Reliability and validity of the 6-min walk test in adults and seniors with intellectual disabilities.

Abstract Introduction Adults with intellectual disabilities (ID) have significantly lower rates of physical activity and fitness than adults without ID. The 6-min walk test (6MWT) is an inexpensive and simple way to test mobility and submaximal work capacity. Purpose To evaluate the test–retest reliability and validity of the 6MWT in adults and seniors with ID and explore factors contributing to the 6MWT distance (6MWD). Methods 46 participants with mild, moderate and severe ID levels (age = 41 ± 11 years) performed the 6MWT three times (T1; T2; T3) to determine test–retest reliability. To test validity, peak oxygen uptake (VO 2 peak) was measured using a treadmill protocol. To analyze factors contributing to the 6MWD, sex, height, fat mass % and fat free mass %, ID level, isometric leg strength and relative VO 2 peak were also measured. Results The walking distances for T1, T2 and T3 were 460.3 ± 76.9; 489.4 ± 81.2 and 491.4 ± 77.9 m, respectively. The 6MWDs between T1–T2 and T1–T3 were significantly different ( p 2 peak and isometric leg strength significantly contributed to the 6MWD ( R 2  = 0.55). Conclusions The 6MWT is an easy, inexpensive, reliable and valid test in adults and seniors with ID. Familiarization is necessary to obtain reliable values. Relative VO 2 peak and leg strength have significant impact on the distance walked.