The Reliability and Validity of a Four-Minute Running Time-Trial in Assessing [Formula: see text]max and Performance.

Traditional graded-exercise tests to volitional exhaustion (GXTs) are limited by the need to establish starting workloads, stage durations, and step increments. Short-duration time-trials (TTs) may be easier to implement and more ecologically valid in terms of real-world athletic events. The purpose of the current study was to assess the reliability and validity of maximal oxygen uptake ([Formula: see text]max) and performance measured during a traditional GXT (STEP) and a four-minute running time-trial (RunTT). Ten recreational runners (age: 32 ± 7 years; body mass: 69 ± 10 kg) completed five STEP tests with a verification phase (VER) and five self-paced RunTTs on a treadmill. The order of the STEP/VER and RunTT trials was alternated and counter-balanced. Performance was measured as time to exhaustion (TTE) for STEP and VER and distance covered for RunTT. The coefficient of variation (CV) for [Formula: see text]max was similar between STEP, VER, and RunTT (1.9 ± 1.0, 2.2 ± 1.1, and 1.8 ± 0.8%, respectively), but varied for performance between the three types of test (4.5 ± 1.9, 9.7 ± 3.5, and 1.8 ± 0.7% for STEP, VER, and RunTT, respectively). Bland-Altman limits of agreement (bias ± 95%) showed [Formula: see text]max to be 1.6 ± 3.6 mL·kg·min higher for STEP vs. RunTT. Peak HR was also significantly higher during STEP compared with RunTT ( = 0.019). A four-minute running time-trial appears to provide more reliable performance data in comparison to an incremental test to exhaustion, but may underestimate [Formula: see text]max.