Boisson salée pour mieux performer quand il fait chaud

Plasma volume is a key element of cardiovascular function. Some studies suggest that hypervolemia (increased plasma volume) promotes thermoregulation, reduces stress on the cardiovascular system, and consequently improves performance in endurance sports.

We know that sodium overload in the form of a drink with a high sodium citrate and sodium chloride (table salt) content increases plasma volume. A study conducted with cyclists has already shown an improvement in performance following sodium overload before the test carried out in a temperate environment.

In this study, Sodium loading aids fluid balance and reduces physiological strain of trained men exercising in the heat (2007), the aim was to determine whether a high-sodium drink consumed before exercise could improve performance in a high-temperature environment in endurance athletes.

Eight trained long-distance runners, with an average age of 36 and an average VO2max of 57.5 mL/kg/min, took part in two exhaustion trials on a treadmill at a controlled temperature of 32°C and relative humidity of 50%: once after ingesting a drink high in sodium citrate and sodium chloride, and once after ingesting a control drink (without electrolytes).

The results reveal a significant advantage in favor of the trial with the high-sodium drink. It should be noted that the time to exhaustion (min) is higher for the salt drink and its average heart rate (bpm) is lower.

A higher rectal temperature was also noted during the trial with the control beverage.

The results of this study suggest that consuming a high-sodium beverage before exercising in high temperatures increases heat tolerance and improves performance in endurance sports.

However, in this study, subjects were required to refrain from drinking during exercise. It is therefore unclear whether sodium overload prior to exercise followed by continuous hydration during exercise, which is particularly essential in hot weather, would have the same beneficial effects.