Oxygen Uptake and Muscle Deoxygenation Kinetics During Skating: Comparison Between Slide-Board and Treadmill Skating

Purpose: this study aimed to compare the oxygen uptake (V̇O2) kinetics during skating on a treadmill and skating on a slide board and discuss potential mechanisms that might control the V̇O2 kinetics responses during skating. Methods: breath-by-breath pulmonary V̇O2 and near-infrared spectroscopy-derived muscle deoxygenation ([HHbMb]) were monitored continuously in 12 well-trained young long track speed skaters. On-transient V̇O2 and [HHbMb] responses to skating on a treadmill and skating on a slide board at 80% of the estimated gas exchange threshold were fitted as mono-exponential function. The signals were time aligned, and the individual [HHbMb]-to-V̇O2 ratio was calculated as the average value from 20–120 s after exercise starts. Results: the time constants for the adjustment of phase II V̇O2 (τ V̇O2) and [HHbMb] (τ[HHbMb]) were low and similar between slide board vs. treadmill skating (18.1 ± 3.4 vs. 18.9 ± 3.6 for τ V̇O2 and 12.6 ± 4.0 vs. 12.4 ± 4.0 s for τ[HHbMb]). The [HHbMb]/V̇O2 ratio was not different from 1.0 (p > 0.05) in both conditions. Conclusion: the fast V̇O2 kinetics during skating suggest that chronical adaptation to skating might overcome any possible restriction in leg blood flow during low intensity exercise. The [HHbMb]/V̇O2 ratio values also suggest a good matching of O2 delivery to O2 utilization in trained speed skaters. The similar τ V̇O2 and τ [HHbMb] values between slide board and treadmill further reinforce the validity of using a slide board for skating testing and training purposes.