A new study published in Nutrients evaluated the hydration status, fluid intake, sweat rate and sweat sodium concentration in recreational tropical native runners.

This study enrolled 102 males and 64 females. Participants ran at their self-selected pace for 30–100 min. 

The findings revealed that males had lower relative fluid intake and greater relative fluid balance deficitthan females. Additionally, males had higher whole-body sweat rates than females, and the mean rates of sweat sodium losswere higher in males than females. 

The results indicated that sweat profile and composition in tropical native runners are similar to reported values in the literature. The current fluid replacement guidelines pertaining to volume and electrolyte replacement are applicable to tropical native runners. Female runners experienced less negative net fluid balance compared to males due to greater fluid intake per body mass and lower sweat loss.

Source: Nutrients. 2021 Apr; 13(4): 1374. Published online 2021 Apr 20. doi: 10.3390/nu13041374