Hemodynamic and autonomic changes induced by Ironman: prediction of competition time by blood pressure variability

hypothesized that the extreme endurance exercise of an Ironman competition would lead to long-standing hemodynamic and auto-nomic changes. We investigated also the possibility of predicting competition performance from baseline hemodynamic and autonomic parameters. We have investigated 27 male athletes before competi-tion, 1 h after, and then for the following week after the competition. The Task Force monitor was used to measure beat-to-beat hemody-namic and autonomic parameters during supine rest and active stand-ing. Heart rate (P 0.001) was increased, and stroke index (P 0.011), systolic blood pressure (P 0.004), diastolic blood pressure (P 0.001), total peripheral resistance index (P 0.001), and baroreceptor reflex sensitivity (P 0.001) were decreased after the competition. The 0.05- to 0.17-Hz band of heart rate and blood pressure variability was increased (P 0.001 and P 0.001, respectively), the 0.17- to 0.40-Hz band of heart rate interval vari