[Substack] Medical Mistakes with Probability, 1

Max Heart Rate

When you do a stress test, say the Bruce Protocol, the administering doctor relies on something called the “age predicted maximum heart rate”, usually 220 minus your age, or some formula slightly more complicated but equally unrigorous. Once you reach that point, they stop, depriving you of potent information — at low risk since they are monitoring via live ECG your cardiac strain. In fact, such an estimation based on age, no matter how complicated its computation, appears to explain only 20% of the variation between individuals. I believe that explained variations are even smaller for, clearly, in the graph above, to the right, samples above 55 are sparce and the expected maxima would be considerably higher.

I noticed this myself as I am easily able to reach the 170s without feeling strain, guessing the effective max would be in the 180s (next test, but would require some live ECG for caution).

Continue reading on Substack – open.substack.com/pub/nntaleb/p/medical-mistakes-with-probability

Office Hours with Nassim Nicholas Taleb at AUB

Office Hours with Nassim Nicholas Taleb at AUB

Dr. Nassim Nicholas Taleb will be holding an open session at the American University of Beirut, hosted by the Maroun Semaan Faculty of Engineering & Architecture.

Event Details

  • Date: Monday, September 15, 2025
  • Time: 5:00 PM
  • Duration: 90 minutes (Open Q&A)
  • Location: Architecture Lecture Hall (ALH), Dar Al Handasah Architecture and Design Building, American University of Beirut
  • Admission: Open to the public