Swedish biathletes have embraced a rapidly growing preparation method known as heat training — high-temperature workouts widely used in cycling, including by Tour de France star Tadej Pogacar. The goal is to trigger the same blood and endurance adaptations as altitude training, but without leaving sea level.
What do these sessions look like?
Imagine training at 38–40 °C, wearing a hat and several layers, with the sole instruction: raise your core temperature and sweat until the body reaches its limit.
Sebastian Samuelsson explains: “I lost three litres of fluids in one afternoon. It’s… unusual. Three to four litres per session is a lot. You have to rethink hydration, recovery, sleep. But it works — I already feel stronger.”
Elvira Oeberg pushed her core temperature to 39 °C: “Honestly, it’s not fun. I felt motion-sick afterwards, my legs were shaky. But altitude adaptation becomes much easier. Just don’t go grocery shopping right after — your immune system is at zero for a few hours.”
Coach Johannes Lukas sets strict rules
Lukas warns: “You must be careful. If anything goes wrong, if an athlete is in the red zone, we stop immediately. You’re flirting with a fever — cross the line, and it’s the hospital.”
This is not improvised “running in a winter jacket.” Every minute and every degree are controlled with sensors, medical monitoring, and heart-rate supervision. It’s science, not folklore — and not suitable for everyone.
“Young athletes and amateurs should avoid it. Focus on consistency and solid foundations first.”
What is heat training?
- Training in 35–40 °C conditions.
- Purposefully elevates core temperature and induces heavy sweating.
- Stimulates increased plasma volume and red blood cell production — similar to a high-altitude camp.
- Sessions last 30–60 minutes under medical supervision.
- Used only by elite athletes to gain the final percentage of performance before major championships.
