Prediction of lactate threshold (LT) and fixed blood lactate concentrations (FBLC) from 3200-m running performance in women

The present study evaluated the accuracy of predicting velocity and oxygen consumption (V̇O₂) at the LT lactate threshold and FBLC fixed blood lactate concentrations from a 3200-m time trial in women. Forty-four women (x̄ age=31.1 yrs, x̄ ht=164.9 cm, x̄ wt=65.0 kg) completed a treadmill protocol for the determination of LT and FBLC and a 3200-m time trial. Velocity and V̇O₂ values at LT, FBLC of 2.0, 2.5, and 4.0 mM, and peak were determined. Mean V̇O₂ and velocity ranged from 27.8±10.8 ml/kg·min^-1 at LT to 42.5 ml/kg·min^-1 at peak and from 129.8±44.0 m·min^-1 at LT to 187.0±52.4 m·min^-1 at peak, respectively. Results indicated that a 3200-m time trial (x̄ time=20.6±6.6 min) was a good predictor of V̇O₂ and velocity at LT, FBLC, and peak. Correlation coefficients (using a quadratic model) for velocity ranged from R=0.96 to R=0.98 with SEE ranging from 9.0 to 13.1 m·min^-1. Correlation coefficients for V̇O₂ ranged from R=0.94 to R=0.96 with SEE ranging from 2.8 to 3.6 ml/kg·min. The validity of these regression equations was examined in 13 women who completed a 12-month running program (V̇O₂ LT, V̇O₂ at FBLC of 2.0, 2.5 and 4.0 mM, and V̇O₂ peak increased by 34.7, 19.9, 16.9, 11.9, and 5.4%, respectively, p<0.05). The regression equations were valid predictors of V̇O₂ and velocity, both before and after training, with correlations between actual and predicted values ranging from r=0.75 to r=0.92 (for velocity) and from r=0.64 to r=0.83 (for V̇O₂). The standard error of the difference scores (SE) were similar to the SEE's of the original equations. We conclude that a 3200-m time trial can be used to predict VO₂ and velocity at LT, FBLC, and peak, as well as changes in these parameters as a result of training.