Scroll through any wellness feed right now and you’ll find two things everywhere:
People sitting in saunas. And people sitting in ice baths.
Both are promoted as longevity tools. Both come with bold claims. Which begs the question:
What’s real here? And what’s hype?
One of these practices has surprisingly strong evidence behind it, while there’s a thinner—though still interesting—case to be made for the other.
First, a Word About Beneficial Stress
A concept worth understanding (because it explains why both practices may be beneficial) is called hormesis.
Hormesis refers to a small and controlled dose of a stressor that makes the body stronger (as compared to a larger and less controlled stressor that causes damage). Strength training is a great example of hormesis. Technically, lifting weights is an assault on your muscles. However, your body responds to that assault by making your muscles stronger than they were before they were stressed.
Heat and cold exposure work on the same logic. The body is briefly stressed (on purpose), so it can adapt to that stress in a positive way.
The key words here are briefly and controlled. More is not automatically better.
The Case for Sauna
Of the two interventions in question, sauna has the stronger evidence base…stronger than most people realize.
Much of what we know about the benefits of sauna comes from long-running studies out of Finland, where sauna use is a routine part of daily life. Researchers there followed thousands of middle-aged men over a period of decades and found that frequent sauna use was associated with lower rates of cardiovascular death and all-cause mortality. Later work suggested associations with lower dementia risk, as well.
Frequency of use seems to matter. Those using a sauna four to seven times per week showed stronger associations than those using it only once weekly.
An important caveat:
These are observational studies. They show a relationship, but not proof of causality. It’s possible that healthier people simply use saunas more often. But the findings have been consistent enough, across enough measures, to be taken seriously.
What might explain the benefits of heat generally, and sauna in particular? A sauna session raises your heart rate and dilates your blood vessels in a way that resembles moderate exercise. It also triggers the production of heat shock proteins—molecules that help to repair damaged proteins inside your cells. Over time, this may support blood vessel flexibility and lower blood pressure.
The Case for Cold
Cold exposure is the more fashionable of the two interventions being discuss. It also may be the more oversold option.
Here’s what’s reasonably well-established:
A cold plunge produces a dramatic surge in norepinephrine, which is why people climb out feeling alert and energized. That effect is real, it’s immediate, and it’s the reason cold therapy has such enthusiastic devotees. There’s also decent evidence that cold water immersion reduces post-exercise muscle soreness.
Here’s what’s less well-established:
Claims about fat loss, metabolic transformation, immune enhancement, and longevity. The research is early, the studies are small, and the effects are modest.
There’s also a genuine tradeoff worth knowing about. Cold immersion immediately after strength training may actually blunt muscle growth by interfering with the inflammatory signaling your body uses to build muscle. If building strength is your goal, save the plunge for a different time of day.
Practical Guidance
If you want to try either of these:
- Sauna—Aim for 15–20 minutes at a time, at several sessions per week if you can. Hydrate well beforehand and afterward to compensate for fluid lost through sweat. Traditional and infrared saunas both have supporters, but the Finnish research was based on traditional dry saunas.
- Cold—Brief is sufficient. Two to five minutes in cold water captures most of its beneficial effects.
- Both—Start conservatively and build your tolerance slowly. If you have cardiovascular disease, uncontrolled blood pressure, or are pregnant, talk to your primary care physician before starting either of these practices.
The Hormone Angle
Both of these practices interact with your endocrine system. Heat and cold each trigger a short-term cortisol and norepinephrine response—which is exactly the point, since that controlled stress is what drives adaptation.
But this is also where things can go wrong. If chronic stress, poor sleep quality, or imbalanced hormones are factors for you, piling on additional stressors may be counterproductive. Your body has a finite capacity to adapt, and that capacity depends heavily on whether your hormones are working properly.
The people who will benefit most from hormetic practices are the ones whose foundation is already solid. In other words, people will see better results from saunas and cold plunges after issues with stress, sleep, or hormone imbalance are addressed.
Do the Basics First
Saunas and cold plunges are worth considering. Sauna in particular has real evidence behind it, and there’s a good argument for making it a habit.
But neither of these is a shortcut. They should be thought of as adjuncts to a foundation that’s built on sleep, movement, nutrition, and balanced hormones—not substitutes for these.
At Renew Youth, we help men and women to build a solid hormonal foundation, so the extras can actually pay off. To learn more, call us at (800) 859-7511 or use our easy contact form to schedule your complimentary 30-minute consultation.