Exercise for Anxiety

Neurotransmitters: the signal carriers

The essence of the link between exercise and anxiety lies in neurotransmitters. Picture them as couriers — some carry good news, some bad — and how you feel depends on them. These chemical messengers play a major role in regulating mood, emotions and the stress response. When it comes to anxiety, two matter most: serotonin and GABA.

Serotonin

Often called the “feel-good” neurotransmitter, serotonin plays a central role in mood. Low serotonin is linked to higher anxiety and depressive symptoms. Exercise has been shown to drive serotonin release in the brain. When we exercise, the body produces tryptophan — serotonin’s precursor. As exercise intensity rises, so does tryptophan availability, and ultimately serotonin levels. This rise lifts mood and reduces anxiety symptoms.

GABA

GABA is the inhibitory neurotransmitter that acts as the brain’s natural calmer. Low GABA is linked to higher anxiety, stress and panic attacks. Exercise has been shown to increase GABA production and receptor sensitivity in the brain. This inhibitory effect counteracts the over-excitation of neural circuits, fostering calm and relaxation.

The stress response: HPA-axis balance

Another key player is the hypothalamic-pituitary-adrenal (HPA) axis — the complex system that regulates the body’s stress response. Chronic stress and a dysregulated HPA axis are closely tied to anxiety disorders. Exercise helps regulate and restore the balance of this system.

Cortisol

Under stress, the adrenal glands release cortisol — the stress hormone. Prolonged high cortisol can feed anxiety symptoms. Although intense activity temporarily raises cortisol, regular exercise teaches the body to regulate and lower its release more efficiently. This adaptive response builds a more resilient stress-response system.

Endorphins

Exercise releases endorphins — the body’s natural painkillers and mood-lifters. These neurochemicals bring a sense of well-being and are the body’s own stress relievers. With regular training, the body gets better at releasing endorphins — a powerful safeguard against anxiety and stress.

Neuroplasticity: reprogramming the brain

Neuroplasticity — the brain’s remarkable ability to reorganise and adapt — plays an important role in managing anxiety. Anxiety is often linked to maladaptive neural connections. Intense exercise has been shown to increase neuroplasticity, driving positive changes in brain structure and function.

The hippocampus

The hippocampus — the brain region tied to memory and emotional regulation — is markedly affected by anxiety. Chronic anxiety can cause hippocampal atrophy, reducing its ability to regulate emotions effectively. Exercise, especially aerobic, is linked to increased hippocampal volume. This neuroplastic change improves emotional resilience and cognitive function.

The prefrontal cortex

The prefrontal cortex, responsible for decision-making and impulse control, is crucial for managing anxiety. Exercise strengthens the connections and efficiency of the prefrontal cortex, so people can better control their emotional reactions and avoid runaway anxiety.

Sleep quality: breaking the anxiety-insomnia cycle

Anxiety and sleep disturbance often go hand in hand, forming a vicious circle. Exercise plays an important role, improving sleep quality and helping break the cycle.

Circadian rhythms

Exercise helps regulate circadian rhythms — the body’s internal clock that governs sleep-wake cycles. Regular activity promotes a more synchronised circadian rhythm, improving the body’s ability to fall asleep and wake at the desired times.

Sleep architecture

People who exercise regularly get more restorative deep sleep (slow-wave sleep) and less REM sleep. These shifts in sleep architecture improve overall sleep quality and reduce anxiety symptoms.

How much exercise to overcome anxiety — and how not to overdo it

The evidence that exercise reduces anxiety is clear, but how much you do matters. For a non-professional, overdoing it is hard — you can only overstrain early on, before the body has adapted. The key is to start slow and build the load gradually. Too much too early is the most common beginner mistake.

The neurotransmitter benefits built up during intense exercise last about 36 hours, so to stay in the “feel-good” cycle you need to exercise daily, at least an hour. The evidence puts the upper limit at roughly 4 hours a day.

You also should not do the same exercise the next day. If you ran 10 km yesterday, do not run today — swim, or work your arms or back. Do not forget the sauna and cold therapy; they mimic the effects of a workout. Mix your sports: padel, swimming, dancing, cycling, stretching.

Frequently Asked Questions