Fig. 2

The relationships between minute ventilation (\(\dot{V}_{\rm E}\)), end-tidal CO₂% (FetCO₂), and trait anxiety. a Linear plot of \(\dot{V}_{\rm E}\) and trait scores. No significant correlation was observed (ρ = 0.384). b Comparison of \(\dot{V}_{\rm E}\) in HT and in LT. No significant difference was observed in \(\dot{V}_{\rm E}\). c Linear plot of FetCO₂ and trait scores. No significant correlation was observed (ρ = −0.038). d Comparison of FetCO₂ in HT and in LT. No significant difference was observed in FetCO₂. Median \(\dot{V}_{\rm E}\) and FetCO₂ in HT and LT were indicated with horizontal bars. The vertical bars indicate the range and the horizontal boundaries of the boxes represent the first and third quartiles