School · Food and hydration · 50 s .
Hydration
How much to drink, and how to find out.
Runners sweat anywhere from about 0.3 to more than 2 litres per hour, depending on heat, pace and the person. Losing more than about 2% of body weight in fluid can start to hurt performance, especially in the heat.
Find your sweat rate: weigh yourself before and after an hour's run, without clothes. Each kilo lost is about a litre of sweat; add what you drank.
Drink to replace part of that, not more: gaining weight during a race means you drank too much, which can dilute blood sodium. Afterwards, drink about 1.5 litres for each kilo lost.
Know your sweat rate, drink to it, never above it.
Quick check .
If you gain weight during a race, what does it mean?
Drinking too much can dilute blood sodium: drink to your sweat, never above it.