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

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.

The effect of acute exercise on the performance of verbal fluency in adolescents and young adults with Down syndrome: a pilot study.

BACKGROUND: The high prevalence of cognitive dysfunction is well documented in individuals with Down syndrome. However, only a few studies have focused on the effect of exercise on cognitive performance in this population. In particular, verbal fluency has been shown to be relevant to the early onset of Alzheimer's disease in individuals with Down syndrome. Thus, this study was aimed at investigating the relationship between acute exercise and verbal fluency in this population. METHODS: It was a pre-post design. Twenty-eight participants (aged 14-31) were assigned to high-intensity exercise (i.e. 70-85% of predicted maximum heart rate) (N = 8), moderate-intensity exercise (i.e. 50-69% of predicted maximum heart rate) (N = 10) or attentional control (N = 10) groups. Two exercise groups walked on a treadmill using an incremental walking protocol, and the attentional control group watched a video for 20 min. Measures of verbal fluency (i.e. semantic fluency and phonetic fluency) were tested pre-intervention and post-intervention. RESULTS: The result showed a quadric trend between semantic fluency and intensity of exercise. The improvement in cognitive performance on semantic fluency test was observed in the moderate-intensity exercise. However, neither a linear trend nor a quadric trend was seen in phonetic fluency. CONCLUSIONS: The result showed an inverted-U relationship between exercise intensity and semantic fluency. A larger sample size, testing time and more reliable psychophysiological measures (e.g. VO2 max and neuroimaging technology), should be considered to explore the underlying mechanisms in this population.

Walking performance in adolescents and young adults with Down syndrome: the role of obesity and sleep problems.

BACKGROUND: High prevalence of obesity and features of obstructive sleep apnea (OSA) are major health issues in individuals with Down syndrome (DS), and both may also affect adversely on their daily activities. Further, lower levels of physical work capacity (PWC) have been reported in this population compared to their peers with intellectual disabilities. However, no study examines the relationships between obesity and sleep problems with PWC in individuals with DS. Thus, this study investigated the influence of body mass index (BMI) and different types of sleep problems on PWC in adolescents and young adults with DS (14-31 years). METHODS: The incremental treadmill walking trial was used to assess PWC. RESULTS: The negative associations were indicated between BMI and walking steps (p = .03) as well as features with OSA and walking steps (p = .04). Thus, BMI and OSA were included in the regression analysis to estimate the walking steps achieved during walking trials. In addition, Bland-Altman plots demonstrated no overestimation and underestimation of variability in the difference between actual and estimated walking steps developed by using BMI and OSA. CONCLUSIONS: Obesity and sleep problem are potentially detrimental to walking performance (i.e., fewer walking steps) in individuals with DS. Thus, individuals with DS may adopt a slow walk speed due to the increased balance deficits and physical fatigue that result from obesity and sleep fragmentation, respectively. Exercise interventions, which have the potential to reduce obesity and OSA, are recommended to improve the accomplishment of PWC in individuals with DS.

Examination of participation and performance of dancing movement in individuals with Down syndrome.

Purpose: Many observations and anecdotes have suggested that individuals with Down syndrome (DS) love music, specifically moving to music. The purpose of this study, with the assumption that the music makes people with DS dance showing more movement than general public's, is to observe the change in movement patterns of people with DS while they dance. Methods: The present study videotaped 10 individuals with DS and 10 mental age-matched (MA) participants dancing in response to five different types of music (e.g. rock fast, rock slow, classical, jazz, pop). Results: Our preliminary results suggest that individuals with DS had significantly more body sway than MA participants. In addition, individuals with DS were more active to the music than MA participants. However, no motor timing deficit was evident. Conclusions: This suggests that individuals with DS actively maintain their posture position in the challenging condition. Furthermore, they clearly enjoyed listening to the music and dancing. Based on our results, we suggest that more research need to be conducted examining the effects of dancing program on postural control, and timing in this population.

Dose-response relationship between intensity of exercise and cognitive performance in individuals with Down syndrome: a preliminary study.

BACKGROUND: Cognitive performance has been shown to be relevant to the early onset of Alzheimer's disease in individuals with Down syndrome. This study was aimed at investigating the dose-response relationship between acute exercise intensity and cognitive performance in this population. METHODS: In the current study, we measured information processing speed and two aspects of executive function (i.e. attention shifting and inhibitory control). Participants were assigned to high-intensity exercise (i.e. 75-85% of predicted maximum heart rate) (N = 6), moderate-intensity exercise (i.e. 50-75% of predicted maximum heart rate) (N = 6) or attentional control (N = 6) groups. Two exercise groups walked on a treadmill using an incremental intensity walking protocol, and the attentional control group watched a video for 20 min. Measures of information processing speed and executive function were tested pre-intervention and post-intervention. RESULTS: Our results indicated that the performance in choice reaction time test was impaired in the high-intensity exercise, whereas improved performance was observed in the moderate-intensity exercise. However, moderate-intensity and high-intensity exercises were beneficial for inhibitory control aspect of executive function. Further, inconsistent with previous studies, a quadric trend was seen in information processing speed, and a liner trend was evident in inhibitory control. CONCLUSIONS: Future research is needed to examine with a larger sample size, and more physiological measures are necessary to explore the underlying mechanisms in the relationship between exercise intensity and cognitive performance in individuals with Down syndrome.

The effects of assisted cycling therapy (ACT) and voluntary cycling on reaction time and measures of executive function in adolescents with Down syndrome.

BACKGROUND: Reports of positive effects of aerobic exercise on cognitive function in persons with Down syndrome are extremely limited. However, a novel exercise intervention, termed assisted cycling therapy (ACT), has resulted in acutely improved cognitive planning ability and reaction times as well as improved cognitive planning after 8 weeks of ACT in adolescents and young adults with Down syndrome. Here, we report the effects of 8 weeks of ACT on reaction time, set-shifting, inhibition and language fluency in adolescents with Down syndrome. METHODS: Adolescents with Down syndrome (age: ~18 years) were randomly assigned to 8 weeks of ACT (n = 17) or voluntary cycling (VC: n = 16), and a convenience sample (n = 11) was assigned to be an inactive comparison group (NC: n = 11). During ACT, the cycling cadence of the participants was augmented to an average cadence that was 80% faster than the voluntary cadence of the VC group. The increase in cadence was achieved with an electric motor in the stationary bicycle. Reaction time, set-shifting, inhibition and language fluency were assessed before and after 8 weeks of intervention. RESULTS: Power output and heart rates of the ACT and VC groups were almost identical, but the ACT cadence was significantly faster. The ACT group, but not the VC or NC groups, showed significantly improved reactions times (Hedges' g = -0.42) and inhibitory control (g = 0.18). Only the VC group showed improved set-shifting ability (g = 0.57). The ACT and VC groups displayed improved semantic language fluency (g = 0.25, g = 0.22, respectively). DISCUSSIONS: These and previous results support the hypothesis of increased neuroplasticity and prefrontal cortex function following ACT and, to a smaller extent, following VC. Both ACT and VC appear to be associated with cortical benefits, but based on current and previous results, ACT seems to maximize the benefits.

The association between a single bout of moderate physical activity and executive function in young adults with Down syndrome: a preliminary study.

BACKGROUND: This study was aimed at investigating the impact of a single exercise intervention on executive function in young adults with Down syndrome (DS). METHODS: Considering the relations among executive function, physical and mental health and early onset of Alzheimer's disease in this population, we tested three components of executive function (e.g. choice-response time, attention shifting and inhibition) that have been shown to be impaired in previous studies. Ten persons with DS were assigned to an exercise group, who walked on a treadmill for 20 min at moderate intensity and ten additional persons with DS were assigned to an attentional control group, who watched a video. Measures of executive function were tested pre and post interventions. RESULTS: These results showed non-significant improvements in choice-response time (P = 0.32) and attention shifting (P = 0.13) but a statistically significant improvement in inhibition (P = 0.03) after the exercise intervention. CONCLUSIONS: Given the improved inhibition ability, exercise may be an effective intervention, even in a signal session. However, only a few studies have focused on this topic. Based on theoretical models linking exercise to executive function, we proposed that exercise may increase arousal status or enhance neural transmission. Hence, future work is needed to examine the exact mechanism in the relationship between exercise and executive function for individuals with DS.

Assisted cycling exercise improves fine manual dexterity in persons with Down's syndrome.

BACKGROUND: This study was aimed at investigating the impact of assisted cycling therapy (ACT) on fine manual dexterity in adults with Down's syndrome (DS). METHODS: Nine persons with DS completed four different interventions: voluntary exercise (VE), voluntary with music (VEM), assisted exercise (AE) and no exercise (NE). Fine manual dexterity (e.g., Purdue Pegboard) was tested pre and post interventions. RESULTS: The results showed dominant and bimanual hands were improved after AE but no evident in either subtest after VE. The assembly subtest, processed by spatial-temporal ability, was only improved after VEM and NE. CONCLUSIONS: It is speculated that AE stimulated more peripheral sensory input to the motor cortex and neurotransmitters than the other interventions. In addition, the involvement of music may enhance spatial intelligence during VEM. Even though the exact mechanisms are still unknown, the implication of our results showed that AE and VEM can improve fine manual dexterity in persons with DS.

Reversal of handedness effects on bimanual coordination in adults with Down syndrome.

BACKGROUND: Research on unimanual tasks suggested that motor asymmetries between hands may be reduced in people with Down syndrome. Our study examined handedness (as assessed by hand performance) and perceptual-motor integration effects on bimanual coordination. METHODS: Adults with Down syndrome (13 non-right-handed, 22 right-handed), along with comparison groups of adults (16 non-right-handed, 21 right-handed) and children (15 non-right-handed, 22 right-handed) without Down syndrome, drummed with auditory, verbal and visual instructions. RESULTS: In contrast to handedness effects in the children and adults without Down syndrome, right-handed participants with Down syndrome led more with the left hand, and had lower coordination stability than non-right-handed participants with Down syndrome. CONCLUSIONS: The reversed handedness effect during bimanual coordination suggests a complex relationship between handedness and task requirements in adults with Down syndrome.