A practical guide to heat training for endurance runners —why it works, the science behind it, and how to apply protocols to boost performance year-round.

Most non-elite endurance athletes are leaving performance gains on the table. Heat training—often dismissed as something you only do before a hot race—is one of the most misunderstood and underutilized tools in the sport. Done right, it can boost cardiovascular capacity, improve recovery, and prepare you to train harder for longer—no matter the conditions on race day.

In this episode of Legwork, Matt and Molly explore the overlooked benefits and surprising versatility of heat training. Through stories from their own racing and coaching, they show how it can be more than a summer survival skill—it’s a year-round performance weapon hiding in plain sight.

Episode Description

This episode is your practical, research-backed guide to heat training—covering nearly everything an endurance athlete needs to know to apply it effectively and safely.

Matt and Molly break down the most up-to-date science on how heat affects performance, the physiological adaptations you’re aiming for, and the three proven methods to achieve them:

• ​Training in hot environments to closely mimic race conditions
• ​Layering to simulate heat when the weather won’t cooperate
• ​Passive post-workout heat exposure like saunas or hot-water immersion

They explain how to choose the right method for your situation—or make the most of the method you have available—and how to time it so benefits carry through to your race. You’ll also learn how long adaptations last, how to maintain them, and what to watch for in hydration, fueling, and recovery to avoid setbacks. Whether your target race is hot, cool, or somewhere in between, this episode gives you the tools to use heat training with precision—and see results when it matters most.

Chapters

00:00 Introduction to Heat Training and Personal Experiences Driving Our Understanding

05:49 The Primary Studies We Reviewed In Preparation For Our Heat Training Episode

08:05 Major Reasons Why You Should Care About Heat Training

12:42 Why Running In The Heat Is Challenging

20:21 Anecdotal Experience with Heat Training In Recent Ultra Performances

23:28 The Three Heat Training Methods We Cover and General Physiological Benefits of Heat Training

28:32 Thermal Regulation and Adaptations

31:12 Protocol by Protocol Analysis

32:53 Protocol 1: Training In A Hot Environment

46:06 Protocol 2: Adding Layers to Augment Heat of The Natural Environment

01:06:39 Protocol 3: Hot Dry Sauna and Hot Water Immersion (HWI) - Actual Implementation Steps

01:10:48 Protocol 3: Hot Sauna Benefits and Considerations

01:14:17 Protocol 3: How Water Immersion (HWI) Benefits and Considerations

01:19:35 Maintaining Heat Training Adaptations

01:22:56 Timing and Strategy for Heat Training

01:27:20 Safety Considerations When Heat Training

Top 5 Takeaways

1. ​Heat training is underutilized by most non-elite athletes—and can deliver benefits year-round, not just for hot races.
2. ​Three general methods to consider, some with higher efficacy than others but all can practically aid you: hot-environment training, layering to simulate heat, and passive heat exposure post-workout.
3. ​Core adaptations include increased plasma volume, earlier/more efficient sweating, electrolyte conservation, and lower core temperature.
4. ​Adaptations fade quickly—often within two weeks without exposure—but can be restored in as little as two days.
5. ​Safety is critical: hydrate before and after, adjust fueling for greater glycogen use, and be aware of individual risks like anemia.