Rooney D, Herkenrath S, Priegnitz C, et al. - In this prospective analysis on obese individuals [(n = 21; 10 females, age 51 ± 15 (mean ± SD), BMI 36 ± 5 kg/m²], researchers compared two routinely used exercise tests, 50 meter and six minutes of walking, and hypoxic challenge testing (HCT), in terms of diagnostic accuracy to determine fitness for air travel. Also, they also assessed the diagnostic potential of perceived dyspnoea as measured with the Borg scale, since this is often recorded subsequent to walking tests. They found that the only test separating the reference groups significantly with AUC 0.87 was HCT. Overall, they concluded that HCT but not simple walking tests can predict in-flight hypoxia in obese individuals.