Quote from the article:

> Recent research has raised alarms about the potential for plaque buildup and scarring in the heart in some long-distance runners. Yet other studies have suggested that when marathoners get heart disease, they may be able to weather it better than non-runners.

All articles discuss scarring and physical signs but no clear link between exercise and worse life outcomes. The article you cited noted most issues resolve themselves within a few weeks after a race. There are literally 0 people exercising at “race intensity” day after day, which is completely different kettle of fish to your regular training run. Kato here certainly isn’t doing that.

Given many professionals and amateurs run over 5 hours per week and easily break 5/6 miles at a time. A quick search will show strong runners regularly hit 6-8 hours per week.

Cyclists will cover greater distances and times and, apart from Pantani (who was doped to the gills), you don’t see them dropping dead of heart attacks despite regularly covering 10-20 hours a week. Similar for triathletes.

So no, the evidence really isn’t there that distance running causes heart disease.

That's another incorrect summary. From the journal article there are multiple studies that have shown worse long-term outcomes from large amounts of exercise:

> Other studies also have confirmed the long-term adverse effects on myocardial structure (18,27–30,32), including one study suggesting that the CAD event rate during 2-year follow-up was significantly higher in the athletes than that in controls

> Recent studies have suggested that long distance runners may have increased levels of atherosclerosis and CAD (18,37). In a study 6 years ago, male marathon runners had paradoxically increased coronary artery calcification (CAC) as measured by computed tomography (CT) CAC scoring (21). A very recent study of men who completed at least one marathon yearly for 25 consecutive years (n = 50) compared with 23 sedentary controls demonstrated increased total plaque volume (P < 0.01), calcified plaque volume (P < 0.0001), and noncalcified plaque volume (P = 0.04) compared with those with EEE (Fig. 3) (37). Despite the fact that runners have better overall CAD risk profiles, these results underscore the potential for very heavy EEE to increase the severity of CAD through mechanisms largely independent of the traditional CAD risk factors.

> Very high doses of running, however, were associated with trends of worse survival compared with either nonrunners or groups of low- and moderate-dose runners.

> However, when dividing runners into quintiles of doses (miles·wk−1, running days per week, min·wk−1, and running speed), with the exception of speed (faster running always had a trend for better survival), quintile 1 (<6 miles·wk−1, 1 to 2 times per week, <51 min·wk−1) had similar mortality reductions as those in quintiles 2 to 4 and a trend to slightly greater benefit than those in quintile 5 (Fig. 4).

There are other studies that have not shown long-term adverse events. The evidence isn't conclusive and most people need more exercise, not less. But it's prudent to caution committed runners about overdoing it with this information so they can make their own informed decision.

> There are other studies that have not shown long-term adverse events. The evidence isn't conclusive

So after all that, you end up agreeing with me.

It's entirely possible that the CAC response is evolved to have some protective factor for endurance running.

Humans didn't evolve for endurance running though. Endurance running although a widespread concept was performed very rarely. For the tribes in Africa used as examples- they endurance hunted one particular animal prone to over heating at one particular time of the year when the ground was muddier and they run slower. Most cultures endurance hunted more rarely than that.

Humans evolved to be upright and thus are poor at running with only 2 legs. But we evolved to have very good heat dissipation since we had the intelligence to easily stay warm, etc without fur. Good heat dissipation gives us good endurance in warm weather, but 4 legged animals out run us for short and long distances as long as they don't get over heated.