The Haywire Heart: How too much exercise can kill you, and what you can do to protect your heart

Chris Case, John Mandrola, MD and Lennard Zinn Velopress 2017

When you saw this book title, maybe you thought, “That can’t happen to me, I’m in really good shape.” Well, not to scare you, but denial is a common response from endurance athletes who do, in fact, have heart problems. So, particularly if you are over the age of 40, this could be a life-saving book that tells you how to stay active, but not damage your heart.

The authors emphasize they are not alarmists and all were long-term endurance athletes until two of them developed heart arrhythmias. Discovering there were many other athletes with the same dilemma, they began extensive research to learn why this was happening.

What is a haywire heart? Generally haywire describes something erratic – here that means arrhythmia, a condition of faulty heartbeat timing. Heart muscle cells function through the smooth transmission of electrical signals – like a wave of communication that helps control heart rhythm. Damage to the heart can disrupt this communication process and then it won’t work properly.

Keep in mind this book is not about “normal” exercise levels but “a highly elevated level of exercise that is not only extremely intense but often competitive and is performed for years, if not decades.” There is growing evidence that endurance exercise increases the risk of heart rhythm disorders and that reducing training intensity and/or length often fixes the problem. Damage can occur because of extreme fluctuations between very high and very low heart rates, inflammation, scarring and stretching that frequently take place in the athletic heart.

Detailed case studies explain that having an identity as a high-performance athlete can make it difficult to accept that there might be a problem. Author John Mandrola is a cardiac electrophysiologist who has seen athletes push through severe symptoms of disease.

“It’s remarkable what an athlete can ignore,” he says. “It’s impossible to quantify one’s pain threshold, but heart disease can come on slowly. The stealthy creep of heart disease can blend with stoicism to mask important symptoms. Be mindful of this. It’s real.”

Mike Endicott compromised his health with a very busy lifestyle of work and competitions that suddenly took him out of a ski marathon. Feeling dizzy and drunk, he was hyperventilating and could hardly stand up. Yet the 50-year-old was lying in a snowbank, feeling frustrated about his unexpected change of plans: “I had work to do that afternoon, phone calls to make. It just wasn’t on my list of things to do – to die on the ski trails.” It took months to find a medical treatment that helped and although he resisted for a long time, he finally accepted his situation and adapted a healthier lifestyle.

Heart problems can involve many contributing factors and, overwhelmingly, these authors believe that physical exercise is a positive thing. However, from the perspective of their personal experience and knowledge, they urge athletes to be realistic about the danger of pushing the limits of your heart.—helen