Exercise as a Treatment for ADHD. A Pseudo Literature Review.
Introduction
Exercise is well known for providing a myriad of benefits for the human body, such as increase in muscle mass, improvement in cardiovascular fitness, increased stamina, improved metabolism, improved circulation, improvement in cognitive function, improved body composition, improved bone density, and many more benefits. However, exercise can also be used as a treatment option for many conditions. While physical conditions, such as chronic pain, are known to be treated with exercise, psychological conditions are not. There is evidence of exercise being an effective treatment for a myriad of psychological conditions such as chronic depression.
ADHD is one of the most common neurodevelopmental disorders in children. ADHD is often diagnosed in childhood and continues into adulthood. People with ADHD may have trouble paying attention, controlling impulsive behaviors, or being overly active. Of course, this is not the limit of symptoms people with ADHD may suffer. There are three types of ADHD: Predominantly Inattentive Presentation, Predominantly Hyperactive-Impulsive Presentation, and Combined Presentation. Predominantly inattentive presentation is hard for the individual to organize or finish a task, to pay attention to details, or to follow instructions or conversations. Predominantly hyperactive-impulsive presentation is when a person fidgets and talks a lot. Individuals affected with this type may have more accidents or injuries. Combined presentation is a combination of both. Presentation is not static. Presentations can change over time. (1)
This literature review covers the use of exercise as a tool for the treatment of ADHD. Exercise is an effective pharmaceutical alternative for multiple psychological conditions, such as depression; however, exercise as a treatment for ADHD is under explored. There is scientific literature covering the topic, but they are not well known. The purpose of this review is to present information on exercise as a treatment option for ADHD in an easier to digest manner. This is not prescriptive writing. This paper is to inform and influence discussion around treatment options for ADHD.
Method
To conduct this review, 12 systematic reviews or meta-analyses were collected from Pudmed’s free text selection. The reason for this is that this paper has no funding and since each review examines a myriad of studies, results will be analogous. Reviews that did not examine exercise as a treatment option for ADHD were removed and sections of reviews that did not address ADHD were ignored.
Study Summaries
Heijer et al found that both cardio and non-cardio exercise has positive acute effects on children with ADHD. The studies Heijer et al examined corroborated that exercise can have a similarly positive effect to stimulants that are typically prescribed to children with ADHD. The researchers examined 25 studies published before April 2016 to find these results. Cardio was shown to have a positive effect on executive function, attention, verbal working memory, and cognitive speed, but some studies showed no association. This can be attributed to small sample sizes among the studies examined. Non-cardio exercise research was few, but found positive effects similar to cardio exercise, but these studies were also plagued by small sample sizes. (2)
Christiansen et al discovered that scientific literature supported that exercise benefits executive functions and attentional control in children with ADHD. They continued to say that the results of exercise were comparable to those reported in PBC with substantial and consistent improvement on tests of several cognitive functions following particularly long-term exercise. Exercise was also found to reduce stress, anxiety, and depression along with improving executive and memory functions. It was also found that exercise that had higher coordination and cardiovascular demands are more engaging and efficient, thus increasing the positive effects for children with ADHD. However, deficits in executive functions may hinder young individual’s adherence to an exercise regimen. (3)
Sun et al conducted a meta-analysis and found that physical exercise can effectively improve attention, motor skills, and executive function in children with ADHD with no adverse side-effects compared with drug therapy but it can not significantly improve hyperactivity symptoms, depression, social problems, or aggressive behavior. Sun et al searched eight Chinese and English electronic databases. All of their studies used included participants between the ages of 5 and 15 years old, they only included random control trials, studies that used a PE program or increased physical activity, and only included studies with primary outcomes of ADHD symptoms of hyperactivity and inattention, and secondary outcomes of depression, social problems, motor skills, and executive function. Unfortunately, because data was pulled from Chinese and English databases, results may not be as accurate since different measurement processes may have been at play. (4)
Torres-Acosta et al researched the cardiovascular effects of ADHD treatment options. They found that ADHD medication raises resting heart rate (RHR) and blood pressure (BP) which can both lead to negative health outcomes. They also found that treatments using omega-3 fatty acids and exercise are a promising alternative to ADHD medication that excludes the cardiac toxicity. The body of data examined revealed that ADHD medications can cause modest elevations in RHR and BP, as well as showing reports of conditions including arrhythmia, nonischemic cardiomyopathy, Takotsubo cardiomyopathy, and sudden death associated with ADHD stimulants. The researchers reported that 5.2% of all U.S. children 2 to 17 years of age are using ADHD prescriptions and that ADHD diagnoses increased 26% and 123% for children and adults respectively between the years of 2007 and 2016. ADHD prescriptions filled by adult females have increased by 344% between 2003 and 2015. The researchers go on to report that adults approx. 50 years old are more likely to be vulnerable to adverse cardiovascular effects of ADHD medication than children are. Exercise is shown to increase several hormones in the prefrontal cortex that individuals with ADHD particularly need higher levels of. Children with ADHD have been found to have lower levels of omega-3 fatty acids while a lack of omega-3 is also associated with lower levels of serotonin and dopamine in animals. Currently, it is unclear if omega-3 has a positive effect on children with ADHD due to few studies and mixed results. (5)
Zang conducted a systematic review and meta-analysis and found that exercise has a major contribution to significant improvement in anxiety and depression, aggressive behaviors, thought and social problems among children suffering from ADHD. Zang also concluded that exercise should be incorporated into the daily life of children with ADHD. The study included 14 studies in the analysis. The studies analyzed showed a significant improvement in negative behaviors in children with ADHD. (6)
Sogard and Mickleborough found that caffeine and exercise should be considered as a treatment option for individuals with ADHD; however, the effect of caffeine on athletes with ADHD is under researched and must be examined further. Regardless, the core symptoms of ADHD are reported to be caused by a lack of norepinephrine ligands for the postsynaptic adrenergic receptors and transporters that reduces overall functioning. The researchers reported that after moderate intensity exercise, 50–70% maximal heart rate, participants with ADHD who had the worst cognitive performance showed improvements in executive function, which was associated with increased brain activity in task-related regions. The review also reported that exercise is a valuable supplement to medication or possibly an alternative treatment plan to manage ADHD symptoms by improving cognitive performance and brain activation during and after exercise. (7)
Mehren et al recommended continued investigation of exercise as treatment for ADHD and borderline personality disorder (BPD) because exercise involves low costs, easy implementation, absence of side-effects, an active role of the patient including possibly enhanced compliance, and non-invasiveness. Exercise is shown to increase the release of neurotransmitters such as dopamine, epinephrine, norepinephrine, and serotonin. While stimulants are the primary treatment medication, exercise may produce a similar effect. Acute benefits of exercise are shown are observed after moderate intensity aerobic exercise, but patient health and fitness levels are an important factor of if exercise is a viable treatment option. Long term exercise studies seem to be a promising alternative or supplement treatment for ADHD. However, both acute and long term studies’ results are flawed in that they focus on healthy participants and the studies are few, along with other issues that confound results. (8)
Montalva-Valenzuela and colleagues found for their systematic review that there are positive effects on executive function through the development of programs and interventions of physical activity, exercise, or sport. The researchers used 21 studies for their review. Their results showed that exercise gaming (such as VR) is a viable intervention method at home, but games need to be personalized to maximize results. In addition, “ball work”, “balance work”, “coordination”, and “trampoline work”, showed promising results as well in improving cognitive flexibility, processing speed, and executive functions. More traditional training was also shown to be effective in benefiting cognitive factors in people with ADHD as well. Sports were also effective, but only 3 studies focused on the effectiveness of sports and ADHD. (9)
Chan et al concluded that sufficiently intense exercise is highly beneficial for children with ADHD. When considering an exercise program for children, game content should be highly considered. The researchers found that aerobic exercise can induce the secretin of neurotransmitters such as serotonin and dopamine in the brain, increase brain blood flow and circulation, enhance the metabolism, and activate the central nervous system. They also found that a single-bout of exercise offers immediate and persistent benefits in cognitive function and long-term exercise training can improve overall fitness and exert long-lasting effects on cognitive function in children. Moderate to high intensity exercise can help alleviate inattention, hyperactivity/impulsivity symptoms, and problems in interpersonal interactions. (10)
Chen et al found that pharmacological or behavioral interventions are not appropriate or effective for many patients, but clinical studies, animal studies, and meta-analyses strongly support the benefits of exercise intervention as treatments for neuropsychological symptoms and diseases. Typical ADHD treatments are plagued by many deficiencies that must be urgently addressed through alternative therapies. Exercise interventions present a potential alternative as it is a natural and essential part of development. Exercise also produces psychological effects very similar to stimulants used for ADHD treatments, offering an alternative with little to no side effects. However, at the time of this review, more long term studies need to be performed. (11)
Berwid and Halperin’s review conclude that current evidence supports the use of exercise as a treatment for ADHD; however, more research must be conducted with studies that are better controlled and examine more facets of exercise interventions and severity of ADHD. Since it has been shown that exercise can enhance neural function which is linked with the remission of ADHD symptoms, a physical fitness program may be able to yield enduring changes in ADHD symptoms. Frequent exercise breaks for school children may be beneficial for in class behavior and productivity, but the intensity of this exercise is lower than what is used for most studies and no long term study has examined these kinds of interventions long term. (12)
Seiffer et al found that moderate to vigorous physical activity presents small to moderate effects for ADHD core symptoms and functional impairment. This review concluded that there was a high risk of bias among the studies examined therefore the quality of the evidence is deemed as weak. However, during the analysis, the researchers found a small but significant improvement of exercise on ADHD symptoms. (13)
Discussion
The studies above present an interesting alternative to standard psychostimulants for ADHD. In many of the reviews, exercise is shown to be effective in eliciting important hormonal and neural transmitter responses that are linked with the reduction or remission of ADHD symptoms.
The reviews also indicate an issue that can be solved by replacing pharmacological solution with exercise or reducing the use of drugs for treatment. Oftentimes, medication comes with side effects that are not desired such as an increase in blood pressure, which may lead to the reliance on more medication. The use of exercise can reduce the side effects since exercise has virtually no negative side effects if done properly. In addition, exercise is far less expensive than medication. However, despite this, there are problems with exercise being used as an alternative.
As the reviews suggest, the studies on exercise as a treatment for ADHD are not the most reliable. Despite promising results, more research must be done in more controlled environments. Different severities of ADHD must be tested and longer term studies must be conducted to better understand the full scope of what exercise can do as a treatment option and what it cannot do. Also, there will be individuals who cannot fully switch over to exercise as a treatment option and of course, some individuals may not be able to effectively utilize exercise as a treatment in general if they have a physical disability or are severely obese. As far as the literature discusses, moderate to high intensity aerobic exercise presents the best results, but the effectiveness of lower intensity exercise may still provide benefit to individuals who are more physically limited. So lower intensity exercise’s effectiveness also needs to be examined and studied.
These reviews also revealed that resistance training was not examined as a treatment option. Aerobic exercise has been shown to be an effective treatment option for many mental conditions; however, many individuals prefer anaerobic training such as resistance training. It is obvious that some exercise is better than none even when examining exercise as a treatment, but the effectiveness of resistance training in this regard is under researched. Resistance training may offer another effective avenue for individuals with ADHD to control their symptoms.
Conclusion
It seems to be clear that exercise has the potential to be a non-pharmaceutical solution to ADHD, but there must be more research conducted. It is fair to say that able bodied individuals with ADHD should include a training regiment to help reduce symptoms. In the better case scenarios, those individuals may be able to reduce the medication they need or eliminate it all together. There is a promising future for exercise as a non-pharmaceutical alternative for the treatment of ADHD.
References
[1] Center of Disease Control. (2022, August 9). What is ADHD? | CDC. Centers for Disease Control and Prevention. Retrieved October 21, 2022, from https://www.cdc.gov/ncbddd/adhd/facts.html
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[9] Montalva-Valenzuela, F., Andrades-Ramírez, O., & Castillo-Paredes, A. (2022). Effects of Physical Activity, Exercise and Sport on Executive Function in Young People with Attention Deficit Hyperactivity Disorder: A Systematic Review. European journal of investigation in health, psychology and education, 12(1), 61–76. https://doi.org/10.3390/ejihpe12010006
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