The Influence of movement velocity on the maximal lactate formation rate in isokinetic cycle ergometer sprint

Oral Presentation

Abstract

DOI: https://doi.org/10.30472/aesa-conf.v7i1

Introduction: The maximal lactate formation rate (νLa_max) is used to estimate the lactic capacity and is measured using a short maximal exercise. Nitzsche et al. (2017) showed an increased νLa_max. with higher movement velocity by resistance loads. Whether this effect is also evident in maximal isokinetic cycle ergometer sprint is unknown. Therefore, the aim of this study was to investigate the effect of the movement velocity during an isokinetic cycle sprint on νLa_max.

Methods: Six male participants (24.8±2.9 years, 178±8.7 cm, 79.0±14.4 kg) completed three 10 second isokinetic sprints on a cycle ergometer with different movement velocities (110 revolutions per minute (rpm), 130 rpm and 150 rpm). Capillary blood samples were collected at rest, after the warm up/before the sprint, immediately after cessation of the test and until the 9^th minute every 30s and further samples until the 15^th minute every 60s after completion of the sprint. νLa_max was estimated using the equation: (La_max – La_pre) × (t_sprint – t_alac)^-1 (La_max = lactate maximum, La_pre = pre-sprint lactate, t_sprint = sprint duration, t_alac = fictional alactic time interval) (Mader, 1994). t_alac was defined as the time from beginning of the test until the maximum load decreased by 3.5%. A repeated measures ANOVA was used to analyze the effect of the different movement velocities on the νLa_max.

Results: The νLa_max were 0.79±0.08 mmol×L^-1×s^-1, 1.09±0.24 mmol×L^-1×s^-1 and 1.36±0.35 mmol×L^-1×s^-1 for 110 rpm, 130 rpm and 150 rpm, respectively. The repeated measures ANOVA showed a statistically significant difference in νLa_max (F= 19.77, p < 0.001, partial η² = 0.80) and t_alac (F= 13.87, p < 0.01, partial η² = 0.74) between the different movement velocities. There was no significant difference in La_pre (F= 1.46, p > 0.05) between the different conditions. Bonferroni adjusted post-hoc tests revealed a significant difference in νLa_max between 110 rpm vs. 130 rpm (p < 0.05, M_diff = -0.30), 110 rpm vs. 150 rpm (p < 0.05, M_diff = -0.57) and 130 rpm vs. 150 rpm (p < 0.05, M_diff = -0.27).

Conclusion: The results indicate that a higher movement velocity results in a higher νLa_max. Therefore, it seems that the highest possible movement velocity should be used to determine the maximal lactate formation rate.