The Effects of Exercise on Mental Health in the Winter Season

Regular exercise and physical activity have long been known to offer significant benefits to overall health and well-being.¹ As ongoing research continues to deepen our understanding, new findings consistently reveal additional advantages of exercise, highlighting its crucial role in promoting health. Exercise is associated with a multitude of health benefits, including a reduced risk of cardiovascular disease, enhanced immune function, improved sleep quality, increased mental clarity, and the prevention of bone loss—all of which contribute to a higher quality of life.^2–4

• Resistance training, for example, has been shown to increase bone mineral density and mitigate age-related bone loss.⁴
• Similarly, cardiovascular exercise can lower resting heart rate and enhance circulation, supporting cardiovascular health.³

Beyond physical health, exercise has been demonstrated to support cognitive function and may offer protective benefits against neurodegenerative diseases, while also contributing to improved mood and emotional regulation.¹ Recent literature has expanded the focus to explore the relationship between exercise and neurological health, particularly its effects on mental well-being.⁵ Specifically, emerging research indicates that exercise can play a critical role in managing and potentially treating various mental health disorders.⁵ While further studies are needed to fully understand the scope of these benefits, both aerobic and resistance exercises have shown promise in alleviating conditions such as depression—including seasonal depression—anxiety, and post-traumatic stress disorder.⁵

In a world where mental health challenges are increasingly common, exercise may offer a valuable, accessible strategy for mitigating the negative impacts of these conditions. The potential of exercise as part of a comprehensive treatment approach emphasizes its importance not just for physical fitness, but for holistic health and mental well-being.

In recent epidemiological studies, lower levels of physical activity have been linked to a higher risk of poor mental health.⁵ A large-scale study involving U.S. adults revealed that individuals who exercised regularly reported better mental health and overall functioning across various demographics.⁶ Furthermore, forming consistent habits of physical activity has been shown to protect against the development of mental health conditions, reducing the likelihood of depression and anxiety symptoms.⁶ Among different types of physical activity, aerobic exercise has the most substantial research support, demonstrating moderate to large improvements in symptoms of depression and anxiety.⁵Whether as an adjunct therapy or a standalone intervention, maintaining an exercise routine can play a vital role in enhancing mental well-being.

While the link between physical fitness and mental health is not yet definitive, numerous studies have presented promising hypotheses.^1,5 Recent research points to three primary explanatory mechanisms underlying the relationship between exercise and improved cognitive health.⁵

• First, physical activity yields direct physical benefits that contribute to better mental health.
• Second, exercise influences neurobiological mechanisms that regulate emotions and mood.
• Lastly, the active nature of exercise fosters behavioral changes due to the self-efficacy it promotes.⁵

The interplay between neurobiological mechanisms and the neural reward system, which bolsters self-efficacy, is believed to explain why physical activity supports mental health improvements.^5,7

Neuroplasticity has emerged as a critical concept linking exercise to mental health benefits.^5,7 Neuroplasticity refers to the brain's capacity for neurobiological remodeling, which is essential for learning and adaptation.⁵ This ability is often impaired in individuals with mental health conditions and tends to decline with age.⁵ The brain’s potential for adaptive learning is what allows behavioral interventions, such as exercise, to positively impact mental health.^5,7

Increasing neuroplasticity is also a proposed mechanism behind several psychiatric treatments, making exercise one of the few behavioral activities capable of boosting this vital capacity.⁷ On a structural level, neuroplasticity involves the growth of new neurons, known as neurogenesis, and the formation of new neural connections that enhance reward sensitivity.⁷ These processes are particularly significant because they occur in brain regions critical for dopamine function and learning.⁷ Studies examining these neural changes have shown that exercise can improve self-esteem, elevate mood, and reduce stress, contributing to better physical and mental health outcomes.¹

Anecdotally, individuals who maintain regular exercise routines report an overall better state of mind and mental well-being.¹ Researchers have linked physical activity to increased production of neurotransmitters such as dopamine, serotonin, norepinephrine, insulin-like growth factor 1 (IGF-1), and endorphins.¹ Dopamine, often called the “happy hormone,” plays a crucial role in the brain’s reward system and fosters a sense of achievement post-exercise.⁸Serotonin contributes to mood regulation and sleep quality, while endorphins support mood enhancement, sleep, and pain response.¹ IGF-1, which is boosted by exercise, has been associated with neuroplasticity and can aid neurogenesis.⁵  Collectively, these neurotransmitters enhance both mental and physical well-being, with exercise acting as a catalyst for their production and release.^5,8 

One hypothesis for the beneficial impact of exercise on stress management, mindset, and emotional regulation involves the improved functioning of the hypothalamus-pituitary-adrenal (HPA) axis¹. The HPA axis is a neuroendocrine system responsible for regulating the body’s stress response, the autonomic nervous system, mood, emotions, metabolism, and cortisol release.⁵ Enhanced HPA axis function is considered a key reason for the positive association between regular physical activity and improved mental health.⁵ This is partly because better HPA axis activity helps modulate the body’s stress response, leading to enhanced emotional regulation and resilience.⁵ Overall, exercise serves as a powerful tool for promoting mental well-being through its diverse effects on brain chemistry and stress-regulation mechanisms.¹

Another widely studied mechanism connecting exercise and mental health is mood enhancement. Exercise is believed to have both immediate effects on mood and long-term benefits for emotional regulation.⁵ Emotional regulation refers to the ability to accept emotions, maintain awareness and clarity about them, and manage responses to them.^9,10 Difficulty with emotional regulation is often associated with mental health disorders, while improvements in this skill correspond with better mental health outcomes.¹⁰ Exercise may boost an individual's capacity to handle higher arousal levels and foster improved emotional regulation.¹⁰

Self-regulatory patterns also play an essential role in promoting self-efficacy, or the confidence in one’s ability to achieve specific goals.¹¹ Increased participation in physical activity has been shown to enhance both confidence and self-efficacy.¹¹ Additional mechanisms linking exercise to mental health involve behavioral processes, including the development of self-regulatory skills. These skills encompass the ability to tolerate and modulate arousal, maintain cognitive control over behavior, sustain attention, and regulate responses to environmental changes.⁹ Improved fitness levels and the reward response associated with completing exercise sessions can help enhance the brain’s reward system, potentially reversing the dysfunctional reward sensitivity seen in depression.⁹

Other suggested mechanisms linking exercise interventions to mental health are specific behavioral mechanisms, including self-regulatory skills, particularly learning to tolerate and modulate arousal, cognitive control over behavior, sustaining attention, and regulating behavioral responses to changes in environment.⁹ Improved fitness and the reward response from completing bouts of exercise help to potentiate the reward response in the brain and can help reverse dysfunctional reward sensitivity that is associated with depression.⁹ 

Seasonal affective disorder (SAD) is a type of recurrent depression that typically occurs during the colder months of autumn and winter. Its severity can range from mild 'winter blues' to significant depression.¹² Although most prevalent in colder regions with limited sunlight and greater distance from the equator, SAD is widespread across the United States.¹² Approximately 5% of the American population reports experiencing SAD each year, affecting around 170 million people.¹² Current theories on the causes of SAD focus on hormonal responses linked to changes in circadian rhythms due to reduced daylight exposure.¹³ Individuals with SAD often struggle to regulate serotonin, a neurotransmitter essential for mood balance.¹³ As daylight diminishes in autumn, serotonin levels drop, contributing to depressive symptoms.¹⁴

Additionally, melatonin production increases, which can further disrupt the circadian rhythm and lead to lethargy.¹³ While not the sole cause, fluctuations in serotonin, melatonin, and vitamin D levels significantly impact SAD.¹⁴ Gender and age are notable factors in SAD prevalence, with four out of five sufferers being women and higher rates observed in younger populations.¹²

Biological, environmental, and sociocultural factors all influence who is affected by seasonal depression.¹⁴ Another significant contributing factor to SAD is social withdrawal and feelings of isolation.¹⁴ Exercise, particularly in a community setting, can help counteract these feelings by promoting connection and supporting consistent activity, which enhances mood and emotional well-being.^14,15

Furthermore, physical activity is commonly recommended for treating depressive disorders and has been shown to be effective in addressing SAD.¹⁴ A previously mentioned, exercise greatly impacts the brain’s release of neurotransmitters like dopamine, serotonin, and endorphins.¹ Exercise positively impacts disrupted circadian rhythms and provides mood-boosting benefits through the increase in these important brain chemicals.¹ In addition to treatments like vitamin D supplements, bright light therapy, and antidepressant medications, physical activity is increasingly recommended for managing SAD.¹⁶ The combination of exercise with bright light therapy has proven particularly effective for improving mood and energy levels.¹⁶

While finding natural sunlight during overcast winter days can be difficult, the benefits of exercise are available regardless of weather conditions. Incorporating regular physical activity can help combat the winter blues, enhance mood, and sustain energy, making it a valuable part of a comprehensive treatment plan for SAD.

In summary, physical activity has profound and multi-faceted effects on mental health, supported by mechanisms that range from neurobiological changes to improvements in self-regulatory behaviors. While further research is needed to establish definitive links, the existing evidence underscores the value of exercise as a key strategy for improving mental well-being.^1,5,7 The combination of physical, neurobiological, and behavioral benefits illustrates why incorporating exercise into daily life is essential for promoting long-term mental health.

Suggested Exercise Routines

1. At least 20 minutes of light to moderate aerobic exercise¹⁷
   1. Low impact aerobic exercise is recommended for SAD¹⁴

1. Yoga
2. Biking
3. Swimming
4. Tai Chi

1. 2-3x resistance training sessions a week¹⁸
   1. 30-70% 1 rep maximum is the recommended intensity¹⁸

1. 55-65% has shown promising improvements in mental health¹⁸

1. 2-3 sets of 10-12 repetitions
1. Large muscle group exercises are suggested
   1. Squat variations
   2. Lunge variations
   3. Overhead presses
   4. Chest presses
   5. Row variations

References

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2. Xiong T, Bai X, Wei X, et al. Exercise rehabilitation and chronic respiratory diseases: effects, mechanisms, and therapeutic benefits. Int J Chron Obstruct Pulmon Dis. 2023;18:1251-1266. doi:10.2147/COPD.S408325
3. Nystoriak MA, Bhatnagar A. Cardiovascular effects and benefits of exercise. Front Cardiovasc Med. 2018;5:135. doi:10.3389/fcvm.2018.00135
4. Russo CR. The effects of exercise on bone. Basic concepts and implications for the prevention of fractures. Clin Cases Miner Bone Metab Off J Ital Soc Osteoporos Miner Metab Skelet Dis. 2009;6(3):223-228.
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8. Pilozzi A, Carro C, Huang X. Roles of β-endorphin in stress, behavior, neuroinflammation, and brain energy metabolism. Int J Mol Sci. 2020;22(1):338. doi:10.3390/ijms22010338
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11. Olson EA, McAuley E. Impact of a brief intervention on self-regulation, self-efficacy and physical activity in older adults with type 2 diabetes. J Behav Med. 2015;38(6):886-898. doi:10.1007/s10865-015-9660-3
12. Drew EM, Hanson BL, Huo K. Seasonal affective disorder and engagement in physical activities among adults in Alaska. Int J Circumpolar Health. 2021;80(1):1906058. doi:10.1080/22423982.2021.1906058
13. Melrose S. Seasonal affective disorder: an overview of assessment and treatment approaches. Depress Res Treat. 2015;2015:1-6. doi:10.1155/2015/178564
14. Peiser B. Seasonal affective disorder and exercise treatment: a review. Biol Rhythm Res. 2009;40(1):85-97. doi:10.1080/09291010802067171
15. Fujii Y, Seol J, Joho K, et al. Associations between exercising in a group and physical and cognitive functions in community-dwelling older adults: a cross-sectional study using data from the Kasama Study. J Phys Ther Sci. 2021;33(1):15-21. doi:10.1589/jpts.33.15
16. Meesters Y, Gordijn MCM. Seasonal affective disorder, winter type: current insights and treatment options. Psychol Res Behav Manag. 2016;Volume 9:317-327. doi:10.2147/PRBM.S114906
17. Maroulakis E, Zervas Y. Effects of aerobic exercise on mood of adult women. Percept Mot Skills. 1993;76(3):795-801. doi:10.2466/pms.1993.76.3.795
18. Strickland JC, Smith MA. The anxiolytic effects of resistance exercise. Front Psychol. 2014;5:753. doi:10.3389/fpsyg.2014.00753