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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 - - 2008
OBJECTIVES: 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. DESIGN: A single-blinded, randomized controlled study. SUBJECTS: Thirty subjects suffering from the stiffness phase of frozen shoulder. METHODS: Subjects were randomly allocated to receive: ...
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 ...
Whitham Martin - - 2008
The cumulative stressors of exercise manifest themselves at a cellular level by threatening the protein homeostasis of the cell. In these conditions, Heat Shock Proteins (HSP) are synthesised to chaperone mis-folded and denatured proteins. As such, the intracellular HSP response is thought to aid cell survival in the face of ...
Harmsze Ankie M - - 2008
The aim of this study was to develop a model to evaluate the efficacy of drugs with expected sweat-reducing properties in healthy subjects in order to select candidate drugs for the systemic treatment of primary generalized hyperhidrosis. A randomized, double-blind, placebo-controlled cross-over study was performed in 8 healthy subjects. Sweating ...
Lambert G Patrick - - 2008
Reduced intestinal blood flow and high intestinal temperatures during exercise-heat stress can lead to intestinal barrier dysfunction. Such dysfunction may increase intestinal permeability to endotoxin. During exercise-heat stress, intestinal barrier dysfunction and endotoxemia can produce gastrointestinal symptoms and increased production of pro-inflammatory cytokines. Such problems may be a warning sign ...
Tucker Ross - - 2008
There are a number of studies which have utilised exercise protocols where subjects are free to vary the work rate rather than having it externally imposed as is the case in fixed intensity exercise. These studies have demonstrated that exercise performance is regulated in advance of an excessive rise in ...
Thambirajah Anita A - - 2008
PURPOSE: Since physical exertion is known to exacerbate the symptoms of chronic fatigue syndrome (CFS) and metabolic changes and including oxidative stress can modulate heat shock protein (HSP) expression responses, we sought to determine whether HSP expression is altered in CFS patients before and after exercise. Heat shock proteins (HSPs) ...
Bates Graham P - - 2008
Significant and poorly documented electrolyte losses result from prolonged sweating. This study aimed to quantify likely sodium losses during work in heat. Male subjects exercised in an environmental chamber on two consecutive days in both winter and summer. Sweat collecting devices were attached to the upper arms and legs. Sweat ...
Enstipp Manfred R - - 2008
Diving endotherms inhabiting polar regions face potentially high thermoregulatory costs. Unless properly insulated, these animals will lose vast amounts of heat when diving in cold water, which has to be balanced by heat production. Heat generated as a by-product of digestion (heat increment of feeding, HIF) or from exercising muscles ...
Duffield Rob - - 2008
The aim of this chapter is to review the literature on the use of cooling interventions in the protection of and recovery of performance from exercise-induced heat stress. This chapter will deal primarily with the effects of pre-cooling on the improvement in exercise performance and the effects of post-exercise cooling ...
Short Rebecca W - - 2008
To assess the effect of exercise-induced sweat on truncal acne, a prospective, single-blinded, randomized, controlled, institution review board-approved clinical trial was conducted on physically active males. Subjects were instructed to exercise long enough to break a sweat 5 days a week for 2 weeks. Group 1 did not exercise (n ...
Hahn Robert G - - 2008
BACKGROUND AND OBJECTIVES: There is a need for simple method allowing detection of dehydration and hypovolemia. Based on a new theory of homeostatic blood states, we hypothesized that hemodilution following standardized crystalloid fluid bolus can be used to discriminate between baseline normohydration and dehydration, also normovolemia and hypovolemia. METHODS: Computer ...
van Houte Marthe - - 2008
OBJECTIVES: Oxybutynin has been proven to be effective in patients with generalized hyperhidrosis. Some dermatoses aggravate as a result of sweating. Therefore, oxybutynin might also be useful in such normohidrotic patients. The aim was to evaluate the efficacy and safety of different doses of oxybutynin on exercise-induced sweating in healthy ...
Mündel Toby - - 2008
Apart from few studies, the majority of the research conducted on the effects of heat stress on energy metabolism during exercise has only been done so in the past two decades. Whilst increasing exercise duration under conditions of heat stress favours the oxidation of carbohydrate (CHO) and appears to increase ...
Grahn Dennis A - - 2008
BACKGROUND: Many individuals afflicted with multiple sclerosis (MS) experience a transient worsening of symptoms when body temperature increases due to ambient conditions or physical activity. Resulting symptom exacerbations can limit performance. We hypothesized that extraction of heat from the body through the subcutaneous retia venosa that underlie the palmar surfaces ...
Hadjicharalambous Marios - - 2008
BACKGROUND: The present experiment examined the responses of peripheral modulators and indices of brain serotonin (5-HT) and dopamine (DA) function and their association with perception of effort during prolonged exercise in the heat after creatine (Cr) supplementation. METHODS: Twenty one endurance-trained males performed, in a double-blind fashion, two constant-load exercise ...
Sandström Marie E - - 2008
The purpose of this study was to investigate the alterations in serum heat shock protein (Hsp) 70 levels during a 15-consecutive-day intermittent heat-exercise protocol in a 29-year-old male ultra marathon runner. Heat acclimation, for the purpose of physical activities in elevated ambient temperatures, has numerous physiological benefits including mechanisms such ...
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