Hydration
Hydration in Hot Weather: How to Train in Heat Without Crashing
Heat changes everything. Your heart rate runs higher, you sweat more, and your pace drops even if you feel “fit”.
Most people don’t fail in the heat because they’re weak — they fail because they under-drink and under-salt.
This is a simple plan for gym sessions, outdoor runs, or Muay Thai.
Why heat feels brutal
In hot conditions you:
- sweat more
- lose more sodium
- run a higher heart rate at the same workload
The Hot Weather Hydration Plan
Rule 1: Start hydrated
Easy check: first pee shouldn’t be dark.
Baseline guide:
Rule 2: Estimate sweat rate once
- Weigh before and after a 60-min session
- 1.0 kg loss ≈ 1.0 liter
Calculator post:
Rule 3: Sodium matters in heat
When you likely need electrolytes:
- 60+ min in heat
- heavy sweating / salty sweat marks
- headaches, cramps, “flat” feeling
Practical sodium target:
- ~300–600 mg sodium/hour for most
- up to ~800–1,000 mg/hour for heavy/salty sweaters
Full guide:
How much to drink (ranges)
30–60 minutes
- 200–500 ml
60–90 minutes
- 400–900 ml
- sodium: 300–600 mg/hour
90+ minutes
- 600–1,200 ml/hour depending on sweat rate
Don’t try to outdrink your sweat.
Cramps: what actually helps
- slow down + cool down
- fluids
- sodium
After training: rehydrate properly
- If you lost ~1 kg, aim for ~1–1.5 liters over the next few hours
- salty meal helps
Training-day hydration structure:
Warning signs (stop and cool down)
- dizziness, confusion
- nausea that doesn’t pass
- chills/goosebumps in heat
- sudden headache + weakness
- no sweating despite overheating
Bottom line
In heat:
1) start hydrated
2) drink based on sweat rate
3) add sodium when losses are high
4) respect warning signs