The running speed at lactate threshold (vLT) determined by the Dmax method was compared using the exponential plus constant (vLTexp) and third level polynomial (vLTpol) curve fitting. Seventeen female recreational runners underwent a treadmill incremental test until voluntary exhaustion. Blood samples were collected between the stages for lactate analysis. The vLTexp (10.9 ± 0.8 km/h) was statistically different (P < 0.05) from vLTpol (10.4 ± 1.1 km/h) using paired Student's t test. The correlation between vLTexp and vLTpol was r = 0.84. The correlations between peak speed and vLT were r = 0.94 (vLTexp) and r = 0.69 (vLTpol). It was concluded that the choice of the blood lactate regression curve influences the vLT value, in which the vLTpol was consistently lower than the vLTexp.
Equation; maximal deviation method; running speed; regression
