23 Result(s)
within
Samuel N. Cheuvront
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Article
Open AccessIterative assessment of a sports rehydration beverage containing a novel amino acid formula on water uptake kinetics
Rapid gastric emptying and intestinal absorption of beverages is essential for rapid rehydration, and certain amino acids (AA) may augment fluid delivery. Three sugar-free beverages, containing differing AA co...
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Open AccessEffects of body size and countermeasure exercise on estimates of life support resources during all-female crewed exploration missions
Employing a methodology reported in a recent theoretical study on male astronauts, this study estimated the effects of body size and aerobic countermeasure (CM) exercise in a four-person, all-female crew compo...
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Article
Open AccessCan an amino acid mixture alleviate gastrointestinal symptoms in neuroendocrine tumor patients?
Neuroendocrine tumors, although relatively rare in incidence, are now the second most prevalent gastrointestinal neoplasm owing to indolent disease biology. A small but significant sub-group of neuroendocrine ...
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Open AccessBody size and its implications upon resource utilization during human space exploration missions
The purpose of this theoretical study was to estimate the effects of body size and countermeasure (CM) exercise in an all-male crew composed of individuals drawn from a height range representative of current s...
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Biological variation of arginine vasopressin
There is growing interest in the measurement of plasma levels of arginine vasopressin (AVP) for the assessment of mild dehydration. However, the principles of biological variation have not been applied to the ...
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Biological variation of resting measures of ventilation and gas exchange in a large healthy cohort
Resting measures of ventilation and gas exchange are impacted by a variety of physiological stressors, such as those resulting from a research intervention or an extreme environment. However, the biological va...
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Article
Open AccessHypohydration and Human Performance: Impact of Environment and Physiological Mechanisms
Body water losses of >2 % of body mass are defined as hypohydration and can occur from sweat loss and/or diuresis from both cold and altitude exposure. Hypohydration elicits intracellular and extracellular wat...
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Article
Effect of Hypohydration on Muscle Endurance, Strength, Anaerobic Power and Capacity and Vertical Jum** Ability: A Meta-Analysis
How hypohydration impacts non-bodyweight (BW)-dependent muscle performance and vertical jum** ability remains to be determined using meta-analytic procedures.
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Article
Assessment of extracellular dehydration using saliva osmolality
When substantial solute losses accompany body water an isotonic hypovolemia (extracellular dehydration) results. The potential for using blood or urine to assess extracellular dehydration is generally poor, b...
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Comparison between blood and urinary indices for dehydration: a different interpretation
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Article
Hypohydration and acute thermal stress affect mood state but not cognition or dynamic postural balance
Equivocal findings have been reported in the few studies that examined the impact of ambient temperature (T a) and hypohydration on cognition and dynamic balance. The purpose of this study was to ...
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Article
Hydration assessment using the cardiovascular response to standing
The cardiovascular response to standing (sit-to-stand change in heart rate; SSΔHR) is commonly employed as a screening tool to detect hypohydration (body water deficit). No study has systematically evaluated S...
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Article
DEET insect repellent: effects on thermoregulatory sweating and physiological strain
Insect repellents (e.g. N,N-diethyl-m-toluamide or DEET) applied to the skin can potentially interfere with sweat production and evaporation, thus increasing physiological strain during exercise-heat stress. The ...
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Article
Potential impact of a 500-mL water bolus and body mass on plasma osmolality dilution
A methodological discrepancy exists in the hydration assessment literature regarding the establishment of euhydration, as some investigations utilize a pre-hydration technique, while others do not (overnight f...
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Article
Hypohydration reduces vertical ground reaction impulse but not jump height
This study examined vertical jump performance using a force platform and weighted vest to determine why hypohydration (~4% body mass) does not improve jump height. Measures of functional performance from a for...
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Article
Efficacy of body ventilation system for reducing strain in warm and hot climates
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 treadm...
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Impact of a protective vest and spacer garment on exercise-heat strain
Protective vests worn by global security personnel, and weighted vests worn by athletes, may increase physiological strain due to added load, increased clothing insulation and vapor resistance. The impact of p...
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Article
Evaluation of the limits to accurate sweat loss prediction during prolonged exercise
Sweat prediction equations are often used outside their boundaries to estimate fluid requirements and generate guidance. The limitations associated with these generalized predictions have not been characterize...
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Article
Thermoregulatory Function During the Marathon
Marathon races are performed over a broad range of environmental conditions. Hyperthermia is a primary challenge for runners in temperate and warm weather, but hypothermia can be a concern during cool-wet or c...
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Marathon Performance in Thermally Stressing Conditions
It is generally appreciated that warm weather negatively affects marathon running performance. This brief review summarises the historical literature on this topic and recent work that our laboratory has perfo...
