Hydration effects on physiological strain  of horses during exercise-heat stress

This study examined the effects of hyperhydration, exercise-induced dehydration, and oral fluid replacement on physiological strain of horses during exercise-heat stress. On three occasions, six horses completed a 90-min exercise protocol (50% maximal O2 uptake, 34.5°C, 48% relative humidity) divided into two 45-min periods ( exercise I and exercise II) with a 15-min recovery between exercise bouts. In random order, horses received no fluid (NF), 10 liters of water (W), or a carbohydrate-electrolyte solution (CE) 2 h before exercise and between exercise bouts. Compared with NF, preexercise hyperhydration (W and CE) did not alter heart rate, cardiac output (Q˙), stroke volume (SV), core body temperature, sweating rate (SR), or sweating sensitivity during exercise I. In contrast, after exercise II, exercise-induced dehydration in NF (decrease in body mass: NF, 5.6 ± 0.8%; W, 1.1 ± 0.4%; CE, 1.0 ± 0.2%) resulted in greater heat storage, with core body temperature ∼1.0°C higher compared with W and CE. In exercise II, the greater thermal strain in NF was associated with significant ( P < 0.05) decreases inQ˙ (10 ± 2%), SV (9 ± 3%), SR, and sweating sensitivity. We concluded that 1) preexercise hyperhydration provided no thermoregulatory advantage; 2) maintenance of euhydration by oral fluid replacement (∼85% of sweat fluid loss) during exercise in the heat was reflected in higher Q˙, SV, and SR with decreased heat storage; and 3) W or an isotonic CE solution was equally effective in reducing physiological strain associated with exercise-induced dehydration and heat stress.

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Core body temperature does not cool down with skin surface temperature during recovery at room temperature after acute heat stress exposure

Livestock Science ◽

10.1016/j.livsci.2016.07.010 ◽

2016 ◽

Vol 191 ◽

pp. 143-147 ◽

Cited By ~ 3

Author(s):

A. Sapkota ◽

A. Herr ◽

J.S. Johnson ◽

D.C. Lay

Keyword(s):

Heat Stress ◽

Body Temperature ◽

Surface Temperature ◽

Room Temperature ◽

Core Body Temperature ◽

Skin Surface ◽

Skin Surface Temperature ◽

Stress Exposure ◽

Acute Heat Stress ◽

Core Body

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The Impact of Central and Peripheral Cyclooxygenase Enzyme Inhibition on Exercise-Induced Elevations in Core Body Temperature

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2016-0382 ◽

2017 ◽

Vol 12 (5) ◽

pp. 662-667 ◽

Cited By ~ 3

Author(s):

Matthijs T.W. Veltmeijer ◽

Dineke Veeneman ◽

Coen C.C.W. Bongers ◽

Mihai G. Netea ◽

Jos W. van der Meer ◽

...

Keyword(s):

Heart Rate ◽

Body Temperature ◽

Skin Temperature ◽

Core Body Temperature ◽

Exercise Tests ◽

Hypothalamic Temperature ◽

Set Point ◽

Exercise Induced ◽

Core Body ◽

The Impact

Purpose:Exercise increases core body temperature (TC) due to metabolic heat production. However, the exercise-induced release of inflammatory cytokines including interleukin-6 (IL-6) may also contribute to the rise in TC by increasing the hypothalamic temperature set point. This study investigated whether the exercise-induced increase in TC is partly caused by an altered hypothalamic temperature set point.Methods:Fifteen healthy, active men age 36 ± 14 y were recruited. Subjects performed submaximal treadmill exercise in 3 randomized test conditions: (1) 400 mg ibuprofen and 1000 mg acetaminophen (IBU/APAP), (2) 1000 mg acetaminophen (APAP), and (3) a control condition (CTRL). Acetaminophen and ibuprofen were used to block the effect of IL-6 at a central and peripheral level, respectively. TC, skin temperature, and heart rate were measured continuously during the submaximal exercise tests.Results:Baseline values of TC, skin temperature, and heart rate did not differ across conditions. Serum IL-6 concentrations increased in all 3 conditions. A significantly lower peak TC was observed in IBU/APAP (38.8°C ± 0.4°C) vs CTRL (39.2°C ± 0.5°C, P = .02) but not in APAP (38.9°C ± 0.4°C) vs CTRL. Similarly, a lower ΔTC was observed in IBU/APAP (1.7°C ± 0.3°C) vs CTRL (2.0°C ± 0.5°C, P < .02) but not in APAP (1.7°C ± 0.5°C) vs CTRL. No differences were observed in skin temperature and heart-rate responses across conditions.Conclusions:The combined administration of acetaminophen and ibuprofen resulted in an attenuated increase in TC during exercise compared with a CTRL. This observation suggests that a prostaglandin-E2-induced elevated hypothalamic temperature set point may contribute to the exercise-induced rise in TC.

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A Real-Time Case Study in Driver Science: Physiological Strain and Related Variables

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2014-0519 ◽

2015 ◽

Vol 10 (8) ◽

pp. 1058-1060 ◽

Cited By ~ 5

Author(s):

Edward S. Potkanowicz

Keyword(s):

Body Temperature ◽

Real Time ◽

Core Body Temperature ◽

Time Data ◽

Physiological Strain ◽

Physiological Strain Index ◽

Probe System ◽

Future Work ◽

Core Body

This case study was conducted as an attempt to quantify racecar-driver core body temperature and heart rate (HR) in real time on a minute-by-minute basis and to expand the volume of work in the area of driver science. Three drivers were observed during a 15-lap, 25-min maximal event. Each driver competed in the closed-wheel, closed-cockpit sports-car category. Data on core body temperature and HR were collected continuously using the HQ Inc. ingestible core probe system and HR monitoring. Driver 1 pre- and postrace core temperatures were 37.80°C and 38.79°C, respectively. Driver 2 pre- and postrace core temperatures were 37.41°C and 37.99°C. Driver 1 pre- and postrace HRs were 102 and 161 beats/min. Driver 2 pre- and postrace HRs were 94.3 and 142 beats/min. Driver 1’s physiological strain index (PSI) at the start was 3.51. Driver 2’s PSI at the start was 3.10. Driver 1 finished with a PSI of 7.04 and driver 2 with a PSI of 3.67. Results show that drivers are continuously challenged minute by minute. In addition, before getting into their cars, the drivers already experience physiological and thermal challenges. The data suggest that drivers are getting hot quickly. In longer events, this represents the potential for severe heat injury. Investigating whether the HRs observed are indicative of work or evidence of a thermoregulatory-associated challenge is a direction for future work. The findings support the value of real-time data collection and offer strong evidence for the expansion of research on driver-athletes.

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Genetic parameters for hair characteristics and core body temperature in a multibreed Brahman–Angus herd1

Journal of Animal Science ◽

10.1093/jas/skz188 ◽

2019 ◽

Vol 97 (8) ◽

pp. 3246-3252 ◽

Cited By ~ 3

Author(s):

Kaitlyn M Sarlo Davila ◽

Heather Hamblen ◽

Peter J Hansen ◽

Serdal Dikmen ◽

Pascal A Oltenacu ◽

...

Keyword(s):

Heat Stress ◽

Body Temperature ◽

Genetic Parameters ◽

Core Body Temperature ◽

Cattle Breed ◽

Measuring Device ◽

Hair Samples ◽

Diameter Core ◽

Humidity Index ◽

Core Body

Abstract Thermal stress in hot humid conditions limits cattle production. The objectives for this study were to estimate genetic parameters for hair characteristics and core body temperature under low and high temperature humidity index (THI) conditions. Hair samples were collected and measured for length and diameter. Core body temperature was measured as vaginal temperature every 15 min over a 5-d period using an iButton temperature measuring device implanted in a blank CIDR in 336 heifers from the University of Florida multibreed herd (ranging from 100% Angus to 100% Brahman). Restricted maximum likelihood procedures were used to estimate heritabilities from multiple bivariate animal models using the WOMBAT program. Estimates of heritability for hair diameter, undercoat length, topcoat length, body temperature under low THI conditions, and body temperature under high THI conditions were 0.50, 0.67, 0.42, 0.32, and 0.26, respectively. The genetic parameters estimated in this study indicate a large, exploitable genetic variance which can be selected upon to improve tolerance in cattle. Breed effects for differing compositions of Brahman and Angus were also estimated. As Brahman breed composition increased by 25% undercoat length, topcoat length, body temperature under low THI conditions, and body temperature under high THI conditions decreased by 1.32 mm, 2.94 mm, 0.11 °C, and 0.14 °C, respectively. Under both low and high THI conditions, cattle with 25% Brahman breed composition or greater maintained a significantly lower body temperature than the 100% Angus breed group. The incorporation of Brahman germplasm is recommended for herds that often experience heat stress conditions in order to increase resilience to heat stress.

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Validation of an intramuscularly-implanted microchip and a surface infrared thermometer to estimate core body temperature in broiler chickens exposed to heat stress

Computers and Electronics in Agriculture ◽

10.1016/j.compag.2016.12.010 ◽

2017 ◽

Vol 133 ◽

pp. 1-8 ◽

Cited By ~ 5

Author(s):

O.S. Iyasere ◽

S.A. Edwards ◽

M. Bateson ◽

M. Mitchell ◽

J.H. Guy

Keyword(s):

Heat Stress ◽

Body Temperature ◽

Broiler Chickens ◽

Core Body Temperature ◽

Infrared Thermometer ◽

Core Body

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The effects of heat stress on cognition in persons with multiple sclerosis

Multiple Sclerosis Journal ◽

10.1177/1352458511422926 ◽

2011 ◽

Vol 18 (4) ◽

pp. 489-497 ◽

Cited By ~ 14

Author(s):

P Hämäläinen ◽

A Ikonen ◽

A Romberg ◽

H Helenius ◽

J Ruutiainen

Keyword(s):

Multiple Sclerosis ◽

Heat Stress ◽

Body Temperature ◽

Cognitive Functioning ◽

Cognitive Deficits ◽

Core Body Temperature ◽

Heat Exposure ◽

Heat Sensitivity ◽

Serial Addition ◽

Core Body

Background: Heat sensitivity and cognitive deficits are typical manifestations of multiple sclerosis (MS). Although cognitive deficits are quite well characterized, practically no data exist on the effects of heat on cognitive performances in MS. Objective: To assess the effects of short-term heat stress on cognitive functioning in subjects with MS. Methods: A total of 23 heat-sensitive MS and 19 healthy control (HC) subjects participated. Moderate heat exposure took place in a Finnish sauna. Cognitive functioning was measured with tests of sustained attention and processing speed, the Paced Auditory Serial Addition Test (PASAT 3” and 2”) and the computerized visual vigilance test, before, during and after heat exposure. Results: During the heat exposure, the core body temperature of the MS group rose significantly more ( p = 0.002) than that of the HC group. The heat stress worsened the performance of the MS group in the PASAT 3” ( p = 0.025) but not in the other cognitive measures. The performance in the PASAT 3” was reversed almost to the baseline level only 1- h after the heat exposure. Conclusions: A significant increase in core body temperature during heat stress is associated with a mild and reversible worsening of the PASAT 3” performance, while visual vigilance performance seems to remain almost unaffected.

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