Hydration that keeps pace with your training.
Runners lose 1–2 liters per hour. Thirsty Girls builds a daily goal around your training load — and actually reminds you to drink it.
Example goal · 130 lbs · Very active
97 fl oz
12.1 cups · 2.9L per day
Most running injuries and bad race days trace back to under-hydration. The challenge isn't knowing you should drink more — it's making it a consistent habit on non-run days too. Because what you drink in the 24 hours before a run matters as much as what you drink during it.
Why hydration matters for runners
Pre-run hydration determines performance
Starting a run even mildly dehydrated (1–2% body weight in water) impairs endurance, elevates perceived effort, and increases injury risk.
Prevents heat illness
Runners are disproportionately at risk for heat exhaustion. Proper daily hydration — not just drinking at the start line — is the best prevention.
Faster recovery between sessions
Dehydration prolongs muscle soreness and fatigue. Hitting your daily goal speeds up the recovery window between runs.
Better long run performance
Consistent pre-hydration all week means you arrive at long run day fully topped up — not playing catch-up from a dehydrated week.
How Thirsty Girls helps
Features designed for your specific needs.
Run-adjusted daily goals
Your goal reflects your training intensity level — set to "very active" or "athlete" depending on weekly mileage — so it scales with your load.
Pre-run and post-run reminders
Smart reminders can target the hour before your usual run time and the recovery window after — the two highest-leverage hydration moments.
Streak tracking for training consistency
Hydration consistency maps directly to training consistency. Daily streaks build the habit, so on race week, staying hydrated is automatic.
HealthKit calorie sync
On days where you log a long run in Apple Health, your water goal automatically adjusts upward to account for the extra energy burned.
Common questions
How much water should I drink as a runner?
A 130 lb runner training 5+ days per week needs roughly 95–105 fl oz daily as a baseline. Your exact number depends on your weight, training volume, and climate.
Should I drink water before a morning run?
Yes — 16–20 oz about 1–2 hours before is a good baseline. Thirsty Girls' smart reminders can be set to prompt you at the right time before your usual run.
What about electrolytes — does the app track those?
Thirsty Girls focuses on water intake. For races or long runs, electrolytes are important alongside your water goal — but getting your base hydration right comes first.
Hydrate like you train
Thirsty Girls is free to download. Your personalized goal is set up on day one.
Get Thirsty Girls — freeRelated
Athletes
Intense daily training adds up to 1200ml to your water requirement. Thirsty Girls calculates your athlete-grade goal and makes sure you actually hit it.
Busy Moms
Thirsty Girls is the hydration app designed for women who are always on — with one-tap logging, smart reminders, and an AI coach that actually gets the chaos.