A new study shows that people who regularly exercise will being to feel depressed and fatigued after just one week of forced inactivity.
Those in the best shape experienced the greatest loss in fitness when they stopped exercising, and the worst negative mood symptoms.
Ali A. Berlin of Bethesda, Maryland based Uniformed Services University of the Health Sciences said she’s not sure the results would apply to someone skipping workouts of their own volition, perhaps to do something fun. She says, “I think future research is needed to really answer that question.”
Sedentary people are more likely to be depressed, and a number of studies have suggested that symptoms of depression like tension, irritability and fatigue can develop even in a fit person if they stop exercising, Berlin et al noted in the March-April issue of Psychosomatic Medicine.
The team studied 40 men and women with regular exercise schedules at least three times a week for at least a half hour. Half the subjects were instructed to stop exercising for two weeks, while the other half continued with their routine as normal. This way, the researchers said, they could get a clear picture of how exercise withdrawal may affect mood.
The team evaluated subjects at one and two weeks for body-related symptoms of depression such as poor appetite, fatigue, sleep difficulties and low energy levels, as well as mental symptoms such as sadness, self-criticalness, anxiety and irritability.
By one week, the scientists found, the subjects who had stopped exercising reported more fatigue and other somatic symptoms than those who had maintained their workout routines. By week two, the non-exercising individuals reported more mental symptoms as well.
While there was no statistically substantial loss of fitness on average, the research team did note that the most fit individuals showed the greatest drop in fitness and sharpest drop in mood.
Berlin and colleagues believe the study indicates that exercise will help preserve one’s mood by shifting the nervous system balance away from the sympathetic nervous system, which is responsible for triggering the body’s “fight or flight” response, toward the parasympathetic nervous system, which calms and quiets the body. She explains, “Exercise can affect this balance, it basically lets you calm down more efficiently.”
Berlin and her team say that stopping regular exercise causes the balance to shift back toward the sympathetic system. She summarizes by saying, “If your body’s revved up all the time, obviously you’re going to start to feel tired.”
The researchers are now analyzing additional data from the current study to further explore their hypothesis.