Posted at 8:00 a.m.
Q. You started teaching physical education in 1969. In 50 years, has knowledge about the benefits of exercise evolved a great deal?
R. It completely exploded. Doing a census of all the major studies on exercise and the brain, I was surprised to see just how many there were. The quantity is phenomenal! It started about 30 years ago, but over the past 15 years, there have been a slew of studies on the cerebral benefits of exercise.
Q. How much exercise do you need to do to experience brain benefits?
R. The beauty is that it doesn’t take much. Twenty minutes of brisk walking – or better, thirty minutes – is enough to make us calmer and in a better mood. It also makes the brain more alert. Great studies have been done in children and adolescents who were given 20 minutes of moderate exercise. Each time, it has been found that children who have exercised have better concentration and better results on psychometric tests. It is the same for older people, provided the exercise is moderate.
PHOTO DOMINICK GRAVEL, THE PRESS
Richard Knight
Q. What is moderate exercise?
R. In the moderate zone, one is able to speak almost normally, but singing becomes more difficult. We breathe a little faster, we can also feel a little heat. It is accessible to everyone.
Q. How do you explain these immediate effects of exercise on mood, anxiety, concentration, memory?
R. It is often said that Plato and Aristotle liked to walk to think. It made them feel good, it helped them think, but physiologically they didn’t know what was going on. Today, we know: moderate-intensity exercise that lasts 20 or 30 minutes causes an influx of molecules in the brain, which I like to call happy molecules. These are neurotransmitters like serotonin, dopamine and GABA. It acts on the mood, it calms us, it lights up our brain and it improves our concentration.
Q. When you exercise regularly, what more can you get out of it?
R. The effects are magnificent. First, a physically active person will better resist stressful situations of everyday life and will recover more quickly than a sedentary person. Exercise makes the parasympathetic system – the one that calms us – predominate over the sympathetic system – the one that excites us. It is also a natural antidepressant: it reduces the risk of depression, and for the person who suffers from depression, it is an adjunctive treatment that helps to get out of it more quickly.
Q. Exercise may even play a role in preventing degenerative diseases, such as Alzheimer’s and Parkinson’s…
R. Yes. It is well known that exercise modifies muscle tissue, that it strengthens the bones, the heart… But what we did not know until maybe fifteen years ago is that exercise also remodels the brain. Among other things, it enlarges a component of the brain called the hippocampus, which is the seat of memory and spatial orientation. Exercise also has an effect on the prefrontal cortex where thinking, decision-making and concentration take place. If exercise protects our cognitive functions and remodels our brain for the better, it will certainly protect us against neurodegenerative diseases.
Q. You write that exercise is probably the most powerful neuroprotective factor. You who taught physical education for 30 years, how do you explain that so many people are sedentary?
R. The technological environment does not favor the exercise. The electronic arm is ubiquitous. It’s very easy to spend the day sitting for eight hours, even more so with the pandemic.
Q. What are your tips for getting motivated to move?
R. Many people imagine that it takes a lot to do, but we now know that a simple 10-minute walk is good enough. The important thing is to get moving. Research has also shown that when you break 30 minutes of exercise into three 10-minute increments, the effects are cumulative.
Q. Besides walking, are there any other types of exercise that should be recommended?
R. I’m talking about walking, because it’s the most accessible exercise, but there are also a lot of studies on aerobic exercises, jogging, cycling, swimming… There are also open-skill activities , such as badminton and tennis, which involve several areas of the brain. To have the maximum effects on the brain, the best exercises are cardio exercises.
Move! For a healthy brain
Richard Knight
Editions La Presse
256 pages