Heat training is a crucial aspect of a cyclist's preparation, especially in the face of extreme temperatures like those experienced during the Tour de France. It involves a combination of active and passive methods to simulate racing conditions in the heat, ultimately enhancing performance and endurance. This article delves into the science behind heat training, its history, and the methods employed by cyclists to adapt to racing in hot environments.
The Science Behind Heat Training
Heat training works by increasing blood plasma volume, which dilutes the blood and reduces the haematocrit (the percentage of blood volume made up of red blood cells). This process triggers the body to produce more red blood cells, similar to the effects of EPO or altitude training. Tim Podlogar, a lecturer in exercise physiology, explains that this adaptation can be achieved through both active and passive heat training methods.
History of Heat Training
The concept of heat acclimatisation dates back to the 19th century, when people were sent to work in hot climates. The American Civil War of the 1860s also saw heat casualties mostly limited to new recruits, with veterans faring better under the summer strain. However, it wasn't until the mid-2010s that heat training became popular among cyclists, and it has since become ubiquitous in professional circles.
Methods of Heat Training
Active heat training involves dressing in winter gear or impermeable suits and pedalling on the turbo or rollers for an hour at Zone 2. The goal is to gradually raise the core body temperature to between 38.5°C and 39.5°C, without exceeding this threshold. Passive heat training methods include sitting in a hot bath or sauna for 30-40 minutes, targeting an elevated core temperature without exceeding 40°C.
The Role of the Core Sensor
The Core sensor, a non-invasive thermometer, is used by many Tour de France teams to measure core temperature in real-time. It estimates core temperature from skin temperature and heart rate, providing a more objective assessment of a rider's heat adaptation. Puck Alkemade, the lead physiology researcher of Core, explains that the sensor helps riders understand their heat tolerance, allowing them to optimise their hydration and fuel intake.
Individualised Heat Training
Podlogar highlights that the science of heat training is still evolving, and individualised approaches are becoming more important. The optimal core temperature for heat training is not yet fully understood, and riders may respond differently to various training methods. As such, monitoring individual responses is crucial for maximising the benefits of heat training.
Heat Training in Numbers
- Optimal core body temperature: 38.5-39.5°C
- Potential boost in cycling performance: 5% after 10 days of heat acclimatisation
- Minimum number of heat exposure sessions: 5-9
- Sweat loss during a single session: up to 2 litres
- Danger zone for core temperature: above 40°C
Conclusion
Heat training is an essential component of a cyclist's training regimen, offering significant performance benefits. While it may seem grueling, the sacrifices made by riders are justified in the pursuit of competitive success in the world's biggest races. As the sport continues to evolve, heat training will undoubtedly play a pivotal role in shaping the future of cycling.
