Table 2.

Synthesis of the systematic search of the scientific literature of the articles selected on the effects of exercise in children with autistic spectrum disorder (ASD).

Author (Year)	Country	Type of Study	Objectives	Sample	Intervention	Data Collection	Data Analysis Method	Outcomes
1. Kern, Koegel & Dunlap (1984)	USA	Non-randomized intervention trial	Manipulate two types of physical exercise: vigorous versus less vigorous exercise. Assess whether these activities would influence the children’s subsequent stereotypic and other responding	N = 3 8.33 ± 2.31 years old	A simultaneous-treatments design was used in which sessions of one condition (e.g., 15 min. jogging) were alternated with sessions of the other condition (e.g., 15 min. ball playing).	Scores of stereotypies from direct observation on three conditions: no exercise, with vigorous physical exercise and moderate exercise. Stereotypies observation time 90 min.	Percentage of occurrences differences	Average reduction of stereotypes: (a) Baseline (24.89) (b) Moderate (37.79) (c) Vigorous (22.88)
2. Levinson & Reid (1993)	Canada	Non-randomized intervention trial	Examined effects of exercise intensity on the stereotypic behaviors.	N = 3 (2M; 1F) 11.0 ± 0.0 years old	Two treatment conditions: a mild exercise (15 min walking) program and a vigorous (15 min jogging).	Number of occurrence of stereotypic behaviors. Stereotypies observation time 90 min.	Percent agreement ratio differences	Average reduction of stereotypes: (a) pre walking (73 ± 3) post walking (75 ± 8) (b) pre jogg (72 ± 3) post jogg (55 ± 6).
3. Oriel et al. (2011)	USA	Within-subjects crossover design Non-randomized intervention trial	Determine whether participation in aerobic exercise before classroom activities improves academic engagement and reduces stereo-typic behaviors.	N = 9 (7M; 2F) 5.2 ± ? years old	The treatment condition included 15 min of running/ jogging followed by a classroom task. The control condition included a classroom task not preceded by exercise.	Number of occurrence of stereotypic behaviors demonstrated, the percentage of on-task behavior, and the numbers of correct/incorrect responses given during academic tasks for each child. Stereotypies observation time 15 + 15 min.	Wilcoxon signed rank test	(a) Intra-class correlation coefficients: correct and incorrect responses, time on task and number of stereotypic behaviors observed (0.97, 0.84, 0.96, and 1.0, respectively). (b) Correct responding: 71.49% on control days vs. 82.57% on treatment days. (c) On-task time and Stereotypic behaviors: no sig. differences.
4. Bahrami et al. (2012)	Iran	Non-randomized intervention trial	Assess the effects of 14 weeks of Kata techniques training on stereotypic behaviours of children in autism spectrum disorders.	N = 30 (26M; 4F) 9.13 ± 3.27 years old	Formal exercises Kata technique, 1 session/day, 4 days/week for 14 weeks (56 sessions). The duration of exercise was increased from about 30 min at the start of the program to 90 min after 8 weeks. The time breakdown was as follows: 15 min of warm-up (10 min for stretching, 5 min for jogging), 65 min for the main activity, and 10 min for cool down.	Scores of stereotypies from direct observation by the subscale of Gilliam Autism Rating Scale—2nd edition (GARS-2). Administer stereotypies subscale before and after intervention (30 to 90 min of exercise).	Performed statistical analyses with an independent samples t-test, a 2-factor mixed-model ANOVAs, and a paired t-test by using SPSS software (Version 11.5).	Average reduction of stereotypes: (a) baseline (12.53 ± 6.92) EG (14.47 ± 7.71) CG (b) post-intervention (7.20 ± 5.65) EG (13.93 ± 8.55) CG (c) follow-up (8.07 ± 5.82) EG (13.40 ± 7.66) CG
5. Liu et al. (2016)	USA	Non-randomized intervention trial	Examine the effects of physical activity on stereotypical behaviors of children with ASD.	N = 23 (16M; 7F) 7.6 ± 0.65 years old	Certain activities were offered to the participants assuming that they would raise the child’s heart rate to the desired intensity level such as jumping on a trampoline, stationary biking, completing an obstacle course, and/or playing dance-dance revolution game, MVPA for 15 min.	In a period of 4 h, children were observed for 2 h at baseline and with intervals of 15 min. Then after 15 min of MVPA participation, children were observed for 2 h with intervals of 15 min and recorded as either engaging in stereotypic behavior (SB) or task engaged behavior (TE). Stereotypies observation time 120 min.	Repeated measures ANOVA analysis Effect-size	All children (100%) were engaged in moderate to vigorous intensity level during physical activity participation. For a 4-h observation period, results showed that physical activity reduction effect on stereotypic behaviours in children with ASD lasted for 2 h for. This was determined by comparing the baseline observation data with the post physical activity observation data, which were recorded in the same way using the 15 min’ interval for SB or TE ratings. Significant differences were found on pre and post percentage scores, F (1, 17) = 7.523, p = 0.009 < 0.05. No significant difference was found on gender, F (1, 17) = 4.253 p = 0.009 > 0.05, and disorder F (2, 17) = 2.949, p = 0.009 > 0.05.
6.Nazemzadegan et al. (2016)	Iran	Non-randomized intervention trial	Evaluating the effectiveness of ball exercises on the reduction of stereotypical behavior of children with autism spectrum disorder	N = 8; 9.0 ± 2.5 years old	Quasi-experimental with pretest-post-test and control group. Sixteen children were selected and were randomly assigned to two groups with eight children each (test and control). Both the experimental and control groups were placed under the Jim ball intervention training for 24 sessions (12 weeks, 2 sessions of 45 min of exercise). Individual training sessions were conducted for each subject.	Scores of stereotypies from direct observation by the subscale of Gilliam Autism Rating Scale—2nd edition (GARS-2). Administer stereotypies subscale before and after intervention (45 min of exercise).	Kolmogorov-Smirnov Test Regression analysis of covariance	Analysis of variance showed a significant difference in post-test scores of both the experimental and control groups (p = 0.01), thus showing the effectiveness of the intervention. Results suggested that the Jim exercise ball could change the stereotypical behavior of children with high functioning autism spectrum disorder.
7. Olin et al. (2017)	USA	Non-randomized intervention trial	Quantify the acute effect of exercise and to assess the influence of duration and intensity on the frequency of stereotypic behaviors in children with ASD	N = 7; 13.0 ± 1.4 years old	Participants were randomly assigned to exercise or control group. Exercisers self-selected a stationary bike, a treadmill or an elliptical ergometer. Continuous aerobic exercise was performed at a low (L) or high (H) intensity for either 10 or 20 min. Four exercise sessions served as experimental conditions: 10L,10H, 20L, and 20H. Intensity was: L between 50% and 65% age-HRmax and between 70% and 85% HRmax via continuous measurement, along with assessment of a rating of perceived exertion every 3–5 min using the OMNI scale.	Participants exhibited observable forms of self-stimulation and other inappropriate behaviors. As these behaviors are different from person to person, each subject´s mannerisms were determined and used for the subsequent measure. The primary SSB identified were hand flapping and echolalia. Stereotypies observation time 60 min.	Repeated-measures 5 × 5 (condition × time) ANOVA, and interaction effects followed-up by examining simple effects of condition within time.	A sig. condition main effect (p < 0.01) and a sig. time condition interaction effect (p < 0.10) were found. Sig. diff. between conditions in the first 15 min after exercise (p < 0.05). Pairwise comparison indicated that 20H produced sig. worse SSB than all other conditions (p < 0.10) except control (p < 0.10). Sig. diff. between conditions at post30 (p < 0.05), with 10L with greater decrease in SSB than 20L or 20H (p < 0.10). Control differed only from 20H (p < 0.10). Sig. diff. between conditions at post45 (p < 0.08) due to the fact that 10L produced sig. greater reductions in SSB compared with all other conditions (p < 0.10). Diff. between conditions also at post60 (p < 0.01), with 10L producing better effects on SSB than Control or 20H (p < 0.05).
8. Toscano et al. (in press)	Brazil	Randomized intervention trial	Effects of a 48-week exercise-based intervention on the metabolic profile, autism traits and perceived quality of life in children with ASD	N = 46; 8.2 ± 1.7 years old	Climbing and support in the bar (Upper limb strength); Release to the basket (Upper limb strength); Work with elastics (Strength of the lower and upper limbs); Walking on steps and inclined plane and step box with target and sequenced march (Strength, Coordination).	Autistic traits scale values decreased across the 48-week of intervention. Administer stereotypies subscale before and after intervention (30 min of exercise for 48 weeks).	Multilevel modeling to examine the responses to the 48-week exercise-based intervention program	Participants from the intervention group revealed a decrease across the 48-weeks of intervention with physical exercise (−8.1, 95% CI, −12.2 to −4.0, effect size = 1.05).