Amsterdam University of Applied Sciences

Oxygenation threshold derived from near-infrared Spectroscopy

reliability and Its relationship with the first ventilatory threshold

Article

<p>BACKGROUND: Near-infrared spectroscopy (NIRS) measurements of oxygenation reflect O2 delivery and utilization in exercising muscle and may improve detection of a critical exercise threshold.</p><p>PURPOSE: First, to detect an oxygenation breakpoint (Δ[O2HbMb-HHbMb]-BP) and compare this breakpoint to ventilatory thresholds during a maximal incremental test across sexes and training status. Second, to assess reproducibility of NIRS signals and exercise thresholds and investigate confounding effects of adipose tissue thickness on NIRS measurements.</p><p>METHODS: Forty subjects (10 trained male cyclists, 10 trained female cyclists, 11 endurance trained males and 9 recreationally trained males) performed maximal incremental cycling exercise to determine Δ[O2HbMb-HHbMb]-BP and ventilatory thresholds (VT1 and VT2). Muscle haemoglobin and myoglobin O2 oxygenation ([HHbMb], [O2HbMb], SmO2) was determined in m. vastus lateralis. Δ[O2HbMb-HHbMb]-BP was determined by double linear regression. Trained cyclists performed the maximal incremental test twice to assess reproducibility. Adipose tissue thickness (ATT) was determined by skinfold measurements.</p><p>RESULTS: Δ[O2HbMb-HHbMb]-BP was not different from VT1, but only moderately related (r = 0.58-0.63, p<0.001). VT1 was different across sexes and training status, whereas Δ[O2HbMb-HHbMb]-BP differed only across sexes. Reproducibility was high for SmO2 (ICC = 0.69-0.97), Δ[O2HbMb-HHbMb]-BP (ICC = 0.80-0.88) and ventilatory thresholds (ICC = 0.96-0.99). SmO2 at peak exercise and at occlusion were strongly related to adipose tissue thickness (r2 = 0.81, p<0.001; r2 = 0.79, p<0.001). Moreover, ATT was related to asymmetric changes in Δ[HHbMb] and Δ[O2HbMb] during incremental exercise (r = -0.64, p<0.001) and during occlusion (r = -0.50, p<0.05).</p><p>CONCLUSION: Although the oxygenation threshold is reproducible and potentially a suitable exercise threshold, VT1 discriminates better across sexes and training status during maximal stepwise incremental exercise. Continuous-wave NIRS measurements are reproducible, but strongly affected by adipose tissue thickness.</p>

Reference van der Zwaard, S., Jaspers, R. T., Blokland, I. J., Achterberg, C., Visser, J. M., den Uil, A. R., Hofmijster, M. J., Levels, K., Noordhof, D. A., de Haan, A., de Koning, J. J., van der Laarse, W. J., & de Ruiter, C. J. (2016). Oxygenation threshold derived from near-infrared Spectroscopy: reliability and Its relationship with the first ventilatory threshold. PLoS ONE, 11(9), e0162914. https://doi.org/10.1371/journal.pone.0162914
Published by  Urban Vitality 15 September 2016

Publication date

Sep 2016

Author(s)

Stephan van der Zwaard
Richard T. Jaspers
Ilse J. Blokland
Chantal Achterberg
Jurrian M. Visser
Koen Levels
Dionne A. Noordhof
Arnold de Haan
Jos J. de Koning
Willem J. van der Laarse
Cornelis J. de Ruiter

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