The Role of Exercise on Mental Health: How to Alleviate Symptoms of Anxiety

In stress management, the Hypothalamic-Pituitary-Adrenal (HPA) axis is a vital communication network among three key endocrine organs. This system forms a hormone feedback loop that controls your body's stress responses by releasing hormones into the bloodstream when the nervous system is activated. The HPA axis comprises the hypothalamus, pituitary gland, and adrenal glands. The hypothalamus in the ventral brain regulates vital functions such as body temperature, hunger, thirst, mood, sex drive, blood pressure, and sleep. Situated beneath the hypothalamus, the pituitary gland oversees the production and release of numerous hormones essential for bodily functions like growth, metabolism, and reproduction. The adrenal glands, positioned above both kidneys, produce steroid hormones, adrenaline, and noradrenaline. The primary role of the HPA axis is to release cortisol, initiating rapid body adjustments to cope with stress.

The influence of exercise on the HPA axis is profound. Increased physical activity enhances HPA axis function, lowering cortisol levels and restoring the equilibrium of leptin and ghrelin, hormones that control hunger and energy usage. This makes exercise a crucial part of managing symptoms of depression and anxiety, as this leads to improved attention, cognition, decision-making, heightened pleasure, and reduced pain sensitivity. During increased physical activity, the pituitary gland produces specific endorphins like opiates and endocannabinoids. These opioid systems may mediate analgesia or reduce pain sensitivity and depression due to the link between beta-endorphins and depressive and anxiety symptoms. For example, individuals who engage in regular aerobic exercise (the recommended amount being 45-60 minutes a day, 3-5 times a week) may experience a decrease in feelings of sadness and worry, as well as an increase in pleasure, alertness, and overall well-being due to the release of these endorphins. Additionally, the pain-relieving effects of exercise can help alleviate physical symptoms associated with depression and anxiety, further improving mental health. This is because often people who have depression tend to have a smaller than usual hippocampus in the brain. The hippocampus is a small yet intricate part of the brain that helps to regulate mood and emotional processing as well as short- and long-term memory. Exercise, however, has been proven to support nerve cell growth and increase levels of BDNF (Brain-Derived Neurotrophic Factor) in the hippocampus, improving nerve cell connections and helping to relieve depression.

Ultimately, incorporating exercise into your routine can be a valuable tool in managing symptoms of depression and anxiety as well as simply improving overall mental health and your brain’s executive functions. While sometimes it is difficult to prioritize exercise, especially with a busy school schedule, simply engaging in 45-60 minutes of low-impact exercise such as walking, jogging, or yoga can have a major effect on your mental health. 

Glossary

Steroid Hormones - Steroid Hormones are hormones that play an essential role in growth, development, energy metabolism, homeostasis, and reproduction according to PubMed Central

Noradrenaline - A neurotransmitter and hormone that plays a role in our "flight or fight" response. It is used as a medication to increase and maintain blood pressure according to Cleveland Clinic

Cortisol - A steroid hormone that is produced by our adrenal glands. It helps regulate our body's response to stress according to the Cleveland Clinic

Leptin and ghrelin - Work to regulate our hunger levels according to Cleveland Clinic

Opioids - A class of drugs that work in a similar manner to endorphins, with effects such as pain relief according to the NIDA

Endocannabinoids - Work with the endocannabinoid system that affects different biological functions including eating, anxiety, learning and memory, reproduction, metabolism, and growth development according to the NIH

Analgesia - The inability to feel pain

Brain-Derived Neurotrophic Factor (BNDF) - Plays an important role in neuronal survival and growth, serves as a neurotransmitter modulator, and plays an important role in learning and memory according to the NIH