I have yet to read the article, but the only way to prove out an intervention, is to test the intervention. "Ability to do X, in absence of intervention, is pre

I have yet to read the article, but the only way to prove out an intervention, is to test the intervention. "Ability to do X, in absence of intervention, is predictive of longevity" does not equate to "Training X as an intervention will increase longevity." That intervention MUST be tested, separately.