Cardiorespiratory fitness (CRF) classification by the 6-minute walk test (6MWT) distance is valid in comparison with VO2max, especially for identifying adults with low CRF, according to a study published in Pulmonology. Victor Z. Dourado, PhD, and colleagues developed a CRF classification using the 6MWT distance in asymptomatic adults considering the treadmill maximum oxygen uptake (VO2max) as the gold standard method. They evaluated O2 and 6MWT distance in 1,295 asymptomatic participants aged 18-80. Age- and sexrelated CRF was classified based on percentiles of very low, low, regular, good, excellent, and superior for both VO2max and 6MWT distance. They also investigated the 6MWT distance cut-off (% prediction) with the highest sensitivity and specificity for identifying each VO2max, classification. VO2max declined by 8.7% per decade in both men and women. The 6MWT distance declined by 9.3% per decade in women and 9.5% in men. Moreover, the 6MWT distance (% prediction) showed excellent ability to identify extremely low CRF (6MWT distance ≤96%) and good ability to differentiate CRF as low (6MWT distance=97%-103%;), excellent (6MWT distance=107%-109%), or superior (6MWT distance >109%).
