n Training for the end of Summer: Staying Hydrated.

When the temperature rises, maintaining hydration is critical – particularly if you’re active and outdoors.

Failing hydration can cost you as much as 11% of your VO2 MAX (how efficiently your body can process oxygen and keep you running). 

How much water you need depends on a number of factors, but thirst is not always the best indicator – if you’re thirsty, you’re already dehydrated, warn most experts.