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Santos CMDA, Quirino PGC, Rizzo JÂ, Medeiros D, Ferreira JJDA, Costa MDC, Gaua N, Freya B, Martins MDO, Junior MACV. Respiratory muscles's thermographic analysis in asthmatic youth with and without bronchospasm induced by eucapnic voluntary hyperpnea. Clin Physiol Funct Imaging 2024; 44:324-331. [PMID: 38544320 DOI: 10.1111/cpf.12878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 02/26/2024] [Accepted: 03/07/2024] [Indexed: 06/06/2024]
Abstract
OBJECTIVE To compare the thermographic pattern of regions of interest (ROI) of respiratory muscles in young asthmatics with and without bronchospasm induced by eucapnic voluntary hyperpnea (EVH). MATERIALS AND METHODS Cross-sectional study carried out with 55 young (55% male and 45% females) aged 12.5 ± 3.3 years, divided in nine nonasthmatics, 22 asthmatics without exercise-induced bronchospasm compatible response (EIB-cr) and 24 asthmatics with EIB-cr. The diagnosis of EIB was given to subjects with a fall in forced expiratory volume in the first second (FEV1) ≥ 10% compared to baseline. Thermographic recordings of respiratory muscles were delimited in ROI of the sternocleidomastoid (SCM), pectoral, and rectus abdominis intention area. Thermal captures and FEV1 were taken before and 5, 10, 15 and 30 min after EVH. RESULTS Twenty-four (52.1%) of asthmatics had EIB-cr. There was a decrease in temperature at 10 min after EVH test in the SCM, pectoral and rectus abdominis ROIs in all groups (both with p < 0.05). There was a decrease in temperature (% basal) in asthmatic with EIB-cr compared to nonasthmatics in the rectus abdominis area (p < 0.05). CONCLUSION There was a decrease in temperature in the ROIs of different muscle groups, especially in asthmatics. The greater drop in FEV1 observed in individuals with EIB-cr was initially associated with a decrease in skin temperature, with a difference between the nonasthmatics in the abdominal muscle area. It is likely that this decrease in temperature occurred due to a temporary displacement of blood flow to the most used muscle groups, with a decrease in the region of the skin evaluated in the thermography.
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Affiliation(s)
- Camila M de A Santos
- Physical Education Department, Associated Postgraduate Program in Physical Education, Universidade de Pernambuco and Universidade Federal da Paraíba, Recife, Brazil
- Allergology and Clinical Immunology Department, Center for Research in Allergy and Clinical Immunology, Clinical Hospital, Federal University of Pernambuco, Recife, Brazil
| | - Polyanna G C Quirino
- Physical Education Department, Associated Postgraduate Program in Physical Education, Universidade de Pernambuco and Universidade Federal da Paraíba, Recife, Brazil
- Allergology and Clinical Immunology Department, Center for Research in Allergy and Clinical Immunology, Clinical Hospital, Federal University of Pernambuco, Recife, Brazil
| | - José Â Rizzo
- Allergology and Clinical Immunology Department, Center for Research in Allergy and Clinical Immunology, Clinical Hospital, Federal University of Pernambuco, Recife, Brazil
- Medicine Department, Child and Adolescent Health Postgraduate Course, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil
| | - Décio Medeiros
- Allergology and Clinical Immunology Department, Center for Research in Allergy and Clinical Immunology, Clinical Hospital, Federal University of Pernambuco, Recife, Brazil
- Medicine Department, Child and Adolescent Health Postgraduate Course, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil
| | | | - Manoel da C Costa
- Physical Education Department, Associated Postgraduate Program in Physical Education, Universidade de Pernambuco and Universidade Federal da Paraíba, Recife, Brazil
| | - Nádia Gaua
- Sport and Exercise Science Department, Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, UK
| | - Bayne Freya
- Sport and Exercise Science Department, Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, UK
| | - Marcelle de O Martins
- Physical Education Department, Associated Postgraduate Program in Physical Education, Universidade de Pernambuco and Universidade Federal da Paraíba, Recife, Brazil
| | - Marco A C V Junior
- Physical Education Department, Associated Postgraduate Program in Physical Education, Universidade de Pernambuco and Universidade Federal da Paraíba, Recife, Brazil
- Allergology and Clinical Immunology Department, Center for Research in Allergy and Clinical Immunology, Clinical Hospital, Federal University of Pernambuco, Recife, Brazil
- Department of Dentistry, Hebiatrics Postgraduation Program, Universidade de Pernambuco, Recife, Pernambuco, Brazil
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Ferreira FC, Padilha MCSV, Araujo-Leite MA, da Silva Soares PP, Rodrigues GD. Heated environment increases blood pressure drop and postural sway during initial orthostasis in healthy subjects. Eur J Appl Physiol 2024:10.1007/s00421-024-05546-8. [PMID: 38935152 DOI: 10.1007/s00421-024-05546-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 06/17/2024] [Indexed: 06/28/2024]
Abstract
PURPOSE We tested the hypothesis that heat stress influences the closed-loop cardio-postural control by an increased blood pressure (BP) drop and postural sway. METHODS Fourteen healthy individuals (eight women) performed two orthostatic tests under thermal reference (TC; ~ 24 ºC) and HOT (~ 38 ºC) conditions. The center-of-pressure (COP) displacements and the electromyography (EMG) activity of the calf muscles (medial gastrocnemius and tibialis anterior) were recorded during the initial orthostasis (ORT onset) after the supine-to-stand challenge. At the same period, BP (beat-to-beat) was continuously monitored, and supine-to-stand variations (∆%) were calculated. Sublingual temperature (Tsl) was measured as a surrogate of internal temperature. RESULTS Tsl increased in HOT compared to TC (TC 36.5 ± 0.3 vs. HOT 36.7 ± 0.3 ºC; p < 0.01). COP distance was greater in HOT compared to TC condition (TC 596.6 ± 242.4 vs. HOT 680.2 ± 249.1 mm; p < 0.01). EMG activity of the gastrocnemius decreased in HOT compared to TC condition (TC 95.5 ± 19.8 vs. HOT 78.4 ± 22.8%mV; p = 0.02). EMG of tibialis did not change between TC and HOT (TC 83.5 ± 42.9 vs. HOT 66.1 ± 31.9% mV; p = 0.29). BP showed a greater fall in HOT compared to TC condition (∆%TC - 24.5 ± 13.2 vs. ∆%HOT - 33.2 ± 20.2%; p = 0.01). CONCLUSION Heat stress causes a greater fall in blood pressure and a reduction in musculoskeletal pump activity during orthostatic onset. These effects could be potential mechanisms that underlie augmented postural instability under a heated environment.
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Affiliation(s)
- Felipe Castro Ferreira
- Laboratory of Experimental and Applied Exercise Physiology, Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, RJ, Brazil
- Clinical Research Unit in Neurology and Neurosciences, Niterói, RJ, Brazil
| | - Michelle Cristina Salabert Vaz Padilha
- Laboratory of Experimental and Applied Exercise Physiology, Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, RJ, Brazil
- Clinical Research Unit in Neurology and Neurosciences, Niterói, RJ, Brazil
| | | | - Pedro Paulo da Silva Soares
- Laboratory of Experimental and Applied Exercise Physiology, Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, RJ, Brazil
| | - Gabriel Dias Rodrigues
- Laboratory of Experimental and Applied Exercise Physiology, Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, RJ, Brazil.
- Clinical Research Unit in Neurology and Neurosciences, Niterói, RJ, Brazil.
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Cinca-Morros S, Álvarez-Herms J. The Importance of Maintaining and Improving a Healthy Gut Microbiota in Athletes as a Preventive Strategy to Improve Heat Tolerance and Acclimatization. Microorganisms 2024; 12:1160. [PMID: 38930542 PMCID: PMC11205789 DOI: 10.3390/microorganisms12061160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 06/04/2024] [Accepted: 06/05/2024] [Indexed: 06/28/2024] Open
Abstract
Exposure to passive heat (acclimation) and exercise under hot conditions (acclimatization), known as heat acclimation (HA), are methods that athletes include in their routines to promote faster recovery and enhance physiological adaptations and performance under hot conditions. Despite the potential positive effects of HA on health and physical performance in the heat, these stimuli can negatively affect gut health, impairing its functionality and contributing to gut dysbiosis. Blood redistribution to active muscles and peripheral vascularization exist during exercise and HA stimulus, promoting intestinal ischemia. Gastrointestinal ischemia can impair intestinal permeability and aggravate systemic endotoxemia in athletes during exercise. Systemic endotoxemia elevates the immune system as an inflammatory responses in athletes, impairing their adaptive capacity to exercise and their HA tolerance. Better gut microbiota health could benefit exercise performance and heat tolerance in athletes. This article suggests that: (1) the intestinal modifications induced by heat stress (HS), leading to dysbiosis and altered intestinal permeability in athletes, can decrease health, and (2) a previously acquired microbial dysbiosis and/or leaky gut condition in the athlete can negatively exacerbate the systemic effects of HA. Maintaining or improving the healthy gut microbiota in athletes can positively regulate the intestinal permeability, reduce endotoxemic levels, and control the systemic inflammatory response. In conclusion, strategies based on positive daily habits (nutrition, probiotics, hydration, chronoregulation, etc.) and preventing microbial dysbiosis can minimize the potentially undesired effects of applying HA, favoring thermotolerance and performance enhancement in athletes.
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Affiliation(s)
- Sergi Cinca-Morros
- Microfluidics Cluster UPV/EHU, Analytical Microsystems & Materials for Lab-on-a-Chip (AMMa-LOAC) Group, Analytical Chemistry Department, University of the Basque Country UPV/EHU, 01006 Vitoria-Gasteiz, Spain
- Microfluidics Cluster UPV/EHU, BIOMICs Microfluidics Group, Lascaray Research Center, University of the Basque Country UPV/EHU, 01006 Vitoria-Gasteiz, Spain
| | - Jesús Álvarez-Herms
- Physiology and Molecular Laboratory (Phymolab), 40170 Collado Hermoso, Spain;
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Santiago HP, Leite LHR, Lima PMA, Fóscolo DRC, Natali AJ, Prímola-Gomes TN, Szawka RE, Coimbra CC. Effects of physical training on hypothalamic neuronal activation and expressions of vasopressin and oxytocin in SHR after running until fatigue. Pflugers Arch 2024; 476:365-377. [PMID: 38308122 DOI: 10.1007/s00424-024-02916-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 02/04/2024]
Abstract
To assess the influence of physical training on neuronal activation and hypothalamic expression of vasopressin and oxytocin in spontaneously hypertensive rats (SHR), untrained and trained normotensive rats and SHR were submitted to running until fatigue while internal body and tail temperatures were recorded. Hypothalamic c-Fos expression was evaluated in thermoregulatory centers such as the median preoptic nucleus (MnPO), medial preoptic nucleus (mPOA), paraventricular nucleus of the hypothalamus (PVN), and supraoptic nucleus (SON). The PVN and the SON were also investigated for vasopressin and oxytocin expressions. Although exercise training improved the workload performed by the animals, it was reduced in SHR and followed by increased internal body temperature due to tail vasodilation deficit. Physical training enhanced c-Fos expression in the MnPO, mPOA, and PVN of both strains, and these responses were attenuated in SHR. Vasopressin immunoreactivity in the PVN was also increased by physical training to a lesser extent in SHR. The already-reduced oxytocin expression in the PVN of SHR was increased in response to physical training. Within the SON, neuronal activation and the expressions of vasopressin and oxytocin were reduced by hypertension and unaffected by physical training. The data indicate that physical training counterbalances in part the negative effect of hypertension on hypothalamic neuronal activation elicited by exercise, as well as on the expression of vasopressin and oxytocin. These hypertension features seem to negatively influence the workload performed by SHR due to the hyperthermia derived from the inability of physical training to improve heat dissipation through skin vasodilation.
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Affiliation(s)
- Henrique P Santiago
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Laura H R Leite
- Departamento de Biofísica e Fisiologia, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil
| | - Paulo M A Lima
- Núcleo de Pesquisa da Faculdade de Medicina da Universidade de Rio Verde, Universidade de Rio Verde, Campus Goiânia, Goiânia, Brazil
| | - Daniela R C Fóscolo
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Antônio José Natali
- Departamento de Educação Física, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | | | - Raphael E Szawka
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Cândido C Coimbra
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Belo Horizonte, MG, 31270-901, Brazil.
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Wang J, Jiang C, Yang G, Bai G, Yu S. Study on thermal health and its safety management mode for the working environment. Front Public Health 2023; 11:1227630. [PMID: 37670839 PMCID: PMC10475595 DOI: 10.3389/fpubh.2023.1227630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 07/31/2023] [Indexed: 09/07/2023] Open
Abstract
Thermal health concerns have gained significant attention due to the heightened health risks faced by workers who are exposed to extreme thermal environments for prolonged periods. To ensure the occupational health and safety of such workers, and to enhance work efficiency, it is imperative to examine the characteristics of thermal health in the working environment. This study proposes three key elements of thermal health in the working environment, namely thermal health states, absence of heat-related illnesses, and heat adaptability, which can be used to develop a safety management framework for thermal health. By exploring the interconnections between these elements, the study summarizes their features and outlines the necessary precautions to safeguard them. The PDCA (plan/do/check/action) cycle management mode is utilized as a framework, with the three components of thermal health forming the core, to establish a safety management mode for thermal health. To ensure that employees work in a safe, healthy, comfortable, and productive environment, the assessment and control objectives of the thermal environment are regularly revised through the use of labor protection technology and thermal environment control technology. This paper presents a PDCA cycle safety management mode based on the characteristics of thermal health, which offers novel insights and approaches for assessing and managing workers' thermal health.
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Affiliation(s)
- Jue Wang
- Key Laboratory of Mine Thermodynamic Disasters and Control of Ministry of Education, Liaoning Technical University, Fuxin, Liaoning, China
- School of Safety Science and Engineering, Liaoning Technical University, Fuxin, Liaoning, China
- School of Civil Engineering, Liaoning Technical University, Fuxin, Liaoning, China
| | - Cheng Jiang
- School of Civil Engineering, Liaoning Technical University, Fuxin, Liaoning, China
| | - Guang Yang
- School of Civil Engineering, Liaoning Technical University, Fuxin, Liaoning, China
| | - Gang Bai
- Key Laboratory of Mine Thermodynamic Disasters and Control of Ministry of Education, Liaoning Technical University, Fuxin, Liaoning, China
- School of Safety Science and Engineering, Liaoning Technical University, Fuxin, Liaoning, China
| | - Shixuan Yu
- School of Civil Engineering, Liaoning Technical University, Fuxin, Liaoning, China
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Ebisuda Y, Mukai K, Takahashi Y, Yoshida T, Kawano A, Matsuhashi T, Miyata H, Kuwahara M, Ohmura H. Acute exercise in a hot environment increases heat shock protein 70 and peroxisome proliferator-activated receptor γ coactivator 1α mRNA in Thoroughbred horse skeletal muscle. Front Vet Sci 2023; 10:1230212. [PMID: 37671280 PMCID: PMC10475567 DOI: 10.3389/fvets.2023.1230212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 08/08/2023] [Indexed: 09/07/2023] Open
Abstract
Heat acclimatization or acclimation training in horses is practiced to reduce physiological strain and improve exercise performance in the heat, which can involve metabolic improvement in skeletal muscle. However, there is limited information concerning the acute signaling responses of equine skeletal muscle after exercise in a hot environment. The purpose of this study was to investigate the hypothesis that exercise in hot conditions induces greater changes in heat shock proteins and mitochondrial-related signaling in equine skeletal muscle compared with exercise in cool conditions. Fifteen trained Thoroughbred horses [4.6 ± 0.4 (mean ± SE) years old; 503 ± 14 kg] were assigned to perform a treadmill exercise test in cool conditions [COOL; Wet Bulb Globe Temperature (WBGT), 12.5°C; n = 8] or hot conditions (HOT; WBGT, 29.5°C; n = 7) consisting of walking at 1.7 m/s for 1 min, trotting at 4 m/s for 5 min, and cantering at 7 m/s for 2 min and at 90% of VO2max for 2 min, followed by walking at 1.7 m/s for 20 min. Heart rate during exercise and plasma lactate concentration immediately after exercise were measured. Biopsy samples were obtained from the middle gluteal muscle before and at 4 h after exercise, and relative quantitative analysis of mRNA expression using real-time RT-PCR was performed. Data were analyzed with using mixed models. There were no significant differences between the two groups in peak heart rate (COOL, 213 ± 3 bpm; HOT, 214 ± 4 bpm; p = 0.782) and plasma lactate concentration (COOL, 13.1 ± 1.4 mmoL/L; HOT, 17.5 ± 1.7 mmoL/L; p = 0.060), while HSP-70 (COOL, 1.9-fold, p = 0.207; HOT, 2.4-fold, p = 0.045), PGC-1α (COOL, 3.8-fold, p = 0.424; HOT, 8.4-fold, p = 0.010), HIF-1α (COOL, 1.6-fold, p = 0.315; HOT, 2.2-fold, p = 0.018) and PDK4 (COOL, 7.6-fold, p = 0.412; HOT, 14.1-fold, p = 0.047) mRNA increased significantly only in HOT at 4 h after exercise. These data indicate that acute exercise in a hot environment facilitates protective response to heat stress (HSP-70), mitochondrial biogenesis (PGC-1α and HIF-1α) and fatty acid oxidation (PDK4).
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Affiliation(s)
- Yusaku Ebisuda
- Sports Science Division, Equine Research Institute, Japan Racing Association, Shimotsuke, Japan
| | - Kazutaka Mukai
- Sports Science Division, Equine Research Institute, Japan Racing Association, Shimotsuke, Japan
| | - Yuji Takahashi
- Sports Science Division, Equine Research Institute, Japan Racing Association, Shimotsuke, Japan
| | - Toshinobu Yoshida
- Sports Science Division, Equine Research Institute, Japan Racing Association, Shimotsuke, Japan
| | - Aoto Kawano
- Department of Biological Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
| | - Tsubasa Matsuhashi
- Department of Biological Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
| | - Hirofumi Miyata
- Department of Biological Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
| | - Masayoshi Kuwahara
- Department of Veterinary Pathophysiology and Animal Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Japan
| | - Hajime Ohmura
- Racehorse Hospital, Miho Training Center, Inashiki, Japan
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Carmo AAL, Goulart KNO, Cabido CET, Martins YAT, Santos GCF, Shang FLT, Prado LS, Soares DD, de Mello MT, Mendes TT, Silami-Garcia E, Wanner SP. Active warm-up and time-of-day effects on repeated-sprint performance and post-exercise recovery. Eur J Appl Physiol 2023; 123:49-64. [PMID: 36152058 DOI: 10.1007/s00421-022-05051-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 09/12/2022] [Indexed: 01/07/2023]
Abstract
PURPOSE This study investigated the effects of both an active warm-up and the time-of-day variation on repeated-sprint performance. A second objective was to compare the post-exercise recovery between the experimental conditions. METHODS Eleven male participants performed ten maximal cycling sprints (6 s each, with a 30-s interval between them) in the morning and late afternoon, either after a warm-up or control condition. The warm-up consisted of cycling for 10 min at 50% of the peak aerobic power. RESULTS Rest measurements of rectal, muscle, and skin temperatures were higher in the afternoon compared to the morning (p < 0.05), with no significant differences in heart rate (p = 0.079) and blood lactate concentration (p = 0.300). Warm-up increased muscle temperature, heart rate, and lactate, and reduced skin temperature (all p < 0.001), though no significant differences were observed for rectal temperature (p = 0.410). The number of revolutions (p = 0.034, ηp2 = 0.375), peak (p = 0.034, ηp2 = 0.375), and mean (p = 0.037, ηp2 = 0.365) power of the first sprint (not the average of ten sprints) were higher in the afternoon compared to the morning, regardless of warm-up. However, beneficial performance effects of warming up were evident for the first (p < 0.001) and the average of ten sprints (p < 0.05), regardless of time of day. More remarkable changes during the 60-min post-exercise were observed for rectal temperature (p = 0.005) and heart rate (p = 0.010) in the afternoon than in the morning. CONCLUSION Warming-up and time-of-day effects in enhancing muscular power are independent. Although warm-up ensured further beneficial effects on performance than the time-of-day variation, a faster post-exercise recovery was observed in the late afternoon.
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Affiliation(s)
- Adriano A L Carmo
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627. Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Karine N O Goulart
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627. Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Christian E T Cabido
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627. Pampulha, Belo Horizonte, MG, 31270-901, Brazil.,Postgraduate Program in Physical Education, Universidade Federal do Maranhão, São Luís, MA, Brazil
| | - Ygor A T Martins
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627. Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Gabriela C F Santos
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627. Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Felipe L T Shang
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627. Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Luciano S Prado
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627. Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Danusa D Soares
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627. Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Marco T de Mello
- Psychobiology and Exercise Study Center, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Thiago T Mendes
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627. Pampulha, Belo Horizonte, MG, 31270-901, Brazil.,Department of Physical Education, Faculty of Education, Universidade Federal da Bahia, Salvador, BA, Brazil
| | - Emerson Silami-Garcia
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627. Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Samuel P Wanner
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627. Pampulha, Belo Horizonte, MG, 31270-901, Brazil.
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Verdel N, Podlogar T, Ciuha U, Holmberg HC, Debevec T, Supej M. Reliability and Validity of the CORE Sensor to Assess Core Body Temperature during Cycling Exercise. SENSORS 2021; 21:s21175932. [PMID: 34502822 PMCID: PMC8434645 DOI: 10.3390/s21175932] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/23/2021] [Accepted: 09/02/2021] [Indexed: 11/16/2022]
Abstract
Monitoring core body temperature (Tc) during training and competitions, especially in a hot environment, can help enhance an athlete's performance, as well as lower the risk for heat stroke. Accordingly, a noninvasive sensor that allows reliable monitoring of Tc would be highly beneficial in this context. One such novel non-invasive sensor was recently introduced onto the market (CORE, greenTEG, Rümlang, Switzerland), but, to our knowledge, a validation study of this device has not yet been reported. Therefore, the purpose of this study was to evaluate the validity and reliability of the CORE sensor. In Study I, 12 males were subjected to a low-to-moderate heat load by performing, on two separate occasions several days apart, two identical 60-min bouts of steady-state cycling in the laboratory at 19 °C and 30% relative humidity. In Study II, 13 males were subjected to moderate-to-high heat load by performing 90 min of cycling in the laboratory at 31 °C and 39% relative humidity. In both cases the core body temperatures indicated by the CORE sensor were compared to the corresponding values obtained using a rectal sensor (Trec). The first major finding was that the reliability of the CORE sensor is acceptable, since the mean bias between the two identical trials of exercise (0.02 °C) was not statistically significant. However, under both levels of heat load, the body temperature indicated by the CORE sensor did not agree well with Trec, with approximately 50% of all paired measurements differing by more than the predefined threshold for validity of ≤0.3 °C. In conclusion, the results obtained do not support the manufacturer's claim that the CORE sensor provides a valid measure of core body temperature.
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Affiliation(s)
- Nina Verdel
- Swedish Winter Sports Research Centre, Mid Sweden University, 83125 Östersund, Sweden;
- Correspondence:
| | - Tim Podlogar
- Faculty of Health Sciences, University of Primorska, 6310 Izola, Slovenia;
- Department of Automation, Biocybernetics, and Robotics, Jozef Stefan Institute, 1000 Ljubljana, Slovenia; (U.C.); (T.D.)
- Human Performance Centre, 1000 Ljubljana, Slovenia
| | - Urša Ciuha
- Department of Automation, Biocybernetics, and Robotics, Jozef Stefan Institute, 1000 Ljubljana, Slovenia; (U.C.); (T.D.)
| | - Hans-Christer Holmberg
- Department of Health, Medicine, and Rehabilitation, Luleå University of Technology, 97187 Luleå, Sweden;
| | - Tadej Debevec
- Department of Automation, Biocybernetics, and Robotics, Jozef Stefan Institute, 1000 Ljubljana, Slovenia; (U.C.); (T.D.)
- Faculty of Sport, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Matej Supej
- Swedish Winter Sports Research Centre, Mid Sweden University, 83125 Östersund, Sweden;
- Faculty of Sport, University of Ljubljana, 1000 Ljubljana, Slovenia
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9
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Aylwin PE, Racinais S, Bermon S, Lloyd A, Hodder S, Havenith G. The use of infrared thermography for the dynamic measurement of skin temperature of moving athletes during competition; methodological issues. Physiol Meas 2021; 42. [PMID: 34320480 DOI: 10.1088/1361-6579/ac1872] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 07/28/2021] [Indexed: 01/28/2023]
Abstract
Objective. To investigate the use of infrared thermography (IRT) for skin temperature measurement of moving athletes during competition and its sensitivity to factors that are traditionally standardised.Approach. Thermograms were collected for 18 female athletes during the 20 km racewalk at the 2019 World Athletics Championships, with a medium-wave, cooled indium antimonide medium wave infrared band (MWIR) and a long-wave, uncooled microbolometer longwave infrared band (LWIR) infrared camera.Main results. The MWIR provided greater clarity images of motion due to a shorter exposure and response time and produced a higher percentage of acceptable images. Analysing acceptable images only, the LWIR and WMIR produced good levels of agreement, with a bias of -0.1 ± 0.6 °C in mean skin temperature for the LWIR. As the surface area of an ROI was reduced, the measured temperature became less representative of the whole ROI. Compared to measuring the whole area ROI, a single central pixel produced a bias of 0.3 ± 0.3 °C (MWIR) and 0.1 ± 0.4 °C (LWIR) whilst using the maximum and minimum temperature pixels resulted in deviations of 1.3 ± 0.4 °C and -1.1 ± 0.3 °C (MWIR) and 1.2 ± 0.3 °C and -1.3 ± 0.4 °C (LWIR). The sensitivity to air and reflected temperatures was lower for the LWIR camera, due to the higher emissivity of skin in its wavelength.Significance. IRT provides an appropriate tool for the measurement of skin temperature during real-world competition and critically during athlete motion. The cheaper LWIR camera provides a feasible alternative to the MWIR in low rate of motion scenarios, with comparable precision and sensitivity to analysis. However, the LWIR is limited when higher speeds prevent the accurate measurement and ability to capture motion.
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Affiliation(s)
- Polly E Aylwin
- Environmental Ergonomics Research Centre, Loughborough University, United Kingdom
| | | | - Stéphane Bermon
- World Athletics, Health and Science Department, Principality of Monaco, Europe.,LAMHESS, Université Côte d'Azur, France
| | - Alex Lloyd
- Environmental Ergonomics Research Centre, Loughborough University, United Kingdom
| | - Simon Hodder
- Environmental Ergonomics Research Centre, Loughborough University, United Kingdom
| | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough University, United Kingdom
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10
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Seeley AD, Giersch GEW, Charkoudian N. Post-exercise Body Cooling: Skin Blood Flow, Venous Pooling, and Orthostatic Intolerance. Front Sports Act Living 2021; 3:658410. [PMID: 34079934 PMCID: PMC8165173 DOI: 10.3389/fspor.2021.658410] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 04/16/2021] [Indexed: 12/28/2022] Open
Abstract
Athletes and certain occupations (e.g., military, firefighters) must navigate unique heat challenges as they perform physical tasks during prolonged heat stress, at times while wearing protective clothing that hinders heat dissipation. Such environments and activities elicit physiological adjustments that prioritize thermoregulatory skin perfusion at the expense of arterial blood pressure and may result in decreases in cerebral blood flow. High levels of skin blood flow combined with an upright body position augment venous pooling and transcapillary fluid shifts in the lower extremities. Combined with sweat-driven reductions in plasma volume, these cardiovascular alterations result in levels of cardiac output that do not meet requirements for brain blood flow, which can lead to orthostatic intolerance and occasionally syncope. Skin surface cooling countermeasures appear to be a promising means of improving orthostatic tolerance via autonomic mechanisms. Increases in transduction of sympathetic activity into vascular resistance, and an increased baroreflex set-point have been shown to be induced by surface cooling implemented after passive heating and other arterial pressure challenges. Considering the further contribution of exercise thermogenesis to orthostatic intolerance risk, our goal in this review is to provide an overview of post-exercise cooling strategies as they are capable of improving autonomic control of the circulation to optimize orthostatic tolerance. We aim to synthesize both basic and applied physiology knowledge available regarding real-world application of cooling strategies to reduce the likelihood of experiencing symptomatic orthostatic intolerance after exercise in the heat.
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Affiliation(s)
- Afton D Seeley
- Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States.,Oak Ridge Institute of Science and Education, Belcamp, MD, United States
| | - Gabrielle E W Giersch
- Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States.,Oak Ridge Institute of Science and Education, Belcamp, MD, United States
| | - Nisha Charkoudian
- Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States
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11
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The Effects of a Passive Exoskeleton on Human Thermal Responses in Temperate and Cold Environments. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18083889. [PMID: 33917655 PMCID: PMC8067969 DOI: 10.3390/ijerph18083889] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 03/29/2021] [Accepted: 03/30/2021] [Indexed: 11/17/2022]
Abstract
The exoskeleton as functional wearable equipment has been increasingly used in working environments. However, the effects of wearing an exoskeleton on human thermal responses are still unknown. In this study, 10 male package handlers were exposed to 10 °C (COLD) and 25 °C (TEMP) ambient temperatures while performing a 10 kg lifting task (LIFTING) and sedentary (REST) both with (EXO) and without the exoskeleton (WEXO). Thermal responses, including the metabolic rate and mean skin temperature (MST), were continuously measured. Thermal comfort, thermal sensation and sweat feeling were also recorded. For LIFTING, metabolic heat production is significant decrease with the exoskeleton support. The MST and thermal sensation significantly increase when wearing the exoskeleton, but thermal discomfort and sweating are only aggravated in TEMP. For REST, MST and thermal sensation are also increased by the exoskeleton, and there is no significant difference in the metabolic rate between EXO and WEXO. The thermal comfort is significantly improved by wearing the exoskeleton only in COLD. The results suggest that the passive exoskeleton increases the local clothing insulation, and the way of wearing reduces the “pumping effect”, which makes a difference in the thermal response between COLD and TEMP. Designers need to develop appropriate usage strategies according to the operative temperature.
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12
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Kang H, Zsoldos RR, Woldeyohannes SM, Gaughan JB, Sole Guitart A. The Use of Percutaneous Thermal Sensing Microchips for Body Temperature Measurements in Horses Prior to, during and after Treadmill Exercise. Animals (Basel) 2020; 10:ani10122274. [PMID: 33276500 PMCID: PMC7761216 DOI: 10.3390/ani10122274] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 11/23/2020] [Accepted: 11/26/2020] [Indexed: 11/16/2022] Open
Abstract
Accurately measuring body temperature in horses will improve the management of horses suffering from or being at risk of developing postrace exertional heat illness. PTSM has the potential for measuring body temperature accurately, safely, rapidly, and noninvasively. This study was undertaken to investigate the relation between the core body temperature and PTSM temperatures prior to, during, and immediately after exercise. The microchips were implanted into the nuchal ligament, the right splenius, gluteal, and pectoral muscles, and these locations were then compared with the central venous temperature, which is considered to be the "gold standard" for assessing core body temperature. The changes in temperature of each implant in the horses were evaluated in each phase (prior to, during, and immediately postexercise) and combining all phases. There were strong positive correlations ranging from 0.82 to 0.94 (p < 0.001) of all the muscle sites with the central venous temperature when combining all the phases. Additionally, during the whole period, PTSM had narrow limits of agreement (LOA) with central venous temperature, which inferred that PTSM is essentially equivalent in measuring horse body temperature. Overall, the pectoral PTSM provided a valid estimation of the core body temperature.
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Affiliation(s)
- Hyungsuk Kang
- School of Agriculture and Food Sciences, The University of Queensland, Gatton, QLD 4343, Australia; (H.K.); (R.R.Z.); (J.B.G.)
| | - Rebeka R. Zsoldos
- School of Agriculture and Food Sciences, The University of Queensland, Gatton, QLD 4343, Australia; (H.K.); (R.R.Z.); (J.B.G.)
| | | | - John B. Gaughan
- School of Agriculture and Food Sciences, The University of Queensland, Gatton, QLD 4343, Australia; (H.K.); (R.R.Z.); (J.B.G.)
| | - Albert Sole Guitart
- School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia;
- Correspondence:
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13
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Viegas F, Mello MTD, Rodrigues SA, Costa CMA, Freitas LDSN, Rodrigues EL, Silva A. THE USE OF THERMOGRAPHY AND ITS CONTROL VARIABLES: A SYSTEMATIC REVIEW. REV BRAS MED ESPORTE 2020. [DOI: 10.1590/1517-869220202601217833] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
ABSTRACT Introduction: Muscle injuries are the most frequent cause of physical disability in sports, representing a large percentage of all sports injuries. In high-performance sports in particular, there is great interest in optimizing the process of diagnosis and rehabilitation of muscle injuries in order to reduce the amount of time taken off by athletes due to their injuries. Infrared thermography, or cutaneous thermometry, is a technique used for complementary investigation of pain. It provides thermal imaging with an infrared camera, to measure the surface temperature of the body. Objective: To conduct a systematic review of the use of thermography as a functional evaluation for the identification and prevention of muscle injuries, and of the control variables used in its applicability. Methods: A systematic review was conducted in the MEDLINE, ResearchGate and Scielo databases, using the search terms: “thermography”, “muscle injury”, “rehabilitation” and “diagnosis”, searching on articles published from 2000 to 2017, in Portuguese, English and Spanish. The eligibility criteria for the studies was the use of thermography as an outcome, and the reporting of standards for evaluating skin temperature variation in athletes. Results: Following the systematic review, 94 studies were retrieved. Of these, only 12 met the criteria for inclusion in the study. Conclusion: Thermography is a suitable tool for the evaluation and prevention of muscle injuries in athletes, and care should be taken with the control variables during its use. The most efficient variables for capturing the thermographic image appear to be an environment with a temperature of between 18 and 25°C, for 15 minutes for acclimatization, and with the individual placed in a pre-determined position, depending on the body segment being evaluated, without contact with another object. Level of evidence I; Systematic review.
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14
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Botonis PG, Miliotis PG, Kounalakis SN, Koskolou MD, Geladas ND. Thermoregulatory and cardiovasculareffects of capsaicin application on human skin during dynamic exercise to temperate and warm conditions. Physiol Rep 2019; 7:e14325. [PMID: 31883232 PMCID: PMC6934878 DOI: 10.14814/phy2.14325] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Thermoregulatory and cardiovascular responses during cycling in temperate and warm environments without and with application of capsaicin on the skin were investigated. We hypothesized that regardless of environmental temperature, capsaicin application would activate heat loss mechanisms attenuating exercise‐induced rectal temperature (Tre) and blood pressure increase. Eight males cycled at 55% of their maximal aerobic power so long as to reach 38.2°C Tre at 20.8 ± 1.0°C and at 30.6 ± 1.1°C ambient temperatures twice: without (NCA) and with (CA) application of capsaicin patches (12 × 18 cm, 4.8 mg). Patches were applied on pectoralis major, trapezius and vastus lateralis muscles. Thermoregulatory (Tre, proximal‐distal skin temperature gradient, sweating rate), cardiovascular variables and oxygen uptake were continuously recorded. In both ambient conditions, during the first 14 min of exercise, the local vasoconstrictive tone as a function of the relative change in Tre was lower in CA than NCA (p < .05, d = 0.84–1.15). Further, sweating rate was higher and occurred at a lower Tre increase in CA compared to NCA (p = .03, d = 0.6) resulting in extended time to reach 38.2°C Tre (p = .03, d = 0.9). Moreover, oxygen consumption was higher in CA than in NCA (p < .001, d = 0.8). Mean arterial pressure was lower during cycling in warm compared to temperate environment, but was unaffected by capsaicin. We conclude that activation of thermal sensors by capsaicin results in lower Tre rise during exercise, which is mediated through greater skin vasodilation along with higher rate and earlier onset of sweating. Nonetheless, capsaicin application has no extra effect on exercise cardiovascular responses.
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Affiliation(s)
- Petros G Botonis
- Section of Sport Medicine and Biology of Exercise, School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| | - Panagiotis G Miliotis
- Section of Sport Medicine and Biology of Exercise, School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| | - Stylianos N Kounalakis
- Faculty of Physical and Cultural Education, Evelpidon Hellenic Army Academy, Vari, Greece
| | - Maria D Koskolou
- Section of Sport Medicine and Biology of Exercise, School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| | - Nickos D Geladas
- Section of Sport Medicine and Biology of Exercise, School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
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15
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Wingo JE, Ng J, Katica CP, Carter SJ. Fan cooling after cardiovascular drift does not reverse decrements in maximal oxygen uptake during heat stress. Temperature (Austin) 2019; 6:260-270. [PMID: 31608305 DOI: 10.1080/23328940.2019.1657344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 08/14/2019] [Accepted: 08/14/2019] [Indexed: 01/07/2023] Open
Abstract
Cardiovascular (CV) drift, the progressive increase in heart rate (HR) and decrease in stroke volume (SV) during constant rate, moderate intensity exercise, is related to reduced maximal oxygen uptake (V̇O2max) during heat stress. Once it has already occurred, it is unknown whether the detrimental effects of CV drift on V̇O2max can be reversed. This study tested the hypothesis that fan cooling after CV drift has occurred attenuates decrements in V̇O2max associated with CV drift. Eight men completed a control graded exercise test (GXT) in 22°C to measure V̇O2max. Then on separate, counterbalanced occasions, they completed one 15-min (15MIN) and two 45-min bouts (45NF and 45FAN) of cycling in 35°C, 40% RH at 60% V̇O2max, each immediately followed by a GXT to measure V̇O2max. For one of the 45-min trials (45FAN), fan airflow (4.5 m/s) was directed at participants beginning ~5 min before the GXT and continuing throughout the remainder of exercise. The purpose of the separate 15- and 45-min trials was to measure V̇O2max during the same time interval that CV drift occurred. HR increased (13.8% and 11.4%) and SV decreased (14.4% and 14.1%) for 45NF and 45FAN, respectively; trials were not different (all P > 0.05). Despite a decrease in mean skin temperature of ~1°C with fan use, V̇O2max decreased similarly between conditions (17% vs. 15% for 45NF and 45FAN, P = 0.54). Fan cooling after CV drift was insufficient to reverse the negative consequences of CV drift on V̇O2max after prolonged exercise in a hot environment. Abbreviations: 15MIN: 15-min trial; 45FAN: 45-min, fan trial; 45NF: 45-min, no fan trial; ANOVA: Analysis of variance; CV: Cardiovascular; GXT: Graded exercise test; HR: Heart rate; SV: Stroke volume; T̅b: Mean body temperature; Tre: Rectal temperature; T̅sk: Mean skin temperature; V̇O2max: Maximal oxygen uptake.
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Affiliation(s)
- Jonathan E Wingo
- Department of Kinesiology, University of Alabama, Tuscaloosa, AL, USA
| | - Jason Ng
- Department of Kinesiology, University of Alabama, Tuscaloosa, AL, USA.,Department of Kinesiology, California State University, San Bernardino, CA, USA
| | - Charles P Katica
- Department of Kinesiology, University of Alabama, Tuscaloosa, AL, USA.,Department of Kinesiology, Pacific Lutheran University, Tacoma, WA, USA
| | - Stephen J Carter
- Department of Kinesiology, University of Alabama, Tuscaloosa, AL, USA.,Department of Kinesiology, Indiana University Bloomington, Bloomington, IN, USA
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16
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Ratnovsky A, Yanovich R, Kesner D, Ketko I, Schermann H, Heled Y, Ovadia-Blechman Z. The relation between central variables, electromyography signals and peripheral microcirculation during intensive treadmill exercise. Clin Biomech (Bristol, Avon) 2019; 67:52-60. [PMID: 31077977 DOI: 10.1016/j.clinbiomech.2019.04.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/29/2019] [Accepted: 04/30/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Aerobic exercise under muscle fatigue can lead to muscular damage and injuries. Finding the correlations between central and peripheral microcirculation variables, as well as with electromyography signals of leg muscles during aerobic exercise, may contribute to early muscle fatigue identification. The goal of this study was to characterize the peripheral compensation following intensive exercise for assessment of muscle performance based on non-invasive techniques. METHODS The experimental protocol included two days of measurements. Electrocardiography tests and anthropometric measurements of the volunteers (N = 14) were carried out. The maximal aerobic ability (first day), as well as electromyography and cutaneous hemodynamic variables (second day) were measured during treadmill run. A score-based Bayesian network machine-learning algorithm was used to predict ventilation values based on cutaneous hemodynamic measurements. FINDINGS Transcutaneous oxygen tension can be used to identify anaerobic threshold for both trained and untrained subjects during treadmill running, while electromyography can be used to identify anaerobic threshold only of trained subjects. Predicted values of ventilation, based on the transcutaneous oxygen tension, showed high correlation with actual values. Prediction accuracy was better among trained subjects, compared to the untrained ones. INTERPRETATION Transcutaneous oxygen tension could be used for prediction of maximal oxygen consumption during intense exercise and thus may provide improved assessment of premature fatigue during exercise.
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Affiliation(s)
- Anat Ratnovsky
- School of Medical Engineering, Afeka - Tel Aviv Academic College of Engineering, Israel
| | - Ran Yanovich
- The Institute of Military Physiology, The Warrior Health Research Institute, Israel Defense Forces, Medical Corps, Israel; Heller Institute of Medical Research, Sheba Medical Center, Tel Hashomer, Israel; The Zinman College of Physical Education and Sport Sciences, Wingate Institute, Israel
| | - Dikla Kesner
- School of Medical Engineering, Afeka - Tel Aviv Academic College of Engineering, Israel
| | - Itay Ketko
- The Institute of Military Physiology, The Warrior Health Research Institute, Israel Defense Forces, Medical Corps, Israel; Heller Institute of Medical Research, Sheba Medical Center, Tel Hashomer, Israel
| | - Haggai Schermann
- The Institute of Military Physiology, The Warrior Health Research Institute, Israel Defense Forces, Medical Corps, Israel; Heller Institute of Medical Research, Sheba Medical Center, Tel Hashomer, Israel
| | - Yuval Heled
- Heller Institute of Medical Research, Sheba Medical Center, Tel Hashomer, Israel
| | - Zehava Ovadia-Blechman
- School of Medical Engineering, Afeka - Tel Aviv Academic College of Engineering, Israel.
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17
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An acute dose of inorganic dietary nitrate does not improve high-intensity, intermittent exercise performance in temperate or hot and humid conditions. Eur J Appl Physiol 2019; 119:723-733. [PMID: 30617465 PMCID: PMC6394696 DOI: 10.1007/s00421-018-04063-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 12/21/2018] [Indexed: 01/13/2023]
Abstract
Purpose Dietary nitrate (NO3−) has repeatedly been shown to improve endurance and intermittent, high-intensity events in temperate conditions. However, the ergogenic effects of dietary NO3− on intermittent exercise performance in hot conditions have yet to be investigated. Methods In a randomised, counterbalanced, double-blind crossover study, 12 recreationally trained males ingested a nitrate-rich beetroot juice shot (BRJ) (6.2 mmol NO3−) or a nitrate-depleted placebo (PLA) (< 0.004 mmol NO3−) 3 h prior to an intermittent sprint test (IST) in temperate (22 °C, 35% RH) and hot conditions (30 °C, 70% RH). The cycle ergometer IST consisted of twenty maximal 6 s sprints interspersed by 114 s of active recovery. Work done, power output, heart rate and RPE were measured throughout; tympanic temperature was measured prior to and upon completion. Results There were no significant effects of supplement on sprint performance in either temperate or hot, humid conditions (p > 0.05). There was a reduced peak (BRJ: 659 ± 100W vs. PLA: 693 ± 139W; p = 0.056) and mean power (BRJ: 543 ± 29W vs. PLA: 575 ± 38W; p = 0.081) following BRJ compared to PLA in the hot and humid condition, but this was not statistically significant. There was no effect of supplement on total work done irrespective of environmental condition. However, ~ 75% of participants experienced performance decreases following BRJ in the hot and humid environment. No differences were observed between trials for tympanic temperature measured at the conclusion of the exercise trial. Conclusion In conclusion, an acute dose of inorganic dietary NO3− does not improve repeated-sprint performance in either temperate, or hot and humid conditions.
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18
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Schweiker M, Huebner GM, Kingma BRM, Kramer R, Pallubinsky H. Drivers of diversity in human thermal perception - A review for holistic comfort models. Temperature (Austin) 2018; 5:308-342. [PMID: 30574525 PMCID: PMC6298492 DOI: 10.1080/23328940.2018.1534490] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 10/04/2018] [Accepted: 10/05/2018] [Indexed: 12/03/2022] Open
Abstract
Understanding the drivers leading to individual differences in human thermal perception has become increasingly important, amongst other things due to challenges such as climate change and an ageing society. This review summarizes existing knowledge related to physiological, psychological, and context-related drivers of diversity in thermal perception. Furthermore, the current state of knowledge is discussed in terms of its applicability in thermal comfort models, by combining modelling approaches of the thermoneutral zone (TNZ) and adaptive thermal heat balance model (ATHB). In conclusion, the results of this review show the clear contribution of some physiological and psychological factors, such as body composition, metabolic rate, adaptation to certain thermal environments and perceived control, to differences in thermal perception. However, the role of other potential diversity-causing parameters, such as age and sex, remain uncertain. Further research is suggested, especially regarding the interaction of different diversity-driving factors with each other, both physiological and psychological, to help establishing a holistic picture.
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Affiliation(s)
- Marcel Schweiker
- Building Science Group, Karlsruhe Institute of Technology, Karlsruhe, Germany
- Heidelberg Academy of Sciences and Humanities, Heidelberg, Germany
| | | | - Boris R. M. Kingma
- Training and Performance Innovations, TNO Netherlands Organisation for Applied Scientific Research, Soesterberg, The Netherlands
- Department of Energy Technology, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Rick Kramer
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands
- Department of the Built Environment, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Hannah Pallubinsky
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands
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19
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Dhahbi W, Sellami M, Chaouachi A, Padulo J, Milic M, Mekki I, Chamari K. Seasonal weather conditions affect training program efficiency and physical performance among special forces trainees: A long-term follow-up study. PLoS One 2018; 13:e0206088. [PMID: 30335826 PMCID: PMC6193725 DOI: 10.1371/journal.pone.0206088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 10/01/2018] [Indexed: 11/18/2022] Open
Abstract
The purpose of the present investigation was to follow-up the effect of specific commandos' training-cycles (SCTCs) on upper-body strength resistance and running endurance performance, as well as determine whether variation in seasonal parameters has any effect on physical performance. Fourteen SCTCs were held over eight years, involving 466 participants. Participants were assigned to four subgroups according to their distribution over the seasons: summer (n = 124), autumn (n = 145), winter (n = 52) and spring (n = 145). Before and after each SCTC, four tests (maximal pull-up, push-up and sit-up repetitions in 70-seconds for muscle strength resistance) and a 5-km cross-country run (endurance) were performed. Seasonal data were continuously recorded during all SCTCs. Body mass decreased significantly (p<0.05) in all groups following SCTCs. These training-cycles induced a significant increase (p<0.05) in the 70-seconds push-ups, pull-ups and sit-ups and a decrease (p<0.01) in the 5-km cross-country running time among all trainees. The main effect of the season was present in all tests (p<0.01). With regard to the percentage of changes, the results from the 70-seconds push-up, pull-up and sit-up tests were significantly higher in winter and spring (p<0.01) compared with the two other seasons, while 5-km cross-country performance improvements were significantly higher (p<0.01) in spring and summer, compared to the two other seasons. In summary,14-week of SCTCs improved upper-body strength resistance and running endurance performance in the commandos. Improvements in strength resistance performance were greater during cool weather (winter and spring), while improvements in running endurance performance were higher during hotter (spring and summer) seasons.
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Affiliation(s)
- Wissem Dhahbi
- Tunisian Research Laboratory “Sport Performance Optimisation”, National Center of Medicine and Science in Sports (CNMSS), Tunis, Tunisia
- Qatar Police College, Training Department, Doha, Qatar
- Tunisian National Guard Commandos School, Oued Zarga, Tunisia
- University of Qatar, College of Arts and Sciences (Qu-CAS), Sport Science Program (SSP), Doha, Qatar
| | - Maha Sellami
- University of Qatar, College of Arts and Sciences (Qu-CAS), Sport Science Program (SSP), Doha, Qatar
| | - Anis Chaouachi
- Tunisian Research Laboratory “Sport Performance Optimisation”, National Center of Medicine and Science in Sports (CNMSS), Tunis, Tunisia
| | - Johnny Padulo
- Tunisian Research Laboratory “Sport Performance Optimisation”, National Center of Medicine and Science in Sports (CNMSS), Tunis, Tunisia
- University eCampus, Novedrate, Italy
- University of Split, Faculty of Kinesiology, Split, Croatia
| | - Mirjana Milic
- University of Split, Faculty of Kinesiology, Split, Croatia
| | - Imed Mekki
- Tunisian National Guard Commandos School, Oued Zarga, Tunisia
| | - Karim Chamari
- Athlete Health and Performance Research Centre, ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
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20
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Hodges GJ, Mueller MC, Cheung SS, Falk B. Cutaneous vasomotor responses in boys and men. Appl Physiol Nutr Metab 2018; 43:1019-1026. [DOI: 10.1139/apnm-2018-0083] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Few studies have investigated skin blood flow in children and age-related differences in the underlying mechanisms. We examined mechanisms of skin blood flow responses to local heating, postocclusive reactive hyperaemia (PORH), and isometric handgrip exercise in adult and prepubescent males, hypothesizing that skin blood flow responses would be greater in children compared with adults. We measured skin blood flow in 12 boys (age, 9 ± 1 years) and 12 men (age, 21 ± 1 years) using laser-Doppler flowmetry at rest, in response to 3-min PORH, 2-min isometric handgrip exercise, and local skin heating to 39 °C (submaximal) and 44 °C (maximal). Using wavelet analysis we assessed endothelial, neural, and myogenic activities. At rest and in response to local heating to 39 °C, children had higher skin blood flow and endothelial activity compared with men (d ≥ 1.1, p < 0.001) and similar neurogenic and myogenic activities (d < 0.2, p > 0.05). Maximal responses to 44 °C local skin heating, PORH, and isometric handgrip exercise did not differ between boys and men (all d ≤ 0.2, p > 0.05). During PORH children demonstrated greater endothelial activity compared with men (d ≥ 0.6, p < 0.05); in contrast, men had higher neurogenic activity (d = 1.0, p < 0.01). During isometric handgrip exercise there were no differences in endothelial, neurogenic, and myogenic activities (d < 0.2, p > 0.3), with boys and men demonstrating similar increases in endothelial activity and decreases in myogenic activity (d ≥ 0.8, p < 0.05). These data suggest that boys experience greater levels of skin blood flow at rest and in response to submaximal local heating compared with men, while maximal responses appear to be similar. Additionally, endothelial mediators seem to contribute more to vasodilatation in boys than in men.
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Affiliation(s)
- Gary J. Hodges
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Matthew C. Mueller
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Stephen S. Cheung
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Bareket Falk
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
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Balmain BN, Sabapathy S, Louis M, Morris NR. Aging and Thermoregulatory Control: The Clinical Implications of Exercising under Heat Stress in Older Individuals. BIOMED RESEARCH INTERNATIONAL 2018; 2018:8306154. [PMID: 30155483 PMCID: PMC6098859 DOI: 10.1155/2018/8306154] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/06/2018] [Accepted: 07/16/2018] [Indexed: 01/27/2023]
Abstract
Climate change is predicted to bring about a greater variability in weather patterns with an increase in extreme weather events such as sustained heat waves. This change may have a direct impact on population health since heat waves can exceed the physiological limit of compensability of vulnerable individuals. Indeed, many clinical reports suggest that individuals over the age of 60 years are consistently the most vulnerable, experiencing significantly greater adverse heat-related health outcomes than any other age cohort during environmental heat exposure. There is now evidence that aging is associated with an attenuated physiological ability to dissipate heat and that the risk of heat-related illness in these individuals is elevated, particularly when performing physical activity in the heat. The purpose of this review is to discuss mechanisms of thermoregulatory control and the factors that may increase the risk of heat-related illness in older individuals. An understanding of the mechanisms responsible for impaired thermoregulation in this population is of particular importance, given the current and projected increase in frequency and intensity of heat waves, as well as the promotion of regular exercise as a means of improving health-related quality of life and morbidity and mortality. As such, the clinical implications of this work in this population will be discussed.
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Affiliation(s)
- Bryce N. Balmain
- School of Allied Health Sciences, Griffith University, Gold Coast, Australia
| | - Surendran Sabapathy
- School of Allied Health Sciences, Griffith University, Gold Coast, Australia
| | - Menaka Louis
- School of Allied Health Sciences, Griffith University, Gold Coast, Australia
| | - Norman R. Morris
- School of Allied Health Sciences, Griffith University, Gold Coast, Australia
- Metro North Hospital and Health Service, Allied Health Research Collaborative, The Prince Charles Hospital, Brisbane, Australia
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22
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The response of peripheral microcirculation to gravity-induced changes. Clin Biomech (Bristol, Avon) 2018; 57:19-25. [PMID: 29894856 DOI: 10.1016/j.clinbiomech.2018.06.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 05/29/2018] [Accepted: 06/04/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND The peripheral microcirculation supplies fresh blood to the small blood vessels, providing oxygen and nutrients to the tissues, removing waste, and maintaining normal homeostatic conditions. The goal of this study was to characterize the response of the peripheral microcirculation, in terms of blood flow and tissue oxygenation variables, to gravity-induced changes. METHODS The study included 20 healthy volunteers and the experiment involved monitoring central and peripheral variables with the right hand positioned at different heights. These positions correspond to various gravitational levels. Peripheral perfusion and oxygenation were monitored using a laser Doppler flowmeter, photoplethysmograph, and transcutaneous oxygen tension monitor. Local blood pressure and respiration rate were also measured. FINDINGS At the heart level, tissue oxygenation displayed a nadir, while capillary flow displayed a peak. Similar but weaker changes were observed at the control hand. In contrast, the photoplethysmograph's amplitude strongly decreased upon reducing the arm position below heart level. Both systolic and diastolic pressures decreased linearly between the highest to lowest arm position. INTERPRETATION The results may reflect peripheral compensation mechanisms, as well as an interaction between the central and peripheral cardiovascular systems, in response to local changes in blood pressure. The observed dependence of the oxygenation pattern on height could lead to important new insights for the diagnosis and treatment of problems in the regulation of tissue perfusion.
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Balmain BN, Jay O, Morris NR, Stewart GM, Shiino K, McFarland AJ, Jayasinghe R, Chan J, Sabapathy S. Folic acid supplementation improves vascular endothelial function, yet not skin blood flow during exercise in the heat, in patients with heart failure. Am J Physiol Regul Integr Comp Physiol 2018; 315:R810-R819. [PMID: 29975566 DOI: 10.1152/ajpregu.00132.2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Heart failure (HF) patients are susceptible to heat strain during exercise, secondary to blunted skin blood flow (SkBF) responses, which may be explained by impaired nitric oxide (NO)-dependent vasodilation. Folic acid improves vascular endothelial function and SkBF through NO-dependent mechanisms in healthy older individuals and patients with cardiovascular disease. We examined the effect of folic acid supplementation (5 mg/day for 6 wk) on vascular function [brachial artery flow-mediated dilation (FMD)] and SkBF responses [cutaneous vascular conductance (CVC)] during 60 min of exercise at a fixed metabolic heat production (300 ẆHprod) in a 30°C environment in 10 patients with HF (New York Heart Association Class I-II) and 10 healthy controls (CON). Serum folic acid concentration increased in HF [preintervention (pre): 1.4 ± 0.2; postintervention (post): 8.9 ± 6.7 ng/ml, P = 0.01] and CON (pre: 1.3 ± 0.6; post: 5.2 ± 4.9 ng/ml, P = 0.03). FMD improved by 2.1 ± 1.3% in HF ( P < 0.01), but no change was observed in CON postintervention ( P = 0.20). During exercise, the external workload performed on the cycle ergometer to attain the fixed level of heat production for exercise was similar between groups (HF: 60 ± 13; CON: 65 ± 20 external workload, P = 0.52). Increases in CVC during exercise were similar in HF (pre: 0.89 ± 0.43; post: 0.83 ± 0.45 au/mmHg, P = 0.80) and CON (pre: 2.01 ± 0.79; post: 2.03 ± 0.72 au/mmHg, P = 0.73), although the values were consistently lower in HF for both pre- and postintervention measurement intervals ( P < 0.05). These findings demonstrate that folic acid improves vascular endothelial function in patients with HF but does not enhance SkBF during exercise at a fixed metabolic heat production in a warm environment.
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Affiliation(s)
- Bryce N Balmain
- School of Allied Health Sciences, Griffith University , Gold Coast , Australia
| | - Ollie Jay
- Charles Perkins Centre, University of Sydney , Australia.,Thermal Ergonomics Laboratory, Exercise and Sport Science, Faculty of Health Sciences, University of Sydney , Sydney , Australia
| | - Norman R Morris
- School of Allied Health Sciences, Griffith University , Gold Coast , Australia.,Metro North Hospital and Health Service, Allied Health Research Collaborative, The Prince Charles Hospital , Brisbane , Australia
| | - Glenn M Stewart
- Division of Cardiovascular Diseases, Mayo Clinic , Rochester, Minnesota
| | - Kenji Shiino
- School of Allied Health Sciences, Griffith University , Gold Coast , Australia
| | - Amelia J McFarland
- School of Pharmacy and Pharmacology, Griffith University , Gold Coast , Australia
| | - Rohan Jayasinghe
- Cardiology, Gold Coast University Hospital , Gold Coast , Australia
| | - Jonathan Chan
- Cardiology, Gold Coast University Hospital , Gold Coast , Australia
| | - Surendran Sabapathy
- School of Allied Health Sciences, Griffith University , Gold Coast , Australia
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24
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Waldock KAM, Hayes M, Watt PW, Maxwell NS. Physiological and perceptual responses in the elderly to simulated daily living activities in UK summer climatic conditions. Public Health 2018; 161:163-170. [PMID: 29914698 DOI: 10.1016/j.puhe.2018.04.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 03/13/2018] [Accepted: 04/19/2018] [Indexed: 10/14/2022]
Abstract
OBJECTIVES The elderly population is at an increasingly significant health risk to heat-related illnesses and mortality when compared with younger people in the same conditions. This is due to an increased frequency and severity of heatwaves, attributed to climate change, and reduced ability of elderly individuals to dissipate excess heat. Consequently, most excess deaths and emergency visits during heatwaves occur in people aged more than 65 years. The aim of this investigation was to assess the physiological and perceptual responses of elderly people during exercise sessions equating to activities of daily living in UK summer climatic conditions. STUDY DESIGN Mixed-method, randomised research design. METHODS Twenty-eight participants (17 males, 10 females and 1 transgender female) were randomly assigned into three experimental groups; 15°C, 25°C or 35°C, with 50% relative humidity. Participants completed one preliminary and three experimental trials within their assigned environment. The data from the preliminary incremental recumbent cycling test was used to calculate participant's individual exercise intensities equating to 2, 4 and 6 metabolic equivalents (METs) for the subsequent trials. During experimental trials, participants completed 30-min seated rest and 30-min cycling. RESULTS No change was observed in thermal comfort ([TC] just uncomfortable in both trials), and only modest changes in ratings of perceived exertion (14 ± 2 vs 15 ± 2) at 6 METs in 25°C compared with those in 35°C were observed. In contrast, thermal strain markers did significantly increase (P < 0.05) across the same conditions, including change in rectal temperature (ΔTre) during exercise (0.27 ± 0.17°C vs 0.64 ± 0.18°C) and peak skin temperature ([Tskin] 32.94 ± 1.15°C vs 36.11 ± 0.44°C). CONCLUSION When completing exercise that equates to activities of daily living, elderly people could have a decreased perceptual awareness of the environment even though physiological markers of thermal strain are elevated. Consequently, the elderly could be less likely to implement behavioural thermoregulation interventions (i.e. seek shade and/or remove excess layers) due to a decreased awareness of an increasingly thermally challenging environment.
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Affiliation(s)
- K A M Waldock
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, BN20 7SN, United Kingdom.
| | - M Hayes
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, BN20 7SN, United Kingdom
| | - P W Watt
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, BN20 7SN, United Kingdom
| | - N S Maxwell
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, BN20 7SN, United Kingdom
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25
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Elliott RO, Alsalahi S, Fisher JP. Impact of acute dynamic exercise on radial artery low-flow mediated constriction in humans. Eur J Appl Physiol 2018; 118:1463-1472. [PMID: 29748721 PMCID: PMC6028889 DOI: 10.1007/s00421-018-3876-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 04/26/2018] [Indexed: 01/22/2023]
Abstract
Purpose A “low-flow mediated constriction” (L-FMC) is evoked in the radial artery by the inflation of an ipsilateral wrist cuff to a supra-systolic pressure. We sought to test the hypothesis that the radial artery L-FMC response is augmented immediately following acute dynamic leg exercise in young healthy individuals. Methods Ten healthy and recreationally active men (23 ± 4 years) undertook a 30-min trial of incremental dynamic leg cycling exercise (10 min at 50, 100 and 150 W) and a 30-min time control trial (seated rest). Trials were randomly assigned and performed on separate days. Radial artery characteristics (diameter, blood flow and shear rate) were assessed throughout each trial, with L-FMC and flow-mediated vasodilatation (FMD) assessments conducted prior to and immediately following (10 min) trials. Results Dynamic leg cycling exercise increased radial artery blood flow, along with mean, retrograde and anterograde shear rate (P < 0.05). Blood flow profiles were unchanged during the time control trial (P > 0.05). Following exercise L-FMC was increased (mean [SD]; − 5.6 [3.3] vs. − 10.1 [3.8] %, P < 0.05), while it was not different in the time control condition (− 8.1 [3.2] vs. − 6.7 [3.4] %, P > 0.05). FMD was not different following either the exercise or time control trials (P > 0.05), but the composite end-point of L-FMC + FMD was enhanced post-exercise (P < 0.05). Conclusions Dynamic exercise with a large muscle mass acutely augments the vasoconstrictor response of the radial artery in response to a reduction in blood flow (L-FMC) in young healthy individuals. The time course of this post-exercise response and the underlying vasoregulatory mechanisms require elucidation.
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Affiliation(s)
- Robert O Elliott
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - Sultan Alsalahi
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - James P Fisher
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, UK.
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Malheiros-Lima MR, Pires W, Fonseca IAT, Joviano-Santos JV, Ferreira AJ, Coimbra CC, Lima NRV, Wanner SP. Physical Exercise-Induced Cardiovascular and Thermoregulatory Adjustments Are Impaired in Rats Subjected to Cutaneous Artery Denervation. Front Physiol 2018. [PMID: 29515451 PMCID: PMC5826067 DOI: 10.3389/fphys.2018.00074] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
This study aimed to investigate the chronic effects of caudal artery denervation on morphometric parameters of the tail vascular smooth muscle and on physical exercise-induced thermoregulatory and cardiovascular adjustments in rats. Male Wistar rats were subjected to caudal artery denervation or the sham procedure. Approximately 26-28 days after these procedures, their thermoregulatory and cardiovascular parameters were evaluated at rest and during or following a fatiguing treadmill run. At the end of the experiments, the rats were euthanized, and samples of their tails were removed to evaluate morphometric parameters of the vascular smooth muscle surrounding the caudal artery. Denervated rats showed morphological adaptations, including increased arterial wall thickness and wall-to-lumen ratios. In resting rats and following the fatiguing exercise, caudal artery denervation barely affected the thermoregulatory and cardiovascular parameters evaluated. By contrast, caudal artery denervation attenuated the increase in tail skin temperature, decreased the spontaneous baroreflex sensitivity, and exacerbated the increases in mean arterial pressure in exercising rats. The increased wall-to-lumen ratio of denervated rats correlated negatively with the maximum tail skin temperature attained or cutaneous heat loss sensitivity but correlated positively with the maximum diastolic blood pressure attained during exercise. In conclusion, cutaneous denervation induces vascular remodeling characterized by morphological adaptations of the tail vascular smooth muscle. This vascular remodeling likely underlies the impaired tail heat loss and blood pressure adjustments in denervated rats subjected to physical exercise. Therefore, we have highlighted the importance of cutaneous vascular innervation integrity in thermal and cardiovascular control in stress-challenged rats. In this sense, our findings advance the understanding of thermoregulatory and cardiovascular system reactions after a sustained cutaneous vascular innervation injury, which is essential for the treatment of some diseases, such as Parkinson's disease and type 1 and type 2 diabetes mellitus.
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Affiliation(s)
- Milene R Malheiros-Lima
- Exercise Physiology Laboratory, Department of Physical Education, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Washington Pires
- Exercise Physiology Laboratory, Department of Physical Education, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Department of Physical Education, Institute of Life Sciences, Universidade Federal de Juiz de Fora, Governador Valadares, Brazil
| | - Ivana A T Fonseca
- Exercise Physiology Laboratory, Department of Physical Education, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Julliane V Joviano-Santos
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Anderson J Ferreira
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Cândido C Coimbra
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Nilo R V Lima
- Exercise Physiology Laboratory, Department of Physical Education, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Samuel P Wanner
- Exercise Physiology Laboratory, Department of Physical Education, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Kent GL, Dawson B, Cox GR, Abbiss CR, Smith KJ, Croft KD, Lim ZX, Eastwood A, Burke LM, Peeling P. Effect of dietary nitrate supplementation on thermoregulatory and cardiovascular responses to submaximal cycling in the heat. Eur J Appl Physiol 2018; 118:657-668. [DOI: 10.1007/s00421-018-3809-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/15/2018] [Indexed: 12/19/2022]
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Potočnik N, Lenasi H. The responses of glabrous and nonglabrous skin microcirculation to graded dynamic exercise and its recovery. Clin Hemorheol Microcirc 2016; 64:65-75. [DOI: 10.3233/ch-162045] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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29
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Balmain BN, Jay O, Sabapathy S, Royston D, Stewart GM, Jayasinghe R, Morris NR. Altered thermoregulatory responses in heart failure patients exercising in the heat. Physiol Rep 2016; 4:e13022. [PMID: 27905297 PMCID: PMC5112500 DOI: 10.14814/phy2.13022] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 10/03/2016] [Accepted: 10/09/2016] [Indexed: 01/11/2023] Open
Abstract
Heart failure (HF) patients appear to exhibit impaired thermoregulatory capacity during passive heating, as evidenced by diminished vascular conductance. Although some preliminary studies have described the thermoregulatory response to passive heating in HF, responses during exercise in the heat remain to be described. Therefore, the aim of this study was to compare thermoregulatory responses in HF and controls (CON) during exercise in the heat. Ten HF (NYHA classes I-II) and eight CON were included. Core temperature (Tc), skin temperature (Tsk), and cutaneous vascular conductance (CVC) were assessed at rest and during 1 h of exercise at 60% of maximal oxygen uptake. Metabolic heat production (Hprod) and the evaporative requirements for heat balance (Ereq) were also calculated. Whole-body sweat rate was determined from pre-post nude body mass corrected for fluid intake. While Hprod (HF: 3.9 ± 0.9; CON: 6.4 ± 1.5 W/kg) and Ereq (HF: 3.3 ± 0.9; CON: 5.6 ± 1.4 W/kg) were lower (P < 0.01) for HF compared to CON, both groups demonstrated a similar rise in Tc (HF: 0.9 ± 0.4; CON: 1.0 ± 0.3°C). Despite this similar rise in Tc, Tsk (HF: 1.6 ± 0.7; CON: 2.7 ± 1.2°C), and the elevation in CVC (HF: 1.4 ± 1.0; CON: 3.0 ± 1.2 au/mmHg) was lower (P < 0.05) in HF compared to CON Additionally, whole-body sweat rate (HF: 0.36 ± 0.15; CON: 0.81 ± 0.39 L/h) was lower (P = 0.02) in HF compared to CON Patients with HF appear to be limited in their ability to manage a thermal load and distribute heat content to the body surface (i.e., skin), secondary to impaired circulation to the periphery.
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Affiliation(s)
- Bryce N Balmain
- Menzies Health Institute, Gold Coast, Queensland, Australia
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia
| | - Ollie Jay
- Thermal Ergonomics Laboratory, Exercise and Sport Science, Faculty of Health Sciences, University of Sydney, Sydney, New South Wales, Australia
- Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Surendran Sabapathy
- Menzies Health Institute, Gold Coast, Queensland, Australia
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia
| | - Danielle Royston
- Menzies Health Institute, Gold Coast, Queensland, Australia
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia
| | - Glenn M Stewart
- Menzies Health Institute, Gold Coast, Queensland, Australia
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
| | - Rohan Jayasinghe
- Menzies Health Institute, Gold Coast, Queensland, Australia
- Cardiology, Gold Coast University Hospital, Gold Coast, Queensland, Australia
| | - Norman R Morris
- Menzies Health Institute, Gold Coast, Queensland, Australia
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia
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Pokora I, Żebrowska A. Application of A Physiological Strain Index in Evaluating Responses to Exercise Stress - A Comparison Between Endurance and High Intensity Intermittent Trained Athletes. J Hum Kinet 2016; 50:103-114. [PMID: 28149347 PMCID: PMC5260640 DOI: 10.1515/hukin-2015-0142] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2016] [Indexed: 11/22/2022] Open
Abstract
The study evaluated differences in response to exercise stress between endurance and
high-intensity intermittent trained athletes in a thermoneutral environment using a
physiological strain index (PSI). Thirty-two subjects participated in a running
exercise under normal (23°C, 50% RH) conditions. The group included nine
endurance trained athletes (middle-distance runners - MD), twelve high-intensity
intermittent trained athletes (soccer players - HIIT) and eleven students who
constituted a control group. The exercise started at a speed of 4
km·h–1 which was increased every 3 min by 2
km·h–1 to volitional exhaustion. The heart rate was
recorded with a heart rate monitor and aural canal temperature was measured using an
aural canal temperature probe. The physiological strain index (PSI) and the
contribution of the circulatory and thermal components to the overall physiological
strain were calculated from the heart rate and aural canal temperature. The
physiological strain index differed between the study and control participants, but
not between the MD and HIIT groups. The physiological strain in response to exercise
stress in a thermoneutral environment was mainly determined based on the circulatory
strain (MD group - 73%, HIIT group – 70%). The contribution of the circulatory
and thermal components to the physiological strain did not differ significantly
between the trained groups (MD and HIIT) despite important differences in
morphological characteristics and training-induced systemic cardiovascular and
thermoregulatory adaptations.
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Affiliation(s)
- Ilona Pokora
- Department of Physiology, the Jerzy Kukuczka Academy of Physical Education, Katowice, Poland
| | - Aleksandra Żebrowska
- Department of Physiology, the Jerzy Kukuczka Academy of Physical Education, Katowice, Poland
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Fernandes ADA, Amorim PRDS, Brito CJ, Sillero-Quintana M, Bouzas Marins JC. Regional Skin Temperature Response to Moderate Aerobic Exercise Measured by Infrared Thermography. Asian J Sports Med 2016; 7:e29243. [PMID: 27217931 PMCID: PMC4870826 DOI: 10.5812/asjsm.29243] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 06/15/2015] [Accepted: 06/17/2015] [Indexed: 12/05/2022] Open
Abstract
Background: Infrared thermography (IRT) does not require contact with the skin, and it is a convenient, reliable and non-invasive technique that can be used for monitoring the skin temperature (TSK). Objectives: The aim of this study was to monitor the variations in the regional TSK during exercise on 28 regions of interest (ROIs) (forehead, face, chest, abdomen, back, lumbar, anterior and posterior neck, and posterior and anterior views of the right and left hands, forearms, upper arms, thighs, and legs) with IRT. Patients and Methods: 12 physically active young males were monitored with IRT during the following three phases: a) 30 minutes before exercise b) while performing one hour of moderate intensity exercise on a treadmill at 60% of the VO2max, and c) 60 minutes after exercise. Results: During pre-exercise, all TSK reached a steady-state (P ≤ 0.05), which ensured adequate thermal stabilisation. At the beginning of exercise, there was a significant reduction in the TSK in most ROIs after 10 minutes of activity, except for the lower limbs (legs and thighs). After one hour of recovery, in the anterior view of the hands and thighs and in the posterior view of the legs, there were significant increases in the TSK compared to pre-exercise. Conclusions: There were significant distinctions in the skin temperature distribution during exercise according to the activity of the area under consideration during exercise, which may be important in the development of physiological models and heat flux analyses for different purposes.
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Affiliation(s)
- Alex de Andrade Fernandes
- Department of Physical Education, Human Performance Laboratory, Federal University of Viçosa, Viçosa, Brazil
- Federal Institute for Education, Sciences and Technology of Minas Gerais, Bambuí, Brazil
- School of Physical Education, Physiotherapy and Occupational Therapy, Federal University of Minas Gerais, Belo Horizonte, Brazil
- Corresponding author: Alex de Andrade Fernandes, Department of Physical Education, Human Performance Laboratory, Federal University of Viçosa, Viçosa, Brazil. Tel: +55-3138992076, Fax: +55-3138992076, E-mail:
| | | | - Ciro José Brito
- Department of Physical Education, Federal University of Juiz de Fora, Governador Valadares, Brazil
| | - Manuel Sillero-Quintana
- Faculty of Physical Activity and Sport Sciences, Universidad Politécnica de Madrid, Madrid, Spain
| | - João Carlos Bouzas Marins
- Department of Physical Education, Human Performance Laboratory, Federal University of Viçosa, Viçosa, Brazil
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Wanner SP, Leite LHR, Guimarães JB, Coimbra CC. Increased brain L-arginine availability facilitates cutaneous heat loss induced by running exercise. Clin Exp Pharmacol Physiol 2016; 42:609-16. [PMID: 25881674 DOI: 10.1111/1440-1681.12407] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 01/20/2015] [Accepted: 04/09/2015] [Indexed: 11/30/2022]
Abstract
The effects of increased brain availability of L-arginine (L-arg), a precursor for nitric oxide synthesis, on core body temperature (Tcore ) and cutaneous heat loss were evaluated in running rats. One week prior to the experiments, adult male Wistar rats received the following implants: a chronic guide cannula in the lateral cerebral ventricle and a temperature sensor in the abdominal cavity. On the day of the experiments, the rats were assigned to receive a 2-μL intracerebroventricular injection of either NaCl (0.15 mol/L) or L-arg solution (0.825, 1.65 or 3.30 mol/L); Tcore and tail skin temperature were measured while the rats ran at a speed of 18 m/min until they were fatigued. L-arginine induced a dose-dependent reduction in the threshold Tcore required for cutaneous heat loss (38.09 ± 0.20°C for 3.30-mol/L L-arg vs 38.61 ± 0.10°C for saline; P < 0.05), which attenuated the exercise-induced hyperthermia. Although the rats treated with L-arg presented a lower Tcore at the end of exercise (~0.7°C lower after treatment with the highest dose), no changes in the time to fatigue were observed relative to the control trial. These results suggest that brain L-arg controls heat loss during exercise, most likely by modulating the sympathetic vasoconstrictor tonus to skin vessels. Furthermore, despite facilitating cutaneous heat loss mechanisms, increased brain L-arg availability did not enhance physical performance.
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Affiliation(s)
- Samuel Penna Wanner
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil.,Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Laura Hora Rios Leite
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil.,Department of Physiology, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Juliana Bohnen Guimarães
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil.,State University of Minas Gerais, Ibirité, Brazil
| | - Cândido Celso Coimbra
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
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Del Pozzi AT, Miller JT, Hodges GJ. The effect of heating rate on the cutaneous vasomotion responses of forearm and leg skin in humans. Microvasc Res 2016; 105:77-84. [PMID: 26808211 DOI: 10.1016/j.mvr.2016.01.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 01/19/2016] [Accepted: 01/20/2016] [Indexed: 11/19/2022]
Abstract
We examined skin blood flow (SkBF) and vasomotion in the forearm and leg using laser-Doppler fluxmetry (LDF) and spectral analysis to investigate endothelial, sympathetic, and myogenic activities in response to slow (0.1 °C·10 s(-1)) and fast (0.5 °C·10 s(-1)) local heating. At 33 °C (thermoneutral) endothelial activity was higher in the legs than the forearms (P ≤ 0.02). Fast-heating increased SkBF more than slow heating (P=0.037 forearm; P=0.002 leg). At onset of 42 °C, endothelial (P=0.043 forearm; P=0.48 leg) activity increased in both regions during the fast-heating protocol. Following prolonged heating (42 °C) endothelial activity was higher in both the forearm (P=0.002) and leg (P<0.001) following fast-heating. These results confirm regional differences in the response to local heating and suggest that the greater increase in SkBF in response to fast local heating is initially due to increased endothelial and sympathetic activity. Furthermore, with sustained local skin heating, greater vasodilatation was observed with fast heating compared to slow heating. These data indicate that this difference is due to greater endothelial activity following fast heating compared to slow heating, suggesting that the rate of skin heating may alter the mechanisms contributing to cutaneous vasodilatation.
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Affiliation(s)
- Andrew T Del Pozzi
- Integrative Exercise Physiology Laboratory, School of Kinesiology, Ball State University, Muncie, IN 47306, United States
| | - James T Miller
- Exercise Physiology Laboratory, Department of Kinesiology, The University of Alabama, Tuscaloosa, AL 35487, United States
| | - Gary J Hodges
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada.
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Wanner SP, Prímola-Gomes TN, Pires W, Guimarães JB, Hudson ASR, Kunstetter AC, Fonseca CG, Drummond LR, Damasceno WC, Teixeira-Coelho F. Thermoregulatory responses in exercising rats: methodological aspects and relevance to human physiology. Temperature (Austin) 2015; 2:457-75. [PMID: 27227066 PMCID: PMC4844073 DOI: 10.1080/23328940.2015.1119615] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 11/02/2015] [Accepted: 11/02/2015] [Indexed: 01/18/2023] Open
Abstract
Rats are used worldwide in experiments that aim to investigate the physiological responses induced by a physical exercise session. Changes in body temperature regulation, which may affect both the performance and the health of exercising rats, are evident among these physiological responses. Despite the universal use of rats in biomedical research involving exercise, investigators often overlook important methodological issues that hamper the accurate measurement of clear thermoregulatory responses. Moreover, much debate exists regarding whether the outcome of rat experiments can be extrapolated to human physiology, including thermal physiology. Herein, we described the impact of different exercise intensities, durations and protocols and environmental conditions on running-induced thermoregulatory changes. We focused on treadmill running because this type of exercise allows for precise control of the exercise intensity and the measurement of autonomic thermoeffectors associated with heat production and loss. Some methodological issues regarding rat experiments, such as the sites for body temperature measurements and the time of day at which experiments are performed, were also discussed. In addition, we analyzed the influence of a high body surface area-to-mass ratio and limited evaporative cooling on the exercise-induced thermoregulatory responses of running rats and then compared these responses in rats to those observed in humans. Collectively, the data presented in this review represent a reference source for investigators interested in studying exercise thermoregulation in rats. In addition, the present data indicate that the thermoregulatory responses of exercising rats can be extrapolated, with some important limitations, to human thermal physiology.
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Affiliation(s)
- Samuel Penna Wanner
- Laboratório de Fisiologia do Exercício; Departamento de Educação Física; Universidade Federal de Minas Gerais ; Belo Horizonte (MG), Brazil
| | - Thales Nicolau Prímola-Gomes
- Laboratório de Biologia do Exercício; Departamento de Educação Física; Universidade Federal de Viçosa ; Viçosa (MG), Brazil
| | - Washington Pires
- Laboratório de Fisiologia do Exercício; Departamento de Educação Física; Universidade Federal de Minas Gerais ; Belo Horizonte (MG), Brazil
| | - Juliana Bohnen Guimarães
- Laboratório de Fisiologia do Exercício; Universidade Estadual de Minas Gerais ; Ibirité (MG), Brazil
| | - Alexandre Sérvulo Ribeiro Hudson
- Laboratório de Fisiologia do Exercício; Departamento de Educação Física; Universidade Federal de Minas Gerais ; Belo Horizonte (MG), Brazil
| | - Ana Cançado Kunstetter
- Laboratório de Fisiologia do Exercício; Departamento de Educação Física; Universidade Federal de Minas Gerais ; Belo Horizonte (MG), Brazil
| | - Cletiana Gonçalves Fonseca
- Laboratório de Fisiologia do Exercício; Departamento de Educação Física; Universidade Federal de Minas Gerais ; Belo Horizonte (MG), Brazil
| | - Lucas Rios Drummond
- Laboratório de Biologia do Exercício; Departamento de Educação Física; Universidade Federal de Viçosa ; Viçosa (MG), Brazil
| | - William Coutinho Damasceno
- Laboratório de Fisiologia do Exercício; Departamento de Educação Física; Universidade Federal de Minas Gerais ; Belo Horizonte (MG), Brazil
| | - Francisco Teixeira-Coelho
- Laboratório de Fisiologia do Exercício; Departamento de Educação Física; Universidade Federal de Minas Gerais; Belo Horizonte (MG), Brazil; Centro de Formação de Professores; Universidade Federal do Recôncavo da Bahia; Amargosa (BA), Brazil
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Santiago HP, Leite LHR, Lima PMA, Rodovalho GV, Szawka RE, Coimbra CC. The improvement of exercise performance by physical training is related to increased hypothalamic neuronal activation. Clin Exp Pharmacol Physiol 2015; 43:116-24. [DOI: 10.1111/1440-1681.12507] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 10/13/2015] [Accepted: 10/13/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Henrique P Santiago
- Department of Physiology and Biophysics; Institute of Biological Sciences; Federal University of Minas Gerais; Belo Horizonte Minas Gerais Brazil
| | - Laura HR Leite
- Department of Physiology; Institute of Biological Sciences; Federal University of Juiz de Fora; Juiz de Fora Minas Gerais Brazil
| | - Paulo Marcelo A Lima
- Department of Physiology and Biophysics; Institute of Biological Sciences; Federal University of Minas Gerais; Belo Horizonte Minas Gerais Brazil
| | - Gisele V Rodovalho
- Department of Physiology and Biophysics; Institute of Biological Sciences; Federal University of Minas Gerais; Belo Horizonte Minas Gerais Brazil
| | - Raphael E Szawka
- Department of Physiology and Biophysics; Institute of Biological Sciences; Federal University of Minas Gerais; Belo Horizonte Minas Gerais Brazil
| | - Cândido C Coimbra
- Department of Physiology and Biophysics; Institute of Biological Sciences; Federal University of Minas Gerais; Belo Horizonte Minas Gerais Brazil
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Capo A, Ismail E, Cardone D, Celletti E, Auriemma M, Sabatini E, Merla A, Amerio P. Joint functional impairment and thermal alterations in patients with Psoriatic Arthritis: A thermal imaging study. Microvasc Res 2015; 102:86-91. [DOI: 10.1016/j.mvr.2015.08.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 08/08/2015] [Accepted: 08/22/2015] [Indexed: 12/12/2022]
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Modeling a healthy and a person with heart failure conditions using the object-oriented modeling environment Dymola. Med Biol Eng Comput 2015; 53:1049-68. [DOI: 10.1007/s11517-015-1384-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Accepted: 08/26/2015] [Indexed: 11/25/2022]
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Ismail E, Capo A, Amerio P, Merla A. Functional-thermoregulatory model for the differential diagnosis of psoriatic arthritis. Biomed Eng Online 2014; 13:162. [PMID: 25494626 PMCID: PMC4320504 DOI: 10.1186/1475-925x-13-162] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 12/05/2014] [Indexed: 11/23/2022] Open
Abstract
Introduction Psoriasis arthritis (PsA) is a chronic inflammatory arthritis of joints of uncertain pathogenesis. PsA may lead to severe disabilities even in the absence of any clinical symptom. Therefore, PsA diagnosis in its early stages is critical. Material and methods This study uses Control System theory to model finger skin thermoregulatory processes overlying the hand joint in response to an isometric exercise. The proposed model is based on a homeostatic negative feedback loop characterized by four distinct parameters that describe how the control mechanisms are activated and maintained. Thermal infrared imaging was used to record a total of 280 temperature curves of 14 finger joints for each of 11 PsA patients and 9 healthy controls. Result and conclusion PsA patients presented delayed and prolonged re-warming processes characterized by the undershoot onset after the end of the isometric exercise followed by a faster temperature increase. Region classification on the basis of the model parameters demonstrated that the interphalageal joint region of thumb better discriminates between patients and controls, providing 100% true-positive discrimination for PsA affected regions and 88.89% of correct classification of healthy regions. Even proved over a limited number of subjects, the proposed method may provide useful hints for early differential diagnosis in the IR assessment of PsA disease.
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Affiliation(s)
- Enas Ismail
- Department of Neuroscience, Imaging and Clinical Sciences, University "G, d'Annunzio", Via dei Vestini, 31, 66013 Chieti, Italy.
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Nybo L, Rasmussen P, Sawka MN. Performance in the heat-physiological factors of importance for hyperthermia-induced fatigue. Compr Physiol 2014; 4:657-89. [PMID: 24715563 DOI: 10.1002/cphy.c130012] [Citation(s) in RCA: 201] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
This article presents a historical overview and an up-to-date review of hyperthermia-induced fatigue during exercise in the heat. Exercise in the heat is associated with a thermoregulatory burden which mediates cardiovascular challenges and influence the cerebral function, increase the pulmonary ventilation, and alter muscle metabolism; which all potentially may contribute to fatigue and impair the ability to sustain power output during aerobic exercise. For maximal intensity exercise, the performance impairment is clearly influenced by cardiovascular limitations to simultaneously support thermoregulation and oxygen delivery to the active skeletal muscle. In contrast, during submaximal intensity exercise at a fixed intensity, muscle blood flow and oxygen consumption remain unchanged and the potential influence from cardiovascular stressing and/or high skin temperature is not related to decreased oxygen delivery to the skeletal muscles. Regardless, performance is markedly deteriorated and exercise-induced hyperthermia is associated with central fatigue as indicated by impaired ability to sustain maximal muscle activation during sustained contractions. The central fatigue appears to be influenced by neurotransmitter activity of the dopaminergic system, but inhibitory signals from thermoreceptors arising secondary to the elevated core, muscle and skin temperatures and augmented afferent feedback from the increased ventilation and the cardiovascular stressing (perhaps baroreceptor sensing of blood pressure stability) and metabolic alterations within the skeletal muscles are likely all factors of importance for afferent feedback to mediate hyperthermia-induced fatigue during submaximal intensity exercise. Taking all the potential factors into account, we propose an integrative model that may help understanding the interplay among factors, but also acknowledging that the influence from a given factor depends on the exercise hyperthermia situation.
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Affiliation(s)
- Lars Nybo
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Denmark
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40
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Ruddock AD, Tew GA, Purvis AJ. Reliability of intestinal temperature using an ingestible telemetry pill system during exercise in a hot environment. J Strength Cond Res 2014; 28:861-9. [PMID: 24561595 DOI: 10.1519/jsc.0b013e3182aa5dd0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Ingestible telemetry pill systems are being increasingly used to assess the intestinal temperature during exercise in hot environments. The purpose of this investigation was to assess the interday reliability of intestinal temperature during an exercise-heat challenge. Intestinal temperature was recorded as 12 physically active men (25 ± 4 years, stature 181.7 ± 7.0 cm, body mass 81.1 ± 10.6 kg) performed two 60-minute bouts of recumbent cycling (50% of peak aerobic power [watts]) in an environmental chamber set at 35° C 50% relative humidity 3-10 days apart. A range of statistics were used to calculate the reliability, including a paired t-test, 95% limits of agreement (LOA), coefficient of variation (CV), standard error of measurement (SEM), Pearson's correlation coefficient (r), intraclass correlation coefficient (ICC), and Cohen's d. Statistical significance was set at p ≤ 0.05. The method indicated a good overall reliability (LOA = ± 0.61° C, CV = 0.58%, SEM = 0.12° C, Cohen's d = 0.12, r = 0.84, ICC = 0.84). Analysis revealed a statistically significant (p = 0.02) mean systematic bias of -0.07 ± 0.31° C, and the investigation of the Bland-Altman plot suggested the presence of heteroscedasticity. Further analysis revealed the minimum "likely" change in intestinal temperature to be 0.34° C. Although the method demonstrates a good reliability, researchers should be aware of heteroscedasticity. Changes in intestinal temperature >0.34° C as a result of exercise or an intervention in a hot environment are likely changes and less influenced by error associated with the method.
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Affiliation(s)
- Alan D Ruddock
- Academy of Sport and Physical Activity, Faculty of Health and Wellbeing, Sheffield Hallam University, Sheffield, United Kingdom
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41
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Cuddy JS, Hailes WS, Ruby BC. A reduced core to skin temperature gradient, not a critical core temperature, affects aerobic capacity in the heat. J Therm Biol 2014; 43:7-12. [DOI: 10.1016/j.jtherbio.2014.04.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 04/08/2014] [Accepted: 04/08/2014] [Indexed: 11/25/2022]
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Costa KA, Soares ADN, Wanner SP, Santos RDGCD, Fernandes SOA, Martins FDS, Nicoli JR, Coimbra CC, Cardoso VN. L-arginine supplementation prevents increases in intestinal permeability and bacterial translocation in male Swiss mice subjected to physical exercise under environmental heat stress. J Nutr 2014; 144:218-23. [PMID: 24259555 DOI: 10.3945/jn.113.183186] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Dietary supplementation with l-arginine has been shown to improve the intestinal barrier in many experimental models. This study investigated the effects of arginine supplementation on the intestinal permeability and bacterial translocation (BT) induced by prolonged physical exercise under heat stress. Under anesthesia, male Swiss mice (5-wk-old) were implanted with an abdominal sensor to record their core body temperature (T(core)). After recovering from surgery, the mice were divided into 3 groups: a non-supplemented group that was fed the standard diet formulated by the American Institute of Nutrition (AIN-93G; control), a non-supplemented group that was fed the AIN-93G diet and subjected to exertional hyperthermia (H-NS), and a group supplemented with l-arginine at 2% and subjected to exertional hyperthermia (H-Arg). After 7 d of treatment, the H-NS and H-Arg mice were forced to run on a treadmill (60 min, 8 m/min) in a warm environment (34°C). The control mice remained at 24°C. Thirty min before the exercise or control trials, the mice received a diethylenetriamine pentaacetic acid (DTPA) solution labeled with technetium-99m ((99m)Tc-DTPA) or (99m)Tc-Escherichia coli by gavage to assess intestinal permeability and BT, respectively. The H-NS mice terminated the exercise with T(core) values of ∼40°C, and, 4 h later, presented a 12-fold increase in the blood uptake of (99m)Tc-DTPA and higher bacterial contents in the blood and liver than the control mice. Although supplementation with arginine did not change the exercise-induced increase in T(core), it prevented the increases in intestinal permeability and BT caused by exertional hyperthermia. Our results indicate that dietary l-arginine supplementation preserves the integrity of the intestinal epithelium during exercise under heat stress, acting through mechanisms that are independent of T(core) regulation.
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43
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Fernandes ADA, Amorim PRDS, Brito CJ, de Moura AG, Moreira DG, Costa CMA, Sillero-Quintana M, Marins JCB. Measuring skin temperature before, during and after exercise: a comparison of thermocouples and infrared thermography. Physiol Meas 2014; 35:189-203. [DOI: 10.1088/0967-3334/35/2/189] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Chen TI, Tsai PH, Lin JH, Lee NY, Liang MT. Effect of short-term heat acclimation on endurance time and skin blood flow in trained athletes. Open Access J Sports Med 2013; 4:161-70. [PMID: 24379721 PMCID: PMC3871901 DOI: 10.2147/oajsm.s45024] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background To examine whether short-term, ie, five daily sessions, vigorous dynamic cycling exercise and heat exposure could achieve heat acclimation in trained athletes and the effect of heat acclimation on cutaneous blood flow in the active and nonactive limb. Methods Fourteen male badminton and table tennis athletes (age = 19.6 ± 1.2 years) were randomized into a heat acclimation (EXP, n = 7) or nonheat acclimation (CON, n = 7) group. For 5 consecutive days, the EXP group was trained using an upright leg cycle ergometer in a hot environment (38.4°C ± 0.4°C), while the CON group trained in a thermoneutral environment (24.1°C ± 0.3°C). For both groups, the training intensity and duration increased from a work rate of 10% below ventilatory threshold (VT) and 25 minutes per session on day 1, to 10% above VT and 45 minutes per session on day 5. Subjects performed two incremental leg cycle exercise tests to exhaustion at baseline and post-training in both hot and thermoneutral conditions. Study outcome measurements include: maximum oxygen uptake (VO2max); exercise heart rate (HR); O2 pulse; exercise time to exhaustion (tmax); skin blood flow in the upper arm (SkBFa) and quadriceps (SkBFq); and mean skin (Tsk). Results The significant heat-acclimated outcome measurements obtained during high-intensity leg cycling exercise in the high ambient environment are: (1) 56%–100% reduction in cutaneous blood flow to the active limbs during leg cycling exercise; (2) 28% drop in cutaneous blood flow in nonactive limbs at peak work rate; (3) 5%–10% reduction in heart rate (HR); (4) 10% increase in maximal O2 pulse; and (5) 6.6% increase in tmax. Conclusion Heat acclimation can be achieved with five sessions of high-intensity cycling exercise in the heat in trained athletes, and redistribution of cutaneous blood flow in the skin and exercising muscle, and enhanced cardiovascular adaptations provide the heat-acclimated athletes with the capability to increase their endurance time in the hot environment.
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Affiliation(s)
- Tsung-I Chen
- Graduate Institute of Sport Science, National Taiwan Sport University, Taoyuan, Taiwan ; Center for Physical Education, Tzu Chi University, Hualien, Taiwan
| | - Pu-Hsi Tsai
- Department of Sport and Leisure, National Quemoy University, Kinmen, Taiwan
| | - Jui-Hsing Lin
- Department of Physical Education, National Pingtung University of Education, Pingtung, Taiwan
| | - Ning-Yuean Lee
- College of Living Technology, Tainan University of Technology, Tainan, Taiwan
| | - Michael Tc Liang
- Department of Kinesiology and Health Promotion, California State Polytechnic University, Pomona, CA, USA
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Kenney WL, Stanhewicz AE, Bruning RS, Alexander LM. Blood pressure regulation III: what happens when one system must serve two masters: temperature and pressure regulation? Eur J Appl Physiol 2013; 114:467-79. [PMID: 23636697 DOI: 10.1007/s00421-013-2652-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 04/19/2013] [Indexed: 11/25/2022]
Abstract
When prolonged intense exercise is performed at high ambient temperatures, cardiac output must meet dual demands for increased blood flow to contracting muscle and to the skin. The literature has commonly painted this scenario as a fierce competition, wherein one circulation preserves perfusion at the expense of the other, with the regulated maintenance of blood pressure as the ultimate goal. This review redefines this scenario as commensalism, an integrated balance of regulatory control where one circulation benefits with little functional effect on the other. In young, healthy subjects, arterial pressure rarely falls to any great extent during either extreme passive heating or prolonged dynamic exercise in the heat, nor does body temperature rise disproportionately due to a compromised skin blood flow. Rather, it often takes the superimposition of additional stressors--e.g., dehydration or simulated hemorrhage--upon heat stress to substantially impact blood pressure regulation.
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Affiliation(s)
- W Larry Kenney
- Department of Kinesiology and Physiology Program, The Pennsylvania State University, 102 Noll Laboratory, University Park, PA, 16802-6900, USA,
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Abstract
During embryonic development, the skin, the largest organ of the human body, and nervous system are both derived from the neuroectoderm. Consequently, several key factors and mechanisms that influence and control central or peripheral nervous system activities are also present and hence involved in various regulatory mechanisms of the skin. Apparently, this is the case for the ion and non-ion selective channels as well. Therefore, in this review, we shall focus on delineating the regulatory roles of the channels in skin physiology and pathophysiology. First, we introduce key cutaneous functions and major characteristics of the channels in question. Then, we systematically detail the involvement of a multitude of channels in such skin processes (e.g. skin barrier formation, maintenance, and repair, immune mechanisms, exocrine secretion) which are mostly defined by cutaneous non-neuronal cell populations. Finally, we close by summarizing data suggesting that selected channels are also involved in skin diseases such as e.g. atopic dermatitis, psoriasis, non-melanoma cancers and malignant melanoma, genetic and autoimmune diseases, etc., as well as in skin ageing.
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Affiliation(s)
- Attila Oláh
- DE-MTA Lendület Cellular Physiology Research Group, Department of Physiology, University of Debrecen, Medical and Health Science Center, Research Center for Molecular Medicine, Nagyerdei krt. 98, H-4032, Debrecen, Hungary
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Seifert T, Secher NH. Sympathetic influence on cerebral blood flow and metabolism during exercise in humans. Prog Neurobiol 2011; 95:406-26. [PMID: 21963551 DOI: 10.1016/j.pneurobio.2011.09.008] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 09/13/2011] [Accepted: 09/19/2011] [Indexed: 11/26/2022]
Abstract
This review focuses on the possibility that autonomic activity influences cerebral blood flow (CBF) and metabolism during exercise in humans. Apart from cerebral autoregulation, the arterial carbon dioxide tension, and neuronal activation, it may be that the autonomic nervous system influences CBF as evidenced by pharmacological manipulation of adrenergic and cholinergic receptors. Cholinergic blockade by glycopyrrolate blocks the exercise-induced increase in the transcranial Doppler determined mean flow velocity (MCA Vmean). Conversely, alpha-adrenergic activation increases that expression of cerebral perfusion and reduces the near-infrared determined cerebral oxygenation at rest, but not during exercise associated with an increased cerebral metabolic rate for oxygen (CMRO(2)), suggesting competition between CMRO(2) and sympathetic control of CBF. CMRO(2) does not change during even intense handgrip, but increases during cycling exercise. The increase in CMRO(2) is unaffected by beta-adrenergic blockade even though CBF is reduced suggesting that cerebral oxygenation becomes critical and a limited cerebral mitochondrial oxygen tension may induce fatigue. Also, sympathetic activity may drive cerebral non-oxidative carbohydrate uptake during exercise. Adrenaline appears to accelerate cerebral glycolysis through a beta2-adrenergic receptor mechanism since noradrenaline is without such an effect. In addition, the exercise-induced cerebral non-oxidative carbohydrate uptake is blocked by combined beta 1/2-adrenergic blockade, but not by beta1-adrenergic blockade. Furthermore, endurance training appears to lower the cerebral non-oxidative carbohydrate uptake and preserve cerebral oxygenation during submaximal exercise. This is possibly related to an attenuated catecholamine response. Finally, exercise promotes brain health as evidenced by increased release of brain-derived neurotrophic factor (BDNF) from the brain.
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Affiliation(s)
- Thomas Seifert
- Department of Anaesthesia and The Copenhagen Muscle Research Centre, Rigshospitalet 2041, University of Copenhagen, Blegdamsvej 9, DK-2100 Copenhagen Ø, Denmark.
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Jay O, Bain AR, Deren TM, Sacheli M, Cramer MN. Large differences in peak oxygen uptake do not independently alter changes in core temperature and sweating during exercise. Am J Physiol Regul Integr Comp Physiol 2011; 301:R832-41. [PMID: 21697517 DOI: 10.1152/ajpregu.00257.2011] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The independent influence of peak oxygen uptake (Vo(₂ peak)) on changes in thermoregulatory responses during exercise in a neutral climate has not been previously isolated because of complex interactions between Vo(₂ peak), metabolic heat production (H(prod)), body mass, and body surface area (BSA). It was hypothesized that Vo(₂ peak) does not independently alter changes in core temperature and sweating during exercise. Fourteen males, 7 high (HI) Vo(₂ peak): 60.1 ± 4.5 ml·kg⁻¹·min⁻¹; 7 low (LO) Vo(₂ peak): 40.3 ± 2.9 ml·kg⁻¹·min⁻¹ matched for body mass (HI: 78.2 ± 6.1 kg; LO: 78.7 ± 7.1 kg) and BSA (HI: 1.97 ± 0.08 m²; LO: 1.94 ± 0.08 m²), cycled for 60-min at 1) a fixed heat production (FHP trial) and 2) a relative exercise intensity of 60% Vo(₂ peak) (REL trial) at 24.8 ± 0.6°C, 26 ± 10% RH. In the FHP trial, H(prod) was similar between the HI (542 ± 38 W, 7.0 ± 0.6 W/kg or 275 ± 25 W/m²) and LO (535 ± 39 W, 6.9 ± 0.9 W/kg or 277 ± 29 W/m²) groups, while changes in rectal (T(re): HI: 0.87 ± 0.15°C, LO: 0.87 ± 0.18°C, P = 1.00) and aural canal (T(au): HI: 0.70 ± 0.12°C, LO: 0.74 ± 0.21°C, P = 0.65) temperature, whole-body sweat loss (WBSL) (HI: 434 ± 80 ml, LO: 440 ± 41 ml; P = 0.86), and steady-state local sweating (LSR(back)) (P = 0.40) were all similar despite relative exercise intensity being different (HI: 39.7 ± 4.2%, LO: 57.6 ± 8.0% Vo(2 peak); P = 0.001). At 60% Vo(2 peak), H(prod) was greater in the HI (834 ± 77 W, 10.7 ± 1.3 W/kg or 423 ± 44 W/m²) compared with LO (600 ± 90 W, 7.7 ± 1.4 W/kg or 310 ± 50 W/m²) group (all P < 0.001), as were changes in T(re) (HI: 1.43 ± 0.28°C, LO: 0.89 ± 0.19°C; P = 0.001) and T(au) (HI: 1.11 ± 0.21°C, LO: 0.66 ± 0.14°C; P < 0.001), and WBSL between 0 and 15, 15 and 30, 30 and 45, and 45 and 60 min (all P < 0.01), and LSR(back) (P = 0.02). The absolute esophageal temperature (T(es)) onset for sudomotor activity was ∼0.3°C lower (P < 0.05) in the HI group, but the change in T(es) from preexercise values before sweating onset was similar between groups. Sudomotor thermosensitivity during exercise were similar in both FHP (P = 0.22) and REL (P = 0.77) trials. In conclusion, changes in core temperature and sweating during exercise in a neutral climate are determined by H(prod), mass, and BSA, not Vo(₂ peak).
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Affiliation(s)
- Ollie Jay
- Thermal Ergonomics Laboratory, School of Human Kinetics, University of Ottawa, Ottawa, Ontario Canada.
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