Effects of gravitational acceleration on cardiovascular autonomic control in resting humans.

Purpose: Previous studies of cardiovascular responses in hypergravity suggest increased sympathetic regulation. The analysis of spontaneous heart rate variability (HRV) parameters and spontaneous baroreflex sensitivity (BRS) informs on the reciprocal balance of parasympathetic and sympathetic regulations at rest. This paper was aimed at determining the effects of gravitational acceleration (a g) on HRV and BRS.

Effects of acceleration in the Gz axis on human cardiopulmonary responses to exercise.

The aim of this paper was to develop a model from experimental data allowing a prediction of the cardiopulmonary responses to steady-state submaximal exercise in varying gravitational environments, with acceleration in the G(z) axis (a (g)) ranging from 0 to 3 g. To this aim, we combined data from three different experiments, carried out at Buffalo, at Stockholm and inside the Mir Station. Oxygen consumption, as expected, increased linearly with a (g).

Determinants of oxygen consumption during exercise on cycle ergometer: the effects of gravity acceleration.

The hypothesis that changes in gravity acceleration (a(g)) affect the linear relationships between oxygen consumption VO2 and mechanical power (w ) so that at any w, VO2 increases linearly with a(g) was tested under conditions where the weight of constant-mass legs was let to vary by inducing changes in a(g) in a human centrifuge. The effects of a(g) on the VO2/w relationship were studied on 14 subjects at two pedalling frequencies (f(p), 1.0 and 1.