Heart Muscle Damage (and Troponin levels) from High Intensity Training

Hi all,

For context I’m a 51yo cyclist with a good few years of structured training under my belt. Had a strong year last year with good weight loss and a decent rise in numbers across different durations although FTP topped out at around 253 (using KM Protocol) which is about as high as I get.

I’ve recently been following the HIT plan on TR to add some high intensity to my training prior to getting into my training cycle for 2021 (SSBMV, SPBMV, RRRSpec). I heard coach Chad saying that he often adds in 3 weeks of VO2 Max training prior to starting a plan and as that type of work is definitely my weak point I thought I’d give it a go. I’ve now completed the first three weeks of HIT LV and i’m in the recovery week.

During this three weeks, I’ve completed a couple of Zwift races which I’ve used to replace one of the HIT sessions. I’ve also added in some circuits twice a week (avg TSS ~38) and some 12 - 15km walks at the weekend. In the last week of the plan my Garmin advised me a couple of times that I was in the red and needed 72 hours rest. I’d rest maybe 48 hours.

Last week I noticed I was getting quite frequent palpitations (without any pain, dizziness or breathelessness) and the day after Eisen my HRV (using Elite HRV) was in the toilet at 2 (sym).

I took myself off to A&E (ER to our US cousins) just to be sure it wasn’t anything sinister and they kept me in for a few hours under observation. Other than the usual concern about my ECG (I have an inverted T-Wave which has been checked and is fine, plus a right bundle branch block which is also fine) the ECG did not show anything signficant, or at least they haven’t advised of anything I should be concerned about, other than they had some concerns that my Troponin levels were around 0.28 (although had dropped to .24 about 3hrs later).

I understand anything over 0.04 is considered of interest and anything over 0.4 means you’ve essentially had a heart attack. I am still getting occasional palpatations but my HRV is back to booming levels and I otherwise feel fine. I’m going to do an easy ride today (Petitt probably) and some light mobility and core work.

I’ve scoured the internetz but can’t find much on how exercise can elevate Troponin and what that actually means for long term Heart health. Does Troponin release indicate heart muscle damage and if so can those cells regenerate (apparently regeneration is slow and so most damage is replaced by scar tissue)?

I’m not overly concerned by the palpatations, as they are not present with any pain or dizziness, although they are a bit of a nuisance and I’m looking forward to them going away. So my question is less about those and more on what higher Troponin levels mean and what actually is high for an endurance athlete. Maybe a question for the team on AACC but I suspect they’ll be busy these next few weeks with other matters…

Any scientists in the room have a view?



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I’m not a scientist but I’d take those palpitations seriously because they aren’t normal.

Personally, I’d find a cardiologist who understands athletes. In the meantime, maybe this book will arm you will knowledge.

I have a friend who gave up cycling because of heart issues. After some years of research, he thinks that his cardiologists didn’t understand athletes and his issues were possibly due to a potassium imbalance.


Thanks for this. I’ll definitely order that book. Good call.

It’s interesting (and a bit sad) to hear about your friend. My different heart pattern confuses and disturbs most clinicians when they conduct an ECG so I’ve had it checked so many times now I’ve become quite well read in to what the readings mean. Still, I suspect most doctors just want to check every box before discounting anything.

Last year I had some blood tests done which showed I was anaemic, but I was hitting my best numbers on the bike and according to Garmin I was at about 62 VO2 Max. I read somewhere that an increase in blood plasma which can occur with high endurance training can show as anaemia. My haematocrit was in the toilet too but the power numbers don’t lie.

I guess the takeaway is perhaps that as certain parts of the population get fitter into older age we’ll need medics that understand what the effects of structured training can do to a body and offset diagnosis accordingly.

I’m getting some further tests done but I suspect the outcome will be that I put myself a bit to far into the Hurt locker this time and will be OK with a little rest.

The Troponin question still bugs me though. I might send a message to the guy who does Medlife Crisis on YT.


I’m definitely no medical expert but I was coincidencentaly listening to a podcast of the same story linked to above.

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Nice, thanks for sharing. I’ll get into that tonight.

This might help set your mind at ease.


As well, and from experience, an “athlete’s heart” mimics quite a few of the same symptoms has a true diseased heart.

As above, seek out a cardiologist who is knowledgable about high performance hearts. Regular docs (and surely reg techs) often misinterpret the readings.

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I’m coming out of a palpitation scare myself, and I have nothing medically-valid to add, other than that for me the cost and time of going through multiple tests was of far greater value than trying to train through it. In the end mine were benign and likely related more to anxiety than physiology, and the cardiac nurse said the amount of palpitations they’ve treated has skyrocketed over the last year as folks have been feeling the stress of the world in a big way. Feel free to DM me if you need someone to vent to- like I said, I have no medical advice, but the psychological aspect of it and how it’s affected my perception of myself as an athlete will take some time to work through and is something I have a ton of thoughts on.


ER doc here. How long after your last workout were you seen at A+E? It is a bit strange that your troponins were elevated. They do take some time to go down after the insult has been corrected (in most cases that is a blocked artery). I wouldn’t be at all surprised if a trop was elevated to some degree after intense exercise, but that isn’t what we are typically dealing with in the ED, so it’s a bit out of my area of expertise. I will say though that those troponins would have gotten you admitted in the US, granted we have different medical-legal system here than pretty much anywhere else in the world (I’m guessing your are UK since you call it A+E). I’d probably want to see a cardiologist, and as other posters have suggested, one who is familiar with athletes who can tell you if that trop is ok or not. Hope this is helpful


I’m 53 and recently experienced heart palpitations after a really grueling VO2max session. I truly believe I just overdid it. I subsequently took a week off of cardio (I bike and run) and then started back training slowly for a week, then added back my VO2max sessions but with less time in VO2max zone and I’ve been fine. I think us older athletes have to be really careful about not doing too much too soon. We have to remember that the heart is a muscle and just like we shouldn’t overdo it with weighted squats because of muscle damage we shouldn’t overdo it with our heart muscle either.


Had a listen to this and it was very interesting (if not a little concerning as well). It seems Lennard’s symptoms are different to mine but absolutely worth a listen if anyone is having any concerns about their cardiac function.

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Very useful thanks. It does appear that ‘vigorous’ exercise can produce similar bio-markers. This is similar to other articles I have read about concerns around anaemia for cyclists, which can in fact just be evidence of a high volume of plasma in the body. Seems more work needs to be done to raise awareness within the general medical community about this.


Hi Sean, sounds like they are working you hard at Trainerroad :smile: If you have some thoughts on it then maybe it would be good to have something on this in the AACC podcast sometime, or a blog, or perhaps a science session with an MD that understand this kind of stuff. Absolutely these palpatations are quite concerning, but mine seem to have abated now. Indeed, I’ve completed Taku and Pettit this week so far and in both cases I felt more ‘normal’ on the bike which is encouraging. The world is definitely a slightly crazier less comfortable place for some, hence why I love the grounding I get through training (with TR of course) and the community on the forum. Glad the tests worked out for you too.


Hi Jeff,

Probably around 12 hours. I’m feeling good now so I put it down to just getting in too deep to the Hurt Locker. In the UK we don’t tend to admit people unless it’s absolutely necessary. I’m all booked in with a Cardiologist to review the data and am being sent a holter so they can get in under the hood. I’m lucky in that I have private healthcare through work and the are insanely thorough.


I’m 40. I had extensive cardiac investigations following palpitations last year. Interestingly/coincidentally, I also have an inverted T wave and a partial RBB. I also have mild LVH (from exercise, it was concluded), and had occasional chest pain.

Long story short, following just about every test under the sun, my heart function was eventually deemed excellent and no problems were found; the palpitations were put down to anxiety and a 5 a day coffee habit. BUT I did have elevated trop levels on several occasions (0.15 iirc - would need to see if I can dig out the paperwork). The cardiologist noted that in his experience, strenuous, long duration exercise consistently elevated trop levels above normal but below MI levels, and provided that there was an ‘explanatory event’, he wasn’t concerned. See https://www.ahajournals.org/doi/10.1161/JAHA.120.015912#:~:text=Exercise‐induced%20troponin%20elevations%20are%20common%20after%20long‐distance%20running,heart%20rate%20in%20this%20process.; “Exercise‐induced troponin elevations are common after long‐distance running”. He also said it was an over-sensitive test and that ‘most’ people had results that were technically ambiguous.

So absolutely go and get checked out, and as others have said, find an exercise-literate cardiologist, but I wouldn’t panic at this stage.

I agree Jack! The only risk with bringing up something like this on the podcast or blog is that it’s so individual for every athlete, and it would be really hard to make any recommendation that could be generalized. But I think there could be real value in speaking with a cardiologist about these issues broadly with the cycling community, or in discussing the psychological implications of injury/ physical setbacks like this on our psyches as athletes. Thank you for the suggestion!

P.S. It is hard work around here, but it’s a labor of love :grinning: I’m glad to hear you’re back on the bike!

Anxiety and 5 coffees a day? I feel like we’re cut from the same cloth.

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I suffer from periodic palpitations too, which seem to recur episodically every 5-6 months or so. I can trigger them by drinking 4-5 beers, so I effectively gave up alcohol a couple of years ago. The first time I noticed them was quite a few years ago, a few days after doing a MTB ultra-endurance event. The doctor said exacerbating factors were a) coffee, b) alcohol, and c) strenuous endurance exercise. He asked if I habitually indulged in any of those three. At the time my life consisted of waking up at 6am, shotgunning a double espresso, doing a one hour tempo effort to work, chugging coffee all day long, then doing a one hour tempo effort back to daycare, then home, then a 7% IPA the second I got in the door on the way to the shower… lol

Anyway, I still drink way too much coffee and probably ride harder (though less volume) and mostly the palpitations are under control…

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I drink a ton of coffee. It doesn’t seem to directly correlate, but I’ve definitely cut down a bit. I completely stopped drinking alcohol for a week or so when the palpitations started, but in the face of no improvement I resumed drinking one beer a few nights a week. I wouldn’t doubt that drinking more than that would trigger them for me, but hangovers for me are so bad that palpitations would be the least of my concerns :face_with_head_bandage:


Yeah, I cut out coffee entirely for a year and was pleased to find it made no difference whatsoever. :slight_smile:

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