Concurrent Validity and Test-retest Reliability of a Submaximal Exercise Test in Adolescents with Autism Spectrum Disorder

Cardiorespiratory fitness (CRF) is a component of health-related physical fitness and is defined as the ability of the circulatory and respiratory systems to supply oxygen to the working muscles during sustained physical activity [1]. Therefore, CRF is also regarded as a reflection of total body health [2] and is considered as a vital health sign [2-4]. In adolescents, higher CRF levels are inversely associated with cardiovascular and metabolic risk factors as well as increased risk of premature cardiovascular morbidity. [3, 5-7]. In addition, recent literature indicates that higher CRF levels are inversely associated with depressive symptoms in adolescents [8]. However, research indicates that adolescents with Autism Spectrum Disorder (ASD) have lower CRF levels compared to their typically developing peers [9-11], increasing their risk to develop adverse health outcomes. Despite the importance of CRF assessment, to our knowledge, no CRF tests have been validated in adolescents with ASD.

A high correlation (r = .820, p < .01) and good ICC (.720, p = .013) between the estimated VO₂ max values of ART 1 and ART 2 were found. The Bland-Altman plot was shown, with a mean bias of 0.02 ml/min/kg and -15.19 ml/kg/min – 15.23 ml/kg/min as 95% LOA. A moderate correlation (r = .580, p < .05), but poor ICC (.381, p = .014) between the estimated VO₂ max (ART 1) and measured VO₂ max (CPET) were found. The Bland-Altman plot was shown, with a mean bias of 11.56 ml/min/kg and -8.04 ml/kg/min – 31.15 ml/kg/min as 95% LOA.

The ART seems to be reliable, but less valid to examine CRF in adolescents with ASD. However, this is an ongoing study and therefore, no firm conclusions can be made yet.