Correlation Between the Cerebral Oxyhaemoglobin Signal and Physiological Signals During Cycling Exercise: A Near-Infrared Spectroscopy Study

Abstract

Near-infrared spectroscopy (NIRS) is a widely used noninvasive method for measuring human brain activation based on the cerebral haemodynamic response. However, systemic changes can influence the signal's parameters. Our study aimed to investigate the relationships between NIRS signals and skin blood flow (SBF) or blood pressure during dynamic movement. Nine healthy volunteers (mean age, 21.3 ± 0.7 years; 6 women) participated in this study. The oxyhaemoglobin (O2Hb) signal, SBF, and mean arterial pressure (MAP) were measured while the volunteers performed multi-step incremental exercise on a bicycle ergometer, at workloads corresponding to 30, 50, and 70 % of peak oxygen consumption (VO2peak) for 5 min. The Pearson's correlation coefficients for the O2Hb signal and SBF at 50 and 70 % VO2peak were 0.877 (P < 0.01) and -0.707 (P < 0.01), respectively. The correlation coefficients for O2Hb and MAP during warm-up, 30 % VO2peak, and 50 % VO2peak were 0.725 (P < 0.01), 0.472 (P < 0.01), and 0.939 (P < 0.01), respectively. Changes in the state of the cardiovascular system influenced O2Hb signals positively during low and moderate-intensity exercise, whereas a negative relationship was observed during high-intensity exercise. These results suggest that the relationship between the O2Hb signal and systemic changes is affected by exercise intensity.

Individual Differences in Hemodynamic Responses Measured on the Head Due to a Long-Term Stimulation Involving Colored Light Exposure and a Cognitive Task: A SPA-fNIRS Study

“…A correlation between MAP and [O 2 Hb] (or StO 2 ) has been reported in various functional studies [ 89 , 98 , 99 ]. Tsubaki et al investigated the relationships between NIRS signals and MAP during exercises on a bicycle ergometer [ 100 ]. They found highly significant correlations between MAP and [O 2 Hb] during warm-up and at workloads corresponding to 30 and 50% of peak oxygen consumption [ 100 ].…”

“…Tsubaki et al investigated the relationships between NIRS signals and MAP during exercises on a bicycle ergometer [ 100 ]. They found highly significant correlations between MAP and [O 2 Hb] during warm-up and at workloads corresponding to 30 and 50% of peak oxygen consumption [ 100 ]. In another recent study, in contrast, a non-significant association between StO 2 and MAP was observed in critically ill adults [ 101 ].…”

Changes in neurovascular coupling during cycling exercise measured by multi-distance fNIRS: a comparison between endurance athletes and physically active controls

“…Furthermore, previous studies revealed exercise-induced activations in prefrontal cortex (PFC) showing that Hb and HHb levels respond as a function of both exercise load and duration in both experts (Rupp et al 2008) and non-experts (Auger et al 2016; Giles et al 2014; Jung et al 2015). However, previous studies focusing on neurovascular coupling at several intensity levels show that there is no consensus concerning the type of exercise (incremental tests with short stages vs. constant-load exercises), duration of exercise (Giles et al 2014; Tsubaki et al 2016) and intensity (Auger et al 2016; Byun et al 2014; Giles et al 2014; Takehara et al 2017; Tsubaki et al 2018).…”

Temporal changes in cortical oxygenation in the motor-related areas and bilateral prefrontal cortex based on exercise intensity and respiratory metabolism during incremental exercise in male subjects: A near-Infrared spectroscopy study

“…The timepoint of significant increase in the O 2 Hb and THb were 50-60% during incremental exercise, while the SBF was 70% during incremental exercise (Figure 3). Moreover, previous studies reported none or negative correlation between the SBF and O 2 Hb at high intensity exercise and cool-down (Tsubaki et al, 2016;Kojima et al, 2021). Although SBF and O 2 Hb appear to increase simultaneously, we considered that changes in cerebral oxygenation were related to increased cerebral blood flow or cortical activation.…”