Estimation of the maximal lactate steady state in postmenopausal women

Abstract

ABSTRACTThis study aimed to estimate the maximal lactate steady-state velocity (vMLSS) from non-invasive bloodless variables and/or blood lactate-related thresholds (BLRTs) 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 BLRTs and bloodless variables, and two to seven CVTs to determine vMLSS. Determined BLRTs were conventionally used lactate threshold (LT) measured either visually (vLT+0.1mM) or mathematically (vLEmin), and 0.5, 1 and 1.5 mmol·L−1 above LT, along with fixed BLRTs. The best single predictor of vMLSS (7.1 ± 1.0 km·h−1) was vLEmin+1.5mM (R2 = 0.80, P < 0.001; SEE = 0.46 km·h−1). The combination of BLRTs and bloodless variables improved the estimation of vMLSS (R2 = 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 vLEmin-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.