ABSTRACT
PURPOSE/HYPOTHESIS: Down syndrome (Ds) or Trisomy 21 is a common genetic birth condition, and those with Ds typically display decreased cardiorespiratory fitness compared to those without Ds, potentially leading to an increased risk for cardiovascular conditions and mortality. Low cardiorespiratory fitness is partially caused by low physical activity levels in this population. The COVID-19 pandemic caused community-based activity programs to shut down, as individuals with Ds are at increased risk for COVID-19 hospitalization and death. Thus, it was vital to explore alternatives of in-person exercise during the pandemic. The purpose of this study was to investigate the effects of a remote 12-week exercise intervention on aerobic endurance in individuals with Ds. NUMBER OF SUBJECTS: Twenty individuals with a medical diagnosis of Down syndrome were recruited and consented to participate. One participant dropped out for reasons unrelated to this study. Data was collected on 19 participants (5 females, 14 males;age: 25.4 ± 4.8 years;height: 156.9 ± 10.5 cm;weight: 72.5 ± 14.6 kg). The participants needed to be generally healthy and sedentary to be included in this study. MATERIALS AND METHODS: Nineteen individuals with Ds completed a structured physical therapist-led 12-week exercise intervention via remote video platform, which consisted of cardiovascular activity, foundational strength exercises targeting core/postural activation and endurance, hip strengthening exercises, and visual-vestibular coordination activities. Using the same platform, aerobic endurance was assessed using the 2 Minute Step Test (2MST). To investigate learning effects of the 2MST, it was performed twice in both the pre- and post-intervention testing sessions. BlandAltman plots were used to assess learning effects and a paired sample t-test was used to assess the effect of the intervention on cardiorespiratory fitness. RESULTS: The Bland-Altman plots showed an increase in the number of steps between first and second execution of 2MST in both pre-intervention (mean difference: -8.9 ± 3.9 = 95% CI [-12.8, -5.04]) and post-intervention testing (mean difference: -5.7 ± 4.5 = 95% CI [-10.2,-1.2]) which suggests a learning effect. Therefore, the second execution of the 2MST was used for pre-post intervention comparisons. A paired sample t-test showed a statistically significant improvement of the 2MST between the pre-intervention (67.6 ± 23.6 steps) and post-intervention (79.4 ± 21.8 steps) measurements (P < 0.01). CONCLUSIONS: This research shows a significant learning effect between the first and second 2MST executions. There was also a significant improvement of cardiorespiratory fitness following the exercise intervention. CLINICAL RELEVANCE: This study shows virtual platforms are an effective mode to deliver an exercise intervention to increase aerobic endurance in those with Ds. The results also support the 2MST as a useful tool to assess aerobic endurance in this population via a virtual platform. It is important to have the participant perform at least 2 trials to account for the learning effect with this test.