Exercise & Mental Health
Mental health disorders are more prevalent now than ever before. According to the Mind charity, 25% of individuals will experience a mental health problem in the UK each year, with 1 in 6 people reporting symptoms of depression and anxiety each week. The lifetime prevalence of a mental health disorder in adults is likely to lie just shy of the 20% mark, with these figures rising sharply particularly in communities with low incomes. The WHO estimates that depression and anxiety affect more than 500 million people across the globe. In the UK, the NHS spends £12 billion on mental health services annually, but the total cost, when lost work hours, social care, treatment and healthcare are considered, is in excess of £100 billion each year.
Exercise and mental health
Exercise has long been associated with improved mental health outcomes. It has consistently seen similar benefits to psychotherapy and pharmacotherapy, whilst typically costing healthcare services less money and also tackling other co-morbidities at the same time. Despite this, it is still common for those with mental health disorders to resist increasing physical activity, for a variety of potentially understandable reasons, including fear of embarrassment and the greater convenience represented by medication.
The two most common mental health conditions are depression and anxiety. Whilst similar, there are some differences:
Depression may manifest itself with symptoms including: Low self worth, sadness and hopelessness, low energy, altered eating habits, poor sleep, or trouble concentrating. One may also find themselves getting no pleasure or interest in activities which they previously enjoyed, or have recurrent suicidal thoughts.
Anxiety is an umbrella term for many other sub-types, including social anxiety (exacerbated by social environments), general anxiety disorder, and panic disorders. They are frequently associated with excessive worry, feeling out of control, feeling as though everyone is watching you, rapid breathing, shakiness, or excessive irritability.
Recently, a huge meta-review paper was published, which compiled the results of just under 100 systematic reviews, over 1000 trials, and 125000 participants to assess the true benefit of physical activity of mental health disorders. The results are shown below.
Physical Activity & Depression
Physical activity was associated with reduced symptoms of depression across a range of different diagnostic tools, including the Profile of Mood States and Beck Depression Inventory. Of the 72 meta-analyses investigating the role of exercise and depression, 70 favoured the introduction of physical activity, whilst only 2 saw no benefit of exercise. The benefits were consistent across a variety of exercise modes (aerobic exercise, resistance exercise, dance, yoga, Pilates), and intensities (low, medium and high). However, resistance exercise elicited the greatest improvement in depressive symptoms, and moderate-to-high intensity exercise was more beneficial than lower-intensity exercise. In general, 4-5 total exercise sessions per week was the most effective frequency for improving symptoms, although a session a day, or fewer than 4 sessions per week, were still associated with mental health benefits. Interestingly, the benefits of regular exercise were similar across a range of study lengths, however effectiveness of exercise dwindled as the study length increased over 24 weeks (although this may be due to participants not adhering to longer interventions compared to shorter ones).
Physical Activity & Anxiety
Exercise was associated with a similar benefit for anxiety as was seen in depression. Of the 28 reviews which assessed physical activity and anxiety symptoms, 26 favoured the introduction of exercise. Just like with depression, all exercise modes were effective, however, with anxiety, lower impact exercises such as yoga, Pilates and other mind-body modes of activity were the most effective. There were fewer studies which investigated the effect of exercise intensity on anxiety symptoms, but those which did found all intensities to be effective, with moderate-intensity potentially most effective. Again, as seen with the depression studies, short-to-mid-length interventions were more effective than longer studies, but as mentioned, this is potentially a participant adherence issue. Once more, 4-5 sessions per week appears optimal, but more and less frequent exercise is also effective. The duration of each individual session made no difference to outcomes.
Key Takeaways
Regular exercise or physical activity, of any mode, intensity, or session duration is likely to improve symptoms of depression and anxiety. It has consistently demonstrated similar, or even slightly greater improvements of symptoms to those seen by other therapies (counselling, medication), and as such it appears as though a combination of these interventions may be optimal.