This study characterized physiological and biomechanical differences between track and treadmill running in elite distance runners at race-relevant intensities. Nine male Tier 4 runners (5000 m personal best: 13:35 ± 0:03 min:s; 10 000 m: 27:44 ± 0:06 min:s) completed six-stage incremental tests (286-375 m·min-1) on both a 300-m track and a motorized treadmill (0% grade) in a randomized crossover design. Blood lactate concentration was significantly higher during track running across all stages (p 2p = 0.784), with the difference increasing progressively from 1.0 mmol·L-1 at stage 1 to 3.7 mmol·L-1 at stage 6 (condition × stage interaction: p 2p = 0.624). Running velocities at fixed blood lactate concentrations were lower during track running at both 4 mmol·L-1 (329.6 ± 4.3 vs. 345.1 ± 4.1 m·min-1; p = 0.008) and 6 mmol·L-1 (344.2 ± 3.1 vs. 359.4 ± 3.8 m·min-1; p = 0.012), corresponding to velocity adjustments of approximately 7-8 s·km-1. Ground contact times were significantly longer during track running at high intensities. In eight runners with 10 000 m season bests, track-based velocity at 6 mmol·L-1 demonstrated superior predictive validity (r = -0.973, R2 = 0.948, p 2 = 0.483, p = 0.061). Track and treadmill lactate assessments are not interchangeable for training prescription; track-based assessment should be prioritized when feasible. At threshold speeds typical of this cohort (~21 km·h-1), treadmill-derived threshold velocities exceeded track-derived values by approximately 7-8 s·km-1. Practitioners should apply this correction in both directions: when transferring treadmill-derived zones to track training, prescribed track velocities should be reduced by this margin; conversely, to replicate equivalent track intensity on a treadmill, treadmill speed should be raised by the same amount. The required correction is speed-dependent and increases at higher running velocities.
Suzuki et al. (Wed,) studied this question.