Blood lactate concentration has been measured in endurance athletes for many years in order to evaluate exercise performance. Blood lactate concentration is mostly used for training adaptation analysis, to predict race outcomes and to prescribe endurance exercise with precise exercise intensities. Over the years, several lactate threshold protocols have been developed to maximize accuracy and reliability while maintaining ease of measurement and application to training and performance.

The purpose of this study was to determine the validity of a novel staged maximal lactate steady state exercise test (sMLSS) in predicting the maximal lactate steady state (MLSS) using the Lactate Plus handheld analyzer. Another aim of the study was to assess the reliability of the Lactate Plus analyzer during exercise testing.

In this study, blood lactate concentration (BLC) was measured in duplicate for all tests. Seven trained cyclists (20 miles per week) performed a V̇O_2max test starting at 100W and increasing by 30W every three minutes until volitional fatigue. Lactate threshold was defined as the previous workload to a 2 mmol.L^-1 increase in BLC. The cyclists performed several other tests and the results were then analysed using dependent t-test and Pearson correlation analysis to determine reliability between lactate trials. Bland-Altman plots, One-way ANOVA, and regression analyses were used to analyze differences between the types of exercise tests.

The results of this study showed that there were no significant differences for duplicate BLC trials for all tests (p= 0.21; r=0.982). The sMLSS was significantly correlated with the MLSSworkload and percentage of max workload (r = 0.997; p=0.001, r = 0.978, p=0.01), respectively. There was no bias noted between sMLSS and MLSS protocols for predicting lactate accumulation.

Harp concluded that the sMLSS was valid in predicting MLSS in trained cyclists. In addition, The Lactate Plus® analyzer was reliable in assessing BLC during exercise testing.

This abstract relates to the Thesis completed by Jacob Benjamin Harp in partial fulfillment of the requirement for the degree of Master of Science

Harp, Jacob B., Validity of a Novel Staged Exercise Test in Measuring Maximal Lactate Steady State in Recreational Cyclists Using the Lactate Plus Analyzer, MASTER OF SCIENCE (Kinesiology), May, 2017, 83 pp., 3 tables, 9 figures, references, 34 titles.

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