There is growing evidence that physical activity reduces symptoms of attention deficit hyperactivity disorder (ADHD). It helps children focus their attention on the task at hand and not be distracted by what is going on around them, two skills that are often lacking in children with this disorder. But what type of physical activity is really beneficial? And at what intensity and for how long is it most effective? A consensus is emerging regarding these parameters and now allows recommendations to be formulated.
In fact, various studies have shown that after moderate-intensity exercise, children with ADHD performed better on reading and math tests, had better attention levels, and had better control. their impulsivity than if they spent that moment reading or watching a video. “Studies even show that children with ADHD benefit from physical activity more than neurotypical children (without ADHD),” points out neuropsychologist Chaïma Meneceur, who is conducting research to determine exactly how long after physical activity the beneficial effects start to appear and how long will last.
“Immediately after physical activity, we do not necessarily observe effects on the child’s cognitive abilities. There is a small latency period during which neurobiological adjustments occur,” says M.me A manager who is doing his PhD at UQAM under the supervision of Claudia Verret, Professor in the Department of Physical Activity Sciences, and Marie-Claude Guay, Professor in the Department of Psychology and Associate Researcher at the Center jeunesse de Montréal-Institut.
Currently, the professional literature indicates that the effects begin to manifest 15 minutes after physical activity and last for approximately one hour. Butme Meneceur hopes to clarify the moment when the effect is optimal on motor hyperactivity (agitation), but also on a cognitive level on different forms of attention, i.e. sustained attention (ability to exert mental effort for several minutes), divided attention (ability to process several different sources of information, such as listening and taking good notes) and selective attention (the ability to focus on relevant things and ignore the rest) that are affected in people with ADHD.
However, there is a “fairly clear consensus” from the studies conducted so far on the impact of physical activity on children and adolescents with ADHD. The practice of regular physical activity (say three times a week) produces beneficial effects – which are sustained over time – on executive functions such as planning actions, the ability to stay focused on a task for longer (sustained attention) as in inhibitory control (which reduces impulsivity).
Action planning is greatly affected in children with ADHD, reminds Mme Threat. “They have difficulty with organization, breaking down a large amount of work into subsections. They go everywhere and miss a lot of information. (They have a deficit in) the ability to plan actions and anticipate, two skills that allow us to achieve the goal optimally without overstretching ourselves,” he explains.
Physical activity parameters
The parameters of physical activity prove to be decisive in the effects we will observe, warns the neuropsychologist. First, intensity is very important. If “it’s light, the effects aren’t necessarily observable all the time,” says M.me Threat. Moderate-intensity activity is optimal for affecting (cognitive) functioning and hyperactivity.” On the other hand, when activity reaches a very high intensity, it can create a “fatigue effect” at which point “the body will instead try to put its energy into regaining some stability , which we call homeostasis. it won’t necessarily have the effect we’re hoping for on hyperactivity and cognitive levels.”
Moderate-intensity activity can vary from person to person, as it corresponds to an intensity of approximately 65% of an individual’s maximum heart rate. Smart watches that measure heart rate can help determine the intensity at which this value is reached.
The same phenomenon is observed with duration. When physical activity lasts less than 15 minutes, we don’t necessarily see spectacular effects. A duration between 30 and 45 minutes at moderate intensity seems optimal. After 45 minutes to an hour, the body can be overwhelmed with fatigue, making it difficult to return to balance. Studies of marathon runners have shown that at the end of their race, many of these athletes had lower cognitive abilities than they normally had before the race, notes M.me Threat.
Aerobic activities, the most studied, are those in which the most remarkable effects have been observed. When aerobic activities such as running, swimming and cycling were compared to somewhat more leisurely activities such as yoga, aerobic type was shown to have a greater effect. Perceptual-motor exercises that require coordination in particular, such as rhythmic dancing, are also proving to be very effective, the scientist emphasizes.
Scientists have observed that aerobics increases blood flow to the brain, which is thus better oxygenated and better supplied with nutrients. It increases the concentration of certain neurotransmitters, including dopamine, which is deficient in people with ADHD. This would also induce the secretion of brain neurotrophic factor (BDNF for “ brain-derived neurotrophic factor ), which promotes neuroplasticity. It is clear that these neurobiological phenomena help alleviate various symptoms of ADHD.
Research also suggests that an exercise program respecting these various parameters should be adopted from an early age by children with ADHD or suspected to be at high risk of developing this disorder. Such a program would be especially important during child development and adolescence.
“We can only recommend physical activity, because children with ADHD are often more at risk by engaging in more sedentary activities. Which may seem paradoxical given that they are hyperactive, but they are particularly drawn to activities such as video games and television. They may even become addicted to video games. Young people with ADHD really have a greater risk of falling into addiction, and this can be on video games, but also on drugs,” emphasizes M.me Threat.
Can physical activity replace medication? It all depends on the severity of the disorder, says Chaïma Meneceur, who works at a clinic with young people with ADHD. “When the disorder is mild, some manage to compensate with physical activity and cognitive-behavioral therapies that help reduce the anxiety that worsens attention difficulties. » In more severe cases, the most reliable studies present physical activity as a complementary treatment, not as a substitute. “The main treatment really remains treatment. But by adding physical activity, and why not cognitive-behavioral therapy, we further improve the chances of reducing symptoms. »