An adaptive reaction is a set of life processes through which an organism adapts to environmental conditions.
Over all the years of observation, a person identified several stages of adaptation depending on the adaptation time - how much time it took to overcome stress and complete recovery to previous values. In accordance with the adaptation time, the adaptation process is divided into acute, restorative, long-term and long-term.
Acute adaptation lasts several hours or days. During this time, significant shifts in the functioning of systems are observed. Reversible changes in morphological elements occur. Also at this time, energy consumption occurs in adaptation processes. The duration of this stage depends on how quickly the environment changes. Based on effectiveness, the following types of adaptation can be distinguished: – short-term; – long-term; - long-term. Short-term adaptation is a short-term change in state. If the environment is functioning successfully for a given organism, then there is no need to change the state. This occurs whenever favorable conditions for the existence of an organism are constantly present in the external environment. The functional indicators of the nervous system are within the limits ensuring the maintenance of normal life support. An example of short-term adaptation is adaptation in a person when moving to warm countries on vacation. A person who lives in a warm climate has imperfect adaptation mechanisms. These same mechanisms are fully demonstrated in people living in cold climates. Under favorable conditions, the body spends a minimum of energy to ensure vital activity and rest from the work of the body. It follows that the long-term absence of external factors affects the body. Short-term adaptation can be carried out for a short period of time (for example, increasing the power of muscle work during training): these will be short-term changes in physical indicators.