Estimation of the maximal lactate steady state in postmenopausal women

This study aimed to estimate the maximal lactate steady-state velocity (_vMLSS) from non-invasive bloodless variables and/or blood lactate-related thresholds (BL_RTs) measured during an Incremental submaximal Shuttle Test (IST), and to determine whether the addition of a Constant Velocity Test (CVT) could improve the estimation. Seventy-five postmenopausal women conducted an IST to determine several BL_RTs and bloodless variables, and two to seven CVTs to determine _vMLSS. Determined BL_RTs were conventionally used lactate threshold (LT) measured either visually (_vLT_+0.1mM) or mathematically (_vLE_min), and 0.5, 1 and 1.5 mmol·L^-1 above LT, along with fixed BL_RTs. The best single predictor of _vMLSS (7.1 ± 1.0 km·h^-1) was _vLE_min+1.5mM (R = 0.80, P < 0.001; SEE = 0.46 km·h^-1). The combination of BL_RTs and bloodless variables improved the estimation of _vMLSS (R = 0.85, P < 0.001; SEE = 0.38 km·h^-1). The addition of a CVT still improved the prediction of _vMLSS up to 89.2%, with lower SEE (0.32 km·h^-1). This study suggests that _vLE_min-related thresholds obtained from a single submaximal IST are accurate estimates of _vMLSS in postmenopausal women, and thus the time-consuming procedure of _vMLSS testing could be avoided. Performing an additional CVT is encouraged because it improves the prediction of _vMLSS.