Staying hydrated, even in the winter, is important for getting the most out of your run. In a study published in the Journal of Strength and Conditioning Research, a group of 14 competitive runners were asked to complete three self-paced 4K laps, resting four minutes between each lap. They performed this same run in warm conditions on two different occasions.
For one of the trials, they were asked to restrict their fluid intake for 22 hours beforehand and were not allowed to drink during the run. Before the other trial, they arrived well hydrated and were given water during each rest break.
Researchers monitored their heart rates, gastrointestinal temperatures, race time, and perceived exertion during both trials. When running while properly hydrated, the runners had lower core body temperatures, safer heart rates, and they finished significantly faster.
So slurp some H2O for an easier, faster, healthier run.