Is Cycling Bad For Your Health, Pt 4

Excerpted from a BikeRadar article:

'Extreme' endurance athletes, such as those of us who ride a lot, may be at a greater risk for developing atrial fibrillation, which is an irregular, usually high, heart rate that interrupts the normal rhythm. Although this is a debated subject among the experts, cardiac electrophysiologists like Dr. John Mandrola and cardiologists like Dr Lisa Rosenbaum have argued that a number of studies show an association between excessive exercise and abnormal heart rhythms. The million-dollar question, of course, is how much is excessive? There is no clear answer.

Warning signs to watch for
Dr. Creswell works with endurance athletes regularly, and writes on his own site, athletesheart.org, as well as EnduranceCorner. Here are five things he says deserve attention.

• Pain in the chest — "particularly if it comes and goes with exertion" 
• Shortness of breath — "that is unusual for you, not just normal gasping at the end of a hard effort" 
• Lightheadedness or blacking out while riding – "not unusual after a race when you stop, but while exerting yourself, that is a serious problem" 
• Unexplained fatigue 
• Palpitations – "the feeling that your heartbeat is abnormally fast or hard or irregular"

Read the full article here.