Environmental hormesis, such as from sauna, cold plunge, exercise, and fasting, activates the NRF2 system.

“Environmental hormesis being things like sauna cold plunge maybe you're swimming in a cold river sometimes when i'm out surfing in the morning even in costa rica i get a little cold because the water is cold and i'm not wearing any wetsuit or the water is relatively cold but exercise also does this fasting does this it appears that sun exposure might even do this so there are clearly things that we experience in our environment heat cold exercise and fasting being the main environmental stressors that appear to be activators of a molecular system called the nrf2 system”