Gabe Mirkin, M.D.
A study from Monash University in Australia shows that you don't have to take fluids in athletic
competitions lasting less than an hour unless the weather is very hot.
The limiting factor in athletic competitions lasting more than an hour is lack of water. Lack of salt and
calories can also tire you, but dehydration is the first factor to tire you during less than all-out exercise.
That's why you see runners and other athletes drinking fluids at the start of and during competition. It
doesn't make any difference what you drink as long as you also get extra salt and calories. You need to
take extra salt during competition to make you thirsty and you need calories to fuel your muscles. It
doesn't make any difference whether the drinks are carbonated, warm or cold. You can use special
exercise drinks or you can drink just water and eat salted foods such as peanuts. In competitions lasting
less than an hour and in cool weather, you don't need to drink because it will only slow you down. On
the other hand, in competitions lasting more than an hour, taking fluids, salt and calories will help you
Medicine and Science in Sports and Exercise March, 1999 p 386