Reliability and convergent validity of the 6-min run test in young adults with Down syndrome

Background

There is limited evidence about the psychometric properties of field tests to measure cardiorespiratory fitness in people with Down syndrome.

Objective

This study aimed at analyzing the reliability and convergent validity of the 6-min run test when performed by young adults with Down syndrome (DS).

Methods

In a cross-sectional design fifty-one young adults with DS (mean age 26.20 ± 7.14 years; 54% women) performed the 6-min run test and the 16-min shuttle run test twice with a one week-interval between test and retest.

Results

The 6-min run test offered high reliability for the distances covered (ICC: 0.974; 95% CI: 0.955–0.985) and good reliability when comparing peak heart rate values obtained in the test and retest (ICC: 0.870; 95% CI: 0.772–0.926). A significant correlation between the 6-min run test and the 16-min shuttle run test was observed for the test (r = 0.705; Sig = 0.001), and retest phases (r = 0.651; Sig = 0.001). The relationship between the estimated maximal oxygen consumption (VO₂ max) peak after the performance of the 16-min shuttle run test and the distance covered by the 6-min run test was statistically significant (r > 0.7). No significant differences were found between the equations that estimate VO₂ peak for both tests.

Conclusions

These findings suggest that the 6-min run test shows high test/retest reliability and moderate to moderately high convergent validity when performed by adults with DS.