A lot has been written on this topic, including an entire book Spark: The Revolutionary New Science of Exercise and the Brain by John Ratey and Eric Hagerman.
Exercise helps with mental health issues like stress, PTSD, depression, and anxiety. It also plays a helpful role in treating addiction. The latest book I’ve read on the subject is Running Is My Therapy by Scott Douglas.
Scott is former chief editor of Running Times, a highly respected publication that is missed by runners (and ex-runners like me). He himself suffers from chronic depression and gives much scientific evidence on how aerobic exercise in general, and running in particular, help with both depression and anxiety, both by themselves and as adjuncts to psychological therapies and medications.
Authors who are themselves runners often rave about the benefits of running but it is difficult to discern what is especially beneficial about running vs. other forms of exercise. I’m sometimes amused to see statements like “running is great for stress. In fact, a study of 192 cyclists showed that … ” But Scott devotes an entire chapter to discussing what specific advantages running might have. Several possible reasons were given, but the one that made most sense to me and matched my experience is: Running at an easy pace is automatically in a good effort range to induce mood improvements. There is solid research evidence, for example, showing exercising at 70% of max heart rate is the optimum pace for inducing mood-improving endocannabinoid levels . There are natural cannabis like natural chemicals stimulated in the body during exercise, a possible source of “runner’s high”. And running at an easy pace tends to be at about the right intensity level.
I can speak from experience as someone who was once a dedicated runner, using it as a primary stress relief and meditation in motion technique. But I had to give it up because of my hip arthritis and have spent years trying out various substitute aerobic activities, some of which worked better than others for mental purposes. For example, walking at an easy pace is a less intense aerobic activity than easy running. But there are ways to make walking a bit harder, like going at a brisker pace, walking up a moderate slope, or using hand weights or nordic poles. I find each of these works better for me than just easy walking on the flat, and provides mental benefits like stress relief and mood improvement similar to how running used to feel. Cycling while seated at an easy pace is also less intense than running easy. But standing up to pedal bumps up the effort level, and I find it provides a similar “feel good” factor to running.
Scott also goes over other medications and other therapies including cognitive behavioral therapy and mindfulness, and how exercise can complement them. A useful point about mindfulness he made is that it can be easier to get in the mindset to exercise mindfully after we have “passed our prime” and are no longer able to chase lifetime PRs. And he made an interesting observation about associative running. There is evidence that paying close attention to our physical activity, or being associative, leads to better performance than a dissociative approach where we try to distract ourselves from discomfort by thinking about something else or listening to music. But the evidence for this is mixed. A good reason might be that sub-elite athletes like me, when trying to be associative, might tend to sabotage ourselves with negative thoughts like “this sucks”, “I can’t keep up this pace, it hurts”, etc. But the attitude in mindfulness is to observe what is happening in the present without judgement. I notice this, for example, when I’m doing intervals. Towards the end of one of my 30 sec sprint repeats I can start thinking “wow this is uncomfortable”, or I can just watch my breathing without judgement. The latter is a lot more relaxing and I actually perform better.
Scott discusses how exercise can also help with recovery from addiction. There are many inspirational books about helping overcome addiction with exercise, including Rich Roll’s Finding Ultra.
- Riachlen, D, “Exercise-induced Endocannabinoid Signalling is Modulated by Intensity”, European Journal of Applied Physiology, 2013 (raichlen.arizona.edi/DavePDF/RaichlenEtAl2013.pdf)