Determinants of performance in 1,500-m runners

Our aim was to investigate the relationship\ud between physiological variables (not previously studied) and\ud performance in elite 1,500-m runners. We assessed eight\ud male athletes with an average personal best time of\ud 233.3 ± 6.9 s (110% of the world record) for the 1,500-m\ud race. Ventilatory measurements, maximal oxygen consumption\ud ð V O2maxÞ; maximal vastus lateralis muscle \ud deoxygenation (∆[deoxy(Hb+Mb)])max via near-infrared spectroscopy (NIRS), and maximal velocity (Vmax) were\ud obtained during an incremental treadmill test. During subsequent\ud constant-speed exercise at Vmax, we determined the\ud time to exhaustion (Tlim), end-exercise blood lactate\ud concentration ([La]bmax), VO2 and ∆[deoxy(Hb+Mb)] kinetics parameters. The mean V O2max; [La]bmax and Vmax\ud were 70.2 ± 3.9 mL kg-1 min-1, 12.7 ± 2.4 mmol L-1,\ud 21.5 ± 0.5 km h-1, respectively. V O2 at Vmax showed a\ud significant negative correlation with Tlim, whereas [La]bmax\ud was positively correlated with Tlim. Race speed was found to\ud significantly correlate with ∆[deoxy(Hb+Mb)]max (79% of\ud maximal value obtained during a transient limb ischemia),\ud ∆[deoxy(Hb+Mb)] slow component (22.9 ± 9.3% of total\ud amplitude) and [La]bmax at Vmax. [La]bmax at Vmax was also\ud significantly correlated with ∆[deoxy(Hb+Mb)] slow component, \ud suggesting a greater release of oxygen from the\ud hemoglobin due to the Bohr effect.We conclude that both the\ud maximal capacity of muscle to extract O2 from the blood and\ud the end-exercise blood lactate accumulation are important\ud predictors of best performance in 1,500-m runners