Ventilatory and pressor response to isometric exercise in normal subjects.

We studied in 8 young, healthy males, the behaviour of heart rate (HR), systolic blood pressure at the upper (SBPUL) and lower (SBPLL) resting limbs, pulmonary ventilation (VE), oxygen uptake (VO2) and production of CO2 (VCO2) during and after two levels of isometric effort (handgrip at 50 and 100% maximum voluntary contraction; MVC). HR, SBPLL, VE, VO2, and VCO2 did not vary between the two efforts, but SBPUL is significantly different between them. The possible mechanism and predominant role of nervous reflexes upon the pressor and ventilatory response to isometric exercise are discussed.