Time Course of Cardiac Arrhythmia Following High‐Volume Exercise in Recreational Cyclists

Figures

• 

  Figure 1. Study protocol timeline and detailed exercise day breakdown A, Overview of the 9‐day monitoring period, comprising 4 preexercise baseline days (−4 to −1), 1 exercise day (0), and 4 recovery days (+1 to +4). B, Detailed schedule of day 0, during which participants completed six 50‐minute cycling bouts, each separated by a 10‐minute passive recovery period. This was followed by ≈18 hours of continuous passive monitoring. HR indicates heart rate; HRR, heart rate reserve; and PA, physical activity.

• 

  Figure 2. Daily frequency and proportion of abnormal cardiac arrhythmias meeting international consensus criteria 22 Data are presented as the binary count of participants experiencing arrhythmias (yes=1, no=0). Ventricular arrhythmias included couplets, triplets, and nonsustained ventricular tachycardia; atrial arrhythmias included paroxysmal supraventricular tachycardia and atrial fibrillation/flutter. Cochran’s Q test was used to assess changes in arrhythmia occurrence across the study timeline. A significant variation was observed for ventricular arrhythmias (P=0.036), but not for atrial (P=0.561) or total arrhythmias (P=0.232). *Ventricular arrhythmia proportion was significantly lower compared with exercise day (P<0.05).

• 

  Figure 3. Relative risk of abnormal cardiac arrhythmia on the exercise day in relation to pre‐exercise arrhythmia occurrence The figure examines whether preexisting arrhythmia patterns affect the likelihood of experiencing abnormal arrhythmias during exercise, using RR ratios. The RR was calculated for individuals who had abnormal cardiac arrhythmia (as defined by international consensus criteria 22 ) on (1) ≥1, (2) ≥2, and (3) ≥3 preexercise days, compared with those with no arrhythmias on any preexercise day (where the RR=1.0). RR indicates relative risk.