I often enough see in the news about the increased risk of sudden cardiac death in elite endurance athletes. As it is usually stated it is often (at the very least) implied that the risk for sudden heart failure is larger for endurance athletes than it is for the general population. But is this really so? I am in particular interested in this question as the recommendations I have heard from this (again from the ordinary news) is that one should not exceed the exercise guidelines by too much. But this seemingly goes counter to what I have heard from you, that the guidelines are more of a minimum than a ‘sweet spot’.
Sudden cardiac death (SCD) incidence in the general population varies slightly between studies, but is ~ 3-4 per 100,000 person years in those without existing heart diseease. In athletes, it’s much lower in most studies at 1-2 per 100,000 person years. I believe there was a study showing enlisted military folks had a WAY higher risk of > 10 per 100,000 person years. There’s more nuance to this data, but that’s the gist.
This has nothing to do with meeting or exceeding exercise guidelines, however, as SCD in individuals without established heart disease tends to be caused my structural abnormalities, inherited arrhythmias, etc.
In general, the risk of SCD in athletes is lower than the gen pop. SCD that does occur in athletes (e.g. those without heart disease) tends to be unrelated to exercise volume- but more luck than anything else. Finally, those who are at the highest risk for SCD are those with heart disease, who benefit from more exercise in a dose-dependent manner.
In the particular new segment I watched the argument for this presented by the MD was of mechanistic form, e.g some structural changes occurring to the heart. From listening to you guys for a couple of years now I have become very sceptical of such arguments in the absence of supporting data.
Yea, we know that exercise produces adaptations to the heart and other structures. These variations are different for different activities based on the static vs dynamic nature of the activity. Many of the adaptations have some overlap with pathological changes such as hypertrophic cardiomyopathy, dilated cardiomyopathy, left ventricular hypertrophy due to high pressure (blood pressure or aortic valve issues). That said, none of these exercise-related adaptive changes seem to increase risk of cardiovascular disease, SCD, or similar.