In this episode of The Athletes Compass Podcast, Dr. Julia Casadio explains how athletes can use heat training as a powerful performance tool, especially when preparing for hot and humid races. Drawing on her experience with Olympic athletes and her research in applied sport physiology, she explains why women often need longer heat adaptation windows than men, how “thermal memory” allows athletes to reacclimate quickly after an earlier heat block, and why heat should be treated as a meaningful training stress rather than an afterthought. The conversation also covers practical strategies such as sauna or hot-tub exposure, timing heat blocks before race day, managing training load, supporting youth athletes in hot conditions, and recognizing signs of heat illness.

• Female athletes often take longer to adapt to heat than male athletes, with women commonly needing closer to 10–14 days rather than 4–7 days.
• Heat training should not be added casually to a hard training week. It works best during easy-to-moderate training blocks.
• Heat is an extra physiological load, so sleep, fueling, hydration, and recovery matter even more during heat exposure.
• A true heat stimulus requires getting genuinely hot: elevated core temperature and heavy sweating are key signals.
• Living in a hot place does not automatically mean an athlete is heat-adapted. The body has to experience repeated, meaningful heat stress.
• Heat blocks can be periodized. Athletes can do a proper block several weeks before an event, then use shorter top-up exposures closer to race day.
• “Thermal memory” means the body can reacclimate faster after prior heat adaptation.
• Passive heat methods such as post-exercise sauna or hot-water immersion can help athletes who do not live in hot climates.
• High-intensity sessions are not ideal for heat loading; easy aerobic sessions are usually safer and more effective.
• Youth athletes need extra caution in the heat because their cooling systems are less developed and they may be less likely to speak up when something feels wrong.
• Warning signs of heat illness include dizziness, lightheadedness, cool clammy skin, sudden performance drop-off, fainting, and, in more serious cases, hot red skin.

• Her Strength - Dr. Julia Casadio
• Paul Warloski - Simple Endurance Coaching
• Marjaana Rakai | Nordic Performance Lab