Hormesis

Hormesis is the dynamic where exposure to a low-dose or short-term exposure induces a beneficial physiological response. Examples of hormetic stressors include exercise, fasting, caloric restriction, cold, radiation, and heat. Hormetic stressors exert different effects but many activate common or similar pathways. For example, exercise, fasting, and cold and heat exposure all induce the expression of heat shock proteins.

Chronic fatigue syndrome
Robert Naviaux found subjects with ME/CFS exhibited the opposite metabolic and phospholipid profile to that found in acute cell danger response, perhaps in response to a chronic cell danger signaling, such as a chronic infection. It is unclear what role, then, hormesis might play in patients with ME/CFS. Many patients as a function of the disease have a diminished ability to respond to hormetic challenges such as exercise, cold or heat. At the same time, some patients report improvement with intermittent fasting or sauna therapy.