Cold Showers
Cold water immersion is associated with improved mood and self-reported wellbeing, though research quality varies[1][2].
Practical Protocol
One effective protocol used in a study:
- Regular warm shower first
- End with 30-90 seconds of cold water
- As cold as tolerable
- Daily for 30 consecutive days
Hot vs Cold for Recovery
Water therapy (hot or cold) can be beneficial for rehabilitation[3].
Safety Considerations
Warning: Extreme cold water (below 4°C/39°F) can be dangerous[4].
Cold showers are generally safe for healthy adults, but avoid if you have:
- Heart conditions or arrhythmias
- High blood pressure (uncontrolled)
- Raynaud's disease
- Recent illness or fever
Start gradually – studies allowed participants to build up tolerance over time.
Common Claims
Norepinephrineⓘ
Myth: "Cold showers boost immune system"
Reality: One study found fewer sick days, but this could be behavioral. The immune mechanism isn't proven.
Reality: One study found fewer sick days, but this could be behavioral. The immune mechanism isn't proven.
Myth: "Cold showers burn significant fat"
Reality: Cold exposure does activate brown fat, but the calorie burn from a brief cold shower is minimal.
Reality: Cold exposure does activate brown fat, but the calorie burn from a brief cold shower is minimal.
---
References
- Cain T, et al. (2025). Effects of cold-water immersion on health and wellbeing: A systematic review and meta-analysis. PLOS ONE. [DOI]
- Various (2019). Cortisol levels after cold exposure are independent of prior habituation. PLOS ONE. [DOI]
- Various (2022). Does aquatic physical therapy affect the rehabilitation of chronic diseases?. PLOS ONE. [DOI]
- Various (2025). Single immersion in cold water below 4°C: A health hazard review. PLOS ONE. [DOI]