The Science Behind How Exercise Reduces Anxiety


It is becoming increasingly well known how the body is intrinsically connected to symptoms of PTSD and complex PTSD, and, accordingly, the vital role of physical therapies in helping to ameliorate these conditions. Indeed, in the UK, more and more doctors are prescribing interventions such as free gym memberships in order to help treat patients suffering from various mental health conditions (especially depression and anxiety). In this article, I want to briefly look at the science behind the anxiolytic effect of exercise :

How Does Exercise Reduce Anxiety?


Exercise Has Beneficial Effects On Nervous System:

Exercise has been shown to reduce the reactivity of the sympathetic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis. These effects on our sympathetic nervous system and HPA axis have the effect of reducing feelings of stress and anxiety. These effects are important for ameliorating symptoms of PTSD and complex PTSD (conditions associated with disruption of the nervous system and the HPA axis as well as a whole host of anxiety disorders such as generalized anxiety disorder, social phobia, and obsessive-compulsive disorder.

Exercise Has Beneficial Effects On Monoamine System:

The three main monoamines are serotonin, dopamine, and noradrenaline. Animal studies have also suggested that aerobic exercise increases levels of serotonin and noradrenaline in the brain

Exercise Increases Activation Of The Brain’s Frontal Regions:

Exercise helps activate the frontal regions of the brain. This is important for those who suffer from anxiety as the brain’s frontal regions help dampen down activity in the brain’s amygdala (the brain’s internal ‘alarm system’ which is activated by the perception of real or imagined threats it has been found that those suffering from borderline personality disorder and complex PTSD may have incurred damage to their amygdalas due to severe and protracted early life stress which, in turn, can make the amygdala over-sensitive and over-reactive, locking us into a state of ‘fight or flight.’)

Exercise Has Beneficial Effects On Endogenous Opioid System:

The endogenous (endogenous means originating from inside the organism as opposed to the external environment) opioid system can be described as the body’s innate PAIN KILLING SYSTEM. Studies suggest that vigorous exercise stimulates increased production of endogenous opioids (endorphins) in the brain which in turn improves mood and reduces feelings of anxiety. Studies also suggest that by stimulating endogenous opioids in both the ventral and peripheral nervous system exercise may also help to diminish some forms of pain.

Exercise Has Beneficial Effects On Brain-Derived Neurotrophic Factors (BDNF):

BDNF has been found to be lowered in individuals suffering from anxiety. (e.g. Duman and Montiggia, 2006) and research suggests that exercise can increase levels of BDNF. Increases in BDNF may also improve the functioning of the serotonergic system (Chen et al., 2006) and augment the growth of neurons (Altar, 1999). Exercise also increases the availability of the neurochemicals gamma-aminobutyric acid (GABA), and endocannabinoids, both of which reduce feelings of anxiety.

Exercise Encourages Growth Of New Brain Cells (Neurogenesis):

Neurogenesis refers to the process in the brain whereby new neurons are formed. Research (e.g. Eisch, 2002) suggests that the growth of new neurons in the brain (particularly the hippocampus) can help to reduce feelings of anxiety. Animal studies suggest exercise can increase neurogenesis in the hippocampus (Duman et al., 2001).

Exercise Increases Tolerance Of Some Of The Symptoms Of Anxiety And Increases Resilience::

Because physical activity causes the body to react in similar ways to some of the body’s reactions to anxiety (such as rapid heartbeat and hyperventilation) repeated exposure to such bodily reactions as a result of exercise may help to habituate the individual to such sensations (Beck and Shipherd, 1997) and therefore help him or her to build up tolerance of them, understand they are not dangerous and thus prevent escalation anxiety.

Exercise Can increase Feelings Of Self-Efficacy And Self-Mastery Which In Turn May Prevent Escalation Of Anxiety Symptoms::

Feelings of self-efficacy and self-mastery have been shown to correlate with a decrease in feelings of anxiety and evidence suggests (Bodin and Martinsen, 2004) that exercise which increases feelings of self-efficacy and self-mastery (e.g. martial arts) is better at reducing individuals’ symptoms of anxiety than exercise that is less likely to lead to these feelings (e.g. riding an exercise bike).

Exercise Acts As A Distraction:

Exercise distracts us from our worries and negative ruminations, especially exercise that allows us to enter a state of ‘flow’. ‘Flow’ is a term used in positive psychology which means, in informal parlance, ‘being in the zone‘ and involves being fully immersed in, and absorbed by, the activity one is performing. The state is both pleasurable and energizing.

Exercise Reduces Muscle Tension:

Tense muscles are one of the symptoms of anxiety and exercise reduces such tension. 

High-Level Exercise Activity Versus Low-Level Exercise.

A study conducted by Schuch et al.(2019) found that high-level exercise was more effective at reducing anxiety than low-level exercise and that such exercise can help reduce anxiety symptoms in those suffering from agoraphobia and complex- PTSD.



David Hosier BSc Hons; MSc; PGDE(FAHE) is reader-supported. When you buy through links on this site, I may earn an affiliate commission.