A new study shows exercise can help protect mental health and reduce the chance of depression and anxiety by up to half.
I can be in the foulest of moods, unable to focus, and yet 20 minutes later, splashing through puddles on my 10k running circuit, I feel like life is manageable again. Exercise for me is a mental salve. I don’t have severe mental health problems, but like many people, I have periods of anxiety, really low moods – or just bad days that I want to escape from. Running or swimming gives me a lift that can carry me through the rest of the day.
Plenty of people feel the same way about physical activity. For Rachael Sacerdoti, 43, anxiety used to be “a constant feature of my life. I had this constant sense of overwhelm, of not being enough,” she says. “I had no confidence to do anything.”
At the time she wasn’t exercising at all. “Even a walk around the block felt like a big deal,” she says. But, with the encouragement of her family, she first started walking, then adding in small workouts at home. Now, exercise is central to her life – she has qualified as a personal trainer, specifically helping women like her who are lacking in confidence to start or restart training. And she says exercise, which she does every morning before her three children get up and before she sees clients, has helped to almost eradicate her anxiety.
“I can decompress, process what’s going on in life, release energy and get the feeling that I have accomplished something for the day. It’s striking that when, for whatever reason, I cannot work out, I am more irritable and more stressed.”
Hollie Grant, the founder of Pilates PT, says that during her first job as a pastry chef, she worked around the clock. “I had no time to do anything outside of work, including exercise,” she says. It led to burnout. Grant was prescribed mild antidepressants for a short spell, which helped, she says, and allowed her the space to explore other coping mechanisms, such as re-finding a love of exercise.
“For me, running outdoors helped the most with my mood – it became a big part of my mental health care,” she says. Grant quit her job and retrained as a Pilates instructor, and now uses meditation, exercise and journaling “to avoid a period that dark again”. While she feels lucky to feel mentally well most of the time, “if I feel myself slipping slightly, I know that getting outside, getting my heart rate up, and getting my body moving will have a huge effect on how I feel.”
The relationship between exercise and mood is still not fully understood. The National Institute for Health and Care Excellence (Nice) recommends group physical activity for those with mild to moderate depression, and many GPs prescribe it. Now a study from the University of Glasgow has found that getting out and doing exercise could help prevent depression and anxiety in the first place. Researchers found that a third of people at risk of mental health problems, including anxiety and depression, could prevent their onset by exercising.
The study published in the journal BMC Medicine followed more than 37,000 people aged between 37 and 73 with various levels of physical activity, who had not previously had anxiety. After being monitored for nearly seven years, on average, around three per cent had developed depression or anxiety.
Using data from fitness trackers given to the participants, researchers estimated that sedentary people who incorporated 75 to 150 minutes a week of vigorous activity would be 29 per cent less likely to develop depression or anxiety. Meanwhile, those who completed 150 to 300 minutes a week of moderate physical activity could reduce the risk of becoming anxious or depressed by nearly half (47 per cent).
The reasons may be down to our brain chemicals. “Exercise improves the secretion of several brain molecules called dopamines that positively affect our mood,” Dr Carlos Celis-Morales, a senior author of the study, explains. Dopamine, known as the “happy hormone”, plays a role in pleasure, motivation and reward.
Exercise also releases other neurotransmitters such as endorphins, which are said to be behind “runner’s high” (though there is no research to bear this out), as well as endocannabinoids, which are biochemically similar to cannabis.
“There is also the social aspect of doing physical activity, which generally occurs in contact with other people; the socialising aspect of exercising is very important for preventing depression,” Celis-Morales says.
There are other mental benefits to physical activity. “Exercise can improve our cognitive capacity by enabling us to think, problem solve and learn,” says Dr Sharmin Aktar, a counselling psychologist at Private Therapy Clinic, “as well as encourage brain plasticity and the development of new connections between cells.”
American researchers found that after exercise, rats displayed an increase in the blood supply to their brains along with the growth of new neurons in the hippocampus, the part of the brain that is essential for learning and memory.
In turn, better sleep has a knock-on effect on mood and mental health. According to The Sleep Foundation, “sufficient sleep, especially REM sleep, facilitates the brain’s processing of emotional information.” Conversely, studies seem to suggest a lack of sleep is harmful to the processing and consolidating of positive emotional content.
However, despite the well-documented benefits of exercise – physical as well as mental – we’re gradually getting less active as a nation, with people around 20 per cent less active than they were in the 60s, according to government figures. Meanwhile, stress is becoming more common: 74 per cent of UK adults have felt so stressed at some point over the past year that they felt overwhelmed or unable to cope, according to a survey by Mental Health Foundation.
Celis-Morales says that “time and motivation” remain barriers to doing enough exercise. But exercise can be built into our daily activities. “Our study suggests that moderate-intensity physical activity, such as brisk walking, could lower the risk of depression,” he says. “Lots of people already walk daily, but the intensity of walking is not always the right one.”
The study showed that light-intensity activities are not associated with a lower risk of depression. “The largest benefits are observed for individuals with sufficient moderate and vigorous physical activity,” Celis-Morales says. That means a combination of intense exercises such as running or gym workouts with regular moderate physical exertion such as brisk walking, cycling or swimming.