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Results 151 - 200 of 1103
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Lopez Rebecca M - - 2009
To critically assess original research addressing the effect of creatine supplementation on exercise heat tolerance and hydration status. We searched the electronic databases PubMed, Scopus, Web of Science, SPORTDiscus, and Rehabilitation & Physical Medicine, without date limitations, for the following key words: creatine, exercise, thermoregulation, dehydration, hyperthermia, heat tolerance, exertional ...
Del Coso Juan - - 2009
PURPOSE: To investigate the effects of caffeine ingestion on thermoregulation and fluid-electrolyte losses during prolonged exercise in the heat. METHODS: Seven endurance-trained ( .VO2max = 61 +/- 8 mL.kg.min) heat-acclimated cyclists pedaled for 120 min at 63% .VO2max in a hot-dry environment (36 degrees C; 29% humidity) on six occasions: ...
Bergeron Michael F - - 2009
One of the biggest challenges facing numerous young athletes is attempting to perform safely and effectively in the heat. An even greater performance challenge and risk for incurring exertional heat injury is encountered when a young athlete has to compete multiple times on the same day, with only a short ...
Beckmann L - - 2009
During physical exercise body muscles are activated and heat is generated. In intensive physical activity, heat will be released by sweating to protect the body of overheating. Sweating and convection implies a water loss which can lead to dehydration. To avoid health problems as a result of dehydration, the body ...
Wingo Jonathan E - - 2009
Cutaneous vascular conductance (CVC) increases in response to local skin heating. Although attenuation of vasoconstrictor responsiveness due to local heating has been demonstrated, the mechanism(s) responsible for this attenuation remains unclear. Nitric oxide has been shown to at least partially contribute to this response, but other mechanisms also may be ...
Crandall Craig G - - 2008
In healthy, noninjured, individuals, passive (i.e., nonexercising) whole-body heating has the potential to cause significant cardiovascular stress that may be second only to the cardiovascular stress associated with exercise. For example, such a heat stress can increase heart rate to well over 100 beats min(-1) with cardiac output increasing upward ...
Hwang Kyung-Mi - - 2008
The kind of salt used in doenjang preparation is one of the most important factors that affect the chemopreventive activities of doenjang. Bamboo salt (BS) is known to exert various therapeutic effects on several diseases. In this study, antimutagenic and anticlastogenic effects of methanol extracts of doenjang made with either ...
Bergeron Michael F - - 2009
A short recovery period between same-day competitions is common practice in organized youth sports. We hypothesized that young athletes will experience an increase in physiological strain and perceptual discomfort during a second identical exercise bout in the heat, with 1 h (21 degrees C) between bouts, even with ample hydration. ...
Cheuvront Samuel N - - 2009
Nutritional adenosine receptor antagonists can enhance endurance exercise performance in temperate environments, but their efficacy during heat stress is not well understood. This double-blinded, placebo-controlled study compared the effects of an acute dose of caffeine or quercetin on endurance exercise performance during compensable heat stress (40 degrees C, 20-30% rh). ...
Gagnon Daniel - - 2009
We examined differences in dynamic heat balance between males and females during intermittent exercise. Six males (M) and six females (F) performed three 30-min bouts of exercise (Ex1, Ex2, Ex3) at a constant rate of metabolic heat production (M - W) of approximately 500 W separated by three 15-min periods ...
Shirreffs Susan M - - 2009
Sweat evaporation can be a key thermoregulatory mechanism and it causes a loss of water from all compartments of the body. Hypohydration can also develop with restricted fluid intake or with intake of diuretics. Hypohydration can affect physical and/or mental performance and/or have implications for dietary recommendations. A variety of ...
Machado-Moreira Christiano A - - 2008
INTRODUCTION: It is generally accepted that the palmar (volar) and dorsal surfaces of human hands display different sudomotor responses to mental or thermal stimuli. We tested the hypothesis that, during thermal stimulation, secretion from the dorsal surfaces would always exceed that from the volar aspect of the hand. METHODS: Sweat ...
Mora-Rodriguez Ricardo - - 2008
PURPOSE: To compare the thermoregulatory responses between constant (CON) and variable-intensity exercise (VAR) in a dry-hot environment (36 degrees C, 29% relative humidity, and 2.5 m x s(-1) airflow). METHODS: In a random order, seven endurance-trained, heat-acclimated subjects cycled either at 60% VO2max (CON) or alternating 1.5 min at 90% ...
Maughan Ronald J - - 2008
Athletes are encouraged to begin exercise well hydrated and to consume sufficient amounts of appropriate fluids during exercise to limit water and salt deficits. Available evidence suggests that many athletes begin exercise already dehydrated to some degree, and although most fail to drink enough to match sweat losses, some drink ...
Chen Yu - - 2009
Inflammatory bowel diseases (IBD) cause the intestines to become inflamed (red and swollen) and typically include Crohn's disease and ulcerative colitis. Heat shock protein (Hsp)70, which exhibits greater expression in the intestines of patients with IBD, may act to protect the intestine against this inflammatory insult. However, most procedures for ...
Goulet Eric D B - - 2008
Whether the use of pre-exercise hyperhydration could improve the performance of athletes who do not hydrate sufficiently during prolonged exercise is still unknown. We therefore compared the effects of pre-exercise hyperhydration and pre-exercise euhydration on endurance capacity, peak power output and selected components of the cardiovascular and thermoregulatory systems during ...
Rosenzweig Bernice R - - 2008
Urban streams play a significant role in the transport of dissolved inorganic nitrogen (DIN) from uplands to sensitive coastal receiving waters. In this study, we investigate the timing of DIN export through monitoring conducted during several storm events of different magnitude and with different antecedent conditions in an urban catchment. ...
Kenny Glen P - - 2008
PURPOSE: Previous studies have shown a rapid reduction in postexercise local sweating and blood flow despite elevated core temperatures. However, local heat loss responses do not illustrate how much whole-body heat dissipation is reduced, and core temperature measurements do not accurately represent the magnitude of residual body heat storage. Whole-body ...
Wingo Jonathan E - - 2008
Grafted skin has impaired blood flow and sweating responses necessary for heat dissipation. Heat acclimation improves temperature regulation in healthy individuals, but it is unknown whether heat acclimation improves temperature regulation of individuals with large areas of grafted skin. A 33-year-old woman with 75% total body surface area grafted skin ...
Ascensão A - - 2008
AIM: Up to now, few studies regarding the impact of motocross heats on functional and physiological variables have been addressed so far. The aim of the present study was to analyze physiological and functional changes induced by a simulated off-road motocross heat. METHODS: Fifteen motocross riders (28.3+/-7.9 yrs; 71.1+/-7.0 kg; ...
Amorim Fabiano T - - 2008
Hsp72 concentration has been shown to be higher in the serum (eHsp72) of runners with symptoms of heat illness than in non-ill runners. Recently, it has been suggested that the rate of heat storage during exercise in the heat may be an important factor in the development of heat stroke. ...
Gagnon Daniel - - 2008
We evaluated the hypothesis that different rates of metabolic heat production between sexes, during exercise at the same percentage of maximum oxygen consumption [VO2 max] give proportional differences in evaporative heat loss. Seven males and seven females, exercised at 41.3 +/- 2.7% VO2 Max for 60-min at 40 degrees C ...
Cheuvront Samuel N - - 2008
Exercise alone or in combination with environmental heat stress can elevate blood S-100beta protein concentrations. However, the explanatory power of exercise with marked environmental heat stress on the appearance of S-100beta is questionable. It is possible that the process of heat acclimation might afford additional insight. PURPOSE: Determine the S-100beta ...
Nava S - - 2008
There is no consensus concerning the best system of humidification during long-term noninvasive mechanical ventilation (NIMV). In a technical pilot randomised crossover 12-month study, 16 patients with stable chronic hypercapnic respiratory failure received either heated humidification or heat and moisture exchanger. Compliance with long-term NIMV, airway symptoms, side-effects and number ...
Partridge Linda - - 2008
This annual review focuses on invertebrate model organisms, which shed light on new mechanisms in aging and provide excellent systems for in-depth analysis. This year, the first quantitative estimate of evolutionary conservation of genetic effects on lifespan has pointed to the key importance of genes involved in protein synthesis, a ...
Hamer Bojan - - 2008
In the present study, we investigated the progressive acclimation of the mussel Mytilus galloprovincialis to different reduced seawater (SW) salinities and its effect on several biochemical markers and biotests. Mussels were purchased from a local mariculture facility during summer (SW temperature 27 degrees C, salinity 37.5 psu) and winter (13 ...
Merry Troy L - - 2008
Dehydration is typical during prolonged exercise. Because training stimulates numerous adaptations, some involving fluid regulation, it is conceivable that training involves adaptations to dehydration. This study tested the hypothesis that trained individuals have altered fluid regulatory, but not behavioural or perceptual responses to exercise when hypohydrated. Six trained (V.O2 peak: ...
von Duvillard Serge P - - 2008
A plethora of investigations examining fluid intake before, during, and after training and competition have suggested that a lack of adequate fluid intake will impair or decrease physical performance. Depending upon the type of training or competition, individuals training for prolonged endurance events should drink fluids containing carbohydrates and electrolytes ...
Selkirk G A - - 2008
This study examined endotoxin-mediated cytokinemia during exertional heat stress (EHS). Subjects were divided into trained [TR; n=12, peak aerobic power (VO2peak)=70+/-2 ml.kg lean body mass(-1).min(-1)] and untrained (UT; n=11, VO2peak=50+/-1 ml.kg lean body mass(-1).min(-1)) groups before walking at 4.5 km/h with 2% elevation in a climatic chamber (40 degrees C, ...
Goosey-Tolfrey Victoria L - - 2008
BACKGROUND: Wheelchair tennis players, competing in hot and humid environments, are faced with an increased risk of heat-related illness and impaired performance. This study examined the effects of head and neck cooling garments on perceptions of exertion (RPE), thermal sensation (TS), and water consumption during wheelchair exercise at 30.4 +/- ...
Tronstad Christian - - 2008
A multichannel logger for long-term measurements of sweat activity is presented. The logger uses skin surface electrodes for unipolar admittance measurements in the stratum corneum. The logger is developed with emphasis on clinical use. The portability of the logger enables recording of sweat activity under circumstances such as daily errands, ...
Khomenok Gennadi A - - 2008
The current study examines the use of hand immersion in cold water to alleviate physiological strain caused by exercising in a hot climate while wearing NBC protective garments. Seventeen heat acclimated subjects wearing a semi-permeable NBC protective garment and a light bulletproof vest were exposed to a 125 min exercise-heat ...
Zumbach B - - 2008
The objective of this study was to describe genetic variability of pig carcass weight as a function of heat stress. Data included carcass weights of 23,556 crossbred pigs [Duroc x (Landrace x Large White)] raised on 2 farms in North Carolina and harvested from May 2005 through December 2006. Weather ...
Kellogg Dean L DL - - 2008
Nitric oxide (NO) participates in locally mediated vasodilation induced by increased local skin temperature (T(loc)) and in sympathetically mediated vasodilation during whole body heat stress. We hypothesized that endothelial NOS (eNOS) participates in the former, but not the latter, response. We tested this hypothesis by examining the effects of the ...
Sunderland C - - 2008
BACKGROUND: It is well documented that heat acclimation of six or more sessions of at least 60 min duration prolongs the time to exhaustion during endurance walking, cycling and running in the heat. However, this type of acclimation is not specific to team sport activity and the effect of acclimation ...
Roelands Bart - - 2008
INTRODUCTION: Acute bupropion (dopamine/noradrenaline reuptake inhibitor) administration significantly improved time trial performance and increased core temperature in the heat (30 degrees C). PURPOSE: The present study was performed to examine the effect of a dopaminergic reuptake inhibitor on exercise capacity and thermoregulation during prolonged exercise in temperate and warm conditions. ...
Carpenter Janet S - - 2008
OBJECTIVE: To evaluate relationships among different measures of hot flashes, perceived hot flash interference, and associated outcomes (positive affect, negative affect) while controlling potential covariates. DESIGN: Breast cancer survivors (N=236) provided demographic data, objective hot flash frequency data via sternal skin conductance monitoring, prospective diary-based hot flash frequency and severity ...
Chinevere Troy D - - 2008
This study determined whether a torso-vest forced ambient air body ventilation system (BVS) reduced physiological strain during exercise-heat stress. Seven heat-acclimated volunteers attempted nine, 2-h treadmill walks at 200 W m(-2) in three environments, -40 degrees C, 20% rh (HD), 35 degrees C, 75% rh (HW), and 30 degrees C, ...
Bruce A S W - - 2008
Although thankfully rare,heat related illness has significant implications for the effective fighting force available to commanders. This is especially pertinent in the current theatres of operations, as previously soldiers have not routinely been subjected to the rigors of operating in hot climates. In addition to Iraq and Afghanistan, various training ...
Rodrigues A G - - 2008
To investigate the influence of medullary adrenal secretion on thermoregulation during exercise, Phy (Eserine, 5x10(-3) M) was injected into the lateral cerebral ventricle of normal (INT) or bilaterally adrenodemedullated (ADM) untrained rats. Body temperature (Tb) and metabolic rate were measured in the rats while they were exercising on a treadmill ...
Peiffer Jeremiah J - - 2009
Cold water immersion (CWI) is a popular recovery modality, but actual physiological responses to CWI after exercise in the heat have not been well documented. The purpose of this study was to examine effects of 20-min CWI (14 degrees C) on neuromuscular function, rectal (T(re)) and skin temperature (T(sk)), and ...
Spolyar Douglas - - 2008
A mechanism is identified whereby dark matter (DM) in protostellar halos dramatically alters the current theoretical framework for the formation of the first stars. Heat from neutralino DM annihilation is shown to overwhelm any cooling mechanism, consequently impeding the star formation process and possibly leading to a new stellar phase. ...
Rowland Thomas - - 2008
PURPOSE: Physiological responses to exercise in the heat differ between prepubertal children and young adults. Whether these maturity-related variations imply lower exercise tolerance, inferior thermoregulation, and greater risk for heat injury in the child is uncertain. This study directly compared thermoregulatory and cardiovascular responses as well as endurance performance between ...
Barwood Martin J - - 2008
INTRODUCTION: Fatigue occurs earlier when working at corresponding exercise intensities in hot compared with cool conditions. Psychological skills training (PST) can modify the responses evoked by thermal stimuli such as the respiratory responses on immersion to cold water. This study tested the hypothesis that a 4-d PST package would significantly ...
Leung May S F MS Physiotherapy Department, Our Lady of Maryknoll Hospital, Hong - - 2008
To determine whether the addition of deep or superficial heating to stretching produces better clinical outcomes than stretching alone in the management of frozen shoulder. A single-blinded, randomized controlled study. Thirty subjects suffering from the stiffness phase of frozen shoulder. Subjects were randomly allocated to receive: (i) deep heating plus ...
Kacin Alan - - 2008
Heat-loss responses during steady-load exercise are affected by an increase in relative work rate induced by muscle ischaemia or hypoxaemia. The present study investigated whether progressive increases in perception of exertion and relative oxygen uptake %VO2peak which occur during prolonged steady-load exercise as a result of progressively increased peripheral fatigue, ...
Bonde Pramod - - 2008
OBJECTIVE: Thoracoscopic sympathectomy has become an accepted therapeutic option for palmar hyperhidrosis. Objective assessment of sweat output after sympathectomy, however, has not been reported to date. We report for the first time sweat output measurements after sympathectomy during a 3-year postoperative period. METHODS: Thoracoscopic sympathectomy was performed by division of ...
Senthilkumar Sivaprakasam - - 2008
This study is focused on the biodegradation of saline tannery effluent by identified halotolerant bacterial consortia in a bench-scale reaction calorimeter. A satisfactory agreement was observed between oxygen uptake rate profiles and heat flux-time curves confirming that, under strict aerobic conditions, calorimetry and respirometry provided the same information. Oxycalorific equivalent ...
Simmons Shona E - - 2008
The capacity to perform exercise is reduced in a hot environment when compared to cooler conditions. A limiting factor appears to be a higher core body temperature (T (core)) and it has been suggested that an elevated T (core) reduces the drive to exercise, this being reflected in higher ratings ...
Marino Frank E - - 2008
The evolutionary history of mammals, but more specifically humans, indicates that heat stress was a decisive and powerful selection pressure. There is good evidence that early hominids had to adapt to a changing environment by assuming an upright posture and consequently bipedalism. Because of further distances between food sources and ...
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