S M Shirreffs

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..The current evidence and opinion tend to favour urine indices, and in particular urine osmolality, as the most promising marker available...

..Effects may persist for hours after intoxication...

..But if rapid recovery (<24 h) is desired or severe hypohydration (>5% body mass) is encountered, aggressive drinking of fluids and consuming electrolytes should be encouraged to facilitate recovery for subsequent competition...

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..The composition and temperature of a drink and the volume and rate of its consumption can all influence the physiological responses to ingestion and can impact on exercise performance...

..This may be a particular concern in the field events and multi-event disciplines when competition can be spread over a number of hours and when there are significant rest periods between activities...

..The results of the present study suggest that milk can be an effective post-exercise rehydration drink and can be considered for use after exercise by everyone except those individuals who have lactose intolerance...

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..However, when exercising in a hot environment (an environmental temperature of 30 degrees C or more), dehydration by 2% of body mass impairs exercise performance and increases the possibility of suffering a heat injury...

..Intravenous fluid replacement after exercise has been investigated to a lesser extent and its role for fluid replacement in the dehydrated but otherwise well athlete remains equivocal...

..1) % reduction by 37 h. Thirst increased from 0-13 h of FR then did not increase further (P>0.05). The subjects reported feelings of headache during the FR trial and also that their ability to concentrate and their alertness were reduced...

..Where more than one competition or training session takes place in a single day and where substantial fluid losses are incurred, recovery will be impaired by the absence of fluid intake...

..There is a limited range of commercially available products that have a composition sufficient to achieve this, even though the public thinks that some of the traditional drinks are effective for this purpose...

..Despite the effect on fluid retention, exercise capacity was not different between skimmed milk and a commercially available carbohydrate-electrolyte drink 4 h following exercise/heat-induced body mass loss...

..Pre-exercise lowering of body temperature may aid some aspects of performance, but the efficacy has not been demonstrated in football...

..The average swimmer remained hydrated during the session, and calculated sweat rates were similar to those in previous aquatic studies...

..This did not, however, result in improved performance 4 h after the end of the rehydration period...

..This study investigated the effect of the osmolality and carbohydrate content of drinks on their rehydration effectiveness after exercise-induced dehydration...

..An appropriate drinking strategy will take account of pre-exercise hydration status and of fluid, electrolyte and substrate needs before, during and after exercise...

..An appropriate, individualized drinking strategy will take account of pre-exercise hydration status and of fluid, electrolyte and substrate needs before, during and after a period of exercise...

..Strategies will vary greatly between individuals and will also be influenced by environmental conditions, competition regulations, and other factors...

..Voluntary fluid intake also shows wide inter-individual variability and is generally insufficient to match fluid losses...

..In conclusion, in situations of voluntary fluid intake, hypertonic carbohydrate-electrolyte solutions are as effective as hypotonic carbohydrate-electrolyte solutions at restoring whole-body fluid balance...

..Recent evidence suggests that the integrity of the blood brain barrier may be compromised by combined heat stress and dehydration, and this may play a role in limiting performance in the heat...

..This, however, is in accord with data in the literature from other levels of soccer players and athletes in other events. These measurements allow for an individualisation of the club's hydration strategy...

..Thus, the purpose of this study was to investigate the effects of milk-based drinks on exercise capacity...

..Total salt (NaCl) loss during training was 4.3+/-1.8 g. The sweat loss data are similar to those recorded in elite players undergoing a similar training session in warm environments, but the volume of fluid ingested is less...

..Body mass change is not always a reliable measure of changes in hydration status and substantial loss of mass may occur without an effective net negative fluid balance...

..These results suggest that there may be a role for drink temperature in influencing thermoregulation during exercise...

..Football training seems to increase bone mass in the weight-bearing limbs, with positive implications for bone health in later life, but some players may be at risk from inadequate calcium dietary intake...

..At present, evidence supports a significant role of catecholaminergic neurotransmission, but there are a number of metabolic and circulatory perturbations occurring within the brain that may also be important in the fatigue process...

..07). These descriptive data show large individual variations in all measured parameters with relatively little difference in sweat parameters between fasting and non-fasting individuals...

..114) and lactate (P = 0.836) concentrations were not different between trials. Ingestion of a BCAA solution prior to, and during, prolonged exercise in glycogen-depleted subjects did not influence exercise capacity in a warm environment...

..963). The heat load and debt induced by periodic drinking resulted in similar body temperatures during low-intensity exercise in conditions of moderate heat stress due to appropriate thermoregulatory reflexes...

..It is concluded that ingestion of hypertonic, energy-dense glucose solutions results in a decrease in plasma and extracellular fluid volume, most likely due to the net secretion of water into the intestinal lumen...

..The results of this study demonstrate that serum S100beta was elevated after water immersion and prolonged exercise in a warm environment, suggesting that blood-brain barrier permeability may be altered...

..To investigate the effect of drink temperature on cycling capacity in the heat...