10.7 ± 3.1% (p < 0.001) at 2800 m as compared to 300 m. During the TT, %V̇O2peak was higher at altitude, corresponding to 75.9 ± 4.5% at 300 m and 78.8 ± 4.2% at 2800 m (p = 0.011), and cycling economy (mL O2 kJ-1 ) was poorer (+3.4 ± 2.7%, p < 0.001). CONCLUSION The %V̇O2peak was higher during a cycling TT at 2800 m of altitude than near sea level, while cycling economy was poorer. This resulted in a similar reduction in performance and V̇O2peak . Future studies should address the physiological mechanisms underlying the elevated %V̇O2peak .
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Affiliation(s)
- Laura Oberholzer
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | | | - Jostein Hallén
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
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Bottenheft C, Groen EL, Mol D, Valk PJL, Houben MMJ, Kingma BRM, van Erp JBF. Effects of heat load and hypobaric hypoxia on cognitive performance: a combined stressor approach. ERGONOMICS 2023; 66:2148-2164. [PMID: 36916391 DOI: 10.1080/00140139.2023.2190062] [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: 12/04/2022] [Accepted: 03/05/2023] [Indexed: 06/18/2023]
Abstract
This study investigates how cognitive performance is affected by the combination of two stressors that are operationally relevant for helicopter pilots: heat load and hypobaric hypoxia. Fifteen participants were exposed to (1) no stressors, (2) heat load, (3) hypobaric hypoxia, and (4) combined heat load and hypobaric hypoxia. Hypobaric hypoxia (13,000 ft) was achieved in a hypobaric chamber. Heat load was induced by increasing ambient temperature to ∼28 °C. Cognitive performance was measured using two multitasks, and a vigilance task. Subjective and physiological data (oxygen saturation, heart rate, core- and skin temperature) were also collected. Mainly heat load caused cognitive performance decline. This can be explained by high subjective heat load and increased skin temperature, which takes away cognitive resources from the tasks. Only the arithmetic subtask was sensitive to hypobaric hypoxia, whereby hypobaric hypoxia caused a further performance decline in addition to the decline caused by heat load.Practitioner summary: Little is known about how multiple environmental stressors interact. This study investigates the combined effects of heat load and hypobaric hypoxia on cognitive performance. An additive effect of heat load and hypobaric hypoxia was found on a arithmetic task, which may be attributed to independent underlying mechanisms.
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Affiliation(s)
- Charelle Bottenheft
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organisation for Applied Scientific Research (TNO), Soesterberg, Netherlands
- Human Media Interaction, Computer Science, University of Twente, Enschede, Netherlands
| | - Eric L Groen
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organisation for Applied Scientific Research (TNO), Soesterberg, Netherlands
| | - Douwe Mol
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organisation for Applied Scientific Research (TNO), Soesterberg, Netherlands
| | - Pierre J L Valk
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organisation for Applied Scientific Research (TNO), Soesterberg, Netherlands
| | - Mark M J Houben
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organisation for Applied Scientific Research (TNO), Soesterberg, Netherlands
| | - Boris R M Kingma
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organisation for Applied Scientific Research (TNO), Soesterberg, Netherlands
| | - Jan B F van Erp
- Human Media Interaction, Computer Science, University of Twente, Enschede, Netherlands
- Department of Human Machine Teaming, Unit Defence, Safety and Security, Netherlands Organisation for Applied Scientific Research (TNO), Soesterberg, Netherlands
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Wait SO, Charkoudian N, Skinner JW, Smith CJ. Combining hypoxia with thermal stimuli in humans: physiological responses and potential sex differences. Am J Physiol Regul Integr Comp Physiol 2023; 324:R677-R690. [PMID: 36971421 PMCID: PMC10202487 DOI: 10.1152/ajpregu.00244.2021] [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: 09/27/2021] [Revised: 03/08/2023] [Accepted: 03/20/2023] [Indexed: 03/29/2023]
Abstract
Increasing prevalence of native lowlanders sojourning to high altitudes (>2,500 m) for recreational, occupational, military, and competitive reasons has generated increased interest in physiological responses to multistressor environments. Exposure to hypoxia poses recognized physiological challenges that are amplified during exercise and further complicated by environments that might include combinations of heat, cold, and high altitude. There is a sparsity of data examining integrated responses in varied combinations of environmental conditions, with even less known about potential sex differences. How this translates into performance, occupational, and health outcomes requires further investigation. Acute hypoxic exposure decreases arterial oxygen saturation, resulting in a reflex hypoxic ventilatory response and sympathoexcitation causing an increase in heart rate, myocardial contractility, and arterial blood pressure, to compensate for the decreased arterial oxygen saturation. Acute altitude exposure impairs exercise performance, for example, reduced time to exhaustion and slower time trials, largely owing to impairments in pulmonary gas exchange and peripheral delivery resulting in reduced V̇o2max. This exacerbates with increasing altitude, as does the risk of developing acute mountain sickness and more serious altitude-related illnesses, but modulation of those risks with additional stressors is unclear. This review aims to summarize and evaluate current literature regarding cardiovascular, autonomic, and thermoregulatory responses to acute hypoxia, and how these may be affected by simultaneous thermal environmental challenges. There is minimal available information regarding sex as a biological variable in integrative responses to hypoxia or multistressor environments; we highlight these areas as current knowledge gaps and the need for future research.
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Affiliation(s)
- Seaver O Wait
- Department of Public Health and Exercise Science, Appalachian State University, Boone, North Carolina, United States
| | - Nisha Charkoudian
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States
| | - Jared W Skinner
- Department of Public Health and Exercise Science, Appalachian State University, Boone, North Carolina, United States
| | - Caroline J Smith
- Department of Public Health and Exercise Science, Appalachian State University, Boone, North Carolina, United States
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de la Garanderie MP, Courtay A, Féral-Basin C, Rainville P, Gaveau J, Pageaux B. Perception of effort and the allocation of physical resources: A generalization to upper-limb motor tasks. Front Psychol 2023; 13:974172. [PMID: 36760904 PMCID: PMC9904170 DOI: 10.3389/fpsyg.2022.974172] [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: 06/20/2022] [Accepted: 11/28/2022] [Indexed: 01/26/2023] Open
Abstract
Purpose The perception of effort (PE) is widely used to prescribe and monitor exercise during locomotor and resistance tasks. The present study examines the validity of PE to prescribe and monitor exercise during upper-limb motor tasks under various loads and speed requirements. Methods Forty participants volunteered in two experiments. In experiment 1, we used four PE intensities to prescribe exercise on a modified version of the box and block test (BBT) and a pointing task. We investigated the possibility of monitoring the exercise intensity by tracking changes in PE rating in response to three different tempos or additional weights. Experiment 2 replicated the possibility of prescribing the exercise with the PE intensity during the BBT and explored the impact of additional weights on performance and PE during the standardized version of the BBT. Muscle activation, heart rate, and respiratory frequencies were recorded. Results In experiment 1, increasing the PE intensity to prescribe exercise induced an increased performance between each intensity. Increasing task difficulty with faster movement tempo and adding weight on the forearm increased the rating of PE. Experiment 2 replicated the possibility to use PE intensity for exercise prescription during the BBT. When completing the BBT with an additional weight on the forearm, participants maintained performance at the cost of a higher PE. In both experiments, changes in PE were associated with changes in muscle activation. Conclusion Our results suggest that PE is a valid tool to prescribe and monitor exercise during upper-limb motor tasks.
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Affiliation(s)
- Marie Payen de la Garanderie
- École de Kinésiologie et des Sciences de l’Activité Physique (EKSAP), Faculté de Médecine, Université de Montréal, Montreal, QC, Canada
- Centre de Recherche de l’Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montreal, QC, Canada
| | - Aymeric Courtay
- École de Kinésiologie et des Sciences de l’Activité Physique (EKSAP), Faculté de Médecine, Université de Montréal, Montreal, QC, Canada
- Centre de Recherche de l’Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montreal, QC, Canada
- INSERM UMR1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences du Sport, Dijon, France
| | - Camille Féral-Basin
- École de Kinésiologie et des Sciences de l’Activité Physique (EKSAP), Faculté de Médecine, Université de Montréal, Montreal, QC, Canada
- Centre de Recherche de l’Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montreal, QC, Canada
| | - Pierre Rainville
- Centre de Recherche de l’Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montreal, QC, Canada
- Département de Stomatologie, Faculté de Médecine Dentaire, Université de Montréal, Montreal, QC, Canada
| | - Jérémie Gaveau
- INSERM UMR1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences du Sport, Dijon, France
- Espace d’Etude du Mouvement—Etienne Jules MAREY, Université Bourgogne Franche-Comte, UFR des Sciences du Sport, Dijon, France
| | - Benjamin Pageaux
- École de Kinésiologie et des Sciences de l’Activité Physique (EKSAP), Faculté de Médecine, Université de Montréal, Montreal, QC, Canada
- Centre de Recherche de l’Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montreal, QC, Canada
- Centre Interdisciplinaire de Recherche sur le Cerveau et l’Apprentissage (CIRCA), Montreal, QC, Canada
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Naito T, Saito T, Muraishi K, Takahashi H. Comparison of the effects of high and low levels of solar radiations on exercise capacity in hot outdoor environments. J Sports Med Phys Fitness 2023; 63:42-52. [PMID: 35415996 DOI: 10.23736/s0022-4707.22.13627-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND High solar radiation from the sun in the heat outdoor may be impaired exercise capacity. This study aimed to compare the effects of different levels of solar radiation on exercise capacity and evaluate skin temperature responses in the heat. METHODS Seven male participants performed cycling exercise at 60% of their maximal oxygen uptake until volitional exhaustion in hot outdoor environments (approximately 33-35°C, 40-50% relative humidity) under both clear sky (high solar radiation trial: 1062±50 W/m2) and under thick clouds (low solar radiation trial: 438±52 W/m2). RESULTS The time to exhaustion of the participants was shorter in the high solar radiation trial (32.0±12.4 min) than in the low solar radiation trial (39.2±18.0 min: P=0.045). Mean skin temperature was significantly higher in the high solar radiation trial than that in the low solar radiation trial (P<0.05); however, the rectal temperature did not differ significantly between the two trials. The high solar radiation trial had narrower core-to-skin temperature gradient, greater the body heat gain from the sun, and higher rating of perceived exertion than the low solar radiation trial. CONCLUSIONS These results indicate that high solar radiation during outdoor exercise in the heat causes a greater increase in skin temperature and body heat gain from the sun than low solar radiation and consequently impairs exercise capacity.
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Affiliation(s)
- Takashi Naito
- Faculty of Law, Hokkai-Gakuen University, Hokkaido, Japan - .,Japan Institute of Sports Sciences, Tokyo, Japan -
| | - Tatsuya Saito
- Japan Institute of Sports Sciences, Tokyo, Japan.,Faculty of Medicine, Tottori University, Tottori, Japan
| | - Koji Muraishi
- Japan Sport Council, Tokyo, Japan.,Graduate School of Community and Human Services, Rikkyo University, Saitama, Japan.,Faculty of Economics, Kanto Gakuen University, Gunma, Japan
| | - Hideyuki Takahashi
- Japan Institute of Sports Sciences, Tokyo, Japan.,Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan
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Chmura P, Liu H, Andrzejewski M, Tessitore A, Sadowski J, Chmura J, Rokita A, Tański W, Cicirko L, Konefał M. Responses of soccer players performing repeated maximal efforts in simulated conditions of the FIFA World Cup Qatar 2022: A holistic approach. PLoS One 2022; 17:e0276314. [PMID: 36490259 PMCID: PMC9733889 DOI: 10.1371/journal.pone.0276314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 10/05/2022] [Indexed: 12/13/2022] Open
Abstract
This study aimed to assess the capacity for repeated maximal effort (RME) of soccer players in the thermo-natural conditions (NC) and in simulated conditions for the 2022 FIFA World Cup in Qatar (QSC). Twenty-four semi-professional soccer players participated in the study. The exercise test consisted of ten 6-second maximal efforts on a cycloergometer. A 90-second passive rest interval was used. The test was performed in a Weiss Technik WK-26 climate test chamber in two different conditions: 1) thermo-neutral conditions (NC-20.5°C; 58.7% humidity); and 2) simulated conditions for the 2022 World Cup in Qatar (QSC-28.5 ± 1.92°C; 58.7 ± 8.64% humidity). Power-related, physiological, psychomotor, blood, and electrolyte variables were recorded. Results showed that (1) players achieved higher peak power (max 1607,46 ± 192,70 [W] - 3rd rep), needed less time to peak power (min 0,95 ± 0,27 [s] - 3rd rep), and had a higher fatigue slope (max 218,67 ± 59,64 [W/sek] - 7th rep) in QSC than in NC (in each repetition of study protocol); (2) between the 1st repetition and subsequent repetitions a number of significants in among physiological, blood-related, and electrolyte variables were noted, but their direction was similar in both simulated conditions (e.g. V'O2/kg 37,59 ± 3,96 vs 37,95 ± 3,17 [ml/min/kg] - 3rd rep, LAC 13,16 ± 2,61 vs 14,18 ± 3,13 [mg/dl] - 10th rep or K 4,54 ± 0,29 vs 4,79 ± 0,36 [mmol/l] - 2nd rep when compare QCS and NC respectively); (3) an 8°C of temperature difference between the climatic conditions did not significantly affect the soccer players' physical and physiological responses in RME. The study results can be used in the design of training programs aimed to increase players' physiological adaptations by simulating soccer-specific conditions of play in terms of anaerobic capacity, in particular, repetitive maximal efforts. These findings will be useful during the upcoming 2022 World Cup in Qatar and in locations where high ambient temperatures are customary.
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Affiliation(s)
- Paweł Chmura
- Department of Team Games, Wrocław University of Health and Sport Sciences, Wrocław, Poland
| | - Hongyou Liu
- School of Physical Education & Sports Science, Guangzhou Higher Education Mega Centre, South China Normal University, Guangzhou, China
| | - Marcin Andrzejewski
- Department of Methodology of Recreation, Poznań University of Physical Education, Poznań, Poland
- * E-mail:
| | - Antonio Tessitore
- Department of Movement, Human and Health Sciences, University of Rome “Foro Italico”, Rome, Italy
| | - Jerzy Sadowski
- Department of Sport Science, Faculty of Physical Education and Health, Józef Piłsudski University of Physical Education in Warsaw, Warsaw, Poland
| | - Jan Chmura
- Department of Human Motor Skills, Wrocław University of Health and Sport Sciences, Wrocław, Poland
| | - Andrzej Rokita
- Department of Team Games, Wrocław University of Health and Sport Sciences, Wrocław, Poland
| | - Wojciech Tański
- 4th Military Teaching Hospital with Clinic, Independent Public Health Care Centre in Wrocław, Wrocław, Poland
| | - Leszek Cicirko
- Department of Physical Education and Sport, Faculty of Physical Education and Health in Biała Podlaska, Józef Piłsudski University of Physical Education in Warsaw, Warsaw, Poland
| | - Marek Konefał
- Department of Human Motor Skills, Wrocław University of Health and Sport Sciences, Wrocław, Poland
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9
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Dennis MC, Goods PSR, Binnie MJ, Girard O, Wallman KE, Dawson BT, Peeling P. Taking the plunge: When is best for hot water immersion to complement exercise in heat and hypoxia. J Sports Sci 2022; 40:2055-2061. [PMID: 36263975 DOI: 10.1080/02640414.2022.2133390] [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: 10/24/2022]
Abstract
This investigation assessed the psycho-physiological and performance effects of hot water immersion (HWI) implemented either before or after a repeated-sprint training in hypoxia (RSH) session conducted in the heat. Ten participants completed three RSH trials (3 × 10 × 5-s sprints), conducted at 40°C and simulated altitude of 3000 m. A 30-min monitoring period preceded and followed all exercise sessions. In PRE, the pre-exercise period was HWI, and the post-exercise period was seated rest in temperate conditions. This combination was reversed in POST. In CON, participants were seated in temperate conditions for both periods. Compared to CON, PRE elicited a reduction in power output during each repeated-sprint set (14.8-16.2%, all p < 0.001), and a significantly higher core temperature (Tc) during the pre-exercise period and throughout the exercise session (p < 0.001 and p = 0.025, respectively). In POST, power output and Tc until the end of exercise were similar to CON, with Tc higher at the conclusion of the post-exercise period (p < 0.001). Time across the entire protocol spent ≥38.5°C Tc was significantly longer in PRE (48.1 ± 22.5 min) than POST (31.0 ± 11.3 min, p = 0.05) and CON (15.8 ± 16.3 min, p < 0.001). Employing HWI following RSH conducted in the heat provides effective outcomes regarding physiological strain and cycling performance when compared to pre-exercise or no HWI.
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Affiliation(s)
- Myles C Dennis
- School of Human Sciences (Exercise and Sport Sciences), The University of Western Australia, WA, Australia, 6009.,Department of Physiology, Western Australian Institute of Sport, WA, Australia, 6010
| | - Paul S R Goods
- Department of Physiology, Western Australian Institute of Sport, WA, Australia, 6010.,Murdoch Applied Sports Science Laboratory, Murdoch University, WA, Australia, 6150.,Centre for Healthy Ageing, Health Futures Institute, Murdoch University, WA, Australia, 6150
| | - Martyn J Binnie
- School of Human Sciences (Exercise and Sport Sciences), The University of Western Australia, WA, Australia, 6009.,Department of Physiology, Western Australian Institute of Sport, WA, Australia, 6010
| | - Olivier Girard
- School of Human Sciences (Exercise and Sport Sciences), The University of Western Australia, WA, Australia, 6009
| | - Karen E Wallman
- School of Human Sciences (Exercise and Sport Sciences), The University of Western Australia, WA, Australia, 6009
| | - Brian T Dawson
- School of Human Sciences (Exercise and Sport Sciences), The University of Western Australia, WA, Australia, 6009
| | - Peter Peeling
- School of Human Sciences (Exercise and Sport Sciences), The University of Western Australia, WA, Australia, 6009.,Department of Physiology, Western Australian Institute of Sport, WA, Australia, 6010
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10
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Yamaguchi K, Kasai N, Hayashi N, Yatsutani H, Girard O, Goto K. Muscle Oxygenation during Repeated Cycling Sprints in a Combined Hot and Hypoxic Condition. Int J Sports Med 2022; 43:708-714. [PMID: 35088397 DOI: 10.1055/a-1495-5612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The aim of the present study was to examine the effects of a combined hot and hypoxic environment on muscle oxygenation and performance during repeated cycling sprints. In a single-blind, counterbalanced, cross-over research design, 10 male athletes performed three sets of 3 × 10-s maximal pedaling interspersed with 40-s recovery between sprints under four different environments. Each condition consisted of a control (CON; 20°C, 20.9% FiO2), normobaric hypoxia (HYP; 20°C, 14.5% FiO2), hot (HOT; 35°C, 20.9% FiO2), and combined hot and normobaric hypoxia (HH; 35°C, 14.5% FiO2). Power output and vastus lateralis muscle oxygenation were measured. Peak power output was significantly higher in HOT (892±27 W) and HH (887±24 W) than in CON (866±25 W) and HYP (859±25 W) during the first set (p<0.05). The increase in total hemoglobin during recovery periods was larger in HH than in HYP (p<0.05), while change in tissue saturation index was smaller in HYP than in CON and HOT (p<0.05). The findings suggest that the combination of hot and hypoxia during repeated cycling sprints presented different characteristics for muscle metabolism and power output compared to temperature or altitude stressor alone.
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Affiliation(s)
- Keiichi Yamaguchi
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
| | - Nobukazu Kasai
- Department of Sports Science, Japan Institute of Sports Sciences, Kita-ku, Japan
| | - Nanako Hayashi
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
| | - Haruka Yatsutani
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
| | - Olivier Girard
- School of Human Science (Exercise and Sport Sciences), The University of Western Australia, Perth, Australia
| | - Kazushige Goto
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
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11
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Yamaguchi K, Imai T, Yatsutani H, Goto K. A Combined Hot and Hypoxic Environment during Maximal Cycling Sprints Reduced Muscle Oxygen Saturation: A Pilot Study. J Sports Sci Med 2021; 20:684-689. [PMID: 35321130 PMCID: PMC8488822 DOI: 10.52082/jssm.2021.684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 07/05/2021] [Indexed: 06/14/2023]
Abstract
The present study investigated the effects of a combined hot and hypoxic environment on muscle oxygenation during repeated 15-s maximal cycling sprints. In a single-blind, cross-over study, nine trained sprinters performed three 15-s maximal cycling sprints interspersed with 7-min passive recovery in normoxic (NOR; 23℃, 50%, FiO2 20.9%), normobaric hypoxic (HYP; 23℃, FiO2 14.5%), and hot normobaric hypoxic (HH; 35℃, FiO2 14.5%) environments. Relative humidity was set to 50% in all trials. The vastus lateralis muscle oxygenation was evaluated during exercise using near-infrared spectroscopy. The oxygen uptake (VO2) and arterial oxygen saturation (SpO2) were also monitored. There was no significant difference in peak or mean power output among the three conditions. The reduction in tissue saturation index was significantly greater in the HH (-17.0 ± 2.7%) than in the HYP (-10.4 ± 2.8%) condition during the second sprint (p < 0.05). The average VO2 and SpO2 were significantly lower in the HYP (VO2 = 980 ± 52 mL/min, SpO2 = 82.9 ± 0.8%) and HH (VO2 = 965 ± 42 mL/min, SpO2 = 83.2 ± 1.2%) than in the NOR (VO2 = 1149 ± 40 mL/min, SpO2 = 90.6 ± 1.4%; p < 0.05) condition. In conclusion, muscle oxygen saturation was reduced to a greater extent in the HH than in the HYP condition during the second bout of three 15-s maximal cycling sprints, despite the equivalent hypoxic stress between HH and HYP.
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Affiliation(s)
- Keiichi Yamaguchi
- Graduate School of Sport and Health Science, Ritsumeikan University, Shiga, Japan
| | - Tomohiro Imai
- Graduate School of Sport and Health Science, Ritsumeikan University, Shiga, Japan
| | - Haruka Yatsutani
- Graduate School of Sport and Health Science, Ritsumeikan University, Shiga, Japan
| | - Kazushige Goto
- Graduate School of Sport and Health Science, Ritsumeikan University, Shiga, Japan
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12
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De Wachter J, Proost M, Habay J, Verstraelen M, Díaz-García J, Hurst P, Meeusen R, Van Cutsem J, Roelands B. Prefrontal Cortex Oxygenation During Endurance Performance: A Systematic Review of Functional Near-Infrared Spectroscopy Studies. Front Physiol 2021; 12:761232. [PMID: 34764885 PMCID: PMC8576380 DOI: 10.3389/fphys.2021.761232] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 09/27/2021] [Indexed: 01/17/2023] Open
Abstract
Introduction: A myriad of factors underlie pacing-/exhaustion-decisions that are made during whole-body endurance performance. The prefrontal cortex (PFC) is a brain region that is crucial for decision-making, planning, and attention. PFC oxygenation seems to be a mediating factor of performance decisions during endurance performance. Nowadays, there is no general overview summarizing the current knowledge on how PFC oxygenation evolves during whole-body endurance performance and whether this is a determining factor. Methods: Three electronic databases were searched for studies related to the assessment of PFC oxygenation, through near-IR spectroscopy (NIRS), during endurance exercise. To express PFC oxygenation, oxygenated (HbO2) and deoxygenated hemoglobin (HHb) concentrations were the primary outcome measures. Results: Twenty-eight articles were included. Ten articles focused on assessing prefrontal oxygenation through a maximal incremental test (MIT) and 18 focused on using endurance tasks at workloads ranging from low intensity to supramaximal intensity. In four MIT studies measuring HbO2, an increase of HbO2 was noticed at the respiratory compensation point (RCP), after which it decreased. HbO2 reached a steady state in the four studies and increased in one study until exhaustion. All studies found a decrease or steady state in HHb from the start until RCP and an increase to exhaustion. In regard to (non-incremental) endurance tasks, a general increase in PFC oxygenation was found while achieving a steady state at vigorous intensities. PCF deoxygenation was evident for near-to-maximal intensities at which an increase in oxygenation and the maintenance of a steady state could not be retained. Discussion/Conclusion: MIT studies show the presence of a cerebral oxygenation threshold (ThCox) at RCP. PFC oxygenation increases until the RCP threshold, thereafter, a steady state is reached and HbO2 declines. This study shows that the results obtained from MIT are transferable to non-incremental endurance exercise. HbO2 increases during low-intensity and moderate-intensity until vigorous-intensity exercise, and it reaches a steady state in vigorous-intensity exercise. Furthermore, ThCox can be found between vigorous and near-maximal intensities. During endurance exercise at near-maximal intensities, PFC oxygenation increases until the value exceeding this threshold, resulting in a decrease in PFC oxygenation. Future research should aim at maintaining and improving PFC oxygenation to help in improving endurance performance and to examine whether PFC oxygenation has a role in other performance-limiting factors.
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Affiliation(s)
- Jonas De Wachter
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
| | - Matthias Proost
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
| | - Jelle Habay
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
| | - Matthias Verstraelen
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
| | - Jesús Díaz-García
- Faculty of Sport Sciences, University of Extremadura, Caceres, Spain
| | - Philip Hurst
- The School of Psychology & Life Sciences, Canterbury Christ Church University, Canterbury, United Kingdom
| | - Romain Meeusen
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
| | - Jeroen Van Cutsem
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium.,VIPER Research Unit, Royal Military Academy, Brussels, Belgium
| | - Bart Roelands
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
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13
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Rabello R, Nodari C, Scudiero F, Borges I, Fitarelli L, Bianchesse J, Rodrigues R. Effects of task and hip-abductor fatigue on lower limb alignment and muscle activation. SPORT SCIENCES FOR HEALTH 2021. [DOI: 10.1007/s11332-021-00854-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Abstract
Purpose
Fatigue-induced hip-abductor weakness may exacerbate lower-limb misalignments during different dynamic single-leg tasks. We sought to evaluate the effects of fatigue and task on lower limb kinematics and muscle activation and to find associations between measurements obtained in two tasks.
Methods
One-group pretest–posttest design. Seventeen healthy adults (9 W) performed the single-leg squat (SLSQUAT) and the single-leg hop (SLHOP) before and after a hip-abduction fatigue protocol. Hip adduction, knee frontal plane projection angle (knee FPPA) and heel inversion displacement were measured during the eccentric phase of the SLSQUAT and the SLHOP, as well as activation of the gluteus medius (GMed), tensor fascia latae (TFL), peroneus longus (PER) and tibialis anterior (TA). Moments and tasks were compared using a repeated-measures two-way ANOVA. Correlation between tasks was evaluated using Spearman’s correlation.
Results
No differences in kinematics or activation were found between moments. Hip-adduction displacement (P = 0.005), GMed (P = 0.008) and PER (P = 0.037) activation were higher during SLSQUAT, while TA activation was higher during SLHOP (P < 0.001). No differences were found between tasks in knee FPPA and heel inversion. Hip-adduction and knee FPPA were not correlated between tasks, while ankle inversion displacement was positively correlated (rs = 0.524–0.746).
Conclusion
Different characteristics of SLSQUAT (slower and deeper) seem to have led to increased hip adduction displacement, GMed, and PER activation and decreased TA activation, likely due to higher balance requirements. However, hip-abductor fatigue didn’t influence lower-limb alignment during the tasks. Finally, evaluations should be performed with different single-leg tasks since they don’t give the same lower-limb alignment information.
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14
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de Korte JQ, Bongers CCWG, Hopman MTE, Teunissen LPJ, Jansen KMB, Kingma BRM, Ballak SB, Maase K, Moen MH, van Dijk JW, Daanen HAM, Eijsvogels TMH. Performance and thermoregulation of Dutch Olympic and Paralympic athletes exercising in the heat: Rationale and design of the Thermo Tokyo study: The journal Temperature toolbox. Temperature (Austin) 2021; 8:209-222. [PMID: 34485618 PMCID: PMC8409773 DOI: 10.1080/23328940.2021.1925618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The environmental conditions during the Tokyo Olympic and Paralympic Games are expected to be challenging, which increases the risk for participating athletes to develop heat-related illnesses and experience performance loss. To allow safe and optimal exercise performance of Dutch elite athletes, the Thermo Tokyo study aimed to determine thermoregulatory responses and performance loss among elite athletes during exercise in the heat, and to identify personal, sports-related, and environmental factors that contribute to the magnitude of these outcomes. For this purpose, Dutch Olympic and Paralympic athletes performed two personalized incremental exercise tests in simulated control (15°C, relative humidity (RH) 50%) and Tokyo (32°C, RH 75%) conditions, during which exercise performance and (thermo)physiological parameters were obtained. Thereafter, athletes were invited for an additional visit to conduct anthropometric, dual-energy X-ray absorptiometry (DXA), and 3D scan measurements. Collected data also served as input for a thermophysiological computer simulation model to estimate the impact of a wider range of environmental conditions on thermoregulatory responses. Findings of this study can be used to inform elite athletes and their coaches on how heat impacts their individual (thermo)physiological responses and, based on these data, advise which personalized countermeasures (i.e. heat acclimation, cooling interventions, rehydration plan) can be taken to allow safe and maximal performance in the challenging environmental conditions of the Tokyo 2020 Olympic and Paralympic Games.
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Affiliation(s)
- Johannus Q de Korte
- Department of Physiology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, The Netherlands
| | - Coen C W G Bongers
- Department of Physiology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, The Netherlands.,Faculty of Health Sciences, Thermal Ergonomics Laboratory, The University of Sydney, Sydney, Australia
| | - Maria T E Hopman
- Department of Physiology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, The Netherlands
| | - Lennart P J Teunissen
- Department of Design Engineering, Delft University of Technology, Delft, The Netherlands
| | - Kaspar M B Jansen
- Department of Design Engineering, Delft University of Technology, Delft, The Netherlands
| | - Boris R M Kingma
- Department of Training and Performance Innovations, Unit Defence, Safety and Security, TNO, the Netherlands Organization for Applied Sciences, Soesterberg, The Netherlands.,Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, University of Copenhagen, Copenhagen, Denmark
| | - Sam B Ballak
- Sport Science & Innovation Papendal, Sportcentrum Papendal, Arnhem, The Netherlands
| | - Kamiel Maase
- Netherlands Olympic Committee Netherlands Sports Federation, Arnhem, The Netherlands
| | - Maarten H Moen
- Netherlands Olympic Committee Netherlands Sports Federation, Arnhem, The Netherlands
| | - Jan-Willem van Dijk
- Institute of Sport and Exercise Studies, HAN University of Applied Sciences, Nijmegen, The Netherlands
| | - Hein A M Daanen
- Faculty of Behavioural and Movement Sciences, VU University Amsterdam, Amsterdam, The Netherlands.,Sizing Science, Soesterberg, The Netherlands
| | - Thijs M H Eijsvogels
- Department of Physiology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, The Netherlands
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15
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de Korte JQ, Bongers CCWG, Hopman MTE, Eijsvogels TMH. Exercise Performance and Thermoregulatory Responses of Elite Athletes Exercising in the Heat: Outcomes of the Thermo Tokyo Study. Sports Med 2021; 51:2423-2436. [PMID: 34396493 PMCID: PMC8514392 DOI: 10.1007/s40279-021-01530-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2021] [Indexed: 11/30/2022]
Abstract
Objective We examined the impact of simulated Tokyo 2020 environmental condition on exercise performance, thermoregulatory responses and thermal perception among Dutch elite athletes. Methods 105 elite athletes from different sport disciplines performed two exercise tests in simulated control (15.9 ± 1.2 °C, relative humidity (RH) 55 ± 6%) and Tokyo (31.6 ± 1.0 °C, RH 74 ± 5%) environmental conditions. Exercise tests consisted of a 20-min warm-up (70% HRmax), followed by an incremental phase until volitional exhaustion (5% workload increase every 3 min). Gastrointestinal temperature (Tgi), heart rate, exercise performance and thermal perception were measured. Results Time to exhaustion was 16 ± 8 min shorter in the Tokyo versus the control condition (− 26 ± 11%, whereas peak power output decreased with 0.5 ± 0.3 W/kg (16 ± 7%). Greater exercise-induced increases in Tgi (1.8 ± 0.6 °C vs. 1.5 ± 0.5 °C, p < 0.001) and higher peak Tgi (38.9 ± 0.6 °C vs. 38.7 ± 0.4 °C, p < 0.001) were found in the Tokyo versus control condition. Large interindividual variations in exercise-induced increase in Tgi (range 0.7–3.5 °C) and peak Tgi (range 37.6–40.4 °C) were found in the Tokyo condition, with greater Tgi responses in endurance versus mixed- and skill-trained athletes. Peak thermal sensation and thermal comfort scores deteriorated in the Tokyo condition, with aggravated responses for power versus endurance- and mixed-trained athletes. Conclusion Large performance losses and Tgi increases were found among elite athletes exercising in simulated Tokyo conditions, with a substantial interindividual variation and significantly different responses across sport disciplines. These findings highlight the importance of an individual approach to optimally prepare athletes for safe and maximal exercise performance during the Tokyo Olympics. Supplementary Information The online version contains supplementary material available at 10.1007/s40279-021-01530-w.
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Affiliation(s)
- Johannus Q de Korte
- Department of Physiology (392), Radboud University Medical Centre, Radboud Institute for Health Sciences, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Coen C W G Bongers
- Department of Physiology (392), Radboud University Medical Centre, Radboud Institute for Health Sciences, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Maria T E Hopman
- Department of Physiology (392), Radboud University Medical Centre, Radboud Institute for Health Sciences, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Thijs M H Eijsvogels
- Department of Physiology (392), Radboud University Medical Centre, Radboud Institute for Health Sciences, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
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16
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Effects of Acute Exposure to Thermal Stress on Cardiorespiratory Function, Skeletal Muscle Oxygenation, and Exercise Performance in Healthy Males. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18147404. [PMID: 34299853 PMCID: PMC8307583 DOI: 10.3390/ijerph18147404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/09/2021] [Accepted: 07/09/2021] [Indexed: 11/25/2022]
Abstract
We investigated the effects of acute thermal stress (30 °C and 40 °C) and ordinary temperature (20 °C) on cardiorespiratory function, skeletal muscle oxygenation, and exercise performance in healthy men. Eleven healthy males (21.5 ± 2.3 years) performed a graded exercise test (GXT) using a cycle ergometer in each environmental condition (20 °C, 30 °C, and 40 °C) in a random order with an interval of 1 week between each test. Before the test, they were allowed to rest for 30 min in a given environmental condition. All dependent variables (body temperature, cardiorespiratory function parameters, skeletal muscle oxygenation profiles, and exercise performance) were measured at rest and during GXT. GXT was started at 50 W and increased by 25 W every 2 min until subjects were exhausted. Body temperature increased proportionally at rest and at the end of exercise as thermal stress increased. There were no differences in the rating of perceived exertion, oxygen uptake, respiratory exchange ratio, and carbon dioxide excretion between environmental conditions. Heart rate (HR), minute ventilation (VE), and blood lactate levels were significantly higher at 30 °C and 40 °C than at 20 °C, and oxygen pulse was significantly lower at 40 °C than at 20 °C at various exercise loads. None of the skeletal muscle oxygenation profiles showed significant changes at rest or during exercise. Maximal oxygen uptake, peak power, and exercise time significantly decreased proportionally as thermal stress increased, and this decrease was most pronounced at 40 °C. Acute thermal stress induces a decrease in exercise performance via increased body temperature, HR, VE, and blood lactate levels and decreased oxygen pulse during load-homogenized exercise. This phenomenon was more prominent at 40 °C than at 30 °C and 20 °C.
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17
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Yamaguchi K, Kasai N, Hayashi N, Yatsutani H, Girard O, Goto K. Acute performance and physiological responses to repeated-sprint exercise in a combined hot and hypoxic environment. Physiol Rep 2021; 8:e14466. [PMID: 32592261 PMCID: PMC7319945 DOI: 10.14814/phy2.14466] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
We investigated performance, energy metabolism, acid-base balance, and endocrine responses to repeated-sprint exercise in hot and/or hypoxic environment. In a single-blind, cross-over study, 10 male highly trained athletes completed a repeated cycle sprint exercise (3 sets of 3 × 10-s maximal sprints with 40-s passive recovery) under four conditions (control [CON; 20℃, 50% rH, FiO2 : 20.9%; sea level], hypoxia [HYP; 20℃, 50% rH, FiO2 : 14.5%; a simulated altitude of 3,000 m], hot [HOT; 35℃, 50% rH, FiO2 : 20.9%; sea level], and hot + hypoxia [HH; 35℃, 50% rH, FiO2 : 14.5%; a simulated altitude of 3,000 m]). Changes in power output, muscle and skin temperatures, and respiratory oxygen uptake were measured. Peak (CON: 912 ± 26 W, 95% confidence interval [CI]: 862-962 W, HYP: 915 ± 28 W [CI: 860-970 W], HOT: 937 ± 26 W [CI: 887-987 W], HH: 937 ± 26 W [CI: 886-987 W]) and mean (CON: 808 ± 22 W [CI: 765-851 W], HYP: 810 ± 23 W [CI: 765-855 W], HOT: 825 ± 22 W [CI: 781-868 W], HH: 824 ± 25 W [CI: 776-873 W]) power outputs were significantly greater when exercising in heat conditions (HOT and HH) during the first sprint (p < .05). Heat exposure (HOT and HH) elevated muscle and skin temperatures compared to other conditions (p < .05). Oxygen uptake and arterial oxygen saturation were significantly lower in hypoxic conditions (HYP and HH) versus the other conditions (p < .05). In summary, additional heat stress when sprinting repeatedly in hypoxia improved performance (early during exercise), while maintaining low arterial oxygen saturation.
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Affiliation(s)
- Keiichi Yamaguchi
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Nobukazu Kasai
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan.,Department of Sports Science, Japan Institute of Sports Sciences, Kitaku, Tokyo, Japan
| | - Nanako Hayashi
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Haruka Yatsutani
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Olivier Girard
- School of Human Science (Exercise and Sport Science), The University of Western Australia, Crawley, Australia
| | - Kazushige Goto
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
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18
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Electromyography: A Simple and Accessible Tool to Assess Physical Performance and Health during Hypoxia Training. A Systematic Review. SUSTAINABILITY 2020. [DOI: 10.3390/su12219137] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hypoxia causes reduced partial pressure of oxygen in arterial blood and induces adaptations in skeletal muscle that may affect individuals’ physical performance and muscular health. These muscular changes are detectable and quantifiable by electromyography (EMG), an instrument that assesses electrical activity during active contraction at rest. EMG is a relatively simple and accessible technique for all patients, one that can show the degree of the sensory and motor functions because it provides information about the status of the peripheral nerves and muscles. The main goal of this review is to evaluate the scientific evidence of EMG as an instrument for monitoring different responses of skeletal muscles subjected to external stimuli such as hypoxia and physical activity. A structured search was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines in Medline/PubMed, Scielo, Google Scholar, Web of Science, and Cochrane Library Plus. The search included articles published in the last 25 years until May 2020 and was restricted to English- and Spanish-language publications. As such, investigators identified nine articles that met the search criteria. The results determined that EMG was able to detect muscle fatigue from changes in the frequency spectrum. When a muscle was fatigued, high frequency components decreased and low frequency components increased. In other studies, EMG determined muscle activation increased during exercise by recruiting motor units and by increasing the intensity of muscle contractions. Finally, it was also possible to calculate the mean quadriceps quadratic activity used to obtain an image of muscle activation. In conclusion, EMG offers a suitable tool for monitoring the different skeletal muscle responses and has sufficient sensitivity to detect hypoxia-induced muscle changes produced by hypoxic stimuli. Moreover, EMG enhances an extension of physical examination and tests motor-system integrity.
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19
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McCleave EL, Slattery KM, Duffield R, Crowcroft S, Abbiss CR, Wallace LK, Coutts AJ. Concurrent Heat and Intermittent Hypoxic Training: No Additional Performance Benefit Over Temperate Training. Int J Sports Physiol Perform 2020; 15:1260-1271. [PMID: 32937599 DOI: 10.1123/ijspp.2019-0277] [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] [Received: 04/10/2019] [Revised: 12/08/2019] [Accepted: 12/16/2019] [Indexed: 11/18/2022]
Abstract
PURPOSE To examine whether concurrent heat and intermittent hypoxic training can improve endurance performance and physiological responses relative to independent heat or temperate interval training. METHODS Well-trained male cyclists (N = 29) completed 3 weeks of moderate- to high-intensity interval training (4 × 60 min·wk-1) in 1 of 3 conditions: (1) heat (HOT: 32°C, 50% relative humidity, 20.8% fraction of inspired oxygen, (2) heat + hypoxia (H+H: 32°C, 50% relative humidity, 16.2% fraction of inspired oxygen), or (3) temperate environment (CONT: 22°C, 50% relative humidity, 20.8% fraction of inspired oxygen). Performance 20-km time trials (TTs) were conducted in both temperate (TTtemperate) and assigned condition (TTenvironment) before (base), immediately after (mid), and after a 3-week taper (end). Measures of hemoglobin mass, plasma volume, and blood volume were also assessed. RESULTS There was improved 20-km TT performance to a similar extent across all groups in both TTtemperate (mean ±90% confidence interval HOT, -2.8% ±1.8%; H+H, -2.0% ±1.5%; CONT, -2.0% ±1.8%) and TTenvironment (HOT, -3.3% ±1.7%; H+H, -3.1% ±1.6%; CONT, -3.2% ±1.1%). Plasma volume (HOT, 3.8% ±4.7%; H+H, 3.3% ±4.7%) and blood volume (HOT, 3.0% ±4.1%; H+H, 4.6% ±3.9%) were both increased at mid in HOT and H+H over CONT. Increased hemoglobin mass was observed in H+H only (3.0% ±1.8%). CONCLUSION Three weeks of interval training in heat, concurrent heat and hypoxia, or temperate environments improve 20-km TT performance to the same extent. Despite indications of physiological adaptations, the addition of independent heat or concurrent heat and hypoxia provided no greater performance benefits in a temperate environment than temperate training alone.
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20
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Coombs GB, Cramer MN, Ravanelli N, Imbeault P, Jay O. Normobaric hypoxia does not alter the critical environmental limits for thermal balance during exercise‐heat stress. Exp Physiol 2020; 106:359-369. [DOI: 10.1113/ep088466] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 03/18/2020] [Indexed: 11/08/2022]
Affiliation(s)
- Geoff B. Coombs
- School of Human Kinetics, Faculty of Health Sciences University of Ottawa ON Canada
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences University of British Columbia (Okanagan) Kelowna BC Canada
| | - Matthew N. Cramer
- School of Human Kinetics, Faculty of Health Sciences University of Ottawa ON Canada
- Defence Research and Development Canada Toronto Research Centre Toronto ON Canada
| | - Nicholas Ravanelli
- Cardiovascular Prevention and Rehabilitation Centre and Research Centre Montreal Heart Institute Montreal QC Canada
- Département de pharmacologie et physiologie Université de Montréal Montreal QC Canada
| | - Pascal Imbeault
- School of Human Kinetics, Faculty of Health Sciences University of Ottawa ON Canada
| | - Ollie Jay
- School of Human Kinetics, Faculty of Health Sciences University of Ottawa ON Canada
- University of Sydney, Faculty of Medicine and Health Thermal Ergonomics Laboratory Sydney NSW Australia
- University of Sydney Charles Perkins Centre Sydney NSW Australia
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21
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Hayashi N, Yatsutani H, Mori H, Ito H, Badenhorst CE, Goto K. No effect of supplemented heat stress during an acute endurance exercise session in hypoxia on hepcidin regulation. Eur J Appl Physiol 2020; 120:1331-1340. [PMID: 32303828 DOI: 10.1007/s00421-020-04365-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 04/04/2020] [Indexed: 12/21/2022]
Abstract
Hepcidin is a novel factor for iron deficiency in athletes, which is suggested to be regulated by interleukin-6 (IL-6) or erythropoietin (EPO). PURPOSE The purpose of the present study was to compare endurance exercise-induced hepcidin elevation among "normoxia", "hypoxia" and "combined heat and hypoxia". METHODS Twelve males (21.5 ± 0.3 years, 168.1 ± 1.2 cm, 63.6 ± 2.0 kg) participated in the present study. They performed 60 min of cycling at 60% of [Formula: see text] in either "heat and hypoxia" (HHYP; FiO2 14.5%, 32 °C), "hypoxia" (HYP; FiO2 14.5%, 23 °C) or "normoxia" (NOR; FiO2 20.9%, 23 °C). After completing the exercise, participants remained in the prescribed conditions for 3 h post-exercise. Blood samples were collected before, immediately and 3 h after exercise. RESULTS Plasma IL-6 level significantly increased immediately after exercise (P < 0.05), with no significant difference among the trials. A significant elevation in serum EPO was observed 3 h after exercise in hypoxic trials (HHYP and HYP, P < 0.05), with no significant difference between HHYP and HYP. Serum hepcidin level increased 3 h after exercise in all trials (NOR, before 18.3 ± 3.9 and post180 31.2 ± 6.3 ng/mL; HYP, before 13.5 ± 2.5 and post180 23.3 ± 3.6 ng/mL, HHYP; before 15.8 ± 3.3 and post180 31.4 ± 5.3 ng/mL, P < 0.05). However, there was no significant difference among the trials during post-exercise. CONCLUSION Endurance exercise in "combined heat and hypoxia" did not exacerbate exercise-induced hepcidin elevation compared with the same exercise in "hypoxia" or "normoxia".
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Affiliation(s)
- Nanako Hayashi
- Graduate School of Sport and Health Science, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Haruka Yatsutani
- Graduate School of Sport and Health Science, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Hisashi Mori
- School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan
| | - Hiroto Ito
- Graduate School of Sport and Health Science, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Claire E Badenhorst
- School of Sport, Exercise and Nutrition, Massey University, Auckland, New Zealand
| | - Kazushige Goto
- Graduate School of Sport and Health Science, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga, 525-8577, Japan.
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No ergogenic effects of a 10-day combined heat and hypoxic acclimation on aerobic performance in normoxic thermoneutral or hot conditions. Eur J Appl Physiol 2019; 119:2513-2527. [PMID: 31555926 DOI: 10.1007/s00421-019-04215-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 08/21/2019] [Indexed: 10/25/2022]
Abstract
PURPOSE Hypoxic acclimation enhances convective oxygen delivery to the muscles. Heat acclimation-elicited thermoregulatory benefits have been suggested not to be negated by adding daily exposure to hypoxia. Whether concomitant acclimation to both heat and hypoxia offers a synergistic enhancement of aerobic performance in thermoneutral or hot conditions remains unresolved. METHODS Eight young males ([Formula: see text]: 51.6 ± 4.6 mL min-1 kg-1) underwent a 10-day normobaric hypoxic confinement (FiO2 = 0.14) interspersed with daily 90-min normoxic controlled hyperthermia (target rectal temperature: 38.5 °C) exercise sessions. Prior to, and following the confinement, the participants conducted a 30-min steady-state exercise followed by incremental exercise to exhaustion on a cycle ergometer in thermoneutral normoxic (NOR), thermoneutral hypoxic (FiO2 = 0.14; HYP) and hot (35 °C, 50% relative humidity; HE) conditions in a randomized and counterbalanced order. The steady-state exercise was performed at 40% NOR peak power output (Wpeak) to evaluate thermoregulatory function. Blood samples were obtained from an antecubital vein before, on days 1 and 10, and the first day post-acclimation. RESULTS [Formula: see text] and ventilatory thresholds were not modified in any environment following acclimation. Wpeak increased by 6.3 ± 3.4% in NOR and 4.0 ± 4.9% in HE, respectively. The magnitude and gain of the forehead sweating response were augmented in HE post-acclimation. EPO increased from baseline (17.8 ± 7.0 mIU mL-1) by 10.7 ± 8.8 mIU mL-1 on day 1 but returned to baseline levels by day 10 (15.7 ± 5.9 mIU mL-1). DISCUSSION A 10-day combined heat and hypoxic acclimation conferred only minor benefits in aerobic performance and thermoregulation in thermoneutral or hot conditions. Thus, adoption of such a protocol does not seem warranted.
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A comparison of different methods to analyse data collected during time-to-exhaustion tests. SPORT SCIENCES FOR HEALTH 2019. [DOI: 10.1007/s11332-019-00585-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Abstract
Purpose
Despite their widespread use in exercise physiology, time-to-exhaustion (TTE) tests present an often-overlooked challenge to researchers, which is how to computationally deal with between- and within-subject differences in exercise duration. We aimed to verify the best analysis method to overcome this problem.
Methods
Eleven cyclists performed an incremental test and three TTE tests differing in workload as preliminary tests. The TTEs were used to derive the individual power–duration relationship needed to set the workload (corresponding to an estimated TTE of 1200 s) for four identical experimental TTE tests. Within individuals, the four tests were subsequently rank ordered by performance. Physiological and psychological variables expected to change with performance were analysed using different methods, with the main aim being to compare the traditional “group isotime” method and a less-used “individual isotime” method.
Results
The four tests, ranked from the best to the worst, had a TTE of 1526 ± 332, 1425 ± 313, 1295 ± 325, and 1026 ± 265 s. Ratings of perceived exertion, minute ventilation, respiratory frequency, and affective valence were sensitive to changes in performance when their responses were analysed with the “individual isotime” method (P < 0.022, ηp2 > 0.144) but not when using the “group isotime” method, because the latter resulted in partial data loss.
Conclusions
The use of the “individual isotime” method is strongly encouraged to avoid the misinterpretation of the phenomenon under study. Important implications are not limited to constant-workload exercise, but extend to incremental exercise, which is another commonly used test of exercise tolerance.
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Levine A, Buono MJ. Rating of perceived exertion increases synergistically during prolonged exercise in a combined heat and hypoxic environment. J Therm Biol 2019; 84:99-102. [PMID: 31466796 DOI: 10.1016/j.jtherbio.2019.06.006] [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] [Received: 02/21/2019] [Revised: 05/31/2019] [Accepted: 06/03/2019] [Indexed: 11/29/2022]
Abstract
The purpose of this study was to determine the cardiovascular, thermoregulatory, and perceived exertion responses during 2 h of moderate intensity exercise in a combined high heat (38 °C, 40% relative humidity) and hypoxic (15% O2) environment. Ten healthy volunteers completed 2 h of treadmill walking at 40% of maximal oxygen uptake in four different conditions, each separated by approximately 1 week: (1) control, 23 °C/20.9% O2, (2) heat, 38 °C/20.9% O2, (3) hypoxia, 23 °C/15% O2, and (4) combined heat/hypoxia, 38 °C/15% O2. Compared to the responses seen in each condition alone, heart rate (HR) and core temperature (Tcore) showed an additive increase in the combined heat and hypoxic environment after 2 h of moderate intensity exercise. The most important new finding was that the mean rating of perceived exertion (RPE) increased synergistically 3.3 units when exercising in the combined high heat and hypoxic environment, compared to 1.9 units in the heat condition alone. The results suggest that RPE is a conscious perception of effort that plays a regulatory function to ensure that the work rate remains at an intensity that can be safely sustained, rather than simply a marker of exercise intensity. Such results also support previous anecdotal reports that exercise on hot days at altitude seem unusually difficult.
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Affiliation(s)
- Ashley Levine
- School of Exercise and Nutritional Sciences, San Diego State University San Diego, CA, 92182, United States
| | - Michael J Buono
- Biology Department, San Diego State University, San Diego, CA, 92182, United States; School of Exercise and Nutritional Sciences, San Diego State University San Diego, CA, 92182, United States.
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25
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Douzi W, Dugué B, Vinches L, Al Sayed C, Hallé S, Bosquet L, Dupuy O. Cooling during exercise enhances performances, but the cooled body areas matter: A systematic review with meta‐analyses. Scand J Med Sci Sports 2019; 29:1660-1676. [DOI: 10.1111/sms.13521] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 07/10/2019] [Accepted: 07/17/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Wafa Douzi
- Laboratoire Mobilité Vieillissement Exercice (MOVE)‐EA6314, Faculty of Sport Sciences University of Poitiers Poitiers France
| | - Benoit Dugué
- Laboratoire Mobilité Vieillissement Exercice (MOVE)‐EA6314, Faculty of Sport Sciences University of Poitiers Poitiers France
| | - Ludwig Vinches
- Department of Mechanical Engineering ‐ Ecole de Technologie Supérieure Montréal QC Canada
| | - Chady Al Sayed
- Department of Mechanical Engineering ‐ Ecole de Technologie Supérieure Montréal QC Canada
| | - Stéphane Hallé
- Department of Mechanical Engineering ‐ Ecole de Technologie Supérieure Montréal QC Canada
| | - Laurent Bosquet
- Laboratoire Mobilité Vieillissement Exercice (MOVE)‐EA6314, Faculty of Sport Sciences University of Poitiers Poitiers France
| | - Olivier Dupuy
- Laboratoire Mobilité Vieillissement Exercice (MOVE)‐EA6314, Faculty of Sport Sciences University of Poitiers Poitiers France
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26
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Bradbury KE, Coffman KE, Mitchell KM, Luippold AJ, Fulco CS, Kenefick RW. Separate and combined influences of heat and hypobaric hypoxia on self-paced aerobic exercise performance. J Appl Physiol (1985) 2019; 127:513-519. [PMID: 31219777 DOI: 10.1152/japplphysiol.00023.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Heat and hypobaric hypoxia independently compromise exercise performance; however, their combined impact on exercise performance has yet to be quantified. This study examined the effects of heat, hypobaric hypoxia, and the combination of these environments on self-paced cycling time trial (TT) performance. Twelve subjects [2 female, 10 male; sea level (SL) peak oxygen consumption (V̇o2peak), 41.5 ± 4.4 mL·kg-1·min-1, mean ± SD] completed 30 min of steady-state cycling exercise (50% SL V̇o2peak), followed by a 15-min self-paced TT in four environmental conditions: SL thermoneutral [SLTN; 250 m, 20°C, 30-50% relative humidity (rh)], SL hot (SLH; 250 m, 35°C, 30% rh), hypobaric hypoxia thermoneutral (HTN; 3,000 m, 20°C, 30-50% rh), and hypobaric hypoxia hot (HH; 3,000 m, 35°C, 30% rh). Performance was assessed by the total work (kJ) completed. TT performance was lower (P < 0.05) in SLH, HTN, and HH relative to SLTN (-15.4 ± 9.7, -24.1 ± 16.2, and -33.1 ± 13.4 kJ, respectively). Additionally, the total work completed in HTN and HH was lower (P < 0.05) than that in SLH. In SLH, HTN, and HH, work rate was reduced versus SLTN (P < 0.05) within the first 3 min of exercise and was consistent for the remainder of the bout. No differences (P > 0.05) existed for heart rate or Ratings of Perceived Exertion at the end of exercise among conditions. The decrease in self-paced TT performance in the heat and/or hypobaric hypoxia conditions compared with SLTN conditions resulted from a nearly immediate reduction in work rate that may have been regulated by environmentally induced changes in physiological strain and perception of effort in response to TT exercise.NEW & NOTEWORTHY This is the first known study to examine the combined effects of heat and hypobaric hypoxia on short-duration self-paced cycling time trial performance. Regardless of environmental condition, subjects utilized an even work rate for the entire duration of the time trial. The presence of both environmental stressors led to a greater performance impairment than heat or hypobaric hypoxia alone, and the performance decrement stemmed from an early reduction of work rate.
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Affiliation(s)
- Karleigh E Bradbury
- Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Kirsten E Coffman
- Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Katherine M Mitchell
- Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Adam J Luippold
- Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Charles S Fulco
- Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Robert W Kenefick
- Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts
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Dekerle J, Ansdell P, Schäfer L, Greenhouse-Tucknott A, Wrightson J. Methodological issues with the assessment of voluntary activation using transcranial magnetic stimulation in the knee extensors. Eur J Appl Physiol 2019; 119:991-1005. [PMID: 30746563 DOI: 10.1007/s00421-019-04089-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 01/30/2019] [Indexed: 12/24/2022]
Abstract
PURPOSE The assessment of voluntary activation of the knee extensors using transcranial magnetic stimulation (VATMS) is routinely performed to assess the supraspinal function. Yet methodological scrutiny of the technique is scarce. The aim of the present study was to examine face validity and reliability of VATMS and its two main determinants (superimposed twitch during a maximal voluntary contraction [SIT100%] and estimated resting twitch [ERT]). METHODS SIT100%, ERT, and VATMS were measured on ten healthy males (age 24 ± 5 years) before and following intermittent isometric fatiguing exercise on two separate occasions. RESULTS The findings indicated issues regarding the accuracy of ERT and suggested a three-point relationship should not be used to determine ERT. Reliabilities for VATMS, SIT100%, and ERT were acceptable pre- but much weaker post-exercise (especially for SIT100%). Despite statistically significant changes in main neuromuscular variables following the intermittent isometric fatiguing exercise (P < 0.05), when post-exercise reliability was considered, the exercise effect on VATMS was smaller than the smallest detectable change in 18 of the 20 individual tests performed, and for the whole sample for one of two visits. Finally, maximal voluntary contraction was reduced significantly following the neuromuscular assessment (NMA) pre-exercise but recovered during the NMA post-exercise. CONCLUSION This is the first study to demonstrate a lack of sensitivity of key neuromuscular measurements to exercise and to evidence both presence of neuromuscular fatigue following the NMA in itself, and recovery of the neuromuscular function during the NMA post-exercise. These results challenge the face validity of this routinely used protocol.
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Affiliation(s)
- Jeanne Dekerle
- Fatigue and Exercise Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, East Sussex, Eastbourne, UK.
| | - P Ansdell
- Fatigue and Exercise Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, East Sussex, Eastbourne, UK.,Department of Sport, Exercise and Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Northumbria, UK
| | - L Schäfer
- Fatigue and Exercise Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, East Sussex, Eastbourne, UK
| | - A Greenhouse-Tucknott
- Fatigue and Exercise Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, East Sussex, Eastbourne, UK
| | - J Wrightson
- Fatigue and Exercise Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, East Sussex, Eastbourne, UK.,Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Canada
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28
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Deb SK, Brown DR, Gough LA, Mclellan CP, Swinton PA, Andy Sparks S, Mcnaughton LR. Quantifying the effects of acute hypoxic exposure on exercise performance and capacity: A systematic review and meta-regression. Eur J Sport Sci 2017; 18:243-256. [PMID: 29220311 DOI: 10.1080/17461391.2017.1410233] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE To quantify the effects of acute hypoxic exposure on exercise capacity and performance, which includes continuous and intermittent forms of exercise. DESIGN A systematic review was conducted with a three-level mixed effects meta-regression. The ratio of means method was used to evaluate main effects and moderators providing practical interpretations with percentage change. DATA SOURCES A systemic search was performed using three databases (Google scholar, PubMed and SPORTDiscus). Eligibility criteria for selecting studies: Inclusion was restricted to investigations that assessed exercise performance (time trials (TTs), sprint and intermittent exercise tests) and capacity (time to exhaustion test, TTE) with acute hypoxic (<24 h) exposure and a normoxic comparator. RESULTS Eighty-two outcomes from 53 studies (N = 798) were included in this review. The results show an overall reduction in exercise performance/capacity -17.8 ± 3.9% (95% CI -22.8% to -11.0%), which was significantly moderated by -6.5 ± 0.9% per 1000 m altitude elevation (95% CI -8.2% to -4.8%) and oxygen saturation (-2.0 ± 0.4%; 95% CI -2.9% to -1.2%). TT (-16.2 ± 4.3%; 95% CI -22.9% to -9%) and TTE (-44.5 ± 6.9%; 95% CI -51.3% to -36.7%) elicited a negative effect, whilst indicating a quadratic relationship between hypoxic magnitude and both TTE and TT performance. Furthermore, exercise less than 2 min exhibited no ergolytic effect from acute hypoxia. Summary/Conclusion: This review highlights the ergolytic effect of acute hypoxic exposure, which is curvilinear for TTE and TT performance with increasing hypoxic levels, but short duration intermittent and sprint exercise seem to be unaffected.
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Affiliation(s)
- Sanjoy K Deb
- a Sports Nutriton and Performance Research Group, Department of Sport and Physical Activity , Edge Hill University , Ormskirk , UK
| | - Daniel R Brown
- a Sports Nutriton and Performance Research Group, Department of Sport and Physical Activity , Edge Hill University , Ormskirk , UK
| | - Lewis A Gough
- a Sports Nutriton and Performance Research Group, Department of Sport and Physical Activity , Edge Hill University , Ormskirk , UK
| | | | - Paul A Swinton
- c School of Health Sciences , Robert Gordon University , Aberdeen , UK
| | - S Andy Sparks
- a Sports Nutriton and Performance Research Group, Department of Sport and Physical Activity , Edge Hill University , Ormskirk , UK
| | - Lars R Mcnaughton
- a Sports Nutriton and Performance Research Group, Department of Sport and Physical Activity , Edge Hill University , Ormskirk , UK.,d Department of Sport and Movement Studies, Faculty of Health Science , University of Johannesburg , Johannesburg , South Africa
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29
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Lloyd A, Havenith G. Interactions in human performance: An individual and combined stressors approach. Temperature (Austin) 2016; 3:514-517. [PMID: 28090553 PMCID: PMC5198808 DOI: 10.1080/23328940.2016.1189991] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Alex Lloyd
- Environmental Ergonomics Research Center, Design School Loughborough University , Loughborough, UK
| | - George Havenith
- Environmental Ergonomics Research Center, Design School Loughborough University , Loughborough, UK
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30
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PÉRIARD JULIEND, RACINAIS SÉBASTIEN. Performance and Pacing during Cycle Exercise in Hyperthermic and Hypoxic Conditions. Med Sci Sports Exerc 2016; 48:845-53. [DOI: 10.1249/mss.0000000000000839] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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31
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Lloyd A, Raccuglia M, Hodder S, Havenith G. Interaction between environmental temperature and hypoxia on central and peripheral fatigue during high-intensity dynamic knee extension. J Appl Physiol (1985) 2016; 120:567-79. [PMID: 26769955 DOI: 10.1152/japplphysiol.00876.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 01/06/2016] [Indexed: 11/22/2022] Open
Abstract
This study investigated causative factors behind the expression of different interaction types during exposure to multistressor environments. Neuromuscular fatigue rates and time to exhaustion (TTE) were investigated in active men (n = 9) exposed to three climates [5 °C, 50% relative humidity (rh); 23 °C, 50% rh; and 42 °C, 70% rh] at two inspired oxygen fractions (0.209 and 0.125 FiO2; equivalent attitude = 4,100 m). After a 40-min rest in the three climatic conditions, participants performed constant-workload (high intensity) knee extension exercise until exhaustion, with brief assessments of neuromuscular function every 110 s. Independent exposure to cold, heat, and hypoxia significantly (P < 0.01) reduced TTE from thermoneutral normoxia (reductions of 190, 405, and 505 s from 915 s, respectively). The TTE decrease was consistent with a faster rate of peripheral fatigue development (P < 0.01) compared with thermoneutral normoxia (increase of 1.6, 3.1, and 4.9%/min from 4.1%/min, respectively). Combined exposure to hypoxic-cold resulted in an even greater TTE reduction (-589 s), likely due to an increase in the rate of peripheral fatigue development (increased by 7.6%/min), but this was without significant interaction between stressors (P > 0.198). In contrast, combined exposure to hypoxic heat reduced TTE by 609 s, showing a significant antagonistic interaction (P = 0.003) similarly supported by an increased rate of peripheral fatigue development (which increased by 8.3%/min). A small decline (<0.4%/min) in voluntary muscle activation was observed only in thermoneutral normoxia. In conclusion, interaction type is influenced by the impact magnitude of the effect of the individual stressors' effect on exercise capacity, whereby the greater the effect of stressors, the greater the probability that one stressor will be abolished by the other. This indicates that humans respond to severe and simultaneous physiological strains on the basis of a worst-strain-takes-precedence principle.
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Affiliation(s)
- Alex Lloyd
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
| | - Margherita Raccuglia
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
| | - Simon Hodder
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
| | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
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Lee BJ, Sukri NM, Ogden H, Vine C, Thake CD, Turner JE, Bilzon JLJ. A comparison of two commercially available ELISA methods for the quantification of human plasma heat shock protein 70 during rest and exercise stress. Cell Stress Chaperones 2015; 20:917-26. [PMID: 26111949 PMCID: PMC4595431 DOI: 10.1007/s12192-015-0610-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Revised: 06/01/2015] [Accepted: 06/04/2015] [Indexed: 10/23/2022] Open
Abstract
This study compared resting and exercise heat/hypoxic stress-induced levels of plasma extracellular heat shock protein 70 (eHSP70) in humans using two commercially available enzyme-linked immunosorbent assay (ELIS)A kits. EDTA plasma samples were collected from 21 males during two separate investigations. Participants in part A completed a 60-min treadmill run in the heat (HOT70; 33.0 ± 0.1 °C, 28.7 ± 0.8 %, n = 6) at 70 % V̇O2max. Participants in part B completed 60 min of cycling exercise at 50 % V̇O2max in either hot (HOT50; 40.5 °C, 25.4 relative humidity (RH)%, n = 7) or hypoxic (HYP50; fraction of inspired oxygen (FIO2) = 0.14, 21 °C, 35 % RH, n = 8) conditions. Samples were collected prior to and immediately upon termination of exercise and analysed for eHSP70 using EKS-715 high-sensitivity HSP70 ELISA and new ENZ-KIT-101 Amp'd(™) HSP70 high-sensitivity ELISA. ENZ-KIT was superior in detecting resting eHSP70 (1.54 ± 3.27 ng · mL(-1); range 0.08 to 14.01 ng · mL(-1)), with concentrations obtained from 100 % of samples compared to 19 % with EKS-715 assay. The ENZ-KIT requires optimisation prior to running samples in order to ensure participants fall within the standard curve, a step not required with EKS-715. Using ENZ-KIT, a 1:4 dilution allowed for quantification of resting HSP70 in 26/32 samples, with a 1:8 (n = 3) and 1:16 (n = 3) dilution required to determine the remaining samples. After exercise, eHSP70 was detected in 6/21 and 21/21 samples using EKS-715 and ENZ-KIT, respectively. eHSP70 was increased from rest after HOT70 (p < 0.05), but not HOT50 (p > 0.05) or HYP50 (p > 0.05) when analysed using ENZ-KIT. It is recommended that future studies requiring the precise determination of resting plasma eHSP70 use the ENZ-KIT (i.e. HSP70 Amp'd(®) ELISA) instead of the EKS-715 assay, despite additional assay development time and cost required.
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Affiliation(s)
- B J Lee
- Department for Health, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
- Department of Biomolecular and Sport Sciences, Coventry University, Priory Street, Coventry, UK.
| | - N M Sukri
- Department for Health, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - H Ogden
- Department for Health, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - C Vine
- Department for Health, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - C D Thake
- Department of Biomolecular and Sport Sciences, Coventry University, Priory Street, Coventry, UK
| | - J E Turner
- Department for Health, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - J L J Bilzon
- Department for Health, University of Bath, Claverton Down, Bath, BA2 7AY, UK
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33
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The influence of a mild thermal challenge and severe hypoxia on exercise performance and serum BDNF. Eur J Appl Physiol 2015; 115:2135-48. [DOI: 10.1007/s00421-015-3193-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 05/21/2015] [Indexed: 01/27/2023]
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34
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Goodall S, Charlton K, Hignett C, Prichard J, Barwood M, Howatson G, Thomas K. Augmented supraspinal fatigue following constant-load cycling in the heat. Scand J Med Sci Sports 2015; 25 Suppl 1:164-72. [DOI: 10.1111/sms.12370] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/15/2014] [Indexed: 12/30/2022]
Affiliation(s)
- S. Goodall
- Faculty of Health and Life Sciences; Department of Sport, Exercise & Rehabilitation; Northumbria University; Newcastle UK
| | - K. Charlton
- Faculty of Health and Life Sciences; Department of Sport, Exercise & Rehabilitation; Northumbria University; Newcastle UK
| | - C. Hignett
- Faculty of Health and Life Sciences; Department of Sport, Exercise & Rehabilitation; Northumbria University; Newcastle UK
| | - J. Prichard
- Institue of Health & Society; Newcastle University; Newcastle UK
| | - M. Barwood
- Faculty of Health and Life Sciences; Department of Sport, Exercise & Rehabilitation; Northumbria University; Newcastle UK
| | - G. Howatson
- Faculty of Health and Life Sciences; Department of Sport, Exercise & Rehabilitation; Northumbria University; Newcastle UK
- Water Research Group; School of Environmental Sciences and Development; Northwest University; Potchefstroom South Africa
| | - K. Thomas
- Faculty of Health and Life Sciences; Department of Sport, Exercise & Rehabilitation; Northumbria University; Newcastle UK
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35
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Girard O, Brocherie F, Bishop DJ. Sprint performance under heat stress: A review. Scand J Med Sci Sports 2015; 25 Suppl 1:79-89. [DOI: 10.1111/sms.12437] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/28/2015] [Indexed: 11/29/2022]
Affiliation(s)
- O. Girard
- ISSUL; Institute of Sport Sciences; Department of Physiology; Faculty of Biology and Medicine; University of Lausanne; Lausanne Switzerland
| | - F. Brocherie
- ISSUL; Institute of Sport Sciences; Department of Physiology; Faculty of Biology and Medicine; University of Lausanne; Lausanne Switzerland
| | - D. J. Bishop
- Institute of Sport; Exercise and Active Living (ISEAL); College of Sport and Exercise Science; Victoria University; Melbourne Victoria Australia
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36
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Crowcroft S, Duffield R, McCleave E, Slattery K, Wallace LK, Coutts AJ. Monitoring training to assess changes in fitness and fatigue: The effects of training in heat and hypoxia. Scand J Med Sci Sports 2015; 25 Suppl 1:287-95. [DOI: 10.1111/sms.12364] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2014] [Indexed: 11/29/2022]
Affiliation(s)
- S. Crowcroft
- Faculty of Health; University of Technology; Sydney New South Wales Australia
| | - R. Duffield
- Faculty of Health; University of Technology; Sydney New South Wales Australia
| | - E. McCleave
- Faculty of Health; University of Technology; Sydney New South Wales Australia
- The New South Wales Institute of Sport; Sydney New South Wales Australia
| | - K. Slattery
- The New South Wales Institute of Sport; Sydney New South Wales Australia
| | - L. K. Wallace
- Faculty of Health; University of Technology; Sydney New South Wales Australia
| | - A. J. Coutts
- Faculty of Health; University of Technology; Sydney New South Wales Australia
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