Sauna and cold showers: what do they do to your body and blood values?

Sauna and cold showers are popular, and for sauna the evidence is strongest. Regular sauna use is associated with a lower risk of cardiovascular disease, while cold exposure mainly seems to help your recovery experience and alertness. Not everything promised online is equally well supported.

I like this topic for honestly separating what holds up from what is hype. Sauna has real data, cold showers mostly enthusiasm.

What does the sauna do to your heart?

Frequent sauna use is associated in large studies with less cardiovascular disease. In a Finnish cohort study, men who sauna bathed four to seven times a week had a clearly lower risk of cardiac death and all-cause mortality than those who went once a week (Laukkanen, 2015). A later study in men and women showed a similar dose-response relationship (Laukkanen, 2018).

These are observational studies, so they show association, not conclusive proof of cause. Still, the signal is consistent.

Does cold showering help your recovery?

Cold exposure can improve muscle soreness and recovery experience after exertion, but the effects are nuanced. A meta-analysis found that cold-water immersion can reduce muscle soreness after strenuous exercise (Leeder, 2012). At the same time, cold right after strength training can slightly blunt muscle adaptation, so timing matters.

For pure muscle growth, an ice bath right after training is therefore not always wise.

What does this mean for your blood values?

Sauna and cold do not change your blood values as directly as nutrition or sleep, but they fit a healthy recovery picture. They mainly influence your heart and recovery status over the longer term. If you want to track your recovery, look at markers such as inflammation and stress.

To measure your recovery, look at CRP and cortisol at rest.

How to approach it sensibly

Use sauna for relaxation and heart health, and use cold for recovery experience on non-strength days. Combine it with the basics that really count: sleep, nutrition and training. To track your recovery markers, compose a panel through our custom blood test.

Also read what poor sleep does to your hormones and the overview blood values for endurance athletes.

My advice: enjoy the sauna and the cold shower, but do not expect miracles if the basics are off. With heart symptoms or doubt, discuss sauna with your GP first.

References

1. Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Internal Medicine. 2015. PMID: 25705824.
2. Laukkanen T, Kunutsor SK, Khan H, et al. Sauna bathing is associated with reduced cardiovascular mortality and improves risk prediction in men and women: a prospective cohort study. BMC Medicine. 2018. PMID: 30486813.
3. Leeder J, Gissane C, van Someren K, et al. Cold water immersion and recovery from strenuous exercise: a meta-analysis. British Journal of Sports Medicine. 2012. PMID: 21947816.

Disclaimer

Every blood test result includes a professional assessment by a BIG-registered doctor. This article gives general information and is not a substitute for medical advice. A blood test is a tool to walk into the conversation with your GP better informed, not a diagnosis in itself. For treatment decisions, discuss your results with your GP.