Cold Exposure: What The Science Actually Says

Cold showers and cold plunges have become trendy. Here is what the evidence actually supports — and what it does not.

Cold Exposure: What The Science Actually Says

Cold showers and cold plunges have become trendy. Influencers swear by them. Podcasts dedicate hours to them.

Here is what the evidence actually supports — and what it does not.

What Cold Exposure Does (With Evidence)

Reduces acute inflammation. Cold water immersion is well-supported for reducing delayed onset muscle soreness (DOMS) and acute inflammation post-exercise. Athletes have used this for decades with good reason.

Activates brown adipose tissue (BAT). Cold exposure activates brown fat — the metabolically active fat that generates heat. Regular cold exposure increases BAT activity over time, with modest but real metabolic effects.

Noradrenaline release. Cold exposure produces a significant spike in noradrenaline — a key neurotransmitter for alertness, focus, and mood. The mental clarity many people experience post-cold is real and has a clear mechanism.

Mental resilience. Deliberately entering an uncomfortable environment and staying calm under duress trains the same mechanisms used to remain calm under other stressors. This is the least measurable but potentially most valuable benefit.

What The Evidence Does Not Support (Yet)

Cold exposure after strength training. This is where it gets nuanced. Cold immersion post-strength session may blunt some of the hypertrophy (muscle building) signalling, specifically mTOR pathway activation. If building muscle is the primary goal, cold plunges immediately after training are not optimal.

A Practical Approach

• Cold showers in the morning: well-supported, practically accessible, good for alertness
• Cold plunge after aerobic training or on rest days: ideal
• Avoid cold immersion immediately after heavy strength sessions if muscle building is the priority
• Temperature: 10–15°C is the most commonly studied range; colder is not necessarily better

Explore the full recovery approach at Health & Performance. Apply for coaching at The System™.