Reproducibility of running time to exhaustion at &OV0312;O2max in subelite runners

Abstract

The purpose of this study was to assess the reproducibility of running time to exhaustion (Tlim) at maximal aerobic speed (MAS: the minimum speed that elicits VO_2max), on eight subelite male long distance runners (29 ± 3-yr-old; VO_2max = 69.5 ± 4.2 ml.kg⁻¹-min⁻¹; MAS = 21.25 ± 1.1 km.h⁻¹). No significant differences were observed between Tlim measured on a treadmill at a l-wk interval (404 ± 101 s vs 402 ± 113 s; r = 0.864); however, observation of individual data indicates a wide within-subjects variability (CV = 25%). In a small and homogenous sample of runners studied, exercise time to exhaustion at MAS was not related to VO_2max (r = 0.138), MAS (r = 0.241), running economy (mlO₂kg⁻¹·min⁻¹ at 16 km.h⁻¹ (r = 0.024), or running performance achieved for 3000 m (km.h⁻¹) (r = 0.667). However, Tlim at MAS was significantly related to the lactate threshold determined by the distinctive acceleration point detected in the lactate curve around 3–5 mmol⁻¹ expresses in % VO_2max (r = 0.745) and to the speed over a 21.1-km race (km.h⁻¹) (r = 0.719). These data demonstrate that running time to exhaustion at MAS in subelite male long distance runners is related to long distance performance and lactate threshold but not to VO_2max or MAS.