Cold Plunge

What it is

• Cold-water immersion (deliberate cold exposure), typically ~3–8°C for short durations.

How it works

• Sympathetic activation → noradrenaline/dopamine spike, brown-fat/thermogenesis, vasoconstriction→rebound vasodilation; a hormetic stressor (Mitohormesis).

Goal relevance

• Mood/alertness, metabolic (cold-induced thermogenesis), recovery. Note: avoid in the 4–8 h after resistance training if hypertrophy/strength is the goal (cold blunts the inflammatory adaptation signal).

How to do it

• A few minutes, a few times per week; earlier in the day preferred (alerting).

Cautions

• Cardiac risk with extreme cold; never alone in open water.