The immediate effects of acute exercise can be measured as improvements in neurocognitive functions of certain neurocognitive domains that are known to give rise to symptoms of ADHD.

The majority of studies examined the effects of moderate-intensity aerobic exercise and found post-exercise improvements in neurocognitive tests such as Flanker task, Stroop task and Go/No Task.

Most commonly, a reduction in reaction time and increased P 300 amplitudes in EEG readings point towards a mechanism whereby aerobic exercise increases cortical arousal levels in brain areas associated with executive functions [6] . This finding is of particular importance for children and young people whose ADHD is predominantly related to impairment in alerting and arousal functions associated with a state of hypo-arousal in prefrontal cortical areas [13] [14] .

The volume of studies examining the effects of coordinative exercise on ADHD symptoms is in contrast to aerobic exercise still small and a matter of growing interest [15] .

Coordinative exercises mobilise prefrontal cortex activity during the execution of a motor task and its practice is considered to improve cognitive functions, in particular inhibitory control [16] . These improvements have been replicated in children and young people with ADHD who demonstrated better-sustained attention and inhibitory control following coordinative exercises [11] [15] [17] .

Furthermore, some research data suggests that in healthy children and adolescents, coordinative exercises provide higher benefits on cognitive function compared to aerobic exercise (Amatriain-Fernández et al. 2021), possibly because coordinative exercises require a higher variety of frontal-dependent cognitive processes [18] [19] .

Studies with coordinative exercises used a combination of dynamic and static balance exercises and authors concluded that both were effective for children and young people with ADHD. Prior to commencing the trial, participants were tested for their coordinative ability and exercises adjusted to the individual’s coordinative skills [20] [21] . Feng et al. noted that the goal of the balanced treatment was to reach a point where patients had the ability to maintain a balanced posture even when experiencing sensory conflict [11] .

There is one study by Ludyga et al. (2017) which provides a comparison between the effects of aerobic and coordinative exercises in children and young people with ADHD showing greater improvements for aerobic exercise on reaction time and thus level of cortical arousal [20] . In contrast, a study by Chang et al. (2014) proposed that the coordinative component of a combined aerobic/coordinative exercise program led to beneficial effects in inhibition control since reaction time was not significantly altered [15] .

Overall, results suggest that differences in effect are likely due to their distinctive characteristics of modus operandi by which aerobic and coordinative exercises exert their beneficial effect on executive functions.

For that reason, some authors are proposing to conduct more targeted and selective exercise programs for future research [1] . Along those lines, Ziereis and Jansen (2015) selected two exercise groups comparing exercises with specific abilities, such as ball handling, balance and manual dexterity with non-specific exercises such as swimming, running, climbing and sports games. Both groups showed beneficial effects on executive functions compared to a non-active control group [22] .

In order to derive the benefits of both aerobic or coordinative exercise the intensity, duration and frequency of the exercise programme is crucial for developing a therapeutic effect. A meta-analysis by Xiao et al. (2021) found that overall executive function was significantly moderated by intervention intensity and exercise sessions of intervention but not by exercise type, suggesting that moderate intensity exercise conducted once or twice weekly over 6 - 12 weeks accounted for moderate-to-large training effects [4] .

Research also highlights the influence of psychosocial effects such as increased patient care and social group activity on engagement and outcome [6] . These aspects are important to consider for the successful implementation of a therapeutic exercise programme for children and adolescents with ADHD.

Clinical research has focused on the effects of physical exercise on the two aforementioned neurocognitive domains of alerting functions and inhibitory control. These two domains are well known to give rise to symptoms of ADHD as supported by an extensive amount of research literature [23] - [28] .

In the first instance, clinicians would have to identify children and young people with ADHD who demonstrate difficulties in their alerting functions or inhibitory control. It would then be possible to recommend and specify the benefits of aerobic exercise on alerting functions and the benefits of coordinative exercise on inhibitory control.

“Alerting” is the ability to prepare for what is about to happen when a warning is received, or to be ready to respond without warning [23] . In taking a history of behaviour, the following features should be present: Children and young people with an alerting deficit tend to react slowly and their responses are inaccurate when time is of the essence. They find it difficult to redirect their wandering mind to the task at hand. A state of low alertness makes it difficult for the child to control or mobilise their responses as shown in behaviours such as making careless mistakes and procrastinating behaviour.

In contrast, children and young people who have marked problems with inhibitory control, demonstrate an inability to suppress irrelevant behaviours as the context changes [23] . The predominant features in the assessment arise as hasty responses leading to mistakes or interruptions during an activity where the child should be trying to keep on task in an ongoing way.

Both, impairment in alerting functions and impairment in inhibitory control are known to bring about behaviours that expand over all three core symptom domains of ADHD (hyperactivity, inattention, impulsivity). As a result, both impairments are known to present as ADHD-combined types in commonly used clinical questionnaires (Conners 3; SNAP IV) rather than differentiating themselves from one another [29] [30] . Subsequently, clinical questionnaires do not lend themselves as an aid in identifying these two neurocognitive domains.

A pivotal addition in aid of the assessment of alerting functions and inhibitory control comes with the wider inclusion of neurocognitive testing such as the Go/No-go Test or continuous performance test (CPT) for the assessment of ADHD in clinical practice [31] - [33] . These tests offer clinicians a direct measurement of neurocognitive domains in a clinical setting.

As an example, one of the commercially available tests, the QbTest, lays out a visual graph, which captures a distinct pattern/profile of performance that can clearly differentiate between impairment in alerting functions ( Figure 1(a) ) and impairment in response inhibition ( Figure 1(b) ) [34] [35] .

Cases demonstrating weaknesses in arousal and alerting functions display in their individual parameters a slow reaction time, elevated variable response time and increased omission errors (failing to respond to the target stimulus), resulting in a graph profile marked by slow, scattered and loose target responses (green circles; Figure 1(a) ).

Cases with impairment in response inhibition and inhibitory control manifest themselves by increased commission errors (failing to suppress response to non-target) with normal reaction time and reaction time variation. The graph profile characteristically shows a red carpet effect reflecting hasty commission errors (red squares; Figure 1(b) ) within a dense responding pattern.

Thus, as part of a comprehensive assessment that includes neurocognitive testing, it is possible to match behaviours that are suggestive of difficulties in e.g. alerting functions or inhibitory control with their corresponding scores and profiles from neurocognitive testing and thus achieving the objective of identifying children and young people with ADHD that would benefit more from aerobic exercises or coordinative exercises ( Table 1 ).