Determinants of performance in 1,500-m runners

Our aim was to investigate the relationship between physiological variables (not previously studied) and performance in elite 1,500-m runners. We assessed eight male athletes with an average personal best time of 233.3 ± 6.9 s (110% of the world record) for the 1,500-m race. Ventilatory measurements, maximal oxygen consumption ð _V O2maxÞ; maximal vastus lateralis muscle deoxygenation (D[deoxy(Hb?Mb)])max via near-infrared spectroscopy (NIRS), and maximal velocity (Vmax) were obtained during an incremental treadmill test. During subsequent constant-speed exercise at Vmax, we determined the time to exhaustion (Tlim), end-exercise blood lactate concentration ([La]bmax), _V O2 and D[deoxy(Hb?Mb)] kinetics parameters. The mean _V O2max; [La]bmax and Vmax were 70.2 ± 3.9 mL kg-1 min-1, 12.7 ± 2.4 mmol L-1, 21.5 ± 0.5 km h-1, respectively. _V O2 at Vmax showed a significant negative correlation with Tlim, whereas [La]bmax was positively correlated with Tlim. Race speed was found to significantly correlate with D[deoxy(Hb?Mb)]max (79% of maximal value obtained during a transient limb ischemia), D[deoxy(Hb?Mb)] slow component (22.9 ± 9.3% of total amplitude) and [La]bmax at Vmax. [La]bmax at Vmax was also significantly correlated with D[deoxy(Hb?Mb)] slow component, suggesting a greater release of oxygen from the hemoglobin due to the Bohr effect.Weconclude that both the maximal capacity of muscle to extract O2 from the blood and the end-exercise blood lactate accumulation are important predictors of best performance in 1,500-m runners.