The body’s response to cold-water immersion and similar cold-exposure techniques like cryotherapy is a robust release of norepinephrine, rapidly setting off a cascade of adaptive effects that influence aspects of metabolism, brain function, and genetic expression. As result, regular, whole-body cold exposure may exert systemic beneficial effects, improving glucose and lipid metabolism, decreasing inflammation, improving cognitive performance, and potentially enhancing immune function – critical aspects of maintaining health in our modern world.

These beneficial effects of cold exposure may be due to hormesis, a favorable biological response to a mild stressor. Hormesis triggers protective mechanisms that provide protection from future, more harmful stressors.

Other hormetic responses to cold exposure include increased production of PGC1-alpha, a protein that promotes mitochondrial biogenesis, the production of new, healthy mitochondria, and the activation of brown fat – a phenomenon once thought to occur only in newborns, but now known to occur in adults, especially after cold exposure.