Immediate reinforcement increased duration of time riding the stationary bicycle in children with autism spectrum disorder: a pilot study

Abstract

The necessity of promoting physical activity in individuals with Autism Spectrum Disorder (ASD) has been emphasized for decades. One of the barriers to participate in physical activity for individuals with ASD is limited interest and motivation. Therefore, understanding the motivation to exercise in this population is important. The objective was to determine the effect of using contingent reinforcement in the form of watching a preferred DVD to increase duration of time pedalling on a stationary bicycle within their predetermined target heart rate zone (THRZ) in children with ASD. Using a crossover design, seven participants (11 2.7 years) who were diagnosed with ASD were randomly assigned to either Group A or B. Time spent pedalling on a bicycle within the THRZ was analysed using a linear mixed-effect model with Bonferroni adjustments. The results showed that the DVD intervention motivated children with ASD to exercise for more than 10 minutes in moderate to vigorous physical activity compared to when they were exercising without watching a DVD. This result is significant as number of studies have revealed that 10 minutes of exercise could bring improvements in activities of daily living such as behaviors and academic performance in school. 

Introduction

The number of people diagnosed with autism spectrum disorder (ASD) is the highest of all neurological disorders and is steadily increasing (Baio et al. 2018). For decades, numerous published studies (Biscaldi et al. 2014; Hanaie et al. 2014; Mody et al. 2017) have found motor deficiencies in individuals with ASD. More than 50% of children with ASD have movement difficulties based on a standard motor-skill assessment (Green et al. 2009). They also have poor motor coordination, deficits in gait and balance, and deficits in movement planning and arm motor functions that may limit their ability to be successful in certain activities (Fournier et al. 2010). Moreover, several researchers have suggested that when compared to a group of typically developing children, children with ASD have dyspraxia (Downey and Rapport 2012) and universal difficulties in several aspects of motor functioning that include gross and fine motor performance and simultaneous coordination of upper and lower-limb which limits their participation in physical activity.

Up to 50% of adults with developmental disabilities, including ASD, live sedentary lifestyles, and it is likely that because of this these individuals have health problems that are considered serious medical disorders (Berghöfer et al. 2008). According to Center for Disease Control and Prevention (CDC), moreover, Limited physical activity puts individuals with ASD at risk for a variety of health-related issues. For example, a lack of physical activity has been linked to obesity prevalence in both children and adults with ASD (CDC 2008). McCoy et al. (2016) reported elevated obesity prevalence using data from the most recent 2011–2012 National Survey of Children’s Health, a nationally representative survey conducted by the CDC National Center for Health Statistics. They found obesity prevalence of 22.2% in children with ASD compared with 14.1% in children without ASD. The consequences of overweight and obesity do not manifest immediately, but could lead to type 2 diabetes, hypertension, cardiovascular disease, gallbladder disease, postmenopausal breast cancer, colon and other cancers, osteoarthritis, back pain, and mental disabilities (Guo et al. 2002). The lower levels of physical activity may also impact deficits in motor planning for individuals with ASD (Lang et al. 2010). Consequently, numerous researchers have reported on the necessity of promoting physical activity in individuals with and without disabilities (Todd and Reid 2006; Srinivasan et al. 2014; Anderson et al. 2017).

There are a number of barriers to participation in physical activity for individuals with ASD that could cause them to be less physically active (Savage 2016). One barrier was limited success in physical activity that may be caused by characteristics of ASD, such as motor impairment, deficits in social interaction, problems with social initiation and response, and limited interest (Obrusnikova and Cavalier 2011). Poor motor functioning is another barrier that limits participation in physical activity for individuals with ASD (Koegel et al. 2001; Reid et al. 2003). Most importantly, motivating individuals with ASD to engage in physical activity is often considered a significant challenge (Lang et al. 2010). Therefore, it is imperative to understand that children with ASD are not motivated to exercise the same way as typically developing children (Newsome 2015). Having a better understanding of preferred activities among children with ASD could be beneficial to better prepare professionals regarding potential motivators for participation in exercise (Eversole et al. 2016).

Reviewing recent literature, it is undeniable that the rate of individuals with ASD using technology (i.e. personal computers, mobile devices, wearable technologies, robotics, videos, television) is increasing steadily (Valencia et al. 2019). Studies have revealed that using child preferred activities has been shown to be a valuable motivator for many activities that are less participated in and less preferred among children with ASD (Koegel et al. 2010; Taylor and Fisher 2010). An unpublished study by Newsome (2015) found that using technology, such as interactive video games, was an effective way to motivate children with ASD to engage in vigorous physical activity. The study explained that understanding the motivation to exercise in children with ASD is important and highlighted that potential motivations should be examined in future research.

Published studies have highlighted that it is critical to provide positive reinforcement immediately once expected/targeted behavior has been demonstrated by students (Gongola and Daddario 2010; Harwell and Jackson 2014; Sigler and Aamidor 2005). Moreover, immediate reinforcers have also been shown to be the preferred method by students in school-age (Luman et al. 2005). A number of researchers have explored whether utilizing immediate reinforcement increases the incidence of the desired motor behavior. Researchers who utilized immediate reinforcement in the motor realm indicated that immediate reinforcement of a desired discrete motor task led to an increase in occurrence of that behavior (Bellamy and Sontag, 1973). Caouette and Reid (1985) conducted a study that investigated the impact that auditory and visual stimulation had on the work output of six adults with intellectual disabilities who all took part in a bicycle ergometer training program. The researchers found that reinforcement contingencies were influential in increasing the subjects’ work output. In addition, Mathieson (1993) conducted a study to examine the effects of contingent and noncontingent reinforcement using television on adults with intellectual disability and found that all participants showed an increased duration of time exercising. Hart et al. (1968) investigated the effect of immediate reinforcement by comparing the presentation of random reinforcement and contingent reinforcement on preschool-age children with ASD and found that only in the latter condition was there a significant change in number of cooperative play in each participants. In addition, Epstein et al. (1994) tested the effects of contingent reinforcement in a family-based weight-control program for obese children and found that contingent reinforcement can produce more weight loss during the treatment phase for childhood obesity.

From 1974 to the present day, there have been fewer than 20 publications on research studies that have investigated interventions to increase motivation to improve engagement in physical activity in individuals with ASD. Only two of those studies, by Todd and Reid (2006) and Anderson et al. (2017), evaluated the effects of different interventions (using self-monitoring board, verbal cuing and edible reinforcers, watching videos during or after cycling) on participation in physical activity for persons with ASD. However, it was not discovered whether providing a participant a preferred DVD immediately after achieving the predetermined goal could increase the engagement in exercise in preadolescents with ASD. Moreover, the two studies were focused on a particular age range of individuals with ASD (9–11 and 15–20 years respectively), so the results from each study are not generalizable to all individuals with ASD in school-age. Therefore, extending the scope of investigation was necessary.

Purpose and hypotheses

Due to the many social, emotional, behavioral, and physical benefits of participating in physical activity for individuals with ASD, it is important to motivate this population to be physically active. Moreover, it is unclear whether participants’ self-selected motivator, DVD in this case, could increase the time engaged in exercise among children with ASD. Thus, the main focus of this study was to investigate the effect of using a participant preferred DVD to motivate children with ASD to ride a stationary bicycle.

The intervention allowed participants to view an individually preferred DVD while they pedalled a stationary bicycle as long as they pedalled fast enough to stay within their target heart rate zone (THRZ). Based on previous literature examining the relationship between reinforcement and physical activity performance (Todd and Reid 2006; Anderson et al. 2017; Bassette et al. 2018; Savage et al. 2018; Kraft et al. 2019), the hypothesis for this research study was that participants would pedal the bicycle longer in their THRZ when they were watching their preferred DVD than they would pedal when they were not watching anything.

Materials and methods

Participants

Seven male participants were recruited from the U-FIT Program that was designed to provide children and adolescents with disabilities and their siblings with art and physical activity. The inclusion criteria were: participants needed to be diagnosed with ASD per the criteria from the DSM-V (American Psychiatric Association 2013), be between 5 to 18 years of age (school-age children), be able to understand English and follow simple instructions for the protocol. Simple instructions provided to all participants were about the procedure of each session (i.e. how long each participants will be pedaling the stationary bicycle, when participants will be watching DVD, when the DVD will stop and resume)

Instrumentation

A LeMond Fitness G-force RT recumbent stationary cycle (LeMond Fitness, Inc., Woodinville, WA) was chosen after careful consideration of safety, comfort, and practicality. The bicycle enables riders to watch a DVD using an iPad with their back being supported and is also more comfortable than an upright cycle. An iPad was placed on the instrument panel with Bose wireless around-ear headphones for watching DVDs once the participants reached their target heart rate zone (THRZ). The DVD intervention was contingent upon the participants being in the THRZ. If the participant went below the THRZ, the video was turned off until they were back in the THRZ. Work intensity was determined by heart rate reserve (HRR) and was measured for each participant while cycling. THRZ has been set at different levels during other studies; however, the American College of Sports Medicine (ACSM 2013) recommends that moderate-intensity physical activity should be performed at approximately 40%–59% of HRR. Moreover, as moderate-intensity physical activity is considered to be effective in children with ASD (Anderson et al. 2017), the rate of 40%–59% of HRR, moderate-intensity physical activity as defined by the ACSM, was set as the THRZ for this study. The THRZ for each participant was calculated by using the HRR and resting heart rate (RHR). The minimum THRZ was computed as (HRR × 0.4) + RHR, and the maximum THRZ was calculated as (HRR × 0.59) + RHR. Heart rate (HR) was measured using the Polar E600 heart rate strap and wrist receiver (Polar Electro, Inc., Kempele, Finland).

Study design

Using a 2 × 2 crossover trial and as can be seen in Figure 1, seven participants were randomly allocated to two study groups; group A and B. A 2 × 2 crossover design, in which each subject receives all intervention and the objective is to study differences among the interventions (Tucker-Drob 2011), was applied as it is an appropriate design to measure the effects of both interventions in the same participants in order to reduce the amount of variability that is caused by differences between participants.

Figure 1.

Protocol timeline.

Each group consisted of two intervention orders (Group A: DVD then No DVD; Group B: No DVD then DVD) with a 2 week of washout between interventions to minimize a possible carryover effect. Participants allocated in group A received intervention X (DVD) first, allowing them to view DVD once they reached THRZ while pedalling at their predetermined resistance rate, followed by intervention Y (No-DVD) pedalling without viewing a DVD and vice versa in group B. Data were collected for five weeks excluding the wash-out period (refer to Figure 1).

Protocol procedures

After confirming eligibility of all participants and obtaining parental consent, all participants were scheduled for different times to participate in the study. A pre-intervention survey was given that asked the participants to list their favorite movies. The researchers then provided one of the preferred DVDs for each participant. Once participants arrived to the study site, a researcher attached a heart rate strap to participants and the researcher wore a wrist receiver. The first session of the protocol was to determine the appropriate resistance level on the bicycle. Each participant started pedalling at level 1 and the level was increased every 3 min until they reached their THRZ. Participants were asked to stop once they reached the level where they could not pedal longer than 3 min and that level was used throughout the intervention.

Using a randomized crossover design, during the second session (2^nd and 3^rd visit), participants in Group A were asked to ride the bicycle at their predetermined resistance rate and were allowed to view their preferred DVD once they reached their THRZ. When participants reached their predetermined THRZ, the research assistant turned on the DVD. On the contrary, if the participants’ heart rate dropped below their predetermined THRZ, the DVD was immediately turned off by the research assistant. However, participants in Group B were asked to ride the bicycle at their predetermined resistance rate without viewing a DVD.

During the third session (4^th and 5^th visit), participants in Group B were asked to ride the bicycle at their predetermined resistance rate and were allowed to view the preferred DVD once they reached their THRZ. When participants reached their predetermined THRZ, as mentioned previously, research assistant turned on the DVD and vice versa. However, those in Group A were asked to ride the bicycle at their predetermined resistance rate without viewing a DVD. The second session and the third session were separated by 2-week washout period. Data on duration of time spent pedalling in the THRZ was collected on each visit. Figure 1 represents the timeline of the protocol. All participants were informed prior to starting each session that the DVD will stop once the heart rate monitor beep which indicates that the participants heart rate dropped below the THRZ and that they have to pedal faster in order to resume the DVD. Therefore, no prompts (e.g. visual, verbal, etc.) were provided while pedaling the stationary bicycle.

Statistical analysis

Descriptive statistics were computed as mean and standard deviation (SD). Normality assumption was justified by using the Shapiro-Wilks test. General linear models were used to test mean differences for cycling duration in the THRZ in group A (DVD first) and B (No-DVD first), respectively, between DVD and No-DVD interventions after adjustment for age. Linear mixed models were used to examine mean differences for cycling duration within the THRZ across group (A, B), time (session 2 vs. session 3), and interventions (DVD vs. no-DVD), respectively. All statistical procedures were performed by using the Statistical Package for Social Sciences (SPSS) software.

Results

Characteristics for study participants are presented in Table 1, as shown in mean age, 11.9 (SD = 2.7), minimum and maximum THRZ^a, 125 (SD = 3.2) and 153.3 (SD = 3.1), respectively. Table 2 indicates that participants in both group A (p = 0.019) and B (p < 0.001) had greater cycling duration within their THRZ with DVD, respectively, compared with children who cycled without viewing DVD. As shown in Figure 2, there were significant mean differences for cycling duration between DVD and No-DVD interventions in which children with DVD had 6.9 min (SEM = 0.95) greater cycling duration in the THRZ when compared with children with No-DVD (p = 0.01). There were no statistical differences in cycling duration between testing order (p = 0.92) and between time periods (p = 0.94), respectively.

Table 1.

Characteristics of the study participants.

Variable	$M^a$	${SD}^b$
Sex
Male ‘..(n)	7
Female (n)	0
Age	11.9	2.7
Severity of ASD (n)
Mild	5
Moderate	2
Severe	0
Minimum of THRZc (bpm)	125	3.2
Maximum of THRZ (bpm)	153.3	3.1

^aMean.

^bStandard Deviation.

^cTarget Heart Rate Zone.

Table 2.

Mean duration of cycling time in the THRZ between DVD and No-DVD intervention by group.^a

Group A		Group B
($M\pm SD$)		$(M\pm SD)$
With DVD	Without DVD	With DVD	Without DVD
10.65 ± 2.92	3.84 ± 0.99	10.83 ± 1.38	3.86 ± 1.02

^aAdjusted for age.

Figure 2.

Mean duration of time pedalling in the THRZ between DVD and No-DVD intervention.

Discussion

This is the first study, to our knowledge, that has examined exercise motivation following a participants’ preferred DVD or No-DVD during stationary cycling in children with ASD and measured exercise time in a moderate THRZ.

The results of this research suggest that providing an intervention that allows individuals with ASD to view selected DVDs as they pedal a stationary recumbent bicycle is an effective technique to increase the amount of time engaged in MVPA, and this is consistent with our hypothesis. Regardless of the order of intervention (e.g. DVD, No-DVD), the DVD group improved in pedalling time in their respective THRZ on a stationary bicycle (see Table 2). These tendencies were consistent in all 7 participants, even though there were differences within the range of improvements (Table 3). Therefore, this is a strong indication that providing the opportunity to view a preferred DVD is an effective way to motivate children with ASD to be physically active.

Table 3.

Mean duration of time pedalling in the THRZ with and without watching a DVD, and the variance of time between the two conditions.

Participant	Group	No DVD	DVD	Variation
1	A	4.21 min.	8.68 min.	+ 4.47 min.
2	B	5.16 min.	12.66 min.	+ 7.50 min.
3	B	3.92 min.	11.05 min.	+ 7.07 min.
4	B	2.68 min.	9.45 min.	+ 6.77 min.
5	A	2.72 min.	14.01 min.	+ 11.29 min.
6	A	4.59 min.	9.27 min.	+ 4.68 min.
7	B	3.68 min.	10.17 min.	+ 6.49 min.

Clinical relevance

Furthermore, participants were able to pedal for more than, or close to 10 min in their THRZ while watching their preferred DVD. While this was statistically significant, it is also clinically very important because research shows that 10 min of MVPA is effective enough to reduce the percentage of time individuals with ASD (age 10-11) engage in stereotypic behaviors during instructional activities in school (Mays 2013) and increase academic engagement (Nakutin and Gutierrez 2019). Moreover, 10 min of exercise improved executive control (Ramos et al. 2017) in typically developing children (age 10.3 ± 0.5) and cognitive function (i.e. memory functioning) in typical young adults (Crush and Loprinzi 2017). Thus, our results of the DVD intervention motivating children with ASD to exercise for more than 10 min moved them into a level of exercise that has shown improvements in real activities of daily living such as behaviors and academic performance in school. In addition, it also has been discovered that 10-minutes of low-intensity exercise reduced echolalia and hand-flapping for individuals with ASD (Losinski et al. 2017)

Immediate reinforcement

The results from this research are analogous with the findings of other researchers who have studied the application of immediate reinforcement in obese children 8-12 years old. Epstein et al. (1994) tested the effects of mastery criteria and immediate reinforcement in a family-based behavioral weight-control program for obese children and their parents over a period of 2 years. Participants were randomly divided into two groups, experimental versus control. The experimental group was targeted and reinforced for mastery of diet, exercise, weight loss, and parenting skills and the control group was taught behavior-change strategies and provided non-immediate reinforcement at the same rate that the experimental group received reinforcement. Through this study, researchers found that children in the reinforcement group showed significant weight change compared to the no reinforcement group; however, these effects were not maintained at 2 years. The findings of the study suggest support for employing immediate reinforcement to improve outcomes during treatment for childhood obesity. Hart et al. (1968) investigated the effect of adult social reinforcement on the cooperative play of a 5-year-old girl in a preschool setting by comparing results of two conditions, presenting reinforcement randomly throughout the school day and presenting the reinforcement contingently—only when cooperative play was observed. The researchers found that only in the contingent condition was a significant change in cooperative play observed. Both studies (Epstein et al. 1994; Hart et al. 1968) showed the significance of immediate reinforcement in influencing weight loss and cooperative play, similarly, we showed immediate reinforcement with a DVD improves exercise cycling time and potentially the related benefits of exercise (e.g. improved behaviors, improved memory, etc.) in children with ASD.

In addition, Mathieson (1993) conducted a study to investigate the effects of immediate and non-immediate reinforcement using television with adults with an intellectual disability. Three adults, aged 21 to 44 years and with IQs ranging from 25 to 43, participated in an exercise-bicycle ergometer training routine three times a week over a 10-week period. During baseline, the adults participated in a 20-minute training session with non-immediate reinforcement of a television played continuously. During the next phase, the availability of the television was made contingent based on each participant’s ability to reach his or her target RPM. Mathieson (1993) found that all participants showed greater improvement in duration of time exercising while they were in the second phase, using television contingently. This is consistent to the findings from the current research, in which immediate reinforcement using a preferred DVD increased the duration of time engaging in stationary cycling in children with ASD.

Limitations

The fact that a small sample was used in this study is a limitation to the findings because it decreases statistical power, which in turn decreases the generalizability of the results to other populations with ASD, however, the results were significant even with a small sample size which indicates that the intervention was very effective. In addition, the small sample size was acknowledged in the title indicating that this is a pilot study. Furthermore, the fact that all participants were male could be a limitation to the generalizability of the results. However, this could be explained as ASD is more commonly diagnosed in males, with a ratio of about 1 female for every 4 males diagnosed. Thus, the findings of the research support applying a self-selected video-based intervention to improve engagement in physical activity for individuals aged 7 to 15 with ASD.

Practical application

For parents, teachers, and physical therapists the results of this study could be generalized to suggest that watching a video during exercise increases exercise time significantly which plays a factor in increased health, decreased clinical symptoms and potential improvements in cognitive function. The results from this study also show that it is important for children to select their preferred DVD of their choice to watch while pedalling in their THRZ on the stationary bicycle.

Further research is needed to examine and compare the difference in effectiveness of various types of interventions that could motivate individuals with ASD to be physically active. It is critical to understand the difference between these interventions as our goal is to increase their motivation and ultimately their quality of life. 

Disclosure statement

No potential conflict of interest was reported by the author(s).