Keep Moving. Facts on Fitness Part 3
We’ve all been faced with the challenge of finding the new normal over the past few months, teasing out what works, what helps and what’s achievable. For me and my youngest (he’s 9), a short morning jog with the dog has become one significant routine that we’ve found paves the way for a better day. It partly makes up for not running around the school playground, so ticks the physical activity box (the UK recommends an average of at least 60 minutes spread throughout the day for kids aged 5-18 (1)), but we’ve found it also helps with our moods and the subsequent brain workout.
Exercise, Learning & the Ageing Brain
Numerous studies have reported that single bouts of exercise improve cognitive performance in children. One study found exercise to be particularly effective for lower performing children (2). There is also evidence that it has moderate to large positive effects on inattention, impulsivity, hyperactivity and executive functioning in children (3). But it isn't just the young brains that benefit. Short bouts of light and moderate exercise have been found to improve cognitive function in both younger and older adults (4). In two groups of healthy women with average ages of 23.2 years and 66.3 years, 30 minutes of moderate-intensity aerobic cycling improved learning, memory, attention and executive control (5).
As we age, the brain, like muscle (see previous blog, Facts on Fitness Part 2), starts to shrink. Some areas, like the hippocampus which is involved in memory, are more affected than others. Exercise can be highly effective at slowing and even reversing this process. A randomised controlled trial with 120 adults aged 55 or older, found aerobic exercise training (40 minutes of walking per week) over the course of a year increased the size of the anterior hippocampus by 2% compared to a control stretch group which showed a 1.4% decline. The aerobic group exhibited improvements in spatial memory and reversed the age-related loss by 1-2 years (6). A recent study published in Neurology found that participants with a mean age of 66 who did a program of six months of aerobic exercise improved by 2.4% on tests of verbal fluency, which was equivalent to the fluency seen in someone five years younger (7,8).
Exercise and Mood
The reason our morning jog has become habit, is undoubtedly due to its effect on our moods. My son was less than enthusiastic to go one morning last week because it was raining and I have to admit I had my doubts about continuing after his feet were soaked by a passing car and the scowls morphed into tears. However, continue we did, and 20 minutes later it didn’t matter that he’d got wet. He was simply in a much happier mood. This isn’t an individualised or one-off consequence: a review of twelve studies found that single bouts of exercise consistently lead to more positive feelings, emotions or moods (9).
Exercise and the Coronavirus Pandemic
The pandemic has had a negative effect on many people's mental health. According to the Office of National Statistics, between the 25th and 28th June 2020, 69% of adults in Great Britain worried about the effects of COVID-19 on their life (10). For some, exercise has been a helpful mood modifier during the lockdown period. A Canadian study looked at whether physical activity had helped the mental health of 1098 adults during the imposed public health measures. The study reported that 33% of inactive participants had become more active, and compared to those that had remained the same or become less active, these participants had significantly lower anxiety (11).
More than 264 million people of all ages suffer from depression, with more women being affected than men (12). Many studies have reported that exercise can positively impact depression. Findings from a meta-analysis of 114 studies on children aged 6-18 found that physical activity interventions lead to lower levels of depression, stress, negative effect and distress and greater self-image, life satisfaction and happiness (13).
In adults, walking, interval and resistance training have all been found to be effective at reducing symptoms of depression (14). A 2019 study from the Harvard TH Chan School of Public Health reported that higher levels of physical activity were linked to reduced major depression in adults (15). According to the authors, even as little as 15 minutes a day of high intensity exercise, like running, or an hour of lower intensity exercise such as walking or housework, can reduce the risk or major depression by 26% (16).
Types of Exercise
Besides walking, high intensity and resistance training, other forms of exercise have also been found to benefit brain function. Several randomised controlled trials reported that Tai Chi and Qigong may be effective treatments for depression, stress, anxiety and mood disturbances (17). A review of 11 studies reported that yoga was likely to help reduce age-related neurodegenerative decline in brain function (18).
How Does it Work?
Physical activity stimulates the release of endorphins, which are produced by the pituitary gland and central nervous system. They act on the opiate receptors in the brain, reducing the perception of pain and raising feelings of euphoria, reward and well-being. But it isn’t just endorphins. Exercise causes structural alterations to the central nervous system and increases oxygen and levels of neurotransmitters, such as dopamine, norepinephrine and serotonin, all of which affect focus and attention. Exercise also increases cerebral blood flow, positively impacting memory. In one study, participants with memory problems either did a program of aerobic exercise or a program of stretching for 12 months. The group that did the aerobic exercise showed a 47% improvement in memory scores, whereas the stretching group showed little change. Brain imaging revealed that the exercise group had increased blood flow to key areas of the brain involved in memory (19, 20).
Exercising with others can make it more enjoyable, help with motivation and support, as well as build friendships and a sense of community. A recent study in 586 community-dwelling Australians aged 65 to 96 years old, found that exercise with social support was associated with less depressive symptomology than exercise alone (21). A study on rowers found that training as a team lead to a heightened endorphin surge compared with similar training carried out alone (22). An article I found particularly interesting and relevant to the success of our morning dog-jog, found that doing exercise or sport together with your child (aged 8-12 years in this study) lead to happier, calmer feelings and reduced stress, anger and sadness, compared to being active alone (23).
The Take Home
The aim of this 3-part blog has been to highlight the numerous benefits of exercise.
“…regular physical activity is an effective way to improve physical performance, improve physical and mental health, and reduce the risk factors for many noncommunicable diseases... In contrast to medication, physical exercise has no negative side effects, costs very little, and targets many health issues at once. If the multitude of beneficial effects of regular exercise were to be combined in a single low-cost drug, it would be prescribed for almost all types of physical and mental health issues,” Andreas Kramer (24).
If exercise is not a regular feature in your life, take a small step towards adding it in today. Perhaps take a short walk or do 5 minutes of achievable exercises. Find a friend or mentor that will support you, help you stay motivated, help you build a habit and to whom you are accountable. The rewards are worth it.