Cerebrovascular haemodynamics during isometric resistance exercise with and without the Valsalva manoeuvre.

Purpose: To examine the interactive effects of VM and isometric resistance exercise on cerebral haemodynamics.

Methods: Eleven healthy participants (mean ± SD 28 ± 9 years; 2 females) completed 20-s bilateral isometric leg extension at 50% of maximal voluntary contraction with continued ventilation (RE), a 20-s VM at mouth pressure of 40 mmHg (VM), and a combination (RE + VM), in randomised order. Mean beat-to-beat blood velocity in the posterior (PCAv) and middle cerebral arteries (MCAv), vertebral artery blood flow, end-tidal partial pressure of CO and mean arterial pressure (MAP) were measured.