Trusted Voices
Scroll through the research from these 3rd-party experts.
Jari Laukkanen, MD, PhD
Cardiologist and professor, University of Eastern Finland
Laukkanen led the sauna research that most people are indirectly quoting when they talk about heat and heart health. Drawing on a Finnish cohort of roughly 2,300 middle-aged men followed for two decades, his team found that frequent sauna bathing was associated with lower cardiovascular and all-cause mortality, with the strongest association among those going four to seven times a week.
The detail that matters: the research was conducted on traditional Finnish saunas. Heated stones, water poured over them, real loyly. Not infrared cabins.
This is validation rather than revelation for us. The sauna was always going to be Finnish. But Laukkanen is the reason we can say plainly why we did not take the cheaper, easier infrared route that most studios in this market did.
Susanna Soberg, PhD
Metabolic scientist, Copenhagen
Soberg studies what cold and heat exposure actually do to human metabolism, including work on brown adipose tissue and on winter swimmers in Denmark. Her research points toward relatively modest weekly doses being sufficient, and toward ending a contrast session on cold rather than heat.
Cold water was already part of my routine. What I did not have was the mechanism or the dosing. Soberg gave me both, and her work is the most direct influence on how we run contrast therapy here: the cycle structure, the durations, and the guidance our staff give first-timers.
She is also the reason we treat contrast as a protocol rather than two amenities that happen to sit near each other.
Peter Attia, MD
Physician, author of Outlive
Attia is the doorway. He is how I found Walker and several of the other voices on this page. But his real contribution was not introducing an idea. It was giving structure and vocabulary to a conviction I already held.
I watched my parents lose their healthspan long before they lost their lifespan. That is the reason this studio exists. I did not want their last decades, and I did not accept that those decades were the default. Attia’s work confirmed that much of what people treat as inevitable decline is trainable, and that the work has to begin decades before it shows.
Where we part company is language. Attia writes about the Centenarian Decathlon and the marginal decade. I understand the framing and I do not use it. We talk about your Strongest Decade, the same argument pointed forward rather than backward. Frailty is not inevitable.
He also validated something I was already doing: working with a functional medicine physician. Attia practices medicine. We do not. That line matters to us, and it is why we refer out rather than pretend otherwise.
The last difference is access. Attia practices concierge medicine, and that is legitimate work at a price point that reflects it. But it puts the measurement he argues for out of reach for most people. The Sisu Assessment exists because it should not be. Same principle, in a studio rather than a clinic, at a price a normal household can absorb.
Matthew Walker, PhD
Neuroscientist, UC Berkeley, and author of Why We Sleep
Walker’s work on sleep is the clearest example of something I learned rather than confirmed. His case is that sleep is not the thing you sacrifice to make room for training and recovery. It is the foundation both of them rest on, tied to memory consolidation, immune function, metabolic regulation, and clearance processes in the brain.
That reframing is why sleep comes up in almost every conversation we have with members, and why several modalities here are positioned around nervous system downshift rather than stimulation. Float, vibroacoustic, and an evening sauna are not add-ons to a training program. For a lot of people they are the intervention.
If you take one thing from this page and change nothing else, make it your sleep.
Michael Easter
Author of The Comfort Crisis and professor, UNLV
Easter’s argument is that modern life has engineered out the difficulty humans evolved with, and that deliberately reintroducing hard things, whether carrying weight, being cold, going without, or taking on something genuinely uncertain, produces adaptations that comfort does not.
This one changed how I think about programming. It is the difference between a studio that helps you avoid discomfort and one that helps you choose it deliberately. Rucking, cold exposure, and the whole idea of hormetic stress belong in a longevity practice, not just a training plan.
It is also the closest thing in the modern literature to what sisu has always meant.
Mike Boyle
Strength and conditioning coach
Boyle has spent decades arguing that training should build capable, resilient bodies rather than specialized ones. A joint-by-joint view of mobility and stability, an emphasis on single-leg and unilateral work, and a long-running warning about early sport specialization.
This one is half learned and half confirmed. Anyone who has spent thirty years in uniform and kept training through it arrives at similar conclusions by trial and error. Boyle explained why the pattern held.
It is the reason the Longevity Training Lab is built around functional movement rather than sport-specific programming, and why we cap cohorts at four so movement quality can actually be coached.
Rhonda Patrick, PhD
Biomedical scientist, FoundMyFitness
Patrick has done more than almost anyone to make the mechanisms of hormesis legible to a general audience. Heat shock proteins, the cellular stress response, and how deliberate short-term stressors can produce durable adaptation. She has also been among the most persistent voices connecting sauna use to cardiovascular and cognitive outcomes.
Her work is why we can explain what is happening in the body during a sauna session rather than simply asserting that it is good for you. That matters to us. Members who understand a mechanism tend to stay consistent with it.
She is also a useful corrective in a field full of confident claims. She is unusually clear about where evidence is strong and where it is preliminary.
Andrew Huberman, PhD
Neuroscientist, Stanford School of Medicine
Huberman’s contribution has been translating neuroscience into protocols people can actually run. Deliberate cold exposure, light exposure and circadian timing, breathwork, and the relationship between stress and adaptation.
For me this was mostly the podcast era catching up with things I had been doing for years without a framework. What his work added was structure: timing, duration, and sequencing, rather than doing the right things at arbitrary moments.
The practical result here is that our staff can tell you when to do something and for how long, not just that it is available.
How We Use This Work
Citing a researcher is not the same as being endorsed by one, and we are careful about the difference. None of the people above have any affiliation with Sisu Longevity Studio. We read their work, we argued about it, and we made decisions about a building and a set of protocols as a result.
We also try to be honest about where the evidence is strong and where it is early. Sauna and cardiovascular outcomes rest on a substantial body of work. Some of what we offer is supported by smaller or shorter studies. We will tell you which is which if you ask, and if a member of our staff does not know, they have been told to say so rather than guess.
Sisu Longevity Studio is a wellness facility, not a medical clinic. Nothing here is medical advice, and nothing we offer is intended to diagnose or treat a medical condition. If you have a health concern, talk to your physician.