Heat training has become one of the most practical “unfair advantages” a normal rider can actually use—without a WorldTour budget.

In this special edition of The Breakaway, we sit down with Reece McDonald (Science to Sport) to break down heat acclimation vs heat acclimatization, and why a simple sauna routine can improve your heat tolerance, your cooling efficiency, and potentially even performance via mechanisms that overlap with altitude-style adaptations.

We cover the real-world, no-lab-coat version:

• The difference between natural heat exposure (riding in summer) vs artificial heat exposure (sauna / hot baths / indoor heat sessions)

• Passive vs active heat training (and why passive is often the easiest win)

• What to track if you don’t have a core temp sensor: cardiac drift, sweat rate, and body mass change

• Why sauna beats steam room for this goal (most of the time)

• How heat training can expand plasma volume, influence hematocrit, and might support a later rise in hemoglobin mass (“poor man’s altitude”)

• Safety and execution: building tolerance, not overdoing the stress, and smart rehydration after sessions

If you ride or race in South African summer conditions—road, gravel, or MTB—this is one of the most accessible training tools you can add this year.

00:00 Intro + why heat training matters

03:14 Heat acclimation vs heat acclimatization (simple definitions)

03:48 Active vs passive heat training (core temp, cardiac drift, sweat rate)

07:02 Is heat training “new”? What the research + pros are doing

10:34 “Poor man’s altitude”: the crossover benefits (heat ↔ altitude)

13:11 Hemoglobin explained (and why EPO mattered in the doping era)

16:04 What actually changes: sweating earlier, plasma volume, cooling efficiency

18:58 Measuring progress: bloods, hematocrit, timelines, expectations

21:06 Sauna protocol: how long, how often, and how to build tolerance safely

24:49 Cold rinse / contrast hacks: helpful or undermining the adaptation?

34:02 Indoor workaround: fan-off cooldown + jacket (smart stress, not all the time)

40:13 Steam room vs sauna + alternatives (hot yoga, indoor heat sessions)

40:36 Hydration + carbs + electrolytes when doing heat work (kidney strain warning)

42:54 Outro + where to find Reece / Science to Sport resources