Cold Plunges: What the Science Really Says About Recovery, Stress, and Sleep

Cold plunges, also known as cold-water immersion (CWI) are gaining popularity for recovery, wellness, and even mental health.

But what does the research actually show? The answer: there are some benefits, but they’re modest, context-dependent, and not a magic cure for health or performance.

Embracing the chill: A man takes a refreshing plunge into icy waters, exploring the health benefits of cold water immersion amidst a snowy landscape.

Post-Exercise Recovery

Systematic reviews and meta-analyses show that CWI can reduce muscle soreness and perceived exertion after exercise.

• Best results: Water temperatures between 10–15°C for 10–15 minutes.

• Other effects: Small improvements in fatigue recovery, faster reduction of creatine kinase and lactate.

• What it doesn’t do well: No significant effect on inflammation markers such as CRP and IL-6.

The physiological rationale for CWI in sports recovery is still not fully understood, and the benefits are mostly short-term.

Stress and Mental Well-Being

CWI can temporarily increase inflammation markers immediately after immersion, but may help reduce stress 12 hours later.

• Linked to better sleep quality and quality of life in certain populations.

• Acute sessions may boost parasympathetic activity (as shown by increased heart rate variability), lower cortisol, and reduce negative mood.

Sleep Quality

Evidence suggests CWI can improve subjective sleep quality ( ie how people feel about their sleep), especially in athletes and individuals with poor baseline sleep.

• A 4-week study with healthy adults (10.4°C for 10 minutes, 3×/week) reduced sleep disturbances.

• Athletes reported “likely” to “very likely” improvements in perceived sleep after training or competition when CWI was used.

• However: Objective measures (like total sleep time or efficiency) often remain unchanged, and benefits may be more noticeable in the first sleep cycle (slow-wave sleep) for poor sleepers.

What CWI Does Not Seem to Do

• No strong evidence for long-term immune system enhancement or illness prevention.

• Limited diversity in study populations and small sample sizes make results less generalizable.

Risks

Cold plunges are generally safe for healthy adults but can pose risks for people with cardiovascular disease or other medical conditions.

The Bottom Line

Cold plunges may offer modest benefits for:

• Reducing post-exercise soreness and fatigue

• Supporting stress management and mood

• Improving subjective sleep quality

For recovery purposes, the optimal protocol appears to be:

• Water temperature: 10–15°C

• Duration: 10–15 minutes

• Timing: Immediately after exercise or in a structured routine

These effects are most relevant for acute recovery, not as a long-term health cure.

References

1. Can Water Temperature and Immersion Time Influence the Effect of Cold Water Immersion on Muscle Soreness? A Systematic Review and Meta-Analysis. Machado AF, Ferreira PH, Micheletti JK, et al. Sports Medicine (Auckland, N.Z.). 2016;46(4):503-14. doi:10.1007/s40279-015-0431-7.

2. Effects of Cold Water Immersion After Exercise on Fatigue Recovery and Exercise Performance--Meta Analysis. Xiao F, Kabachkova AV, Jiao L, Zhao H, Kapilevich LV. Frontiers in Physiology. 2023;14:1006512. doi:10.3389/fphys.2023.1006512.

3. Effects of Cold-Water Immersion on Health and Wellbeing: A Systematic Review and Meta-Analysis. Cain T, Brinsley J, Bennett H, et al. PloS One. 2025;20(1):e0317615. doi:10.1371/journal.pone.0317615.

4. Influence of Acute and Chronic Therapeutic Cooling on Cognitive Performance and Well-Being. Knill-Jones J, Shadwell G, Hurst HT, et al. Physiology & Behavior. 2025;289:114728. doi:10.1016/j.physbeh.2024.114728.

5. Cardiovascular and Mood Responses to an Acute Bout of Cold Water Immersion. Reed EL, Chapman CL, Whittman EK, et al. Journal of Thermal Biology. 2023;118:103727. doi:10.1016/j.jtherbio.2023.103727.

6. The Effects of Cold Exposure (Cold Water Immersion, Whole- And Partial- Body Cryostimulation) on Cardiovascular and Cardiac Autonomic Control Responses in Healthy Individuals: A Systematic Review, Meta-Analysis and Meta-Regression. Jdidi H, Dugué B, de Bisschop C, Dupuy O, Douzi W. Journal of Thermal Biology. 2024;121:103857. doi:10.1016/j.jtherbio.2024.103857.

7. What Is the Biochemical and Physiological Rationale for Using Cold-Water Immersion in Sports Recovery? A Systematic Review. Bleakley CM, Davison GW. British Journal of Sports Medicine. 2010;44(3):179-87. doi:10.1136/bjsm.2009.065565.

8. Cold Water Immersion: Kill or Cure?. Tipton MJ, Collier N, Massey H, Corbett J, Harper M. Experimental Physiology. 2017;102(11):1335-1355. doi:10.1113/EP086283.