The boring cardio extends your life.

• The famous pitch for this protocol — “11% lower risk of dying in 8 weeks” — is a category error: it welds an 8-week fitness change from 40 young men onto a mortality correlation measured across 2.26 million different people over decades. No paper contains the fused claim, and the one randomized trial that could test it was null on its primary endpoint.
• The real session is ~40 minutes with warm-up, recoveries, and cool-down — not the 16 minutes of hard work — so the full dose costs ~2 hours a week.

Unstable angina, recent heart attack, severe aortic stenosis, and pregnancy are standard reasons to skip a hot sauna; alcohol plus heat is a documented way to die in one.