How much water to drink per day when you train
How body weight, training, cardio and heat change how much water you need, how much is too much in an hour and how to track your progress day by day.
The baseline
The European Food Safety Authority suggests about 2 L a day for women and 2.5 L for men, including water from food. That's for fairly inactive people in a mild climate: if you train, do cardio or live somewhere hot, you need more.
What increases your needs
Body weight, activity level, training days, cardio minutes and temperature. An hour of cardio can call for an extra half litre, and a very hot day as much again. That's why your target shouldn't be the same every day.
How much is too much
Your kidneys clear about 0.8 to 1 L per hour. Drinking more than that in an hour, or very large amounts in a day, can dilute the sodium in your blood (hyponatremia). Headache, nausea, confusion or swelling are signs to stop and seek help. Spread your water across the day.
Tracking your progress
Logging each glass shows whether you're drinking more or less than in previous weeks. In FitHandy every day is saved: you see your 7, 30 and 90-day average, the comparison with the previous period, the days you hit your target and your current streak. The target is calculated in code from your weight, goal, training, cardio and heat.
Frequently asked questions
Do coffee and tea count?
They count towards hydration in normal amounts, but water should be the base. Stick to the caffeine limit of about 400 mg a day for healthy adults.
What if I have kidney or heart problems?
In that case the amount should come from whoever looks after your health. The app uses a lower range and explains why.