For healthy children up to 15 years of age, no data exist regarding water turnover as directly measured using stable isotope techniques. Water turnover was measured in 171 healthy children (88 girls, 83 boys, age: 6 weeks-15 years) whilst living in their normal environment. Water turnover was calculated from the equilibrium of 2H2O concentration reached [...]
The effect of alcohol consumption on the restoration of fluid and electrolyte balance after exercise-induced dehydration [2.01 +/- 0.10% (SD) of body mass] was investigated. Drinks containing 0, 1, 2, and 4% alcohol were consumed over 60 min beginning 30 min after the end of exercise; a different beverage was consumed in each of four [...]
This study examined changes in children's thirst and drink preferences during exercise-induced hypohydration and their spontaneous rehydration during a 30-min recovery. Twenty-four 9- to 13-year-old children (14 females, 10 males) participated in four intermittent 90-min cycling sessions in the heat (35 degrees C, 20% relative humidity); the sessions differed in the drinks the children were [...]
The homeostasis of body fluid traditionally is viewed as involving the regulation of its osmolality and of blood volume. However, the control of thirst is more complex than can be described in a two-factor model, and consideration of plasma sodium concentration and of arterial blood pressure also must be included in the discussion. This review [...]
Arginine vasopressin (AVP), synthesized in hypothalamic neurons, is transported in axons either to the pituitary for release into the circulation or to different brain areas. In our previous experiments we documented central antipyretic AVP pathways from the hypothalamus to the ventrolateral septal area in the limbic system. In the present study we investigated if osmotic [...]
Total body water was determined on 59 boys and 59 girls and on 40 boys and 45 girls attending junior and senior high schools, respectively. The volunteers were studied for three years. They were given D2O (99.8%) orally, and urine samples were used for determination of the ratio of heavy hydrogen to normal hydrogen by [...]
Effects of water temperature and flavoring on fluid consumption and body weight losses were studied in fourteen unacclimatized men (21-33 years) during 6 hr of treadmill exercise (4.8 km.hr-1, 5% grade for 30 min.hr-1) in a hot environment. Subjects consumed each of four beverages (15 degrees C water, 40 degrees C water, 15 degrees C [...]
Alterations in urine concentrating ability with age were examined in 98 active community-dwelling volunteers (aged 20-79 years) who were free from evidence of diseases known to adversely affect renal function. There was a significant decrease in urine osmolality reached after 12 h dehydration with advancing age, which could not be correlated with the age-related decline [...]
This study was performed to determine whether a) children voluntarily dehydrate while exercising in hot climate; b) such dehydration affects their well-being and thermoregulation. Eleven 10p to 12-yr old, partially acclimatized boys underwent two work-in-the-heat protocols (cycle rides, 45% aerobic capacity at 39 degrees C, 45% rh). During one session they drank only voluntarily when [...]