For runners
How Much Water Should Runners Drink?
Quick answer
Runners should start with their normal daily water target, then add fluids for training. For runs under an hour, daily hydration plus thirst is usually enough. For longer or hotter runs, start around 400–800 ml per hour, use electrolytes when sweat loss is high, and refine the plan with a sweat-rate test.
Fine-tune
Your daily goal: 96 ounces, 11.5 glasses.
Your daily goal
of water a day · about 11.5 glasses or 5.5 half-litre bottles
- 2.8
- Litres
- 96
- Ounces
- 11.5
- Glasses
Your sip schedule
- 7:00 AM · Start the day2 glasses
- 9:48 AM · Top up2 glasses
- 12:36 PM · Top up2 glasses
- 3:24 PM · Top up2 glasses
- 6:12 PM · Top up2 glasses
- 9:00 PM · Wind down2 glasses
Ease off after 9:00 PM for better sleep.
Electrolytes? Skip them today
For everyday hydration, plain water and a normal diet cover your electrolytes just fine.
A friendly estimate for healthy adults, not medical advice. Your needs rise with heat, exercise, illness, pregnancy, and some medications. Don't drink more than ~1 litre per hour.
Daily water for runners
Your daily target still starts with body weight, climate, and lifestyle. Running adds another layer: sweat. If you run most days, choose the active setting in the calculator. On long-run or workout days, add your session fluid on top.
Before, during, and after
Before a longer run, drink steadily in the hours beforehand instead of chugging at the door. During runs over about an hour, sip according to thirst and conditions. After a sweaty run, replace the remaining loss over a few hours with food or electrolytes so you retain the fluid.
When electrolytes matter
Electrolytes are most useful for long runs, hot weather, humid weather, and runners who finish with salt marks on clothing. For short easy runs, water and normal meals usually do the job.
Frequently asked
How much water should I drink before running?
A simple pre-run target is 400–600 ml in the 2–3 hours before a longer run, then a few small sips closer to start time if you are thirsty. For short easy runs, normal daily hydration is usually enough.
Do I need water during a 5K or 10K?
Most runners do not need fluid during a 5K. For a 10K, it depends on heat, pace, and duration; many runners are fine without drinking in cool weather, but hot or slower runs may justify small sips.
How much should I drink after a run?
If the run was sweaty, replace roughly 125–150% of the fluid you lost over the next few hours. The easiest way to know is to weigh before and after the run and use a sweat-rate calculator.
Sources
- 1.American College of Sports Medicine, Exercise and Fluid Replacement — Athletes should start exercise euhydrated, limit body-mass losses during training, and replace fluid and sodium after heavy sweat losses.
- 2.Sawka et al., ACSM Position Stand — Sweat rate varies widely by athlete, heat, intensity, clothing, and acclimation, so pre/post body-weight checks are the practical way to individualise fluid plans.
- 3.U.S. National Academies (IOM/NAM), 2005 — Adequate total water intake of about 3.7 L/day for men and 2.7 L/day for women, including water from food and all beverages.