J Therm Biol
December 2024
Single-variable analyses have limited ability to explain complex phenomena such as the regulation of prolonged physical (aerobic) performance. Our study aimed to identify predictors of performance in rats subjected to incremental-speed running exercise. Notably, most variables assessed were associated with rats' thermoregulation.
View Article and Find Full Text PDFJ Therm Biol
July 2024
Recent heatwaves have highlighted the importance of accurate and continuous core temperature (T) monitoring in sports settings. For example, accentuated rises in T caused by physical exercises under environmental heat stress increase the risk of heat illnesses. Thus, using valid and reproducible devices is essential to ensure safe sports practice.
View Article and Find Full Text PDFJ Therm Biol
July 2024
Athletes with tetraplegia may experience marked hyperthermia while exercising under environmental heat stress due to their limited ability to dissipate heat through evaporative means. This study investigated the effectiveness of two external cooling strategies (i.e.
View Article and Find Full Text PDFIntroduction: Alcohol ingestion influences metabolism during a subsequent exercise session, as evidenced by increased blood lactate concentration during fixed-intensity exercise. Therefore, augmented blood concentrations of alcohol may interfere with the anaerobic metabolism during high-intensity, short-duration exercise bout, thereby leading to impaired athletic performance.
Objective: This study investigated whether the acute ingestion of alcohol as ethanol modulates performance parameters derived from the power-duration relationship in a 3-min all-out cycling test that allows for identifying the power output related to heavy and severe exercise intensities.
Objective: The present study assessed the influence of physical training on cardiac autonomic activity in individuals with spinal cord injury (SCI) during different sleep stages.
Methods: Twenty-six volunteers were allocated into three groups: 9 sedentary individuals without SCI (control, CON); 8 sedentary tetraplegic individuals with chronic SCI (SED-SCI); 9 physically trained tetraplegic individuals with chronic SCI (TR-SCI). All participants underwent nocturnal polysomnography to monitor sleep stages: wakefulness, non-rapid eye movement (NREM) sleep (N1, N2, and N3 stages), and REM sleep.
J Therm Biol
January 2024
This study investigated the impact of long-term heat acclimation (HA) training on mouse thermoregulation, metabolism, and running performance in temperate (T) and hot (H) environments. Male Swiss mice were divided into 1) Sedentary (SED) mice kept in T (22 °C; SED/T), 2) Endurance Trained mice (ET, 1 h/day, 5 days/week, 8 weeks, 60 % of maximum speed) in T (ET/T), 3) SED kept in H (32 °C; SED/H), and 4) ET in H (ET/H). All groups performed incremental load tests (ILT) in both environments before (pre-ET) and after four and eight weeks of ET.
View Article and Find Full Text PDFIce slurry ingestion during prolonged exercises may improve performance in hot environments; however, the ideal amount and timing of ingestion are still uncertain. We determined whether ad libitum ice slurry ingestion influences physiological and perceptual variables and half-marathon performance while comparing the effects of the amount and moment of ingestion between ice slurry and water at 37 °C. Ten trained participants (28 ± 2 years; mean and SD) were required to run two half marathons while consuming either ice slurry (-1 °C; Ad-1) or water (37 °C; 37 CE) ad libitum.
View Article and Find Full Text PDFCore temperature is used in several situations, including studies on biological rhythms and circadian markers of physical performance. Measuring the inner eye canthus (Tco) temperature is a method proposed to identify core temperature, but it has shown little concordance in physical exercise situations and has not yet been used in studies with measurements taken throughout the day. The objective of this study was to compare the measurements and daily behavior of Tco obtained by infrared thermography with rectal temperature (Tre) during a prolonged waking protocol.
View Article and Find Full Text PDFAntarctic expeditions include isolation and exposure to cold and extreme photoperiods (with continuous natural light during summer) that may influence psychophysiological responses modulated by luminosity and sleep. We assessed changes in night sleep patterns by actigraphy, salivary biomarkers, and perceptual variables in seven participants in the following time points along a 50-day camping expedition in Antarctica (Nelson Island): Pre-Field (i.e.
View Article and Find Full Text PDFPLoS One
August 2023
Environmental heat stress impairs endurance performance by enhancing exercise-induced physiological and perceptual responses. However, the time course of these responses during self-paced running, particularly when comparing hot and temperate conditions, still needs further clarification. Moreover, monitoring fatigue induced by exercise is paramount to prescribing training and recovery adequately, but investigations on the effects of a hot environment on post-exercise neuromuscular fatigue are scarce.
View Article and Find Full Text PDFThis study systematically reviewed the literature reporting the changes in rats' core body temperature (T) induced by either incremental- or constant-speed running to fatigue or exhaustion. In addition, multiple linear regression analyses were used to determine the factors contributing to the T values attained when exercise was interrupted. Four databases (EMBASE, PubMed, SPORTDiscus, and Web of Science) were searched in October 2021, and this search was updated in August 2022.
View Article and Find Full Text PDFObjectives: Acute physical exercise acts as a metabolic stressor, promoting activation of the immune system, and this response could be relevant in the adipose tissue remodeling process. In addition, some cytokines have important functions in lipolysis. Because chronic exercise improves obesity-related metabolic and inflammatory dysfunction, herein we investigated the effect of acute exercise on the inflammatory responses in the adipose tissues of lean and obese mice.
View Article and Find Full Text PDFPurpose: TRPV1 desensitization or blockade promotes hyperthermia in rodents. Daily changes in core body temperature (Tc), spontaneous locomotor activity (SLA), and glucocorticoids are temporal cues for peripheral clocks. Thus, this study aimed to evaluate the effects of both desensitization and blockade of TRPV1 on Tc, SLA, blood corticosterone, and the clock genes Per1 and Bmal1 in the liver and adrenal.
View Article and Find Full Text PDFWe identified the neural pathway of the hyperthermic response to TRPV1 antagonists. We showed that hyperthermia induced by i.v.
View Article and Find Full Text PDFNew Findings: What is the central question of this study? The aim was to identify the factors predicting the body core temperature of athletes at the end of a 10 km self-paced run in a hot environment. What is the main finding and its importance? Hyperthermia in athletes subjected to self-paced running depends on several factors, highlighting the integrated control of core temperature during exercise under environmental heat stress. Five of the seven variables that significantly predicted core temperature are not invasive and, therefore, practical for use outside the laboratory environment: heart rate, sweat rate, wet-bulb globe temperature, running speed and maximal oxygen consumption.
View Article and Find Full Text PDFInt J Biometeorol
May 2023
Understanding the factors that underlie the physical exercise-induced increase in body core temperature (T) is essential to developing strategies to counteract hyperthermic fatigue and reduce the risk of exertional heatstroke. This study analyzed the contribution of six factors to T attained at fatigue in Wistar rats (n = 218) subjected to incremental-speed treadmill running: ambient temperature (T), distance traveled, initial T, body mass, measurement site, and heat loss index (HLI). First, we ran hierarchical multiple linear regression analyses with data from different studies conducted in our laboratory (n = 353 recordings).
View Article and Find Full Text PDFPurpose: 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.
Thermoregulatory changes may influence the rats' prolonged physical performance and are commonly evaluated during treadmill running. Therefore, we determined the reliability of performance and thermoregulatory parameters in rats subjected to incremental-speed exercises (i.e.
View Article and Find Full Text PDFPhysical exercise can acutely and chronically modulate immunological responses. Women and men have different innate and adaptive immune responses, and in this sense, these two groups may also have different acute immunological responses induced by exercise. In addition, it is essential to understand further whether the effects of physical exercise on the immune system responses depend on sex because limited scientific evidence on this topic is available.
View Article and Find Full Text PDFBackground: This study aimed to analyze the extent of fatigue responses after female soccer matches and the ensuing recovery time course of performance, physiological, and perceptual responses.
Methods: Three databases (PubMed, Web of Science, and SPORTDiscus) were searched in October 2020 and updated in November 2021. Studies were included when participants were female soccer players, regardless of their ability level.
An Acad Bras Cienc
June 2022
Open-water diving in a polar environment is a psychophysiological challenge to the human organism. We evaluated the effect of short-term diving (i.e.
View Article and Find Full Text PDFAnxiety resulting from psychogenic stimuli elicit stress-induced hyperthermia in rats, often called "psychogenic fever", which is part of a coordinated response to situations seen as novel or distressing. Brain transient receptor potential vanilloid 1 (TRPV1) channels modulate both thermoregulation and animal behavior; however, the role of peripheral TRPV1 channels in regulating these responses during exposure to an anxiogenic environment has not been determined. Thus, the present study aimed to investigate the involvement of abdominal TRPV1 channels in stress-induced hyperthermia and behavior in rats subjected to an unconditioned anxiety test.
View Article and Find Full Text PDFWe evaluated the influence of a 32-day camping in Antarctica on physical performance and exercise-induced thermoregulatory responses. In Brazil, before and after the Antarctic camping, the volunteers performed an incremental exercise at temperate conditions and, two days later, an exercise heat stress protocol (45-min running at 60% of maximum aerobic speed, at 31°C and 60% of relative humidity). In Antarctica, core temperature was assessed on a day of fieldwork, and average values higher than 38.
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