Figure 3From: Heart rate variability and short duration spaceflight: relationship to post-flight orthostatic intoleranceThe parasympathetic nervous system indicator. The parasympathetic nervous system (PNS) indicator pre-flight, landing day and post-flight with respect to the stand test (3A) and susceptibility to landing day orthostatic intolerance (3B). Symbols denote values different (p < 0.05) from: *, supine or finisher, and #, pre-flight.Back to article page