Endurance training and cardiac fibrosis

Training Q&A [Moderated]
1

I have asked a similar question (although more info now) and have listened to the episode on endurance exercise and impacts on the heart.

I have some scarring (from what the cardiologist said was potentailly the result of myocarditis at point) and “right bundle branch block”. Nothing that warranted any actions. I got ECGs and MRI to figure out the root of hypertension which were ruled to be genetic.

After my second visit to the cardiologist, and after wearing a holter monitor, she showed me some variations in the gaps between some beats, which I believe to be common in athletes. She mentioned this was something we (she) needed to keep an eye on with annual follow ups.

I was advised against training for a marathon as she mentioned it can lead to further fibrosis or make the arrytimtia worse, with longer term implications.

On the flip side, in order to reach my marathon training goals, I need to be doing quite a large amount of volume or else temper my time expectations (which is ideally not something I want to do).

Getting a repeat subscription again this month I asked my GP the same question and he tried to steer me away from doing too much cardio (It’s nothing out of the ordinary for a middle of the pack marathoner).

Could this lead to potential issues (heart failure) down the road or is it overly cautious. I would re-evalute my goals if it was genuinely detrimental to my health. Otherwise I do almost everything I can lifestyle wise to manage things like CVD risk.

2

Hey Adam,

This is more of a consultation type question, as it requires more medical information as well as discussion of risks and benefits.

It’s not clear to me if how the cardiac fibrosis was diagnosed (e.g. cardiac MRI) and how the origin was attributed to myocarditis (e.g. a particular location) vs. the more common R ventricle/septum location for athletes.

~ 7-20% of athletes are suggested to have myocardial fibrosis, though existing evidence does not suggest these athletes are at higher risk of complications related to this issue. Not a ton of data here and there’s more to the story, which is why a consultation would be necessary to weigh-in on your specific case.

We talk about this a bit in our extreme exercise podcast: