Easy Prediction of the Maximal Lactate Steady-State in Young and Older Men and Women

Maximal Lactate steady-state (MLSS) demarcates sustainable from unsustainable exercise and is used for evaluation/monitoring of exercise capacity. Still, its determination is physically chal-lenging and time-consuming. This investigation aimed at validat-ing a simple, submaximal approach based on blood lactate accu-mulation ([ increment lactate]) at the third minute of cycling in a large co-hort of men and women of different ages. 68 healthy adults (40 male, 28 female, 43 +/- 17 years (range 19 -78), VO2max45 +/- 11 ml-1 center dot kg-1 center dot min- 1 (25 -68)) performed 3-5 constant power output (PO) trials with a target duration of 30 minutes to determine the PO corresponding to MLSS. During each trial, [ increment lactate] was calculated as the dif-ference between the third minute and baseline. A multiple linear regression was computed to estimate MLSS based on [ increment lactate], subjects` gender, age and the trial PO. The estimated MLSS was compared to the measured value by paired t-test, correlation, and Bland-Altman analysis. The group mean value of estimated MLSS was 180 +/- 51 W, not significantly different from (p = 0.98) and highly correlated with (R2 = 0.89) measured MLSS (180 +/- 54 watts). The bias between values was 0.17 watts, and imprecision 18.2 watts. This simple, submaximal, time-and cost-efficient test accurately and precisely predicts MLSS across different samples of healthy individuals (adjusted R2 = 0.88) and offers a practical and valid alternative to the traditional MLSS determination.