Whilst Critical Speed (CS) has been successfully translated from the laboratory into the field, this translation is still outstanding for the related maximum running distance (D'). Using iso-duration exhaustive laboratory and field runs, this study investigated the potential interchangeable use of both parameters, D' and CS. After an incremental exercise test, 10 male participants (age: 24.9±2.1 yrs; height: 180.8±5.8 cm; body mass: 75.3±8.6 kg; V̇ ˙VO2peak 52.9±3.1 mL∙min-1∙kg-1) performed 3 time-to-exhaustion runs on a treadmill followed by 3 exhaustive time-trial runs on a-400 m athletics outdoor track. Field time-trial durations were matched to their respective laboratory time-to-exhaustion runs. D' and CS were calculated using the inverse-time model (speed=D'/t+CS). Laboratory and field values of D' and CS were not significantly different (221±7 m vs. 225±72 m; P=0.73 and 3.75±0.36 m∙s-1 vs. 3.77±0.35 m∙s-1, P=0.68), and they were significantly correlated (r=0.86 and 0.94). The 95% LoA were ±75.5 m and ±0.24 m∙s-1 for D' and CS, respectively. Applying iso-durations provides non-significant differences for D' and CS and a significant correlation between conditions. This novel translation method can consequently be recommended to coaches and practitioners, however a questionable level of agreement indicates to use D' with caution. © Georg Thieme Verlag KG Stuttgart · New York.