Effect of a prior intermittent run at vVO2max on oxygen kinetics during an all-out severe run in humans.

Background. The purpose of this study was to examine the influence of prior intermittent running at VO 2max on oxygen kinetics during a continuous severe intensity run and the time spent at VO 2max . Methods. Eight long-distance runners performed three maximal tests on a synthetic track (400 m) whilst breathing through the COSMED K4 portable telemetric metabolic analyser: i) an incremental test which determined velocity at the lactate threshold (vLT), VO 2max and velocity associated with VO 2max (vVO 2max ), ii) a continuous severe intensity run at vLT+50% (vA50) of the difference between vLT and vVO 2max (91.3±1.6% vVO 2max ) preceded by a light continuous 20 minute run at 50% of vVO 2max (light warm-up), iii) the same continuous severe intensity run at vΔ50 with a prior interval training exercise (hard warm-up) of repeated hard running bouts performed at 100% of vVO 2max and light running at 50% of vVO 2max (of 30 seconds each) performed until exhaustion (on average 19±5 min with 19±5 interval repetitions). This hard warm-up speeded the VO 2 kinetics: the time constant was reduced by 45% (28±7 sec vs 51±37 sec) and the slow component of VO 2 (ΔVO 2 6-3 min) was deleted (-143±271 ml.min -1 vs 291±153 ml.min -1 ). In conclusion, despite a significantly lower total run time at vA50 (6 min 19±0 min 17 vs 8 min 20±1 min 45, p=0.02) after the intermittent warm-up at VO 2max , the time spent specifically at VO 2max in the severe continuous run at vA50 was not significantly different.