- Exercise is critical for physical, mental, and brain health.
- Exercise-induced changes in synaptic plasticity and brain volume are associated with improvements in brain health.
- Regular physical activity appears as effective as psychotherapy for the treatment of mild-to-moderate depressive symptoms.
- Adults should be active most days, preferably every day: each week, this should include between 2.5 to 5 hours of moderate intensity; 1.25 to 2.5 hours of vigorous intensity physical activity; and muscle-strengthening activities as part of your daily physical activity on at least 2 days each week.
Today, I want to discuss the effects of exercise on brain health and mental health! In our current COVID times and the corresponding lockdowns (at least here in Australia), developing an exercise routine has been rather difficult. All gyms are closed, national parks closed, and very few people have the room or finances for a home gym. You may be feeling sluggish, and even may be noticing some poor mental health outcomes. Today, I will be discussing the effects of exercise on brain health, and I will provide you with some recommendations on the requirements for exercise each week (they may surprise you!).
Not only does exercise reduce the risk of type 2 diabetes and some cancers, it helps in maintaining strong muscles and bones, and it also creates opportunities for socialising and meeting new people – there is an increasing amount of evidence supporting the relationship between regular exercise and cognitive brain health and also mental health (Truyol, n.d.). These benefits of exercise stem from improved function of the central nervous system, as well as the promotion of resistance against neurological disorders (Truyol, n.d.). I will be focusing on three of these central nervous system functions. First, I will talk about the role that exercise has on synaptic plasticity. Second, the effect of exercise on brain volume. And lastly, how exercise impacts trophic factors, and how trophic factors influence brain health.
Synaptic neuroplasticity is defined as long-lasting changes in efficacy of synaptic connections (i.e., long-term potentiation (LTP) or long-term depression (LTD)). You may remember in one of my previous posts that I discuss the role of LTP in human memory (click here to check it out!). Summarising some key information from that post, it is argued that learning and memory are mediated by changes in the strength of synapses in neural circuits (Sigurdsson et al., 2007). According to this hypothesis, neural activity during learning gives rise to long-term changes in synaptic strength, which is both necessary and sufficient for memories to be stored and later retrieved (Lynch, 2004).
Because it is difficult to measure LTP in the living human, many studies use rodent models to determine the effects of exercise on LTP. In experimental studies with young rodent models, regular exercise is observed to enhanced the LTP of synaptic activity in hippocampal cells (Cabral et al., 2019). Other studies have utilised a 12-week exercise intervention (Kumar et al., 2012) and an 8-month exercise intervention (O’Callaghan et al., 2009) and found increased LTP and improved performance in discrimination tasks, spatial learning, and object recognition memory. This means that your memory and learning performance may increase after regular exercise!
Researchers use measures of brain volume as an indicator of brain health. A relationship exists between brain size i.e. volume, and cognition in humans (de Sousa & Proulx, 2014). For example, while studies on brain volumes and IQ tend to overestimate the relationship between the two concepts, there is some truth to the premise (Pietschnig et al., 2015). This may remind you of the blog post @jovanaacevska wrote on brain volume (if you have not read that article yet, I recommend that you check that article out by clicking here!). The aging brain undergoes selective atrophy, mainly in the prefrontal cortices and medial temporal lobes (Cabral et al., 2019). Decreased age-related atrophy has historically been implicated in explaining exercise-mediated improvements in cognitive performance for the older adult population (Cabral et al., 2019). Exercise interventions spanning from 12 weeks (Matura et al., 2017), all the way up to 6 months (Kleemeyer et al., 2016) have shown increases in whole-brain grey matter volume and increased neuron density when compared to control conditions. In addition, a low- to moderate-intensity aerobic exercise has been associated with increased regional brain volume in both gray and white matter areas relevant to the processing of attentional control and memory processes (Cabral et al., 2019). This provides evidence for the overall effect of exercise on maintaining a healthy brain volume, which is associated with greater cognition.
Physical activity may play an important role in the management of an array of mental health diseases, especially depression and anxiety. Although people with depression tend to be less physically active than non-depressed individuals, increased aerobic exercise has been shown to reduce depressive symptoms significantly (Pauluska & Schwenk, 2000). Similarly, those who suffer from anxiety symptoms and panic disorder may show some improvement with their symptoms after a regular exercise program. Pauluska & Shwenk (2000) have shown that regular physical activity appears as effective as psychotherapy for the treatment of mild-to-moderate depressive symptoms; state anxiety improves with acute exercise; and individuals diagnosed with clinical depression with more severe symptoms or the need for psychological care manifest the greatest improvement in mood following increased physical activity. Beneficial effects have also been reported for short- and long-term aerobic exercise, anaerobic exercise, and metabolically less-demanding activities (e.g., yoga, relaxation, somatic awareness training), on subjective stress perception and overall stress levels (Herbert et al., 2020). Exercise has a significant role on mental health, not only cognitive health.
Recommendations for Exercise
Adults should be active most days, preferably every day. Each week, adults should do either:
- 2.5 to 5 hours of moderate intensity physical activity – such as a brisk walk, golf, mowing the lawn or swimming
- 1.25 to 2.5 hours of vigorous intensity physical activity – such as jogging, aerobics, fast cycling, soccer or netball
- an equivalent combination of moderate and vigorous activities.
Include muscle-strengthening activities as part of your daily physical activity on at least 2 days each week. This can be:
- squats or lunges
- lifting weights
- household tasks that involve lifting, carrying or digging.
Doing any physical activity is better than doing none. If you do no physical activity right now, start by doing some, then slowly build up to the recommended amount.
If you are interested in learning more, watch the following videos on the benefits of exercise on the brain!
Latest From Instagram
Cabral, D. F., Rice, J., Morris, T. P., Rundek, T., Pascual-Leone, A., & Gomes-Osman, J. (2019). Exercise for brain health: an investigation into the underlying mechanisms guided by dose. Neurotherapeutics, 16(3), 580-599.
de Sousa, A., & Proulx, M. (2014). What can volumes reveal about human brain evolution? A framework for bridging behavioral, histometric, and volumetric perspectives. Frontiers In Neuroanatomy, 8.
Herbert, C., Meixner, F., Wiebking, C., & Gilg, V. (2020). Regular physical activity, short-term exercise, mental health, and well-being among university students: the results of an online and a laboratory study. Frontiers in psychology, 11, 509.
Kleemeyer, M. M., Kühn, S., Prindle, J., Bodammer, N. C., Brechtel, L., Garthe, A., … & Lindenberger, U. (2016). Changes in fitness are associated with changes in hippocampal microstructure and hippocampal volume among older adults. Neuroimage, 131, 155-161.
Kumar, A., Rani, A., Tchigranova, O., Lee, W. H., & Foster, T. C. (2012). Influence of late-life exposure to environmental enrichment or exercise on hippocampal function and CA1 senescent physiology. Neurobiology of aging, 33(4), 828-e1.
Lynch, M. A. (2004). Long-term potentiation and memory. Physiological reviews, 84(1), 87-136.
Matura, S., Fleckenstein, J., Deichmann, R., Engeroff, T., Füzéki, E., Hattingen, E., … & Pantel, J. (2017). Effects of aerobic exercise on brain metabolism and grey matter volume in older adults: results of the randomised controlled SMART trial. Translational psychiatry, 7(7), e1172-e1172.
O’Callaghan, R. M., Griffin, E. W., & Kelly, A. M. (2009). Long‐term treadmill exposure protects against age‐related neurodegenerative change in the rat hippocampus. Hippocampus, 19(10), 1019-1029.
Sigurdsson, T., Doyère, V., Cain, C. K., & LeDoux, J. E. (2007). Long-term potentiation in the amygdala: a cellular mechanism of fear learning and memory. Neuropharmacology, 52(1), 215-227.
Truyol, Q. (n.d.). Exercise and Brain Health.
Featured Image Credit Benjavisa Ruangvaree Art/Shutterstock
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