By now most of us have been sold on the health benefits of exercise, including its anxiety-reducing effect. For the ‘worried well’, it’s a ‘no-brainer’. This article, however, is primarily for the ‘worried-unwell’, and for those struggling to swallow the pill.
Exercise and anxiety: the neurobiological factors
Re-regulation of arousal state
Broadly speaking, regular exercise results in physiological changes and adaptations in the human body that widen our ‘window of tolerance’. Hence, exercise is widely prescribed for both promotion of stress resilience and treatment of disorders associated with chronic arousal state dysregulation including anxiety, depression, post traumatic stress disorder, chronic pain, and substance/behaviour use disorders.
Indeed, the literature is replete with studies finding that regular exercise (including ‘anaerobic’- strength training, stretching, yoga etc) is associated with lower sympathetic nervous system and hypothalamic-pituitary-adrenal (HPA) axis (stress response) reactivity.
Additionally, significant increases in cardiac output raises levels of atrial natriuretic peptide, which in turn inhibits hyper-arousal.
Exercise also activates the frontal regions of the brain responsible for executive function, thus keeping in check the amygdala, our ‘smoke detector’ for real or imagined threats to survival.
Neurotransmitter effects- the monoamine system
A major component of the sensory-emotional brain centres determining arousal state are chemical messengers including serotonin, noradrenaline, dopamine and GABA.
An overwhelming body of evidence suggests exercise achieves neurotransmitter changes comparable to and synergistic with many medication-based anxiety treatment approaches.
Epigenetic effects
The ‘switching on and off’ of our genes (read more about gene expression and epigenetics here) has an overarching effect on our ability to adapt to adverse life events.
Evidence suggests that exercise-induced increases in a molecule called brain-derived neurotrophic factor (BDNF), which increases neuro-plasticity (helping the brain selectively grow and cull neurons), occurs at the epigenetic level. As an interesting aside, decreased BDNF levels in the hippocampus (memory, learning, emotions) are found in sufferers of trauma and chronic stress, reiterating the model of exercise-EMDR synergy discussed above and in other articles.
Similar links to exercise are emerging regarding increases in other messenger-RNA compounds (involved in gene expression), including galanin, which modulates the activity of a major brain centre involved in our physiological responses to stress and panic (the locus coeruleus).
….Stay tuned for frontier neurobiological exercise research findings regarding other neurotropics: vascular endothelial growth factor,and insulin-like growth factor…
Opioid System
Another possible mechanism for the anxiety-reducing effects of exercise is via mediation by the endogenous opioid system. Endogenous opioids have a role in the regulation of mood and emotional responses. The endorphin hypothesis posits that the mood elevations and reduced anxiety following acute exercise is due to the release and binding of β-endorphins to their receptor sites in the brain. Studies demonstrate that exercise increases endogenous opioid activity in the central and peripheral nervous system and may induce a euphoric state and reduce pain.
Anti-Inflammatory Effects
Moderate exercise has anti-inflammatory effects, regulating the immune system and excessive inflammation. This is important, given the new insight neuroscience is gaining into the potential role of inflammation in anxiety and depression.
Metabolic effects
As we start using our muscles, the body metabolises a proportion of fat molecules in the blood stream to fuel them. These free fatty acids compete with tryptophan to catch a ride on our transport proteins, elevating its concentration in the blood stream. To equalise its levels, tryptophan pushes through the blood brain barrier, and is used as a building block for “feel good” serotonin.
Strengthened circadian rhythm
With exposure to natural light a major determinant of maintaining a healthy circadian rhythm, many researchers assert that outdoor physical activity can be as effective as prescription sleep medications. Proposed subsequent benefits include a stronger immune system, lowered risk of diabetes and heart disease, lower blood pressure, improved mood, better decision-making and increased attention and focus.
Exercise and anxiety: the psychological factors
Self-efficacy, positive re-inforcement, emotional resilience.
According to social cognitive theory, one’s sense of self-efficacy (ability to exert control over potential threats) has an important relationship to anxiety arousal. Individuals who trust their ability to manage potential threats (high self-efficacy) are not plagued by thoughts of worry and experience lower levels of anxiety arousal.
It has been proposed that exercise can increase self-efficacy by supplying experiences (later encoded and consolidated as memories- more of that later!) of successfully accomplishing (realistic) goals and coping with the stress of exercising.
Distraction
The proposition that the anxiolytic benefits of exercise result largely from it being a distraction from stressors and a “time out” from daily activities has been widely debated. As one researcher puts it:
The results of meta-analyses supporting this hypothesis are mixed. Exercise and cognitively based distraction techniques were shown to have equal effectiveness at reducing state anxiety, however exercise was more effective in reducing trait anxiety. In addition, the anxiolytic effects of exercise have been shown to last for a longer period of time than those produced by therapies based on distraction techniques.
‘Grounding’/mindfulness
Every time we move a muscle, sensory receptors send a variety of information to our brains depending on the receptor type. Doing this intentionally through exercise helps our minds become more aware of our body’s position in space, enhancing our interoception (physical-emotional self-awareness).
Consonant with many evidence-based psychotherapies, as we develop this body awareness, our perception of ourselves changes as we start identifying with the movements of our chosen exercise. This can be beneficial in installing positive neural networks. For example, long-distance runners might perceive themselves as possessing grit and resilience, with these traits ‘remembered’ upon facing other types of challenging tasks or stressors.
Social connectivity
For those not liable to exacerbation of anxiety symptoms (see below) in particular social environments, exercising with others boosts mental health through the release of dopamine, which helps with stress, anxiety, and depression.
Again, a trigger for some, social accountability can improve motivation to complete exercise in many individuals.
Am I there yet?
Many sources quote figures for the average time of onset and duration of the anxiety-reducing effect of a bout of exercise, adding multiple qualifications and disclaimers: ‘immediate’ and ‘2 hours’ are the most commonly extolled.
Understanding the FITT principle of exercise (Frequency, Intensity, Type and Time), where the last term has the double-meaning of ‘duration’ and ‘time of day’, can help guide you toward discovering the most suitable form of anxiety-reducing exercise for you.
Additionally, snippets from RCT (Randomised Controlled Clinical Trials- the gold standard for ascertaining the efficacy and safety of a treatment) findings reviewed for this article include:
- Long-term resistance training programs lasting 10-12 weeks either at high or low intensity showed decreased tension and anxiety symptoms compared to those that did not exercise.
- Among adults, a 20-minute class combining tai chi movements and yoga postures showed large reductions in anxiety levels immediately after the class was completed.
- Exercise frequency of three to four times per week elicited the largest reductions in anxiety levels.
- Exercise sessions lasting 21–30 minutes potentially provided the most anxiety reductions compared to short or longer durations.
- Adults that participated in a 12-week yoga program (three 60 minutes sessions per week) compared with adults in a walking program demonstrated larger reductions in anxiety and reported feeling more tranquil and revitalised.
- Moderate to high intensity exercise routines influenced the greatest reduction in anxiety symptoms when compared to low intensity.
- Providing positive feedback during exercise produces a significantly larger reduction in anxiety than no or negative feedback.
- A 45 minute martial arts class achieved a much larger decreases in anxiety levels and a larger reported increase in mood and outlook than a 45 minute stationary bike session.
‘My exercise is not working!’
Here follows a summary of the (non-evidence-based) ‘collective wisdom’ that inevitably follows this utterance:
- You have unrealistic expectations and/or are relying too much on exercise as a stand-alone anxiety management strategy.
- You are prone to avoiding exercise as you have had bad experiences or it triggers further anxiety; you need to address this issue.
- You have not been flexible enough and/or experimented according to FITT principles.
- You may have chosen an inappropriate exercise environment.
A ‘cure worse than the disease’ for some?
Like anxiolytic (anxiety-reducing) medications, exercise prescriptions involve informed, branched decision-making beginning with questions around the type of anxiety being targeted and progressing through further decisions around exercise type, timing (duration, frequency, time of day), mode (solitary, collaborative, competitive, measured, supervised, supported, restricted), and environment.
State anxiety vs trait anxiety is a useful model for differentiating between brief experiences of “adaptive” short term distress provoked by an adverse or threatening event (state) and a stable long-term “maladaptive” tendency (trait) across a lifespan of responding with acute state anxiety in the anticipation of threatening situations (whether they are actually deemed threatening or not).
Not only does the process appear provocative, the efficacy of exercise prescriptions for sufferers of ‘trait’ anxiety has also rung alarm bells for some researchers:
the evidence for the anxiolytic effects of exercise in people with a diagnosis anxiety/stress disorders is equivocal and has considerable limitations.
(Stubbs, 2017)
the current research evidence for exercise in patients with anxiety and stress-related disorders is mainly based on data from participants who completed the intervention This may skew results, favouring individuals who fully engage with exercise, while ignoring those who have been unable or unwilling to take part in the intervention
(Frederiksen, K.P., et al., 2021)
Exercising caution
Anxiety sensitivity is defined as the tendency to misinterpret and catastrophise anxiety-related sensations based on the belief that they will result in disastrous physical, psychological, and/or social outcomes.
Highly anxiety-sensitive people tend to avoid the physiological sensations of exercise due to this pattern of thinking.
Cognitive behaviour therapy (CBT) and exposure therapy (including EMDR) are evidence-based approaches to addressing this issue at the root cause level.
As an interesting side-note, a degree of convergence of exercise and EMDR in memory processing models has been alluded to by some researchers:
Generally, when the acute bout of exercise occurs shortly before memory encoding or during memory consolidation, episodic memory is enhanced, whereas when it occurs during memory encoding, episodic memory is impaired. However, as detailed elsewhere, the intensity of exercise and the memory type may moderate these effects.
(Loprinzi, 2019)
Sport and exercise psychologists
Notwithstanding the fact that the majority of RCTs to date have not examined the anxiolytic effects of exercise in combination with evidence-based psychotherapy, clear intent to move in this direction justifies increasing awareness of the unique suitability (based on knowledge, training and experience) of sport and exercise psychologists (SEPs) in optimising the delivery of exercise-integrated psychotherapies.
..the relationship between SEP and other disciplines of psychology has been intense and beneficial in a reciprocal way.
(Lindahl, J., Stenling, A., et al., 2015)
A further insight into this branch of psychology may be garnered from a research review finding:
..motivation, coping with anxiety and stress, physical activity behaviour change, and methodological issues were identified as the most recurrent topics in SEP.
(Latinjak, A.T., Hatzigeorgiadis, A., 2021)
If you think you might benefit from talking with a sport and exercise psychologist, please feel free to contact us for further information.
References & Resources
Health Anxiety – Fear Of Exercise! Are You Scared To Workout?
https://www.youtube.com/watch?v=kIj95divxqc
Mindful running App
https://www.nike.com/au/nrc-app
Vancampfort, D. et al. (2021). Dropout from exercise randomized controlled trials among people with anxiety and stress-related disorders: A meta-analysis and meta-regression. Journal of Affective Disorders Volume 282, 1 March 2021, Pages 996-1004.
Stubbs, B., et al. (2017). An examination of the anxiolytic effects of exercise for people with anxiety and stress-related disorders: A meta-analysis. Psychiatry Research Volume 249, March 2017, Pages 102-108.
Henriksson, M. (2022). Effects of exercise on symptoms of anxiety in primary care patients: A randomized controlled trial. Journal of Affective Disorders 297 (2022) 26–34.
Frederiksen, K.P., et al. (2021). Physical exercise as an add-on treatment to cognitive behavioural therapy for anxiety: a systematic review. Behavioural and Cognitive Psychotherapy, 49(5), 626-640.
Thomas, J., et al. (2020). Effects of combining physical activity with psychotherapy on mental health and well-being: A systematic review. Journal of Affective Disorders, Volume 265, 2020, Pages 475-485.
Javanbakht, A. (2021) How exercise changes your brain biology and protects your mental health. HEALTH — FEBRUARY 26, 2021. https://bigthink.com/health/neurobiology-of-exercise/
Ha, A., et al. (2023). Depression and PTSD as Predictors of Attrition in Older Adult Exercise ProgramsA Systematic Review. Topics in Geriatric Rehabilitation 39(1):p 31-38, January/March 2023.
Loprinzi, P.D. (2019). The Effects of Exercise on Long-Term Potentiation: A Candidate Mechanism of the Exercise-Memory Relationship. OBM Neurobiology 2019; 3(2).
Anderson, E., Shivakumar, G. (2013). Effects of exercise and physical activity on anxiety. Frontiers in Psychiatry. April 2013,Volume 4, Article 27.
Jayakody, K., et al. (2016). Exercise for anxiety disorders: systematic review. Br J Sports Med 2014;48:187–196
Latinjak, A.T., Hatzigeorgiadis, A. (2021) The Knowledge Map of Sport and Exercise Psychology: An Integrative Perspective. Front. Psychol., 16 June 2021.
Lindahl, J., Stenling, A., et al. (2015). Trends and knowledge base in sport and exercise psychology research: a bibliometric review study. Int. Rev. Sport Exerc. Psychol. 8, 71–94.