Athletes often consume insufficient fluid and electrolytes before or during training and competition. "Hard trainers" may require additional sodium and get benefitted from a hydration plan tailored to their physiology, unlike non-athletes and athletes who do not engage in frequent rigorous training sessions. 

The present study thus determined whether a hydration plan tailored to an athlete′s sweat rate and sodium loss improves anaerobic and neurocognitive performance during moderate to hard training and heart rate recovery.

The study enrolled Collegiate athletes who were injury free and could exercise at ≥ 75% of their maximum heart rate for a minimum of 45 min. The study subjected the participants to complete a questionnaire assessing hydration habits and then randomized them to either a prescription hydration plan (PHP), which considered sweat rate and sodium loss or instructed them to follow their normal ad libitum hydration habits (NHP) during training. It assessed attention, awareness, and lower body anaerobic power (standing long jump) immediately before and after a moderate to a hard training session of ≥ 45 min. The study also measured Heart rate recovery. 

After a washout period of 7 days, the PHP group repeated the training bout with their normal hydration routine, while the NHP group received a PHP plan. The study then assessed them as previously described. 

It observed the enrollment of fifteen athletes from three different sports, aged 20 ± 0.85 years, for the study. The majority of the participants documented feeling somewhat or very dehydrated after a typical training session. Also, those who followed a PHP jumped 4.53 ± 3.80 in. farther, tracked moving objects 0.36 ± 0.60 m/second faster, and exhibited a faster heart rate recovery than their NHP after a moderate to hard training session of 45–120 min in duration.

This study shows the usefulness of a tailored hydration plan based on an athlete′s fluid and sodium loss in improving anaerobic power, attention, awareness, and heart rate recovery time.

Ayotte Jr D, Corcoran MP. Individualized hydration plans improve performance outcomes for collegiate athletes engaging in in-season training, Journal of the International Society of Sports Nutrition. 2018;15:1, DOI: 10.1186/s12970-018-0230-2