I was invited to review the book The Haywire Heart, written by Dr. John Mandrola, Lennard Zinn and Chris Case, recently published by VeloPress. This book primarily addresses electrical problems in athletes’ hearts but also touches on plumbing issues (clogged arteries, or atherosclerosis).
The book’s cornerstone is the observation that lifelong endurance athletes seem to be developing heart arrhythmias, including the case of one of the authors, VeloNews tech editor Zinn, who was the focus of the cover story on the topic in VeloNews in 2015 that led to the writing of the book. The book investigates the question of whether continued exercise for sport, above and beyond what is good for health, is beneficial, or can it reach a point where it becomes detrimental?
Who should read this book?
• Anyone who does intense or long endurance training, especially over many years
• Anyone who exercises and has a history or any sort of arrhythmia
As I started reading this book I had questions in mind around two of its central theses.
First, is the observation that more arrhythmias are appearing in lifelong athletes real, or is it simply that there are now more older endurance athletes? After all, more arrhythmias are observed in non-athletes as they age, as well. The 60- and 70-year-old athletes represent the first generation of people who have been lifelong athletes, and this may just be part of normal aging.
The second question has to do with how much exercise is too much. What is “extreme endurance training,” and am I doing it? Am I actually hurting my heart by being a lifelong recreational, yet competitive, cyclist. Should I back off?
Almost Like a Medical Journal
The book went into great detail explaining the various heart ailments that may show up in endurance athletes and reads like a medical journal at times. To greatly summarize, arrhythmias are any abnormal impulse in the heart, such as atrial flutters (very fast heart rate), atrial and ventricular arrhythmias (fast and irregular heartbeats), and tachycardia (fast heart rate).
These conditions may be caused by extreme endurance exercise, as such activity can lead to stretching, inflammation, scarring and enlargement of the heart tissue, which are all factors that can lead to arrhythmias. The authors make a fairly convincing argument that extreme endurance exercise causes these conditions that can then set the stage for arrhythmias.
Another factor that may lead to arrhythmias is the low heart rate experienced by many endurance athletes, which may lead to premature heart beats. Endurance athletes can experience a wide range of heart rates, from very high during exercise to very low at rest. The authors present information that indicates that endurance athletes appear to have a greater occurrence of arrhythmias than sedentary counterparts, thus answering my first question.
There are treatments for arrhythmias, which include drugs and surgical (ablation) procedures, where areas of the heart tissue are actually burned and destroyed. These treatments all contain side effects and risks and may not be completely effective in controlling the arrhythmias.
In March 2016, we published a Heart Health issue of RBR Newsletter that contains six articles by regular RBR contributors documenting our own histories and experiences with heart issues.
The book also touches on atherosclerosis and heart attacks. This was of particular interest to me as I have experienced a clogged coronary artery despite my fit lifestyle. As the authors point out, while “exercise is protective, it isn’t a panacea” and it doesn’t make athletes immune from atherosclerosis.
The second half of the book gets into symptoms of heart problems you can look for yourself to determine if and when you should seek medical help. Some symptoms are less serious than others, such as palpitations. Others are much more serious, such as racing heart, chest pain and difficulty breathing.
The book then discusses the sort of tests to expect if you do see a doctor, and the information you should take with you. It’s pointed out that athletes have a high pain threshold and tend to downplay pain and discomfort and may try to brush aside and ignore symptoms.
Being Fit Not the Same as Being Healthy
It’s important to realize that being fit is not necessarily the same as being healthy. (There are countless examples of extremely fit, well-known athletes who have died of heart attacks or other heart ailments they never knew they had; a commonality seemed to be the assumption on their part of good health and thus the lack of regular medical checkups.) And the book presents some evidence that long-term endurance training may not protect against atherosclerosis.
Answers to my second question – how much exercise is too much – are less clear, and the answers may not be known at this time.
Throughout the book the authors use terms such as “elite athletes,” “extremely intense” and “competitive.” They utilize several case studies highlighting very elite athletes who were on the U.S. national cycling team, U.S. Ski Team, competed in world running championships and masters athletic championships.
The non-elite athlete case studies involved athletes who were very driven, in some cases obsessed, exercisers who participated in multiple marathons or ultra-marathons and typically had type-A personalities both in sport and in other aspects of their lives. These case studies appear to be extreme examples.
For instance, one recreational athlete was an independent sales representative who worked and played hard, often on the same day. He admits he was burning the candle at both ends and that he was chronically overtrained. He would do a ski marathon on Saturday, drive to another on Sunday, and do some work in between. He experienced ventricular tachycardia followed by cardiac arrest at age 50. He was fortunate to survive. He admits he did it to himself through by letting his personality drive him to extremes in every aspect of his life.
I don’t put in nearly the quantity of training that the athletes in these case studies did, although I often do intense training along with long slower distance training, and have done so for 44 years. I was somewhat comforted by the statement: “These are a highly selected groups of athletes.... They represent a tiny fraction of elite athletes. The vast majority of endurance athletes do not develop severe ventricular arrhythmia.”
The book asks the question “So why do most endurance athletes not have arrhythmia? It is not known who will be affected, but overdosing on exercise appears to increase risk of arrhythmias.”
What To Do With This Information?
What we do with this information appears to be an open question that each of us must answer for ourselves. And most likely it is a very individual situation where some of us may be more immune and others more susceptible. What is too much for one person may be tolerable to another. We may not know until it is too late.
As I read this book I kept asking myself, “Does this describe me?” or “Could this happen to me?” The odds are in my favor that it won’t, but I thought the same about cardiovascular disease – and it did happen to me.
On the other hand, I recently read another book, also published by VeloPress, titled “Fast After 50,” by Joe Friel, which advocates for continuing to do intense training into old age to maintain fitness. Each of us must balance the risks and benefits and make our own decisions.
As a coach, I have worked with two cyclists who have had heart rhythm issues, including one in his 30s who ended up having an ablation procedure done, so I understand it does happen. The Haywire Heart does give us reason to pause and consider our circumstances.
For example, another thing the book considers is, if you are a middle-aged or older athlete who took up sport later in life, you may carry along years of accumulation of poor fitness and perhaps poor health (e.g. atherosclerosis), which may be exacerbated when taking up an endurance sport.
Suggestions From the Authors
The authors provide some suggestions to help avoid or detect problems.
One is to “rest as hard as you train.” Fatigue seems to be a central theme among athletes developing arrhythmias. Avoiding overtraining may be one key to staying healthy, as well as managing stress in all aspects of our lives while training.
Another suggestion is to wear a heart rate monitor at all times while training. This can help detect problems we may not be aware of, and can serve as useful information to a doctor should an episode occur.
So How Will This Book Affect Me?
I expect I will continue training and racing. I will likely wear my heart rate monitor more often now, and I will certainly be more cognizant of any irregular sensations related to heart rate. I don’t believe the authors are trying to get us all to stop our intense or competitive endurance training regimes (although sometimes it sounds like it). Instead, it seems, they do want to raise awareness of the issues and provide some information about behaviors that may lead to problems down the road.
Coach David Ertl is a USA Level 1 cycling coach with the Peaks Coaching Group. He also is a national coach for the JDRF Ride To Cure Diabetes Charity Ride program and writes the training blogs for RAGBRAI, the weeklong ride across Iowa every summer. He has written more than 10 eBooks and eArticles on cycling training and nutrition, available in RBR’s eBookstore at Coach David Ertl, including the best-selling Pedal Off the Pounds. Click to read David's full bio.