Heat acclimation is a proven method for preparing athletes to race in hot conditions. When used correctly, it helps the body adapt quickly to elevated temperatures, reducing the shock of competing in the heat. It is also increasingly valued as a performance-enhancement tool, similar to altitude training. By increasing thermal strain—heat stress rather than training intensity—the body works harder to regulate core temperature, causing cardiovascular drift (a rising heart rate at steady power) and higher sweat rates. To train effectively, athletes must understand heat zones, which indicate the level of thermal stress. The goal is to reach and maintain Heat Zone 3, where meaningful adaptations occur without overloading the body. Athletes should avoid drifting into Zone 4 (excessive strain) or remaining in Zones 1–2 (insufficient stimulus). Awareness of effort and signs such as heart-rate decoupling helps ensure sessions target the productive Zone 3 range. With repeated exposure, the body adapts by expanding plasma volume and improving oxygen and energy delivery to working muscles. These benefits support racing in hot climates and can also enhance performance in cooler conditions. This seven-week indoor-bike protocol provides a structured and progressive heat-acclimation block. Weeks 1 and 7 include fitness testing to measure progress, while Weeks 2–6 deliver the core heat-training sessions, increasing from 60 to 90 minutes. Weekly overview: • Week 1: Fitness tests + sweat-rate test (2 sessions) • Week 2: Start of heat protocol (4 sessions) • Weeks 3–6: Progressive heat sessions (3 per week) • Week 7: Final fitness test (1 session) Required equipment: • Indoor trainer with power • Heart-rate monitor • Heat or sauna suit • Scales for body-mass checks • Adequate fluids and electrolytes Proper hydration is essential. To fully benefit from this demanding training stimulus, it is important to replace lost fluids and electrolytes accurately during and after each session.