If we do not stay hydrated, physical performance can suffer.
This is particularly important during intense exercise or high heat.
Dehydration can have a noticeable effect if you lose as little as 2% of your body’s water content. However, it is not uncommon for athletes to lose up to 6-10% of their water weight via sweat (1Trusted Source, 2).
This can lead to altered body temperature control, reduced motivation, increased fatigue and make exercise feel much more difficult, both physically and mentally (3Trusted Source).
Optimal hydration has been shown to prevent this from happening, and may even reduce the oxidative stress that occurs during high intensity exercise. This is not surprising when you consider that muscle is about 80% water (4Trusted Source, 5).
So, if you exercise intensely and tend to sweat, then staying hydrated can help you perform at your absolute best.