Artificial gravity training improves orthostatic tolerance in ambulatory men and women

Orthostatic intolerance (OI) continues to be a problem experienced by astronauts upon return from spaceflight. Artificial gravity (AG) training via short radius centrifugation has been suggested as a countermeasure to this OI. The purpose of our research was to determine effects of three weeks of intermittent (+1 to +2.5 G z for 35 min/day) AG exposure on normal, ambulatory men and women. The results of this study indicate that 3 weeks of AG training improved orthostatic tolerance in a group of 14 men and 12 women by an average of 13.6%. This improvement was associated with a decrease in arterial pressure and vascular resistance, and increases in stroke volume and low frequency (0.04–0.15 Hz) arterial pressure and heart rate spectral power. These results suggest that improvement may be attributable to increased venous return possibly as a function of increased stress-induced sympathetic activity and/or vascular sympathetic responsiveness.