Are your training habits bad for your heart?

When I was taking sport ‘seriously’ in the late ‘90s and early 2000s, I went through a phase where almost all of my training and racing was done religiously with a heart rate monitor on.

Before GPS watches and power meters were widely available, heart rate was ‘the thing’ to measure and, as a young sports science student, I was keen to get to grips with it on a practical level. 

As funny as it seems now, it was with a lot of pride that I used to print out heart rate traces from my old Polar Accurex Plus and stick them meticulously into my training diary to keep a record of how high I’d managed to hold my heart rate during key training sessions and races. Simple things amuse simple minds I guess!

When I was in peak condition in my early-to-mid 20s I would frequently see 202 bpm when going flat out (usually running, my maximum was a few beats lower on the bike) and I could hold it well over 180 bpm for extended periods.

I’d rarely train below 140 bpm (except for during really long, easy bike rides) and was routinely clocking up 18-22 hours of total training and racing each week. My resting heart rate usually sat in the low 40s when I measured it in bed in the mornings.

One of my most memorable heart rate traces was from a PB I ran at the 2003 Bath Half Marathon:

 

Andy's heart rate trace from Bath Half

 

As you can see, my bpms drifted up to the mid 180s over the first few minutes and basically sat there (effectively on the rev limiter!) for the whole time that I was running.

This was in March when my ‘A’ races for the year were not until July and August!

Looking at my diary, on the previous day I’d also competed in a hilly 18 mile cycle time trial where I’d held an average heart rate of 183 bpm for another 47 minutes. It was a pretty full on weekend for my ticker (and legs) and I backed it up with another 18 hour training block in the next 7 days.

This sounds pretty extreme to me now (based on my current ~5 hour a week ‘habit’), but when I look back at my old training diaries it was not all that unusual at that point in my life.

But, if you’d have asked me about my state of fitness and health at the time, I’d have said (probably in a slightly smug, self-satisfied way) that I was in tip-top shape and a complete picture of health. And in one very narrow dimension of fitness, I suppose I was. I was winning races and could swim, cycle and run pretty darn hard for long periods of time.

However, looking back, these days I'm a lot less sure about exactly how healthy what I was doing was and how it has (or might have) affected my body in the long term, especially if I’d have kept up that level of high intensity training and racing for more years than I did.

I say this now in large part due to something quite sobering that seems to be happening to a small but growing number of people in my wider circle of friends, the development of significant heart problems in middle age.

I did a count recently, prompted by an email from a friend who is a Masters track and time trial cyclist about a recent diagnosis he’d had of ‘Athletic Heart Syndrome’ and, off the top of my head, came up with a list of no less than eight close acquaintances (all past or present competitive endurance athletes) who have suffered with heart-related ailments in middle age that have been traced back to their athletic endeavours.

Of the unfortunate octet, I’ve sadly attended one funeral now and have narrowly dodged another after a mate suffered a cardiac event when out on a trail run (he was lucky to be revived dangerously close to the point of no return).

Two of the group now have pacemakers implanted in their chests for the rest of their lives. None of this ‘club’ are older than 65 years old and four are actually under 45.

None remotely fit the stereotype that would spring to mind if I asked you to visualise someone with a heart condition.

Going through the list gave me serious pause for thought and prompted me to do some further reading on the subject to learn more about it and why it might be happening.    

I came across a couple of very well-researched articles in the New York Times and another in Velonews.

After reading those, things progressed quickly to buying a copy of the book The Haywire Heart by Dr. John Mandrola and Lennard Zinn and Chris Case. It's a fascinating read and I motored through it in a just a couple of days. 

If you’re keen to do a deeper dive into the subject, I’d strongly recommend getting a copy but here are the key points I took away from it: 

 

1) Exercise, per se, is definitely NOT bad for your heart

It may be wholly obvious, but it's worth re-iterating that, almost overwhelmingly, the available evidence suggests that undertaking endurance exercise is massively beneficial to overall health and, in particular, cardiac health.

The debate here is therefore not a polarised one of whether or not exercise is ‘good or bad’ for your heart (as it's often portrayed in the mass media). It's a lot more nuanced than that...

 

2) Relatively little is known about what effect multi-decade participation in high-intensity, competitive endurance sport has on the heart

This is because the generation of athletes now hitting their 40s, 50s and 60s are basically the first cohort to have had the opportunity to pursue a high level of endurance exercise for the majority of their adult lives.

The fact that a small but significant number of this demographic seem to be developing heart conditions related primarily to the effects of exercise is undeniably alarming and warrants further research as participation in endurance events continues to rise.

 

3) The most common heart issue to affect middle-aged endurance athletes is 'Atrial Fibrillation (AF)'

AF is characterised by a ‘fluttering’ feeling in the chest (often called ‘palpitations’), shortness of breath, loss of power and possibly chest pains, light headedness or fainting and fatigue. It'll likely be visible on a heart rate monitor if you’ve got one on, as you’ll see periods of extreme and uncharacteristically high readings.

 

4) It seems that AF can often be brought on by a combination of relatively hardcore exercise habits and more general life stresses

This might be a big reason why it's presenting itself more commonly in middle-aged endurance athletes.

These are often the folks who are classed as having ‘Type A’ personalities, cramming in high levels of training and racing alongside busy jobs and juggling family and social commitments - a very different situation to that in which of a lot of professional athletes have to train and compete.

 

5) At the moment there's no universal consensus on how to fully diagnose the root causes and treat AF and other ‘Athletic Heart’ conditions

But more doctors and cardiologists are becoming familiar with manifestations of it. so the knowledge base is improving all of the time.

 

6) Whilst there's no simple ‘cure’ for athletic heart problems, long term management can be successful

And management does not always require invasive surgery or complete cessation of training and competing, although often a reduction in training volume and intensity is a key part of what’s needed to stabilise symptoms in the long run.

 

7) Athletic heart conditions are one possible manifestation of what happens when the 'dose > response' relationship of exercise exceeds an individual’s maximum tolerable healthy level 

In other words - as much as many competitive athletes hate the idea - exercise with a degree of moderation is likely to be a good thing. But what constitutes training for absolute peak performance is unlikely to be the same as training for peak long-term health.

I have to say that the combination of seeing a small group of people I know start to have heart issues and reading Haywire Heart prompted me to reflect on the way that I approached training and racing in the past, as well as how I'm should view it these days.

A big thing it highlighted (and there's a whole chapter in the book devoted to this as it popped up time and time again in the case studies presented) is that it’s clearly very hard for an individual to spot when they cross the line from a ‘healthy’ level of engagement and participation in endurance sports to doing ‘too much’. 

To make things even harder, the question of what constitutes 'too much' is nigh on impossible to quantify as there are so many individual variables involved. What's acceptable to one person might be too much for another.

That’s summed up very neatly in a a quote from Dr John Mandrola - one of the authors of The Haywire Heart:

“What’s too much? That’s the $64,000 question. Though I will say it’s a little like what the judge said about indecency: ‘I know it when I see it.’”

When I look back at my own attitude to sport in the past I can see that I definitely crossed the line at times into a place where training and racing was harming my body more than it was benefitting it.

A case in point was when I started to suffer with persistent knee issues in 2004/2005. I failed to back off at that point and continued to train through the pain alongside lobbying my doctor to give me a number of cortisone treatments to help manage the symptoms so I could plough on despite what my body was telling me.

I justified getting the risky treatments by telling the doctor (and myself) that I was ‘an elite athlete’ and that I needed to keep training and racing because it was fundamentally who I was and what I did.

My personal identity had become so intertwined with doing sport that I genuinely could not imagine what I would do, or who I would be, without it.

The upshot of this attitude was probably predictable to anyone looking in from the outside; it ended with knee surgery in 2010 after 3 years of barely being able to train consistently at all, and with me even struggling to walk pain free some of the time.

What I find really interesting in hindsight is that, for me, it took a pretty serious injury and subsequent surgery and rehab to get me to to back off from training and competing flat out. 

Whilst I’d like to think differently, I suspect that had my knee not given out I’d have kept going with my foot flat to the floor for many more years and would perhaps have ended up breaking or over stressing another part of my body instead.

Of course, this would not necessarily have been my heart (there are plenty of people who compete at a high level for decades without cardiac issues) but, when comparing my own backstory to many of the case studies in Haywire Heart, I can see a lot of parallels.

What having the injury and subsequent downtime from sport forced me to do was to switch my main focus from ‘being an athlete’ to putting more effort into my work.

That's probably something that actually afforded me the time and energy to devote to starting Precision Hydration. Although I’ve definitely done more than just keep my hand in with competitive sport since founding the business, it's with a very different attitude and level of expectation.

I hope it's a little more balanced than was the case in the past. I still try to train on more days than I don’t, but the majority of my sessions are 30-60 minutes long and, whilst I do a few long races and push myself pretty hard from time to time, I tend to let the intensity be dictated more by how I feel on a given day than anything else.

Don’t get me wrong: I look back at the time when I was training and racing full-on with a lot of fondness and I'm actually grateful I got to do it when I did.

I’m also proud of my modest accomplishments as an athlete. Overall, I gained a huge amount from going ‘all in’ on something and pursuing excellence for a number of years and wouldn't trade the experiences it gave me for anything in the world.

I was very lucky to be able to do it at a time in my life when I had few external responsibilities, so my ‘life-stress’ was extremely low and with hindsight that (along with youth) is probably why I was able to cope with the volume of high intensity exercise I was doing back then.

But, I'm also genuinely glad that I feel like I've started to find a place for sport in my life that feels somewhat healthier and more sustainable in the long run.

I still watch events like Kona and the London Marathon and get pretty inspired and fired up, wondering if I could/should have ‘one more go’ at achieving a PB or winning something big (albeit at an age-group level).

I still have a lot of mates who are smashing it up at a high level and I still harbour a level of admiration for the working people who're putting in big miles and racking up PBs in their 40s, 50s and beyond. There’s always something impressive about that.

But, I ultimately don’t feel like going ‘all in’ with training and racing would be beneficial or healthy for me at this point in time.

With a young family and a growing business I can see that I would be a candidate for going down the route of burning the candle at both ends and, as the Haywire Heart seems to suggest, that might be a bit too much like rolling the dice!

It’s important to point out that this is definitely not me knocking the idea of being a competitive middle-aged endurance athlete.

Far from it.

Despite the potential pitfalls, I still see training for endurance sport as being a hugely positive activity for people to engage in (on many different levels) and would hate to put anyone off doing so.

It also seems like the risks, from a statistical point of view at least, are very much skewed away from heart conditions being problematic for most athletes rather than the other way round.

I do, however, think it’s always worth reflecting on your own training and racing habits and how they interact with your lifestyle to make sure you're not overstepping the mark and doing something more detrimental than beneficial to your health.

 

Has this struck a chord with you? Here's some further reading...

https://www.newyorker.com/tech/annals-of-technology/extreme-exercise-and-the-heart

https://www.velonews.com/cycling-to-extremes-heart-health-and-endurance-sports

https://www.velopress.com/books/the-haywire-heart/


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