What's Cool In Road Cycling

Toolbox Bookshelf: The Haywire Heart

Being avid cyclists, few things get our heart racing like pushing our bodies to the limit on the bike. However, can too much exercise damage our heart and risk our health? Our “The Haywire Heart” book review explores the potential link between too much exercise and potential heart damage.

I was at a social event last night talking with a fellow masters cyclist about how friends who are not endurance athletes just don’t get it. About how great it feels to come back home at the end of the ride utterly exhausted, with our legs close to spasms, a cough in our throat from riding so hard, and our eyes sting from so much sweat dripping into them.

Indeed, endurance sports exist a world apart from any ball or team sports like basketball, hockey, or soccer. Sports like cycling, running, triathlon, and cross-country skiing have the sole purpose of getting across the line first, which often reduces itself to a very basic question of who is willing to suffer the most and push themselves harder than their competitors.

Hasselt - Belgium - wielrennen - cycling - radsport - cyclisme - Greipel Andre - Prof. Dr. Bert Op’t Eijnde pictured during medical testing of Lotto Soudal Team at the Hasselt University , Belgium - photo VK/PN/Cor Vos © 2015

The Haywire Heart
Of course, the paradox is that underlying all this fetish for suffering, an explicit or implicit reason for cycling in the first place is to be healthy. Therefore, a very reasonable and logical question is whether cycling, especially very intense training or competition, is actually healthy for us. This is the focus of the book “The Haywire Heart” by Chris Case, John Mandrola MD, and Lennard Zinn.

The book grew out of Zinn’s – a long-time frame builder and renowned tech guru – personal experience with developing heart issues a few years ago. Like many of us, Zinn loved to train hard and compete in both cycling and XC skiing. Then one day during a Strava KOM bid he felt what felt like his heart skipping a beat.

What followed that same day was a trip to the ER and a cardiologist, followed by some rest, denial, return to hard training, more symptoms, and an eventual diagnosis of multifocal atrial tachycardia. Eventually, the progression in symptoms led Zinn to retire from racing in either sport, a psychologically difficult process that is also detailed in the book.

The Hard Science
The Haywire Heart itself was a three-way collaboration, with Dr. John Mandrola MD, a cardiac electrophysiologist who is also a runner and cyclist. Notably, Dr. Mandrola also has experienced atrial fibrillations and has similarly reduced his competitive load. Dr. Mandrola authored the critical scientific chapters of the book, notably ones on

Heart attacks, arrhythmias, and endurance athletes: the foundational primer into different forms, symptoms, and causes of electrophysiological heart issues.

The evidence: explores the epidemiological and other evidence that chronic and extreme endurance exercise can increase the risk for electrophysiological issues.

These two chapters are extremely detailed scientifically, for instance laying out the differences between ventricular fibrillation, ventricular arrhythmia, hypertrophic cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy. For the most part, despite the complex terminology and the seemingly fine distinctions between different forms of electrophysiological issues, these chapters are written in a pretty accessible and understandable format for the lay reader.

Wiring vs Plumbing
This raises one of the key points of the book, namely the focus on electrophysiological issues in the heart. It goes to great pains to distinguish the difference versus the generic term of “heart attack” or myocardial infarction. This alone is a valuable service of the book, clearing up the misunderstanding from generically lumping all heart problems together.

Due to our generally healthy lifestyle of exercise and diet, endurance athletes are indeed less at risk for “plumbing” related problems in our blood vessels, such as hardening (arteriosclerosis) or clogging (atherosclerosis) of arteries.

In contrast, the book advances the case that chronic and extreme demands on the heart can combine with a variety of causes (e.g., genetics, heart tissue scarring) to cause long-term problems in proper electrical signalling throughout the heart that is critical to providing a smooth and coordinated heart beat.

Diagnosis and Treatment
The third chapter by Dr. Mandrola is ”What to look for in yourself,” which starts with his own experiences developing AF. Being both a patient and an expert in the field, Mandrola provides excellent insight into the hesitations a patient may have, how to navigate the process of diagnosis along with dealing with family doctors versus cardiac specialists, how even specialists may not understand the unique nature of endurance sports, and what information such as your own heart rate data while exercising you might want to provide.

Dr. Mandrola’s fourth major chapter is on “Treatment options for athlete arrhythmia.” One of the scariest things when first receiving a diagnosis about any medical issue is our lack of knowledge of options, and internet searches can often add to the confusion. Therefore, this chapter is valuable in being a solid primer on what is available.

Case and Zinn
To start the book, Case and Zinn present solid primers on the anatomy of the heart ”How the heart works” along with the demands on the heart of an endurance athlete ”The athlete’s heart. These two chapters are well-written and accessible even for people who may be decades past their high school biology class.

Another chapter provided by Case includes one on exercise addiction, which probably many of us cyclists either suffer from at least mildly or else are in denial about it.

Meanwhile, Zinn adds a chapter detailing his own personal journey that led to this book, from finding the right doctor, the multitudes of testing, his stages of denial, and eventually acceptance and life after arrhythmia. This chapter, as expected, is heartfelt and personal, and is of value in helping others see the entire process through another person’s eyes.

Case Studies
Another feature of the book is that each of the nine chapters includes a case study of an athlete who has developed some form of electrophysiological problem. Personally, I found that these weren’t that interesting and didn’t add much to the value of the book. The main message of most was “take heart symptoms seriously” which is probably already preaching to the choir for anyone actually reading the book. The interview with Ironman legend Dave Scott in the chapter on ”Exercise addiction” I found particularly strange and rambling.

Overall, I found ”The Haywire Heart” a good read overall on a topic that has hit home with me, as I’m turning 49 this summer, have been training and racing hard for >30 years, and am thus in the prime demographic for both electrophysiological cardiac issues and the book itself. Several good racing friends have also experienced these issues and stopped racing.

Is the book going to change my cycling? No, because I love that thrill of exertion and racing too much, and that isn’t necessarily the purpose of the book.

Is it going to keep me more alert to the myriad of potential issues that may arise, and will it make me take any symptoms with absolute seriousness and urgency? Yes, it absolutely has, making the book a valuable “knowledge is medicine” addition to my bookshelf.

The Haywire Heart by Lennard Zinn, Dr. John Mandrola, and Chris Case

Check out “The Haywire Heart” at VeloPress.

About Stephen:
Stephen Cheung is a Canada Research Chair at Brock University, and has published over 90 scientific articles and book chapters dealing with the effects of thermal and hypoxic stress on human physiology and performance. Stephen’s Cutting-Edge Cycling, a book on the science of cycling, came out April 2012, and the new “Cycling Science,” with Dr. Mikel Zabala from the Movistar Pro Cycling Team, will be published in late June 2017. Stephen can be reached for comments at [email protected] .

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