Alterations in the autonomic and haemodynamic response to prolonged high-intensity endurance exercise in individuals with coronary artery calcification.

Endurance exercise is associated with increased life duration and improved life quality. Paradoxically, high exercise intensity is also associated with increased coronary artery calcification (CAC) and a small but significant increased risk of adverse cardiac events during exercise. The mechanisms underlying the development of CAC during prolonged high-intensity endurance exercise are unknown.

Optimizing support vector machines and autoregressive integrated moving average methods for heart rate variability data correction.

Heart rate variability (HRV) is the variation in time between successive heartbeats and can be used as an indirect measure of autonomic nervous system (ANS) activity. During physical exercise, movement of the measuring device can cause artifacts in the HRV data, severely affecting the analysis of the HRV data. Current methods used for data artifact correction perform insufficiently when HRV is measured during exercise.