MLS EDUCATIONAL RESEARCH www.mlsjournals.com/Educational-Research-Journal ISSN: 2603-5820

Educational Research Journal 2017, Vol 1 n. 1;

Abstract

Currently, it is common to find students with difficulties at the classroom. Among the most common ones, there are the Attention Deficit Hyperactivity Disorder (ADHD), a neurodevelopment disorder characterized by a persistent pattern of not paying attention and/or hyperactivity-impulsiveness that interferes in the development of the social, academic/working capacities (DSM5, 2013). Approximately, 5% of children and teenagers are diagnosed, with no differences between ages (Polanczyk, Salum, Sugaya, Caye & Rohde, 2015) ADHD is associated with deficiencies in the executive functions: working memory, mental organization and planning, behavior attention and control (Diamond, 2013) and it is as well associated with psychiatric conditions like the defiant opposition/negative and a low mood or anxiety (Van der Oord, Prins, Oosterlaan & Emmelkamp, 2008). At preschool, between three and six, the disruptive behaviors like tantrums, the search for attention, the non-compliance and the hyperactivity can be associated with the classmates’ rejection and the low academic performance during the elementary school years (Egger & Angold, 2006). As well, during childhood, the presence of aggressive and antisocial behaviors is linked to future serious behavior problems and delinquency in adult life (Broidy et al., 2013).

There are two main treatments for children diagnosed with ADHD, change behavior and drugs administration. In some cases, the drugs administration has side effects or is not effective in behavior variables, so the change behavior treatment is preferred. It consists of therapy with specialized psychologists who show children to control impulsiveness and aggressivity. In this way, since they are capable of controlling their emotions, they can take advantage of their perceptive abilities and to have a better performance in their tasks (Watson, Richels, Michalek & Raymer, 2015) Nevertheless, Chronis et al. (2004) observed the benefits from the change behavior treatments are neither effective in all cases, and have disadvantages such as a loss in efectiveness throughout time and important rates for giving up on the treatment. Conversely, it is well-known that at the physiological-structural level, children diagnosed with ADHD show a deficit in neurotransmitters and dopamine in the frontal lobe (Sharma & Couture, 2014), which is the reason for most of them to be taking drugs when they are six, a treatment based on stimulants like methylphenidate and amphetamines that act by raising the dopamine levels in the brain, which in turn improves the executive functions (Hodgkins, Shaw, Coghill & Hechtman, 2012).

Kim et al. (2011) observed in rats that exercising in a race 30 minutes/day for 5 days/week x 28 days, same as with methylphenidate improved hyperactivity induced by the ADHD as so they did with the memory impairment while learning via the improvement of the dopamine synthesis and the expression of the neurotrophic factor tht is derived from the brain evidence that exercising elevates the dopamine and norepinephrine levels in the brain. In humans, Wing et al. (2003) observed that exercising frees dopamine in the prefrontal cortex and the basal ganglia. Furthermore, results from transversal and longitudinal studies with intervention through aerobic trainings show they have antidepressant and anxiolityc effects, and protects against the stress’ harmful effects (Slamon, 2001).

However and to the knowledge of this paper’s authors, there has not been yet an analysis of the studies evaluating doing exercise by taking part in a race, prior to the school day and its effects on children’s behavior (6-12 years old) who are diagnosed with ADHD by clinical specialists. Most of the papers focus on knowing the effect of exercising on the cognitive performance (Cornelius, Fedewa, & Ahn, 2017; Grassmann, Alves, Santos-Galduroz, & Galduroz, 2014).

Hence, the question we are raising in this review is the following: Could organizing a race prior to the school day improve the behavior of ADHD children at school? This review article is focused on children, for the first credible diagnosis of ADHD can be done from age six, a stage at which school conflicts and dependency are associated with bad academic results and behavior problems in future years (Hamre & Pianta, 2001).

The methodology used for this study was the systematic review. At first, the search engines and the selection criteria were determined. Subsequently, every one of the authors conducted an own search. The obtained results were discussed, duplicated articles that were not in accordance with the search limits for their heading or abstract were dismissed. Finally, according to the selection criteria, the articles were selected by consensus and the summary table that includes the main aspects of each article was written.

Search limits

The search was made in three data bases (PubMed, SportDiscus and Web of Science). The search dates were: Januay 2000-July 2017. The journals had to have peer review and had to be indexed in ISI, with journals which included articles written in English. The search terms were:

• Race, running, walking, treadmill, cardiovascular exercise, active displacement.
• Attention-deficit hyperactivity disorder, ADHD, attention deficit disorder, ADD.
• Children, childhood, school-age youth, student.
• Behavior, behavior, mood, conflicts.

Table 1 shows the search strategies that were followed for each of the data bases, as well as the filters used and the articles obtained in every search.

Table 1.

Search strategy in the data bases

Selection Criteria

The selected studies to be included in this article were contrasted following these criteria:

• Complete report published in a journal with peer review.
• The population of study was children diagnosed with ADHD (6-12 years old).
• The study included written in English.
• The study used an interventional study prior to the school day.
• Behavior variables were measured with valid and credible tools.
• There are no exclusion criteria due to ethnicity.

Quality level’s evidence

All the articles included in this study rely on a high quality (see Table 2). They meet the selection criteria established in accordance with other standardized evaluation lists (Ruiz-Ariza, Grao-Cruces, de Loureiro & Martínez-López, 2017) and also with out inclusion criteria. The list included six items about design, population, internvention, measures and result reports. Each item was classified as 0 (non-compliance or was unclear), 1 (moderately informed) or “2” (completely informed). For all the studies, the total score was calculated by counting the number of positive items (total score between 0 and 12). Three evidence levels were established. The studies were tagged as counting with a Low Quality (LQ) if their score wasunder five. A total score between five and eight was defined as Average Quality (AQ) and between nine and twelve was classified as High Quality (HQ). All the articles included in this systematic review rely on a high quality (see Table 2).

Table 2.

List of included studies with the quality scores

The chart flow corresponding to the results of the review process is shown in Figure 1. In the main search, 92 articles were obtained. 24 were dismissed for being duplicated, so 92 were left. In the following step, 65 articles were ruled out, basing on the information provided by the heading or the abstract, for non-compliance with the inclusion criteria or for not being able to find the full text. So, three studies were reviewed with the selection cirteria, performing an in-depth read of the full texts that met the selection criteria (Chang, Liu, Yu & Lee, 2012; Hung, Huang, Tsai, Chang & Hung 2016; Tantillo, Kesick, Hynd & Dishman, 2002).

In this review paper, three articles were included, all of them with an interventional design, and with the participants being assigned to different groups or conditions randomly. All evaluate the effect of an intervention in a race, with moderate-high intensity, controlled by heart rate, on a treadmill, and also controlled by an specialist in sports and exercise science. The different behavior variables were evaluated before and after the intervention. Children who participated in the different studies were diagnosed with by specialized clinical psychologists using the DSM-III-R (Tantillo et al., 2002) or DSM-IV (Chang et al., 2012; Hung et al., 2016).

This review includes data from 117 participants, from which 25 were girls (29,25%) and 92 were boys (70,75%), so the sample size of the different studies were between 34 (Hung et al., 2016) and 43 (Tantillo et al., 2002) participants. The studies were perfoemed in wto countries: two in China (Chang et al., 2012; Hung et al., 2016) and one in Georgia (Tantillo et al., 2002).

Table 3.

Three articles from the past 17 years that evaluate the effect of the race at a moderate-high intensity on the behavior of children diagnosed with ADHD

Behavior evaluation

Showing opposition/negative, defiant behaviors, low moods and high anxiety levels are typical in children aged between 6 and 12 diagnosed with hyperactivity/attention disorder (Van der Oord, Prins, Oosterlaan & Emmelkamp, 2008). The selected studies evaluated the students’ behavior through using the tests STAL-C, observation by the teacher during the school day, and during the Stroop and Wsct tests, the Chinese version of the ADHD test and the Chinese version of the CBCL test; data was obtained regarding sociability, opposition, defiant behavior, anxiety level and risk of suffering from depression.

Effect of the moderate-high intensity race on the behavior

A total of three studies analyzed the immediate effect of a race with a moderate-high intensity on the behavior (Chang et al., 2012; Hung et al., 2016; Tantillo et al., 2002). All of them only did one intervention in one session, evaluating the short term effect of exercising prior to the school day. All the studies carried out the measurements within 24 to 48 hours after having suspended the administration of the drugs to treat the ADHD symptoms.

The study of Tantillo et al. (2002) was one of the first to measure the effects of exercising on the cognition of children diagnosed with ADHD, which is why it is a reference in the area of cognition in children with learning difficulties. This study followed a design based on a control and an experimental group, the students from the control group remained seated and expectant, without making any movement and talking to each other, meanwhile, the students from the experimental group took part in a race, at a submaximal intensity, on a treadmill, in such a way that they completed the first 5 minutes at a low intensity, approximately 40% and after that, the treadmill’s speed was incremented, as well as the race’s speed did, until reaching a maximal oxygen consumption between the 65-75% of the VO2 max. In the students of the experimental group, the state anxiety and the trait anxiety diminished in comparison with the control group, the improvements were most notable in girls than in boys. Chang et al. (2012) differentiated between the control group from the experimental group, the control group watched a documentary while seated, at the same time, the experimental group took part in a race at a moderate-high intensity on a treadmill. The intensity was controlled by using a heart rate monitor, the speed was regulated to keep the intensity at a 50-70% of the maximal heart rate, calculated with the Karvonen, Kenthla and Mustala formula (1957). In the experimental group, the impulsiveness levels were reduced during the tests, such improvements were not found in the control group. Hung et al. (2016) carried out a study that was very much similar to the one of Chan et al. (2012), the design was different in the fact that instead of working with two groups, they did an offset, in such a way that the original group was randomly divided into two subgroups. One group was assigned as the control, and watched a video for 30 minutes, and the other was then the experimental, and were those who took part in a race on a treadmill for 30 minutes, at a 50-70% intensity of the maximal heart rate, monitored by a pulse meter; a week after, the participants shifted their conditions. This time, the measurements were took on the same schedule and school conditions, but in a laboratory at which the possible polluting variables, such as the noise and the temperature, could be controlled,. The students improved the ADHD symptoms and the associated behavior after exercising, there were no changes in the video intervention.

These results are similar to those obtained by Flohr, Saunders, Evans and Raggi (2004), when exercising in the stationary bicycle for 25 minutes before starting the school day, at a moderate intensity, 40-50 VO2 max, the participants (90 boys, aged 7-11) improved their behaviors during the lessons and the tests, also improving in their test results that assessed their skills in algebra and reading comprehension.

These systematic review has analyzed the studies from the past 17 years that evaluate the effect of the race at a moderate-high intensity on the behavior of children (6-12 years old) diagnosed with ADHD. The search was limited to three data bases and to studies published between January 2000 and June 2017. A total of three articles met the selection criteria, all used a longitudinal design with an intervention on a treadmill prior to the school day, for at least 20-30 minutes and with a high quality as a result and being published in some of the most famous journals in the world. The intensity of the exercise was monitored by the heart rate and controlled by specialists in exercise and sports science. The results have shown that the race boosts an improvement in behavior, diminishes the impulsiveness and the anxiety (Chang et al., 2012; Hung et al., 2016; Tantillo et al., 2002). In addition to that, it had a positive effect on the executive functions and the academic performance. None of the studies proved a negative association.

The lack of specific studies with children diagnosed with ADHD has made it difficult to establish direct comparisons. Working with populations experiencing some learning difficulties makes the task harder, even more if the intention is to intervene in the school environment, for there are other students who must continue with their lessons as long as the study is being done. The inclusion of exercising to start the day means having available and moving all the materials to the center, a no easy task for which multiple permission requests are needed before the intervention. Therefore, the results have been occasionally discussed basing on the evidences found in interventions in which another type of similar intervention is made or in which teenagers also participate, as well as studies in which population with no learning difficulties is involved (Craig et al., 2016).

There are various mechanisms to explain the effect produced by the physical exercise on the behavior. In children, there is a correlation between the catecholamines release and the exercise. Both in children diagnosed with ADHD and in children with no learning difficulties, when they exercise, the excess in catecholamines is eliminated, reaching a lower anxiey and stress level (Wigal et al., 2003). Likewise, exercising activates the release of epinephrine and norepinephrine, increasing the neurotransmitters’ concentration in the brain space, being them the responsibles for controlling the executive functions and the body’s correct functioning. As well, such enhance the physical condition, which is positively linked to the cognitive performance (Ardoy et al., 2014) as it is so to the academic performance regarding algebra and language (Carral, Pérez & Espiño, 2016). Exercising has a relaxing effect, diminishes the cortisol levels, which in turn reduces the anxiety and stress levels (Hillier et al., 2011). Exercising could be considered as the best natural drug equivalent to anti-depressants, anxiolytic, and also protects against the negative consequences that stress entails (Salmon, 2001). Young people with ADHD frequently have trobule sleeping (Owens, 2005). Quality sleep in young people with ADHD (9-12 years old) has a positive association with variables such as quality of life, the ability to stay focused and the hemoglobin levels (Yehuda, Rabinovitz-Shenkar & Carasso, 2011). In addition to that, since they are capable of controlling their emotions, they can take advantage of their perceptive abilities and to have a better performance in their tasks (Watson et al., 2015).

In this study, differences were found regarding gender in one of the included articles (Tantillo et al., 2002), for the girls experienced a greater improvement than boys. This could be due to the dose-response effect (Martínez-Gómez et al., 2011). That is to say, girls are usually more sedentary than boys (Verloigne et al., 2012), which is why there is a higher impact in girls before the same physical exercise stimulus.

Weaknesses and strengths

This review presents many weaknesses that have to be recognized. Weaknesses such as the little number of included articles, in spite of that their homogeneity was optimized through a rigorous selection process based on selection and exclusion criteria. Most of the researches analyze a small but homogeneous number of individuals, which may be due to the fact that the ADHD’s prevalence is approximately 5% of children and youth (Polanczyk et al., 2015). Most of the participants in the study are boys (70.75%) and not girls (29.25%), and this may be due to a greatest prevalence in boys than in girls (Wittchen et al., 2011). This paper includes researches that were carried out in just two different countries.

Even so, this systematic review relies on great strengths, on the one hand, all the studies that have been selected include boys and girls who have been diagnosed by specialists, and the analysis has been done via reliable, standardized and credible diagnosis tests, dismissing any other kind of learning disorders or difficulties. Likewise, all the articles clearly describe the dependent variable (behavior) and the independent variable (race intervention, duration and precise intensity) specifying the exact moment and procedure that was followed during the data collection, even when in the previous 24-48 hours to the measurements, the administration of the drugs to treat the ADHD symptoms had been suspended. This paper includes studies published within a 17 years period of time, in English language journals, with peer review, being all the included articles of a high quality. Lastly, this review only included longitudinal studies with an intervention that was carried out prior to the school day of the students with ADHD and the interventions were controlled by specialists in science and exercise sciences.

Conclusions and practical applications

This review selected a total of three intervention articles, that analyzed the immediate effect of taking part in a race at a moderate-high intensity, being the intensity controlled by using a heart rate monitor. All the interventions lasted fr around 25-30 minutes. In the three cases, the intervention prior to the school day showed an improvement in behavior, a less impulsive attitude and lower anxiety and stress levels in children aged between 6 and 12 years old diagnosed with ADHD by clinical psychologists. The totality of the studies that were analyzed have proved that aerobic exercise has a beneficial effect, if made at a moderate-high intensity in order to work the cardiorespiratory endurance, on the behavior of students with ADHD, apart from other benefits at an academic and cognitive level.

Recent studies say that youth’s physical activity level is really low. And point at the time spent in front of a screen, the family friend environments as the main causes for the youth to have a sedentary or inactive lifestyle (Vidal-Conti, 2016). We have observed that the benefits are extended depending on the intervention time; physical activity improves not only the behavior, but also the control of emotions, the socialization, the physical condition, the fine and gross motor skills, the executive functions, the school grades, and of course the health status, when exercise is duly structured, lasts for 25-30 minutes and is done at a moderate-high intensity. Plenty of physical activities can be done which are easily adaptable to the skills, motivation and availability of resources. Catching the attention by making use of the new technologies, active video games, active games based on gamification or Smartphone apps. From the World Health Organization (WHO) it is recommended that children and youth between 5 and 17 years old dedicate at least 60 minutes every day to physical activities done at a moderate-high intensity. Such activities comprise games, sports, movements, recreational activities, physical education or scheduled exercises within the family, school or the community activities’ context. With the aim of enhancing the cardiorespiratory and muscle functions as well as the bone health, for reducing the risk of non-communicable diseases, great benefits that are added to the ones that have been already shown regarding the behavior.

Future research lines

Nevertheless, further researches are needed to justify the effect’s duration, as well as the possible benefits for the children with ADHD doing this type of systematic controlled interventions at the beginning of the school day. The use of well-structured physical activities, combined with tasks that demand from a cognitive work and their combination with psychological treatments to modify the behavior should be promoted during childhood in the educational and family environment. Specially, its is recommended to clarify the influence of confounding variables. If we perform a quick search in the same data bases but focused on children who have not been diagnosed with learning difficulties of any kind, we find a great variety of studies that make use of various variables such as the mother’s education, the physical condition indicators, the body mass index, the body fat percentage, or the inclusion of the breastfeeding time. Such aspects, together with the differentiated effect of different stimulus, duration, intensity and frequency could help create a complete program that is adjusted to every child’s individual needs.

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