Physical activity implies in changes to the water and electrolyte homeostasis which may result in adverse effects on performance and possibly on health if the body liquids lost by sweating are not completely replaced. Hydration efficiency also depends on gastric emptying, which is affected by several factors, including the temperature of the ingested liquid. The objective of this study was to critically assess the fluid replacement practices used by individuals who practice physical activities and discuss how the effect of liquid temperature on gastric emptying influences this hydrating behavior. Studies on the theme have found contradicting results, probably due to the different methods used. The studies that investigate liquid temperature in the gastrointestinal tract during exercise are limited. Considering the total gastric emptying time during rest, extreme liquid temperatures have no significant effect on the total gastric emptying time, since the temperature inside the stomach normalizes quickly after ingestion of the liquid. However, there are clear scientific evidences that the ingestion of ice-cold liquids increases gastric emptying in the first minutes after ingestion. This fact needs to be better investigated when it is associated with other pre-competition factors, such as the psychological state of the athlete. However, low temperatures improve the palatability of the drink, implying in greater consumption by the athletes and reducing the risk of dehydration. The effects of low temperature on gastric emptying are not decisive, since fluid replacement has intervention factors that are more relevant than temperature.
Gastric emptying; Exercise; Fluid therapy
