Comparison of the Lactate Pro and the YSI 1500 Sport Blood Lactate Analyzers

To determine the agreement, reliability, and linearity of the Lactate Pro with the YSI 1500 Sport lactate analyzer, seven male and five female volunteers performed a discontinuous incremental exercise test at discrete percentages of their maximum aerobic power on a cycle ergometer. Five blood samples were collected for each subject; one after each of five increasing workloads. Agreement was evaluated by comparing, in parallel, measurements from the Lactate Pro and the YSI 1500 using Bland-Altman plots. Reliability was determined by performing 10 repeated assays on blood collected at 160 W and 370 W in a randomly selected subject. Strength of association was determined by performing linear regression analysis of the measures obtained from both analyzers. Bland-Altman analysis revealed that blood lactate concentrations from the Lactate Pro were 0.5 ± 1.0 mM (mean ± SD) higher than the YSI 1500 with the limits of agreement being 0.2 to 0.7 mM. Coefficients of variation from blood collected at 80 W and 370 W were 7.1% and 8.9%, respectively. The linear regression equation was Lactate Pro = 1.067(YSI 1500) + 0.036 (R2 = 0.967). In conclusion, the Lactate Pro is reliable and has sufficient agreement and linearity with the YSI 1500 for use in submaximal research and athletic testing.