Extremely high priority
Anew Sourcedcopperoral health
Top ChoiceOral Health
Removes 75% of mouth bacteria your toothbrush misses.
Cost$8.99
TimeNone
EnergyEffortless
ImpactHigh
29Lower priorityEvidence: mixed
Cold plunge
Priority Matrix
The numbers.
Four dimensions, scored 1–6, where six is always the good end: cheapest, quickest, easiest, highest impact. Priority is Impact squared, divided by what it costs you in energy, money and time.
Cost$200+
Time10–15 min
EnergyVery hard
ImpactModerate
How sure we are
MixedReal studies disagree, or the effects are small and noisy.
Kept separate from the priority score on purpose: confidence in the evidence never raises how worth-it something is.
What we read
- Health effects of voluntary exposure to cold water – a continuing subject of debate
International Journal of Circumpolar Health · 2022
A review of human studies on voluntary cold-water immersion finds some signals for cardiovascular, immune, and mood outcomes, but the trials are small, heterogeneous, and often uncontrolled.
- Cold water immersion: kill or cure?
Experimental Physiology · 2017
Cold water can kill via cold shock and drowning within minutes; claimed health benefits are biologically plausible but not established at the doses marketed as a cold plunge.
Research from UiT The Arctic University of Norway · University of Portsmouth. We cite their published work. They have no involvement with Anew.
Where this falls down
Not for everyone. Unsupervised cold water is a bad idea for anyone with heart disease, arrhythmia, or who cannot get out quickly — cold shock can kill before hypothermia does.
Still unknown. No trial has shown that a dedicated plunge tub outperforms a cold shower, or that the dopamine spike some studies report changes any outcome that lasts past the afternoon.
Topics
Where it fits.
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