Consistency Beats Intensity, and the Data Agrees

Beware the study that measures a biomarker and asks you to imagine the outcome. Moving a number on a panel is not the same as living longer or better, and the history of medicine is littered with interventions that improved the surrogate while doing nothing, or worse, to the thing you actually cared about. Demand the hard endpoint.

Cardiovascular fitness, measured properly, is one of the strongest predictors of how long you will live that we know how to change. Unlike genetics or age, it responds to training at any starting point, and the largest gains come from the least fit moving to merely average. The floor is where the leverage is.