Fig. 4
Subjective stress perception. Visual analog scale of subjective stress perception. Stress levels in the WF+ group were significantly decreased (compared to control) and shown a trend to a specific waterfall effect (WF+ to CO p = 0.000, R 2 = 0.615; WF+ to WF−: p = 0.054, R 2 = 0.179; WF– to CO p = 0.066, R 2 = 0.496). Data shown in means (±SD). Statistical analysis calculated with linear regression