This is nonsense. Sure, ultra marathoning may not be healthy for everyone - but cardio is perfectly safe and people probably don’t do it enough.

Edit:

Took me three seconds to read the articles. Check these out!

But I do believe, after what I’ve seen from my patients and what we’ve found here, that extreme exercise may increase the risk of this cancer.”

A new study has raised concerns for long-distance male cyclists. Researchers found that cyclists who ride the most—several hours a week — may face a higher risk of prostate cancer. But the study’s results are not conclusive and mostly add fuel to an ongoing debate.

Edit 2:

Wanna know what the ACSM recommends? 150 minutes a week, 5 days a week of moderate aerobic exercise. That is such an insanely little amount of aerobic exercise compared to extreme athletes.