As you probably know from the day you forget to bring your waterbottle to the gym, even mild dehydration can affect athletic performance. But were you aware that not drinking enough water can also affect your cognitive ability?

Water is vital for optimal brain function, as the dehydrated brain causes the release of cortisol. This stress hormone, which is also linked to an increase in fat storage and muscle depletion, can negatively affects the brain's capacity to store and create information.

Though the jury is still out on whether it's necessary to drink the previously suggested eight glasses a day, you'd do well to still drink at least half that amount. Your body and your brain (which are made up of 70 and 75 percent water, respectively) will thank you for it.