Effects of Physical Activity, Exercise and Sport on Executive Function in Adults Diagnosed with Attention Deficit Hyperactivity Disorder: A Systematic Review

Abstract

The main characteristics of attention deficit hyperactivity disorder (ADHD) are associated with inattention, impulsivity, and/or hyperactivity. Those diagnosed with this neurodevelopmental disorder present with executive function and motor difficulties, which have repercussions in educational, occupational, or social areas. On the other hand, it has been evidenced that the regular practice of physical activity or exercise or sport could produce improvements in areas with difficulties. It is for this reason that the objective of the present review was to describe and analyze the effects of the practice of physical activity, exercise, or sport on executive functions in adults diagnosed with ADHD through the scientific literature (registry: INPLASY202530105). The articles indexed in PubMed (1145), Scopus (43), and WoS (2910) were searched using the following keywords: “Adult” OR “Adults” AND “Attention-Deficit/Hyperactivity Disorder” OR “Attention-Deficit with Hyperactivity Disorder” AND “Physical activity” OR “Exercise” OR “Sports” OR “Sport” AND “Executive Function”. In addition, four articles were identified using other search engines. A total of 10 articles met the selection criteria. TESTEX was used to assess the quality of the articles, and TIDierR was used to report the results. Of the ten included studies, nine mention an improvement in inhibitory control, six in selective attention, three in cognitive flexibility, and one in working memory (all p < 0.05). It was concluded that the practice of physical activity, exercise, or sport has a positive and significant effect on the executive functions of adults with ADHD, specifically on selective attention, inhibitory control, and cognitive flexibility. Furthermore, benefits were observed in depression, brain activation, and stability. Among the limitations is the lack of a meta-analysis, which makes it difficult to quantify and recommend which intervention is most effective for this population. Furthermore, the various types and degrees of ADHD were not considered.

1. Introduction

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that begins in childhood and persists into adulthood, evidencing 2.58% in adult ADHD persistence and 6.76% in symptomatic adults worldwide by 2020 [1]. This disorder is characterized by complications in the areas of executive function in people who are affected [2,3]. This results in difficulties in attention, concentration, organization, and following instructions, among others associated with compulsive behavior, which makes it difficult for sufferers to manage emotions [4,5].

Executive function (EF) is linked to the development of processes and skills that occur in the brain; these are working memory, attention, decision-making, and cognitive flexibility, among others, which begin their development in childhood and reach their maximum maturity in adulthood [6,7]. This set of mental abilities allows people to manage daily life activities such as planning, problem solving, and the ability to control impulses to prioritize goals [8]. These EFs allow predicting behavior and academic performance in the child and adolescent population, which are transferable to various areas of academic, personal, social, or occupational development [9]. In this sense, within the EF, inhibitory control is the ability to control automatic responses, selective attention allows focusing on a specific stimulus, cognitive flexibility allows changing tasks or actions according to the context, and working memory allows maintaining and manipulating relevant information in a temporary manner [6,8].

In children or adolescents with ADHD, EF is affected when attention, organization, planning, or following instructions is required thanks to working memory to perform activities. They also have difficulties in controlling impulses and emotions, which hinders socialization, academic performance, and other activities they are required to develop [10,11,12]. In the case of adults with ADHD, EF is also affected in the same areas as in children and adolescents, but, in addition, in the case of the latter, decision-making and performance in work activities and educational, personal, social, or family-level activities are also affected [13,14].

Although treatment in children and adolescents diagnosed with ADHD, as in adults, is pharmacological [15], psychological therapies, devices, and complementary and alternative methods have been gaining ground [16]. Regarding complementary or alternative methods, systematic reviews have shown the use of physical activity, exercise, or sport to produce improvements in EF, allowing benefits on working memory, inhibitory control, and cognitive flexibility, among others [17,18]. A systematic review has shown the benefits of the practice of physical activity, exercise, or sport interventions on executive function in children or adolescents [19]. However, a bibliometric review has pointed out that in the last 50 years the line of research in ADHD, to date, tends towards a medical model [20], which could limit the options for collaboration from other areas not directly associated with medicine. Based on the above, the development of a systematic review in the adult population would allow obtaining scientific evidence on the contribution of these interventions to executive function in this population. In this way, the type of intervention, duration, and changes in executive function that are produced by this type of intervention or program could be evidenced.

In accordance with the above, this systematic review aimed to describe the effects of the practice of physical activity, exercise, or sport on executive functions in adults diagnosed with ADHD through scientific literature.

2. Materials and Methods

2.1. Databases and Strategy

This systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guide [21]; its protocol has been registered and published in the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY) (INPLASY202530105). The Patient, Intervention, Comparison, and Outcome (PICO) strategy was used for the development of the research question [22], which allowed obtaining the keywords and subsequently developing the search strategy. The following search strategy was performed: “Adult” OR “Adults” AND “Attention-Deficit/Hyperactivity Disorder” OR “Attention-Deficit with Hyperactivity Disorder” AND “Physical activity” OR “Exercise” OR “Sports” OR “Sport” AND “Executive Function” in the following databases: PubMed, Web of Science and Scopus (

Table 1. Databases, search strategy, and total number of records.

Database	Search Strategy	Total No. of Records
PubMed	(((((((((“Adult”[Title/Abstract]) OR (“Adults”[Title/Abstract])) AND (“ADHD”[Title/Abstract])) OR (“Attention-Deficit/Hyperactivity Disorder”[Title/Abstract])) OR (“Attention-Deficit with Hyperactivity Disorder”[Title/Abstract])) AND (“Physical activity”[Title/Abstract])) OR (“Exercise”[Title/Abstract])) OR (“Sports”[Title/Abstract])) OR (“Sport”[Title/Abstract])) AND (“Executive Function”[Title/Abstract])	1445
Web of Science	(((((((((TS=(“Adult”)) OR TS=(“Adults”)) AND TS=(“ADHD”)) OR TS=(“Attention-Deficit/Hyperactivity Disorder”)) OR TS=(“Attention-Deficit with Hyperactivity Disorder”)) AND TS=(“Physical activity”)) OR TS=(“Exercise”)) OR TS=(“Sports”)) OR TS=(“Sport”)) AND TS=(“Executive Function”)	2910
Scopus	(TITLE-ABS-KEY (“Adult”) OR TITLE-ABS-KEY (“Adults”) AND TITLE-ABS-KEY (“ADHD”) OR TITLE-ABS-KEY (“Attention-Deficit/Hyperactivity Disorder”) OR TITLE-ABS-KEY (“Attention-Deficit with Hyperactivity Disorder”) AND TITLE-ABS-KEY (“Physical activity”) OR TITLE-ABS-KEY (“Exercise”) OR TITLE-ABS-KEY (“Sports”) OR TITLE-ABS-KEY (“Sport”) AND TITLE-ABS-KEY (“Executive Function”))	43

Own elaboration.

). All studies published up to January 2025 were included. No limitation was applied regarding the language of the articles. The PRISMA checklist is available in Supplementary Table S1.

2.2. Selection Criteria

For this systematic review, the inclusion criteria were as follows: (i) randomized controlled trials (RCTs) or quasi-experimental clinical trials that used physical activity, exercise, or sport as an intervention; (ii) the objective of improving some component of executive functions in adults with ADHD; and (iii) persons older than 18 years of age of both sexes. In addition, studies were incorporated into the systematic review using the PICO framework (population: adults with ADHD; intervention: physical activity, exercise, or sport; comparator: control group; outcomes: some improvement in executive functions).

Exclusion criteria were as follows: (i) cross-sectional, retrospective, or prospective studies; (ii) studies with an intervention not focused on physical activity, exercise, or sport; (iii) studies with a co-intervention, such as medications, nutritional supplements, or an educational program; (iv) non-original articles (e.g., translations, book reviews, letters to the editor); (v) duplicate articles; (vi) review articles (e.g., narrative reviews, systematic reviews, meta-analyses); and (vii) case studies.

2.3. Selection of Studies

Two working groups were created independently, each composed of two researchers (J.H.A., S.G.C.; A.J.R., N.G.R.). After eliminating duplicates, the articles were selected by title and abstract. Subsequently, both groups applied the inclusion and exclusion criteria to evaluate the full text of the selected articles. In the case of discrepancy between the groups, a fifth and sixth investigator (F.M.-V.; A.C.-P.) agreed on the final decision, applying the same criteria.

2.4. Data Collection

The two working groups (J.H.A., S.G.C.; A.J.R., N.G.R.) extracted the data from the studies. In case of disagreement, one investigator independently compared the data and made the final decision (A.C.-P). The collected data were synthesized following the template for description and replication of TIDieR interventions (Supplementary Table S2) [23], and a summary table is also presented, including the following: Author; Study Design; Groups (n) and Female Sample Size (%); Mean Age (Years); Frequency and Intensity of the Intervention; Data Collection Instruments; Main Results According to Executive Function; and Other Results Observed (Table 2).

2.5. Evaluation of Methodological Quality

Two authors (F.M.-V.; A.C.-P.) independently assessed the methodological quality of the studies included in this review using the Tool for the Evaluation of Study Quality and Reporting in Exercise (TESTEX) scale. The TESTEX scale includes 15 items: 5 items for quality study and 10 items for reporting. The scale provides a comprehensive review of exercise trials [24]. Each study is evaluated based on 12 criteria, internal and external validity, for a total score from 0 to 15 (score equal to or below 7: low quality study; score between 7 and 11: good quality study; score above 11: high quality study).

Table 2. Summary of the articles included.

Authors	Study Design	Groups (n) and Female Sample Size (%)	Mean Age (Years)	Frequency and Intensity of the Intervention	Data Collection Instruments	Main Results According to Executive Function	Other Results Observed
Converse et al. [25]	RCT	21 EG: 9 CG: 12 (Active Control 5; Inactive Control 7) 67% Female	20.7 20.7	Tai Chi Training: 60 min, 2 times a week, for 7 weeks. Intensity not mentioned.	CAARS-S:L FFMQ PSQI Postural Stability Measures	Inhibitory control and selective attention: (ADHD Self-report): Inattention (p < 0.01) ↑ r = 0.87 (large effect). Hyperactivity/Impulsivity (p < 0.05) ↑ r = 0.75 (large effect). Cognitive flexibility: Mean score correlation with inattention (p < 0.05) ↓ r = −0.47 (medium effect). Change follow-up vs. baseline (p < 0.01) ↑ r = 0.81 (large effect). Variability correlation with inattention (p < 0.01) ↓ r = −0.61 (large effect).	Postural stability: Eyes open (p < 0.05) ↑ r = 0.76 (large effect). Eyes closed (p < 0.01) ↑ r = 0.89 (large effect). Sleep—Daytime dysfunction (PSQI): Correlation with inattention (p < 0.01) ↑ r = 0.57 (large effect). Mindfulness—Acting with awareness (FFMQ): Correlation with inattention (p < 0.001) ↓ r = −0.74 (large effect) ↓.
Dinu et al. [26]	RCT	159 EG1: Cycling 40 EG2: Hatha yoga 42 CG1: Cycling 38 CG2: Hatha Yoga 39 69% Female	26.62 23.01	Cycling or Hatha yoga: 10 min of cycling or Hatha yoga. For cycling, 50–70% of HRmax.	Test of Variables of Attention (TOVA) Delay Discounting Test (DDT) Iowa Gambling Task (IGT)	Inhibitory control: Temporal Impulsivity (p = 0.012 (Cycling) η2p = 0.033 (small effect). / p = 0.004 (Yoga)) ↑ η2p = 0.18 (medium effect).	Not mentioned.
Fritz & O’Connor [27]	RCT	32 EG: 16 CG: 16 100% Female	20.16 20.16	Bikram yoga training: 2 sessions of 90 min per week, for 6 weeks. Intensity not mentioned.	Flanker Inhibitory Control and Attention Test. Dimensional Change Card Sort test (DCCS). List Sorting Working Memory test. State-Trait Anxiety Inventory.	Inhibitory control: Flanker Inhibitory Control and Attention test (p > 0.153) ↔. Cognitive flexibility: Dimensional Change Card Sort test (p > 0.216) ↔. Working Memory: List Sorting Working Memory test (p > 0.305) ↔.	Fatigue: Yoga group—lower fatigue at 6 weeks vs. control ↓ d = 0.82 (large effect). Mindfulness (trait): Yoga group—increase at 6 weeks ↑ d = 0.50 (medium effect). Wrist hyperactivity (during cognitive tasks): Yoga group—lower than control at 6 weeks ↓ d = 0.95 (large effect).
Gapin et al. [28]	NRCT	20 EG: 10 CG: 10 40% Female	21.1 24.40	Treadmill jogging: A single 40 min session. 50–65% of HRmax.	Stroop Test TMT Digit Span Blood sampling for BDNF	Inhibitory control: Stroop Test Color (p < 0.05) ↑ d = 0.36 (small effect). Color-Word (p < 0.05) ↑ d = 0.82 (large effect). Cognitive flexibility: Task B (p < 0.05) ↓ in the non-ADHD group only, d = 1.24 (large effect). Working memory: Backward span (p < 0.05) ↑ in the non-ADHD group only, d = 0.63 (medium effect).	BDNF: No significant pre–post changes in either group (ns) ↔. No baseline differences between ADHD and non-ADHD (ns) ↔.
Kallweit et al. [29]	NRCT	72 EG: 36 CG: 36 44.4% Female	31.3 31.7	Bicycle ergometer: A single 13 min session. 70–78% of HRmax.	“Tour-/Routenplaner”	Selective attention: Inattention (p < 0.001) ↓ ηp2 = 0.443 (large effect). Global concentration (p < 0.001) ↑ ηp2 = 0.195 (medium effect). Inhibitory control: Hyperactivity (p < 0.001) ↓ ηp2 = 0.448 (large effect). Global calmness (p < 0.001) ↑ ηp2 = 0.323 (large effect).	Not mentioned.
Kouhbanani et al. [30]	RCT	52 EG: 25 CG: 27 100% Female	35.24 35.40	Pilates Training: 60 min, 3 times a week for 24 weeks. Intensity not mentioned.	Wisconsin Card Sorting Test Continuous Performance Task	Cognitive flexibility: Perseverative errors (p = 0.013) ↑ ηp2 = 0.900 (large effect). Non-perseverative errors (p = 0.007) ↑ ηp2 = 0.911 (large effect). Selective attention: Omission errors (p < 0.001) ↑ ηp2 = 0.959 (large effect). Inhibitory control: Commission errors (p < 0.001) ↑ ηp2 = 0.959 (large effect). Reaction time (p < 0.001) ↑ ηp2 = 0.951 (large effect).	Not mentioned.
LaCount et al. [31]	NRCT	36 EG: 18 CG: 18 50% Female	20.8 20.8	HIIT: A single 16 min session. 85% of HRmax.	DASS-M BAARS-M AX-Continuous Performance Test	Selective attention: Reaction Time (p = 0.02) ↑ η2p = 0.15 (medium effect). Omission Errors (p = 0.03) ↑ η2p = 0.05 (small effect). Inhibitory control: Inattention (p = 0.01) ↓ η2p = 0.23 (large effect). Hyperactivity/Impulsivity (p = 0.01) ↓ η2p = 0.16 (medium effect).	Mental health: Depression (p = 0.04) ↓ / d = 0.47 (medium effect). Anxiety (p = 0.64) ↔. Stress (p = 0.18) ↔.
Mehren et al. [32]	NRCT	40 EG: 20 CG: 20 17.5% Female	31.4 29.5	Bicycle ergometer: A single 30 min session. 50–70% of HRmax.	IPAQ-LF Go/No-go task	Inhibitory control: Correlation between control performance and exercise (p = 0.001) ↓ r = −0.70 (large effect).	Brain activation: Additional activation increases in ADHD patients in 5 clusters (p = 0.015) ↑
Mehren et al. [33]	NRCT	40 EG: 20 (ADHD group) CG: 20 (Control group) 20% Female	29.9 29.0	Bicycle ergometer: A single 30 min session. 50–70% of HRmax.	Flanker Task Visual Task IPAQ-LF	Selective attention and inhibitory control: Reaction time (p = 0.004) ↑ η2 = 0.20 (large effect). Interference (p = 0.006) ↓ η2 = 0.18 (medium effect). Reaction time variability (p = 0.007) ↓ η2 = 0.18 (medium effect).	Physical fitness: Correlation with fitness (VO2peak) in incongruent trials: (p = 0.031) ↑ r = 0.48 (medium effect).
Rassovsky & Alfassi [34]	NRCT	31 EG: 14 CG: 17 74.2% Female	24.13 24.13	Treadmill walking: A single 14 min session (speed of 5 km/h).	Conners Continuous Auditory Test of Attention	Inhibitory control: Reaction Time (p = 0.02) ↓ η2p = 0.172 (medium effect). Selective attention: Omission Errors (p = 0.03) ↓ η2p = 0.157 (medium effect).	Not mentioned.

RCT: randomized controlled trial; NRCT: no randomized controlled trial; EG: experimental group; CG: control group; FFMQ: Five Facet Mindfulness Questionnaire; PSQI: Pittsburgh Sleep Quality Index; BDNF: brain-derived neurotrophic factor; DDT: Delay Discounting Test; BAARS-M: Barkley Adult ADHD Rating Scale; IPAQ-LF: International Physical Activity Questionnaire; CV: coefficient of variation; DCCS: Dimensional Change Card Sort; HRmax: maximum heart rate; ↑: significant increase (p ≤ 0.05); ↓: significant decrease (p ≤ 0.05); ↔: no significant changes (p > 0.05).

Table 2. Summary of the articles included.

Authors	Study Design	Groups (n) and Female Sample Size (%)	Mean Age (Years)	Frequency and Intensity of the Intervention	Data Collection Instruments	Main Results According to Executive Function	Other Results Observed
Converse et al. [25]	RCT	21 EG: 9 CG: 12 (Active Control 5; Inactive Control 7) 67% Female	20.7 20.7	Tai Chi Training: 60 min, 2 times a week, for 7 weeks. Intensity not mentioned.	CAARS-S:L FFMQ PSQI Postural Stability Measures	Inhibitory control and selective attention: (ADHD Self-report): Inattention (p < 0.01) ↑ r = 0.87 (large effect). Hyperactivity/Impulsivity (p < 0.05) ↑ r = 0.75 (large effect). Cognitive flexibility: Mean score correlation with inattention (p < 0.05) ↓ r = −0.47 (medium effect). Change follow-up vs. baseline (p < 0.01) ↑ r = 0.81 (large effect). Variability correlation with inattention (p < 0.01) ↓ r = −0.61 (large effect).	Postural stability: Eyes open (p < 0.05) ↑ r = 0.76 (large effect). Eyes closed (p < 0.01) ↑ r = 0.89 (large effect). Sleep—Daytime dysfunction (PSQI): Correlation with inattention (p < 0.01) ↑ r = 0.57 (large effect). Mindfulness—Acting with awareness (FFMQ): Correlation with inattention (p < 0.001) ↓ r = −0.74 (large effect) ↓.
Dinu et al. [26]	RCT	159 EG1: Cycling 40 EG2: Hatha yoga 42 CG1: Cycling 38 CG2: Hatha Yoga 39 69% Female	26.62 23.01	Cycling or Hatha yoga: 10 min of cycling or Hatha yoga. For cycling, 50–70% of HRmax.	Test of Variables of Attention (TOVA) Delay Discounting Test (DDT) Iowa Gambling Task (IGT)	Inhibitory control: Temporal Impulsivity (p = 0.012 (Cycling) η2p = 0.033 (small effect). / p = 0.004 (Yoga)) ↑ η2p = 0.18 (medium effect).	Not mentioned.
Fritz & O’Connor [27]	RCT	32 EG: 16 CG: 16 100% Female	20.16 20.16	Bikram yoga training: 2 sessions of 90 min per week, for 6 weeks. Intensity not mentioned.	Flanker Inhibitory Control and Attention Test. Dimensional Change Card Sort test (DCCS). List Sorting Working Memory test. State-Trait Anxiety Inventory.	Inhibitory control: Flanker Inhibitory Control and Attention test (p > 0.153) ↔. Cognitive flexibility: Dimensional Change Card Sort test (p > 0.216) ↔. Working Memory: List Sorting Working Memory test (p > 0.305) ↔.	Fatigue: Yoga group—lower fatigue at 6 weeks vs. control ↓ d = 0.82 (large effect). Mindfulness (trait): Yoga group—increase at 6 weeks ↑ d = 0.50 (medium effect). Wrist hyperactivity (during cognitive tasks): Yoga group—lower than control at 6 weeks ↓ d = 0.95 (large effect).
Gapin et al. [28]	NRCT	20 EG: 10 CG: 10 40% Female	21.1 24.40	Treadmill jogging: A single 40 min session. 50–65% of HRmax.	Stroop Test TMT Digit Span Blood sampling for BDNF	Inhibitory control: Stroop Test Color (p < 0.05) ↑ d = 0.36 (small effect). Color-Word (p < 0.05) ↑ d = 0.82 (large effect). Cognitive flexibility: Task B (p < 0.05) ↓ in the non-ADHD group only, d = 1.24 (large effect). Working memory: Backward span (p < 0.05) ↑ in the non-ADHD group only, d = 0.63 (medium effect).	BDNF: No significant pre–post changes in either group (ns) ↔. No baseline differences between ADHD and non-ADHD (ns) ↔.
Kallweit et al. [29]	NRCT	72 EG: 36 CG: 36 44.4% Female	31.3 31.7	Bicycle ergometer: A single 13 min session. 70–78% of HRmax.	“Tour-/Routenplaner”	Selective attention: Inattention (p < 0.001) ↓ ηp2 = 0.443 (large effect). Global concentration (p < 0.001) ↑ ηp2 = 0.195 (medium effect). Inhibitory control: Hyperactivity (p < 0.001) ↓ ηp2 = 0.448 (large effect). Global calmness (p < 0.001) ↑ ηp2 = 0.323 (large effect).	Not mentioned.
Kouhbanani et al. [30]	RCT	52 EG: 25 CG: 27 100% Female	35.24 35.40	Pilates Training: 60 min, 3 times a week for 24 weeks. Intensity not mentioned.	Wisconsin Card Sorting Test Continuous Performance Task	Cognitive flexibility: Perseverative errors (p = 0.013) ↑ ηp2 = 0.900 (large effect). Non-perseverative errors (p = 0.007) ↑ ηp2 = 0.911 (large effect). Selective attention: Omission errors (p < 0.001) ↑ ηp2 = 0.959 (large effect). Inhibitory control: Commission errors (p < 0.001) ↑ ηp2 = 0.959 (large effect). Reaction time (p < 0.001) ↑ ηp2 = 0.951 (large effect).	Not mentioned.
LaCount et al. [31]	NRCT	36 EG: 18 CG: 18 50% Female	20.8 20.8	HIIT: A single 16 min session. 85% of HRmax.	DASS-M BAARS-M AX-Continuous Performance Test	Selective attention: Reaction Time (p = 0.02) ↑ η2p = 0.15 (medium effect). Omission Errors (p = 0.03) ↑ η2p = 0.05 (small effect). Inhibitory control: Inattention (p = 0.01) ↓ η2p = 0.23 (large effect). Hyperactivity/Impulsivity (p = 0.01) ↓ η2p = 0.16 (medium effect).	Mental health: Depression (p = 0.04) ↓ / d = 0.47 (medium effect). Anxiety (p = 0.64) ↔. Stress (p = 0.18) ↔.
Mehren et al. [32]	NRCT	40 EG: 20 CG: 20 17.5% Female	31.4 29.5	Bicycle ergometer: A single 30 min session. 50–70% of HRmax.	IPAQ-LF Go/No-go task	Inhibitory control: Correlation between control performance and exercise (p = 0.001) ↓ r = −0.70 (large effect).	Brain activation: Additional activation increases in ADHD patients in 5 clusters (p = 0.015) ↑
Mehren et al. [33]	NRCT	40 EG: 20 (ADHD group) CG: 20 (Control group) 20% Female	29.9 29.0	Bicycle ergometer: A single 30 min session. 50–70% of HRmax.	Flanker Task Visual Task IPAQ-LF	Selective attention and inhibitory control: Reaction time (p = 0.004) ↑ η2 = 0.20 (large effect). Interference (p = 0.006) ↓ η2 = 0.18 (medium effect). Reaction time variability (p = 0.007) ↓ η2 = 0.18 (medium effect).	Physical fitness: Correlation with fitness (VO2peak) in incongruent trials: (p = 0.031) ↑ r = 0.48 (medium effect).
Rassovsky & Alfassi [34]	NRCT	31 EG: 14 CG: 17 74.2% Female	24.13 24.13	Treadmill walking: A single 14 min session (speed of 5 km/h).	Conners Continuous Auditory Test of Attention	Inhibitory control: Reaction Time (p = 0.02) ↓ η2p = 0.172 (medium effect). Selective attention: Omission Errors (p = 0.03) ↓ η2p = 0.157 (medium effect).	Not mentioned.

RCT: randomized controlled trial; NRCT: no randomized controlled trial; EG: experimental group; CG: control group; FFMQ: Five Facet Mindfulness Questionnaire; PSQI: Pittsburgh Sleep Quality Index; BDNF: brain-derived neurotrophic factor; DDT: Delay Discounting Test; BAARS-M: Barkley Adult ADHD Rating Scale; IPAQ-LF: International Physical Activity Questionnaire; CV: coefficient of variation; DCCS: Dimensional Change Card Sort; HRmax: maximum heart rate; ↑: significant increase (p ≤ 0.05); ↓: significant decrease (p ≤ 0.05); ↔: no significant changes (p > 0.05).

3. Results

A total of 4098 articles were found; duplicates were eliminated, leaving 3417 for analysis; 3405 articles were left out based on reading titles and abstracts; 12 were selected for final reading; 11 could be retrieved for full reading; and 4 were left out due to exclusion criteria: 2 for study design and 2 for including participants under 18 years of age. To these 7, 3 articles were added due to a gray literature search. Finally, 10 met the eligibility criteria. Figure 1 shows the flow diagram.

3.1. Evaluation of the Methodological Quality of Studies Using TESTEX

Of the ten articles included, eight were rated as articles of good methodological quality and two as articles of low methodological quality (

Table 3. Analysis of the methodological quality of the studies using the TESTEX scale.

Studies	1	2	3	4	5	6	7	8	9	10	11	12	Total
Converse et al. [25]	1	1	1	1	1	1	1	2	1	0	0	0	10
Dinu et al. [26]	1	1	0	1	0	1	1	2	1	0	1	1	10
Fritz & O’Connor [27]	1	1	0	1	0	2	1	2	1	1	0	0	10
Gapin et al. [28]	1	0	0	1	0	1	1	2	1	0	0	1	8
Kallweit et al. [29]	1	0	0	1	0	1	0	2	1	0	0	1	7
Kouhbanani et al. [30]	1	1	1	1	0	2	1	2	1	0	1	0	11
LaCount et al. [31]	1	0	0	1	0	2	1	2	1	0	1	1	10
Mehren et al. [32]	1	0	0	1	0	1	1	2	1	1	0	1	9
Mehren et al. [33]	1	0	0	1	0	1	1	2	1	1	0	1	9
Rassovsky & Alfassi [34]	1	0	0	1	0	1	0	1	1	0	0	0	5

Note. Column numbers refer to TESTEX scale criteria: 1: eligibility criteria; 2: randomization; 3: allocation concealment; 4: similar baseline situation; 5: blinded assessor; 6: 85% outcome measures (three items available for >85% adherence, adverse event reporting, and attendance reporting); 7: intention-to-treat analysis; 8: between-group comparison (two items available for primary and secondary outcome measures); 9: point measures and variability; 10: control group activity monitoring; 11: constant relative intensity; 12: exercise volume and expenditure.

).

3.2. Characteristics of the Studies According to TIDieR

In accordance with TIDier guidelines, the author, intervention, rationale, materials, procedures, professionals, modality, location, duration, adaptations, protocol compliance, modifications, and measurement are presented (Supplementary Table S2. The summary table of the articles included in the review is also presented (Table 2)).

3.3. Results of Executive Functions and Collection of Instruments

In the research of Converse et al. [25], they conducted a 7-week Tai Chi training, where they trained two times a week, 60 min per session. Of the 21 participants who were between 18 and 23 years old, only 19 approved the publication of their final data, where 9 went to the Tai Chi experimental group, 4 to the active control group, and 6 to the inactive control group. All sessions in the Tai Chi group were based on Tai Chi’s own sequence of 24 Yang-style forms; the active control group participated in an aerobic kickboxing workshop, and the control group remained without physical activity. They assessed inattention using the CAARS-S:L DSM-IV subscale. This subscale contains 9 of the 66 4-point CAARS-S:L items, with a range from 0 to 27, where the higher the score, the more severe the symptoms. At baseline, participants reporting higher levels of symptoms (primary outcome of CAARS-S:L DSM IV inattention subscale) reported lower levels on the “Acting with Mindfulness” subscale of the Five Facet Mindfulness Questionnaire (FFMQ). r = −0.74, n = 20, p < 0.001 uncorrected, p < 0.05 corrected for multiple comparisons. Finally, we see a reported improvement in the response to the FFMQ “Total Mindfulness” due to Tai Chi training, translated into improved attention in students with ADHD.

In the intervention of Dinu et al. [26], 159 adults between 18 and 35 years old (77 were categorized as healthy control and 82 diagnosed with ADHD) were randomly assigned to the aerobic cycling or Hatha yoga group where they performed a single session of 10 min of cycling or 10 min of Hatha yoga. Before and after exercise, participants completed the Attention Variables Test, the Delay Discounting Task, and the Iowa Gambling Task to measure attention and impulsivity. Both exercise groups showed improvement in temporal impulsivity after the intervention; cycling was beneficial for all participants, whereas yoga only benefited those with ADHD (p < 0.01). No effects of exercise on attention, cognitive or motor impulsivity, or movement were observed in people with ADHD.

Fritz & O’Connor [27] conducted a 6-week Bikram yoga intervention, two 90 min sessions per week, in which 32 women between 18 and 24 years of age participated. They were divided into two groups of 16 women each (experimental and control); those in the control group were asked to maintain their routine as normal. Each session included 26 yoga postures. Thirty minutes after finishing the exercise, they were asked about the overall perceived exertion and pain intensity experienced using the Borg scale. Inhibitory control was measured using the Flanker Inhibitory Control and Attention Test, cognitive flexibility was measured using the Dimensional Shift Card Sorting Test, and working memory was measured using the List Sorting Working Memory Test. No significant group-time interactions were observed for any of the outcome variables on the Flanker Inhibitory Control and Attention test (p > 0.153), the Dimensional Change Card Sorting Test (p > 0.216), or the List Sorting Working Memory test (p > 0.305). These results did not change when covariates were included.

The study by Gapin et al. [28] involved 20 college students aged 18–25 years, where 10 participated in the experimental group with ADHD and 10 in the control group without ADHD. The Stroop test was used to measure inhibition, the Trail Making Test (TMT) to assess task switching, and the DS test, a subtest of the Wechsler Adult Intelligence Scale, to assess working memory. Participants performed a single exercise session on a treadmill, which included a 5 min warm-up to reach the target heart rate (HR) zone, a 30 min steady exercise at a moderate intensity of 50–65% of HR, and a 5 min cool-down to bring the HR close to the resting level. Significant improvements were found between pretest and posttest in the Stroop Color and Stroop Color-Word conditions for the ADHD group, with significantly shorter completion times in the posttest (p < 0.05). There were no significant differences between pretest and posttest in the TMT-Part A or B conditions in the ADHD group. There were no significant differences between the pretest and posttest in either the forward or backward DS test in the ADHD group.

The work of Kallweit et al. [29] involved 36 adults with ADHD and 36 adults in the healthy control condition, all over 18 years of age. Participants in the experimental group spent 13 min on a cycloergometer. After 3 min, they were to reach an HR of 70% of their maximal HR, and for the next 10 min, they were to remain in a range between 70% and 85% of maximal HR. After completing the task, they were assessed using a complex planning task (“Tour-/Routenplaner”) and four new-construct executive function tasks. Adults with ADHD scored higher in concentration after exercise, whereas healthy controls did not (p < 0.01). Acute exercise led to slightly less reported inattention (p = 0.019) and less calmness for all participants (p = 0.018).

Kouhbanani et al. [30] performed 24 weeks of Pilates, 3 times per week, progressively until 1 h sessions were achieved. Pilates exercises were performed 8 to 10 times in two or three sets. The intensity of the exercises was increased if they were too easy for the participants. In addition, the exercises started at level one and gradually increased to level three. Fifty-two women between 20 and 50 years of age participated and were divided into two groups: 27 for the control group and 25 for the experimental Pilates group. Attention was assessed using the Wisconsin Card Sorting Test and sustained attention using the Continuous Performance Task. The Pilates experimental group showed significant improvement in sustained attention at posttest and follow-up, especially in omission errors, commission errors, and reaction time (p < 0.05). Furthermore, the results suggested that attention alternation improved substantially at posttest in perseverative errors, non-perseverative errors, and total errors (p < 0.05).

In the intervention by LaCount et al. [31], 36 adults between 18 and 25 years of age participated, who were divided into two groups of 18, an ADHD experimental group and a control group. The experimental group performed 16 min of HIIT, consisting of eight sets of 20 s of cycling followed by 120 s of rest (8 × 20 × 120), always aiming for an HR of 85% of the maximum HR. After finishing the last set, participants were given 15 min of rest to perform the cognitive test. The Barkley Adult ADHD Rating Scale-Modified (BAARS-M) and the AX Continuous Performance Test (AX-CPT) were used to measure executive functions. Four indices of CPT performance were obtained: errors of omission (failure to respond when presenting the target), errors of commission (response when not presenting the target), reaction time, and reaction time variability. Omission errors were used as a measure of sustained attention; commission errors, as a measure of inhibition; reaction time, as a measure of processing speed; and reaction time variability, as a measure of response variability. Intragroup pairwise comparisons revealed that HIIT was associated with a moderate reduction in reaction time variability in individuals with ADHD (p = 0.01); also on reaction time in the ADHD group (p = 0.01); a small, nonsignificant effect of the Group x Condition interaction on commission errors was observed (p = 0.44). Finally, HIIT was associated with a small reduction in the severity of hyperactivity and impulsivity symptoms.

The study by Mehren et al. [32] involved 46 adults with an average age of 30 years, 23 with ADHD and 23 healthy controls. In the experimental group, they cycled continuously on a cycloergometer for 30 min. Throughout the session, the target heart rate was between 50 and 70% of the individual maximum heart rate. The control group was kept watching a movie. Executive function was assessed using the Go/No-go task. In the results it is mentioned that participants with ADHD, compared to healthy controls, showed greater brain activation during successful inhibition in exercise, compared to the control group, in the parietal, temporal, and occipital regions (p < 0.05). Exercise did not improve behavioral performance in either group, but in ADHD subjects, exercise-related increases in brain activation and performance on behavioral tasks (i.e., rate of correct inhibition) correlated negatively with the rate of correct inhibition in the control group.

Mehren et al. [33] performed a single cycloergometer session for 30 min, aiming for a heart rate between 50 and 70% of maximum heart rate. Forty-six adults with an average age of 30 years participated, 23 with ADHD and 23 healthy controls. Executive functions were measured through the Eriksen flanker task, which serves to measure selective attention and interference control. The exercise group significantly improved reaction times on congruent and incongruent trials of the Eriksen flanker test in adults with ADHD, but not in healthy controls (p < 0.001). No changes in brain activation were observed between the two conditions in either group. However, a subgroup analysis of the ADHD group with a higher degree of cardiorespiratory fitness revealed decreased activation in premotor areas during congruent trials and in the premotor and medial frontal cortex during incongruent trials in the exercise compared to the control condition.

In the work of Rassovsky & Alfassi [34], 31 adults aged 18–42 years were divided into two groups: 17 to the ADHD experimental group and 14 to the control group. All adults completed the Conners Continuous Auditory Test of Attention (CATA). The test was performed twice: sitting at baseline and walking on a treadmill at a speed of 5 km per hour, where they completed 14 min, long enough to complete the CATA task. Compared to baseline, the ADHD group showed faster reaction times during exercise (25.4 milliseconds faster) and a decrease in omission errors (1.5% better), while the control group showed the opposite pattern (15.9 milliseconds slower and 0.88% worse, respectively).

3.4. Results of Other Measured Variables

In the study by Gapin et al. [28], they took blood samples to assess BDNF (brain-derived neurotrophic factor); the blood sample was centrifuged, distributed in aliquots in storage tubes, and frozen until analysis for BDNF. No significant changes in BDNF level were observed before or after the test in either the ADHD or non-ADHD group.

In the intervention by LaCount et al. [31], anxiety, depression, and stress levels were measured using the Dass-21 questionnaire. The ADHD group reported moderate improvements in depression, and participants with ADHD reported greater anxiety and stress in both sessions than their non-ADHD peers.

4. Discussion

The aim of this systematic review was to describe the effects of physical activity, exercise, or sport on executive functions in adults diagnosed with ADHD. Of the 10 studies included, 9 mention an improvement in inhibitory control [25,26,28,29,30,31,32,33,34], 6 in selective attention [25,29,30,31,33,34], 3 in cognitive flexibility [25,28,30], and 1 in working memory [28]. However, similarly, one study was found that reported no improvement [27].

Regarding the intervention types of the ten articles, one focused on Tai Chi [25], two on yoga [26,27], two on a treadmill [28,34], three on cycloergometer [29,32,33], one on Pilates [30], and one on HIIT [31], demonstrating a heterogeneity of interventions but agreeing on significant improvements.

Regarding intervention times, there is wide diversity, but a common point: single sessions, where we found from 10 [26], 13 [29], 14 [34], 16 [31], 30 [32], 30 [33], or 40 min [28], respectively, up to 6 weeks with 2 sessions of 90 min per week [27]; 7 weeks with a frequency of 2 days per week [25]; 24 weeks with a frequency of 3 times per week for 1 h [30]. This makes comparison difficult; however, it suggests that physical activity, exercise, or sport can generate both acute and chronic effects on executive functions. It is very important to further investigate to corroborate this idea.

Furthermore, based on the intensities reported in the included studies, it appears that to benefit from exercise on inhibitory control, selective attention, working memory, and cognitive flexibility, one should aim for an intensity of at least 50% of maximum heart rate. However, further research and review of the benefits and intensities for cognitive flexibility and working memory are needed, as of all the articles that reported benefits for working memory and cognitive flexibility, only one stated the intensity achieved during the session [28].

Another important point within the review was that the only study that did not report significant improvements in executive functions was the study by Fritz & O’Connor [27], which was based on a yoga program; however, another study included in the review was also based on a yoga intervention [26] and did report significant improvements. Chen et al. [35] mentioned that a high-intensity exercise allows achieving a significant improvement in executive functions in patients with ADHD, so it is necessary to continue reviewing whether the benefits obtained from the practice of physical activity, exercise, or sport are conditioned to the intensity of the exercise or depend on the heart rate worked during the session.

Secondarily, benefits were found in depression levels from the Dass-21 questionnaire, but not in anxiety and stress levels [31], which is a result that suggests exploring the mental health of adults with ADHD, since anxiety and stress are two factors that affect the functioning of executive functions; specifically, stress influences decision-making and anxiety influences sustained attention [36]. Moreover, both are important parameters within quality of life [37].

Finally, it was found that there is no increase in BDNF from the practice of 30 min on the treadmill in adults with ADHD [26], which could mean that one session is not enough to obtain an increase in BDNF, that the exercise intensity was not sufficient for that stimulus, or that improvements in executive functions would be given from other mechanisms of action. Schmolesky et al. [38] mentions that to obtain a significant improvement in BDNF, it is necessary to have at least an intensity of 80% of heart rate and at least 40 min of exercise and that the longer the exercise, the greater the probability of significant improvement. Therefore, it would be interesting to continue exploring this variable. This is because dopamine modulation is relevant in people with ADHD, since exercise can produce improvements in the increase in dopamine [39], contributing to the improvement of executive functions [40]. Similarly, physical activity or exercise can promote self-regulation linked to executive functions such as overriding or inhibiting behaviors, which are supported by Baumeister’s Self-Control Strength Model. From this point of view, this type of intervention has a moderating effect on cognitive and brain health [41].

4.1. Limitations and Strengths

Among the limitations, we find the wide heterogeneity of the interventions, which makes it difficult to choose or recommend which intervention is more effective or feasible for ADHD. Also, the lack of a meta-analysis does not allow us to quantify or calculate the effect of the interventions; this analysis was also not performed due to the differences between the types of interventions, variables, and outcomes. The possible influence of psychiatric or psychological comorbidities in the patients was not considered. The degree or type of ADHD of the participants was not taken into account when presenting the results, as the included articles only mention the participation of individuals diagnosed with ADHD; although diagnoses were confirmed, there was no differentiation by subtype or grade. Therefore, differences in the benefits obtained according to the different types of ADHD cannot be ruled out. No comparisons were made between men and women, a point that could be important to consider in future research, since we do not know if the benefits obtained from exercise are equal for both sexes. Furthermore, there is a predominance of small sample sizes, so we also recommend taking the results with due caution and encourage expanding the sample sizes of future studies. Although there was a predominance of good scores on the TESTEX scale, a common limitation is the lack of blinding during the protocol and the lack of information on the exercise intensity achieved in some interventions, which can lead to bias in the results and difficulties in generalizing the conclusions. Finally, we understand that the concepts of physical activity, sport, and exercise are different, but for practical purposes, they were used as synonyms, as they were named differently depending on the context and the author but with a common focus. Furthermore, the use of these terms alone meant that other interventions such as physical therapy, compensatory sport, or adapted sport could have been excluded from this review.

Among the strengths, we found the inclusion of gray literature, which allowed increasing the number of articles included in the review. There is also a greater number of articles of good methodological quality, which is always beneficial in conclusions.

4.2. Practical Implications

Aerobic sessions from 10 min to two or three weekly sessions with a minimum duration of 30 min for at least 6 weeks can be a beneficial alternative to improve executive functions and, therefore, the quality of life of adults with ADHD. We recommend always accompanying such activities or programs with a professional or expert on the subject and, above all, considering personal tastes and interests in order to maintain this habit in the long term.

More specifically, tai chi, hatha yoga, Pilates, a HIIT workout, or even walking on a treadmill or an ergometer bike can be a viable option to obtain such benefits, as long as you achieve at least a 50% heart rate during the session, and ideally above that.

4.3. Future Lines of Research

It would be very interesting to explore the benefits of physical activity, exercise, or sport on executive functions in older adults with ADHD and to review the association between heart rate and the benefits obtained with exercise, since it seems to be a variable that predominates in these benefits. To explore the mental health of participants with ADHD and the effect of the practice of physical activity, exercise, or sport. It will also be interesting to explore whether the improvements are episodic or projected over the long term. Furthermore, compare whether the improvements obtained in adults with ADHD are equal to, less than, or greater than those of their counterparts without ADHD. Finally, to delve into high-intensity training such as HIIT can be a good alternative for studying, given the shorter time required for each session and the limited time available in today’s society.

5. Conclusions

It is concluded that the practice of physical activity, exercise, or sport has a positive and significant effect on the executive functions of adults with ADHD, specifically on selective attention, inhibitory control, and cognitive flexibility. In addition, benefits were observed in depression, brain activation, and stability, both acutely and chronically; therefore, it is a concrete and effective alternative that can be considered as an additional or complementary treatment to improve ADHD symptomatology. Specifically, from single sessions of 10 min to two or three weekly sessions with a minimum duration of 30 min for at least 6 weeks, benefits in executive functions are generated in adults with ADHD.