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.