Sauna vs Cold Plunge: Which Is Better, and for What? Sauna vs Cold Plunge

Neither is better overall; they do different jobs. Sauna has the stronger long-term health data, mainly large Finnish studies linking frequent use with fewer fatal heart events. Cold plunges have the better evidence for short-term recovery, such as next-day muscle soreness, but used straight after lifting they can blunt muscle growth. Both are stressors with real risks for some people. A 2015 Finnish cohort study (Laukkanen et al.) is the main source for sauna’s heart claims; a 2022 meta-analysis of 52 studies (Moore et al.) is the main source for cold water and recovery.

This page summarizes research for general information. It is not medical advice. Heat and cold both strain the heart and circulation; check with a clinician first if you have heart or blood-pressure problems, are pregnant, or take regular medication.

Side-by-side

Sauna: what the evidence shows

The Kuopio cohort study (Laukkanen et al., 2015) followed 2,315 Finnish men aged 42–60 for a median of 20.7 years. Compared with one session a week, 4–7 sessions a week was linked with a lower risk of sudden cardiac death (hazard ratio 0.37), and sessions longer than 19 minutes were linked with lower risk than sessions under 11 minutes (hazard ratio 0.48). Similar links were seen for fatal heart disease and death from any cause.

These are associations. Men who could use a sauna most days may have been healthier to begin with, and the study only included middle-aged Finnish men. A 2018 review by the same group lists plausible reasons sauna might help the heart, including lower blood pressure, less arterial stiffness and better blood-vessel function, but those mechanisms come mainly from short-term studies.

A broader systematic review of regular dry sauna use (Hussain and Cohen, 2018) found 40 studies with 3,855 participants. Only 13 were randomized trials, and most had fewer than 40 people. Most reported benefits, and the authors concluded that “Regular dry sauna bathing has potential health benefits”, but called for higher-quality data. For session lengths and temperatures, see the sauna protocol.

Cold plunge: what the evidence shows

Most cold-water research is about exercise recovery.

• Soreness: a meta-analysis of 9 randomized trials (Machado et al., 2016) found cold water slightly better than passive rest for muscle soreness, with the best results at about 11–15 °C for 11–15 minutes.
• Performance and perceived recovery: the 2022 meta-analysis of 52 studies found that after high-intensity exercise, cold water improved muscle soreness, muscular power and how recovered people felt 24 hours later. It did not help strength recover.
• Health and wellbeing: a 2025 review of 11 studies (Cain et al.) with 3,177 participants found inflammation markers rose immediately after cold immersion, and stress was lower 12 hours later. One included study reported a 29% reduction in sickness absence in people who took cold showers. The authors noted “Improvements were also observed in sleep quality and quality of life, but not mood”, and called the evidence base limited by few randomized trials and small samples.

The cold response itself is strong. In a classic lab study (Šrámek et al., 2000), sitting in 14 °C water up to the neck for an hour raised noradrenaline by 530% and metabolic rate by 350%. A typical plunge is far shorter, so the response is smaller. See the cold plunge protocol for practical temperatures and times. The dopamine rise from the same study, and why it says little about motivation, is covered on cold plunge dopamine.

If you lift weights: timing matters

This is where the choice matters most. In a 12-week training trial (Roberts et al., 2015), 21 men did either 10 minutes of cold water immersion or an active cool-down after each session. Strength and muscle mass rose more with the active cool-down; type II muscle fibre size grew 17% in that group and did not change significantly with cold water. A 2024 meta-analysis of 8 studies (Piñero et al.) found the same direction: cold water immediately after resistance training “may attenuate hypertrophic changes”, though study quality was fair to poor.

Sauna has not been shown to have this effect. If muscle growth is your goal, use the sauna after lifting, or save the cold plunge for rest days or several hours later. The detail is on cold water after strength training.

Safety: different risks

• Cold: the first moments in cold water bring a sharp rise in breathing, heart rate and blood pressure. A review of cold water immersion (Tipton et al., 2017) covers how this cold shock can lead to drowning and cardiac arrest. Never plunge alone in open water, and get in slowly.
• Heat: the 2018 sauna review reports annual sauna death rates of 0.06 and 2 per 100,000 people in Sweden and Finland, with half or more involving alcohol, and bathing alone a common risk factor. Mild side effects were heat discomfort and light-headedness.
• Both: skip alcohol, stay hydrated, and get out if you feel dizzy, confused or unwell.

What neither has shown

Many popular claims for both practices run ahead of the research. The 2017 cold water review concluded that while most claims have a credible rationale, “in some instances the supporting data remain at the level of anecdotal speculation.” That applies to fat loss, immunity and mental health claims for cold plunges. For sauna, the strongest data are observational, and the 2018 systematic review noted that the best frequency and duration for specific health goals are still unknown. No trial has compared regular sauna use with regular cold plunging head to head for any health outcome.

How to choose

Many people use both, alternating between them. That habit, and whether to finish on cold, is covered on the Søberg principle page. For the bigger picture on heat and cold, see the cold and heat exposure guide.