Lactate Equivalent for Maximal Lactate Steady State Determination in Soccer

ABSTRACT

Purpose: The association between an overlooked classical Lactate Threshold (LT), named “Minimum Lactate Equivalent” (LE_min), with Maximal Lactate Steady State (MLSS) has been recently described with good MLSS prediction results in endurance-trained runners. This study aimed to determine the applicability of LE_min to predict MLSS in lower aerobic-conditioned individuals compared to well-established blood lactate-related thresholds (BLTs). Method: Fifteen soccer players [velocity at MLSS (MLSS_V) 13.2 ± 1.0 km·h⁻¹; coefficient of variation (CV) 7.6%] conducted a submaximal discontinuous incremental running test to determine BLTs and 3–6 constant velocity running tests to determine MLSS_V. Results: LE_min did not differ from conventional LTs (p > .05) and was 24% lower than MLSS (p < .001; ES: 3.26). Among LTs, LE_min best predicted MLSS_V (r = 0.83; p < .001; SEE = 0.59 km·h⁻¹). There was no statistical difference between MLSS and estimated MLSS using LE_min prediction formula (p = .99; ES: 0.001). Mean bias and limits of agreement were 0.00 ± 0.58 km·h⁻¹ and ±1.13 km·h⁻¹, respectively. LE_min best predicted MLSS_V (r = 0.92; p < .001; SEE = 0.54 km·h⁻¹) in the pooled data of soccer players and endurance-trained runners of the previous study (n = 28; MLSS_V range 11.2–16.5 km·h⁻¹; CV 9.8%). Conclusion: Results support LE_min to be one of the best single predictors of MLSS. This study is the sole study providing specific operational regression equations to estimate the impractical gold standard MLSS_V in soccer players by means of a BLT measured during a submaximal single-session test.

KEYWORDS:

• Owles’ point
• aerobic-anaerobic threshold
• aerobic capacity assessment
• OBLA

Additional information

Funding

This work was supported by the Spanish government (Ministerio de Ciencia, Innovación y Universidades, Programa Estatal de Generación de Conocimiento y Fortalecimiento Científico y Tecnológico del Sistema I+D+i) subproject Mixed method approach on performance analysis (in training and competition) in elite and academy sport under Grant number [PGC2018-098742-B-C33] as a part of the coordinated project New approach of research in physical activity and sport from mixed methods perspective (NARPAS_MM) [SPGC201800X098742CV0].