Relationships and significance of lactate minimum, critical velocity, heart rate deflection and 3 000 m track-tests for running

摘要

Aim. The running velocities associated to lactate minimum (V_(lm)) heart rate deflection (V_(HRd)), critical velocity (CV), 3 000 m (V_(3000)) and 10 000 m performance (V_(10km)) were compared. Additionally the ability of V_(lm) and V_(HRd) on identifying sustainable velocities was investigated. Methods. Twenty runners (28.5±5.9 y) performed 1) 3 000 m running test for V_(3000); 2) an all-out 500 m sprint followed by 6 x 800 m incremental bouts with blood lactate ([lac]) measurements for V_(lm); 3) a continuous velocity-incremented test with heart rate measurements at each 200 m for V_(HRd); 4) participants attempted to 30 min of endurance test both at V_(lm)(ETV_(lm)) and V_(HRd)(ETV_(HRd)). Additionally, the distance-time and velocity- 1/time relationships produced CV by 2 (500 m and 3 000 m) or 3 predictive trials (500 m, 3 000 m and distance reached before exhaustion during ETV_(HRd)), and a 10 km race was recorded for V_(10km). Results. The CV identified by different methods did not differ to each other. The results (m·min~(-1)) revealed that V_(lm) (281±14.8) < CV (292.1±17.5)=V_(10km) (291.7±19.3) < V_(HRd) (300.8±18.7)=V_(3000) (304±17.5) with high correlation among parameters (P < 0.001). During ETVlm participants completed 30 min of running while on the ETV_(HRd) they lasted only 12.5±8.2 min with increasing [lac]. Conclusion. We evidenced that CV and Vlm track-protocols are valid for running evaluation and performance prediction and the parameters studied have different significance. The V_(lm), reflects the moderate-high intensity domain (below CV), can be sustained without [lac] accumulation and may be used for long-term exercise while the V_(HRd) overestimates a running intensity that can be sustained for long-time. Additionally, V_(3000) and V_(HRd) reflect the severe intensity domain (above CV).