High Gear: “The Haywire Heart” is essential reading for ultrarunners (book review) | SummitDaily.com

High Gear: “The Haywire Heart” is essential reading for ultrarunners (book review)

A runner on the trail with his dogs. In "The Haywire Heart," Boulder-based doctors and athletes discuss the heart issues associated with high-intensity endurance training, complete with scientific breakdowns and real-life case studies.
Getty Images / Special to the Daily | iStockphoto

“The Haywire Heart” by Chris Case, John Mandrola and Lennard Zinn

Nutshell: Complete with the subtitle “how too much exercise can kill you and what you can do to protect your heart,” this book is essential reading for endurance athletes who want (and need) to learn more about the effects of high-intensity training on the body

Pages: 320

Photos: Illustrations and medical diagrams

“The Haywire Heart” is printed by VeloPress of Boulder. To purchase or find out more, see Amazon.com or the VeloPress website.

Editor’s note: This review originally appeared in Ultrarunning magazine.

Ultrarunners and other endurance athletes should pay attention to the main message of “The Haywire Heart,” a fascinating new book from Boulder’s VeloPress: Decades of intensive training and racing can cause long-term damage to your heart.

Surely we have all wondered if hard efforts at 200-plus beats per minute in interval workouts, hill climbs and races were really harmless for the heart. Here, the authors explain what can happen, and I speak as one who has, for the last several years, suffered from a modest fibrillation problem.

Heart scars

As background, I ran a 2:47 marathon in 1980. Readers will know that that requires much intense training, but years of high-intensity exertion can cause scar tissue to form in the heart, and this tissue can conduct electrical impulses in a way that throws off the normal, steady rhythm of the heart. Because the extra beats pump little or no blood, one must stop a run and rest or walk until it passes. If it doesn’t pass within a few hours, medical intervention might be needed.

For me, the fibrillation (actually a “flutter”) has always stopped within anywhere from one minute to a few hours. But arrhythmia comes in many flavors: atrial fibrillation (aka flutter), ventricular tachycardia or fibrillation, premature beats and more. Ventricular fibrillation is very serious and often fatal.

My flutter is under control and I now can go months without getting it. I always monitor my heart rate, but it is best to sense a potential onset and back off immediately. Many athletes, from weekenders to Olympians, have resorted to treatment by catheter ablation (destruction of a very small section of the heart), which sometimes works, perhaps after multiple tries — and sometimes doesn’t.

This affects young athletes too. Nordic skier and Olympic champion Charlotte Kalla recently suffered from her first fibrillation episode during a race. In general, women seem less affected by these issues, but of course Kalla shows women are not immune.

It can be tricky to combat or even recognize heart issues. For the first 10 days of the past Nordic ski season, I had some flutter every day, often when my heart rate was at 125 bpm. But since then, I have trained and raced hard with almost no episodes, despite hitting 155 bpm in races.

This illustrates the mystery: It is not clear exactly what sets off unwanted electrical stimulation — heart rate alone isn’t the only indicator. I have learned to start races a little conservatively, and this sort of warm-up seems to help, allowing me to go hard near the end.

Science meets experience

“The Haywire Heart” was written by a who’s who of endurance experts: Chris Case, editor of Velo News; Dr. John Mandrola, a cardiac electrophysiologist, runner and cyclist who is both an expert in (and suffers from) heart arrhythmia; and Lennard Zinn, a former U.S. national team bike racer.

The book alternates between sometimes-technical (but always interesting) chapters by Mandrola and material by the other authors, along with several highly relevant case studies, such as the death of fabled ultramarathoner Micah True.

The case of Mike Endicott is truly gripping. At age 50, he almost died from a bout of ventricular tachycardia during a Nordic ski race, when he left the course to return to the lodge but passed out before he got there. He would have likely died in the snow had some skiers not spotted him. Endicott comments that, had he seen a heart doctor the day before the race, he would have been pronounced perfectly healthy — an electrocardiogram would have shown normal because he was having no symptoms.

Ultrarunners and other endurance athletes will learn quite a bit from this book about the chemical and electrical complexity that keeps the heart working steadily for about a billion beats in a lifetime. The case studies, together with Zinn’s contributions, show how athletes have coped with heart arrhythmias.

Pulse or heart rate?

Perhaps the bottom line for younger athletes is: Should I do anything differently now to avoid problems later?

This is a very difficult question. Speaking for myself, I have no regrets about the decades of hard training and racing, but then again, what I have been struck with now seems fairly minor. Another interesting point is that the “calcium score” — a measure of calcium deposits in the heart’s arteries — can be elevated in endurance athletes. Yes, mine is quite elevated, but those deposits do not necessarily hinder blood flow, and my flow is fine.

The book fails to mention an important point. The common abbreviation “HR” refers to heartbeats in a minute, but athletes often find a “pulse” at their wrists. For almost everyone, almost all of the time, HR and pulse are the same. But when the heart is not beating properly, the HR can be 200 or more bpm, while the pulse is 100 bpm. This is because the extraneous beats are pumping almost no blood.

The book suggests that a wristwatch-style monitor (such as a FitBit, which gives the wrist pulse) is the same as a chest-strap device; it is not. When in fibrillation or flutter, the pulse at the wrist is irregular — things get back to normal when it is back to a steady rhythm.

Another confusing point is that the numbers, such as 200-300, that define atrial flutter are counting atrial “activations,” not heartbeats. Nothing is beating, so they should not be called beats. When a person is outside of normal rhythm, the activations do not all turn into heartbeats — a large portion is actually filtered out by the “safety valve” that is the atrioventricular node. This all means that an atrial activation count of 300 can become a heart rate of 150 bpm, and that might lead to a pulse of 80.

Addicted to the run

The book covers many types of fibrillation, but does not overly dwell on any single type, and so it is not encyclopedic. But it does discuss in detail the large body of research that convincingly shows how endurance athletes are at greater risk for heart arrhythmia.

Two chapters of interest discuss whether endurance athletes are “addicted” to their sport. I would guess that, in the technical sense of the term, the number of addicts among ultrarunners is small, but that most ultrarunners would surely be very unhappy if a heart condition forced a stop to their running.

A final chapter discusses supplements that might have an effect on heart function. The authors mention Coenzyme Q10, L-carnitine, iodine, magnesium, garlic, hawthorn and aspirin, but it is hard to know which of these, if any, would help athletes who suffer from arrhythmia.

Then there’s Endicott who, after much research, blames his own personality for the problem.

“Yeah, I did all this to myself — by personality,” Endicott is quoted in the book. “And if someone would have gone to me before this happened — and this is a key part of reality — and said you need to back off because this is your future, would I have changed anything? Probably not. I would likely do the same activities, but I would rest and recover more, just because that’s the nature of a lot of us. We enjoy doing it, we’re probably doing it too much, we’re selfish about it, and we’re going to be in denial.”

If heart function, present and future, interests you, read this book to learn the basics about how the heart works and how it reacts to the life of an endurance athlete.

Stan Wagon of Silverthorne (StanWagon.com) is the founding editor of Ultrarunning magazine, where this review first appeared in April 2017.

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