See the full article: Training During a Heatwave
Training in a heatwave
What happens to your body, and what to do about it
CORE TEMPERATURE THRESHOLDS
37°C38.5°C39.5°C40°C+
Normal training
Performance drops
Heat illness risk
THREE RULES THAT MATTER MOST
🕐When to train
Before 9 AM or after 7 PM. Peak heat 11 AM–5 PM: move indoors.
↓ 25% intensity above 32°C💧Hydration
500 ml 2 hrs before. 150–250 ml every 15–20 min during.
+ electrolytes after 60 min❤️Intensity
Use RPE, not pace. Same effort = 5–10 BPM higher in heat.
Slow down. Not a weakness.ACCLIMATISATION: 10–14 DAYS
1–3
4–6
7–9
10–12
✓ Fully adapted
Days 1–34–67–910–1213–14+
↑ Days 1–5: elevated HR, high fatigue — peak risk window
↓ Days 7+: plasma volume ↑, sweat efficiency ↑, strain ↓
SLEEP & RECOVERY
🌙Optimal sleep temp
15–19°C for deep recovery. Disrupted slow-wave sleep = reduced muscle repair.
💨Practical steps
Blackout curtains during the day. Fan for airflow. Cool shower before bed.
STOP IMMEDIATELY IF YOU NOTICE
Confusion or disorientation
Skin hot and dry, no sweat
Sweating stops despite effort
HR not recovering at rest
Nausea or vomiting
Muscle cramps (severe)
Headache + dizziness
Sudden extreme weakness
■ Red: heat stroke, call emergency services immediately
■ Coral: heat exhaustion, stop, move to cool place, hydrate
Based on peer-reviewed sports physiology research. Not a substitute for medical advice. vyvo.ch
