Really enjoyed this breakdown and I love the “altitude in disguise” framing!
From a clinician’s lens, the most interesting part is that the adaptation seems to be systems-level (blood volume/hemoglobin mass + cardiac filling/stroke volume), not just “feeling tougher in the heat.” That’s exactly why VO₂max is such a powerful health marker: it reflects oxygen delivery capacity and physiologic reserve, not a single organ or lab value.
I also appreciate the nuance you highlighted: the intervention raised the ceiling (VO₂max / vVO₂max) without obviously shifting economy or threshold, which suggests passive heat may be a smart “multiplier” for the right person rather than a replacement for training.
Practical point for readers: heat is a real stressor. Starting conservatively (shorter, cooler, fewer sessions) and respecting contraindications (syncopal history, unstable cardiac disease, dehydration, pregnancy, etc.) matters as much as the protocol.
Curious if you’ve seen comparable effects with sauna vs hot-water immersion in the literature!
I have—a few (recent) studies compare them and find equivalent benefits with sauna and hot bath. Some adaptations even favor baths (I believe it was Hb mass but would have to look at the study).
This is such a great study! Those effects are huge. Almost hard to believe. Thanks for sharing. I have a home sauna and use it for 30 minutes almost daily. I think it’s helped my running. My only issue with implementing the study is the part about doing the heat exposure immediately after running. When I finish running I need to do something else right away (either go to work or eat dinner with my family). Do you think it’s ok if I do the sauna at a more convenient time? Also, 45 minutes is a long time.
Yes—you’ll get benefits even if the run and sauna are separated by several hours. Perhaps more effective when right after? Yes. How much more? Not sure. But maybe a percent worth.
Really enjoyed this breakdown and I love the “altitude in disguise” framing!
From a clinician’s lens, the most interesting part is that the adaptation seems to be systems-level (blood volume/hemoglobin mass + cardiac filling/stroke volume), not just “feeling tougher in the heat.” That’s exactly why VO₂max is such a powerful health marker: it reflects oxygen delivery capacity and physiologic reserve, not a single organ or lab value.
I also appreciate the nuance you highlighted: the intervention raised the ceiling (VO₂max / vVO₂max) without obviously shifting economy or threshold, which suggests passive heat may be a smart “multiplier” for the right person rather than a replacement for training.
Practical point for readers: heat is a real stressor. Starting conservatively (shorter, cooler, fewer sessions) and respecting contraindications (syncopal history, unstable cardiac disease, dehydration, pregnancy, etc.) matters as much as the protocol.
Curious if you’ve seen comparable effects with sauna vs hot-water immersion in the literature!
I have—a few (recent) studies compare them and find equivalent benefits with sauna and hot bath. Some adaptations even favor baths (I believe it was Hb mass but would have to look at the study).
nobody talks about HOT baths!!!! love this!
This is such a great study! Those effects are huge. Almost hard to believe. Thanks for sharing. I have a home sauna and use it for 30 minutes almost daily. I think it’s helped my running. My only issue with implementing the study is the part about doing the heat exposure immediately after running. When I finish running I need to do something else right away (either go to work or eat dinner with my family). Do you think it’s ok if I do the sauna at a more convenient time? Also, 45 minutes is a long time.
Yes—you’ll get benefits even if the run and sauna are separated by several hours. Perhaps more effective when right after? Yes. How much more? Not sure. But maybe a percent worth.
I imagine you'd still want to cold plunge afterwards to get BP back up, or at least HR down?
Perhaps but not necessary—an adequate cool down period of sitting should do the trick.