Lukas Zwingmann1,2, Sarah Strütt2,3, Agnès Martin2, Prisca Volmary2, Wilhelm Bloch1,2, Patrick Wahl1,2. 1. a Department of Molecular and Cellular Sport Medicine , Institute of Cardiology and Sport Medicine, German Sport University Cologne , Cologne , Germany. 2. b The German Research Centre for Elite Sport Cologne , German Sport University Cologne , Cologne , Germany. 3. c Department of Preventive and Rehabilitative Sport Medicine , Institute of Cardiology and Sport Medicine, German Sport University Cologne , Cologne , Germany.
Abstract
OBJECTIVE: To investigate the influence of different approaches for first-rise determination on the accuracy of Dmax as an estimate of the maximal lactate steady state (MLSS). METHODS: Seventeen male cyclists and 18 male runners with different levels of endurance performance completed graded exercise tests either on a cycle ergometer or treadmill to determine Dmax, calculated by the final data point and five modifications of the first rise in blood lactate concentration. Two or more constant load tests over 30 min were performed to determine MLSS. Differences between the modifications of the first rise in blood lactate concentration as well as the corresponding Dmax variants and MLSS were tested, using one-way repeated measure ANOVA with Bonferroni post-hoc tests, and illustrated, using the Bland-Altman method. The absolute agreement was observed, using intra-class correlation coefficients, based on a single measure, absolute agreement, 2-way mixed effects model. RESULTS: The peak power output/running velocity of the groups averaged 275 ± 43 W and 4.3 ± 0.4 m · s-1, respectively. The mean power output/running velocity at MLSS was 229 ± 38 W and 3.77 ± 0.38 m · s-1. For both running and cycling the original Dmax described by Cheng et al. was significantly lower than MLSS (p < 0.01). All modifications showed good agreement with MLSS (ICC ≥0.75). According to the Bland-Altman method the mean differences of the modifications compared to MLSS in cycling ranged from -7 (43) to 2 (41) W. In running the mean differences ranged from -0.12 (0.34) to -0.08 (0.35) m· s-1. CONCLUSION: We suggest using the first rise in blood lactate concentration for calculating Dmax instead of the first data point of a lactate curve as originally described. The approach of first rise determination has no substantial influence on the accuracy of Dmax compared to MLSS in cycling and running.
OBJECTIVE: To investigate the influence of different approaches for first-rise determination on the accuracy of Dmax as an estimate of the maximal lactate steady state (MLSS). METHODS: Seventeen male cyclists and 18 male runners with different levels of endurance performance completed graded exercise tests either on a cycle ergometer or treadmill to determine Dmax, calculated by the final data point and five modifications of the first rise in blood lactate concentration. Two or more constant load tests over 30 min were performed to determine MLSS. Differences between the modifications of the first rise in blood lactate concentration as well as the corresponding Dmax variants and MLSS were tested, using one-way repeated measure ANOVA with Bonferroni post-hoc tests, and illustrated, using the Bland-Altman method. The absolute agreement was observed, using intra-class correlation coefficients, based on a single measure, absolute agreement, 2-way mixed effects model. RESULTS: The peak power output/running velocity of the groups averaged 275 ± 43 W and 4.3 ± 0.4 m · s-1, respectively. The mean power output/running velocity at MLSS was 229 ± 38 W and 3.77 ± 0.38 m · s-1. For both running and cycling the original Dmax described by Cheng et al. was significantly lower than MLSS (p < 0.01). All modifications showed good agreement with MLSS (ICC ≥0.75). According to the Bland-Altman method the mean differences of the modifications compared to MLSS in cycling ranged from -7 (43) to 2 (41) W. In running the mean differences ranged from -0.12 (0.34) to -0.08 (0.35) m· s-1. CONCLUSION: We suggest using the first rise in blood lactate concentration for calculating Dmax instead of the first data point of a lactate curve as originally described. The approach of first rise determination has no substantial influence on the accuracy of Dmax compared to MLSS in cycling and running.
Authors: Lorie De Maré; Berit Boshuizen; Carmen Vidal Moreno de Vega; Constance de Meeûs; Lukas Plancke; Yannick Gansemans; Filip Van Nieuwerburgh; Dieter Deforce; Jean Eduardo de Oliveira; Guilherme Hosotani; Maarten Oosterlinck; Catherine Delesalle Journal: Front Physiol Date: 2022-03-22 Impact factor: 4.566