This study investigated the effects of moderate dehydration (~2.5% body weight) on muscle strength and endurance using percutaneous electrical stimulation to quantify central and peripheral fatigue, and isolate the combined effects of exercise-heat stress and dehydration, vs. the effect of dehydration alone. Force production and voluntary activation were calculated in 10 males during 1 brief [...]
INTRODUCTION: The relative frequencies of the causes of hypernatraemia in children after the neonatal period are unknown. Salt poisoning and osmoregulatory dysfunction are extremely rare and potentially fatal. In this retrospective 10-year study, the incidence, causes and differential biochemistry of hypernatraemia in children is examined. METHODS: Children with hypernatraemia (sodium ≥150 mmol/litre) aged >2 weeks [...]
It is difficult to describe hydration status and hydration extremes because fluid intakes and excretion patterns of free-living individuals are poorly documented and regulation of human water balance is complex and dynamic. This investigation provided reference values for euhydration (i.e.; body mass; daily fluid intake; serum osmolality; M +/- SD); it also compared urinary indices in initial morning samples and 24-hr collections. Five observations of 59 [...]
To determine if athletes' muscle mass affects the usefulness of urine specific gravity (U(sg)) as a hydration index. Nine rugby players and nine endurance runners differing in the amount of muscle mass (42 +/- 6 vs. 32 +/- 3 kg, respectively; P = 0.0002) were recruited. At waking during six consecutive days, urine was collected [...]
PURPOSE: This article aimed to study the effect of preexercise ingestion of an electrolyte-containing beverage and meal on fluid balance during exercise in men and women. METHODS: Twenty healthy, college-aged people (10 males, 10 females; mean +/- SD = 51.2 +/- 9.8 mL x kg x min(-1)) exercised at 58 +/- 4% V O 2 peak for 90 min, 45 min after ingesting 355 mL of [...]
PURPOSE: This study was conducted to determine whether preexercise ingestion of a highly concentrated sodium beverage would increase plasma volume (PV) and reduce the physiological strain of moderately trained males running in the heat. METHODS: Eight endurance-trained (.VO2max: 58 mL.kg(-1).min(-1) (SD 5); 36 yr (SD 11)) runners completed this double-blind, crossover experiment. Runners ingested a [...]
We studied the relationship between plasma osmolality, arginine vasopressin (AVP), and fluid input in patients during the acute phase of a first stroke. Fifteen consecutive patients were studied (median age 79) and their blood sampled on days 0, 1, 2, 3, 7 and 14. Plasma osmolality was related to fluid input over days 0-3 (p = 0.0013) and AVP over 14 days (p less [...]
OBJECTIVE: To investigate the reliability and validity of refractometry, hydrometry, and reagent strips in assessing urine specific gravity in collegiate wrestlers. DESIGN AND SETTING: We assessed the reliability of refractometry, hydrometry, and reagent strips between 2 trials and among 4 testers. The validity of hydrometry and reagent strips was assessed by comparison with refractometry, the [...]
In an experiment, multiple reagent test strips from 90 urine samples were examined twice: observed visually by one of two persons and analyzed by spectrophotometry. Interobserver and intra-observer agreement were calculated and expressed as Cohen's K. Interobserver and intra-observer agreement were moderate to good, but lower than one might expect. Enhancing discoloration of the test pads could improve reproducibility. FULL-TEXT AVAILABRLE IN [...]
This is the protocol for a review and there is no abstract. The objectives are as follows: To determine the diagnostic accuracy of state, minimally invasive clinical and physical signs (or sets of signs) to be used as screening tests for detecting impending or current water-loss dehydration, or both, in older people by systematically reviewing [...]