Summary:

In this episode of the Athletes Compass podcast, hosts Paul Warloski and Dr. Paul Laursen, along with guest Marjaana Rakai, delve into the science and strategies behind heat acclimatization for endurance athletes. They discuss the physiological processes that occur when the body is exposed to heat, including increased heart rate and sweating, and the importance of evaporative cooling. The episode also covers genetic factors influencing heat tolerance, practical tips for acclimatizing to heat, and the benefits of active versus passive heat adaptation methods. Additionally, they explore the impact of fitness levels, nutritional strategies, and the critical balance between training stress and recovery.

Key Takeaways:

• Evaporation is Key: Cooling occurs through the evaporation of sweat, not just sweating itself. Humidity hinders this process.
• Genetic Factors: Some people have a genetic predisposition for better heat tolerance, influenced by heat shock proteins.
• Active Acclimatization: Engaging in aerobic activities in the heat is more effective than passive methods like sitting in a sauna.
• Training Adaptations: Aim for 5-14 days of heat exposure to see adaptations such as lower core temperature, increased sweat rate, and improved performance.
• Hydration and Nutrition: Consume cold fluids and consider increasing carbohydrate intake during exercise in the heat due to higher glycolysis rates.
• Avoid High Intensity in Heat: High-intensity workouts in heat can be overly stressful; focus on aerobic sessions in hot conditions.
• Progressive Exposure: Gradually increase heat exposure time to adapt without overloading the body.
• Mental Preparation: Mentally prepare for heat challenges and pace accordingly during races to manage core temperature.

• From Lab to Real World: Heat Acclimation Considerations for Elite Athletes - PubMed