>> I'm almost certain the way they technically define "biological age" is misleading

> I'd be curious how you came to that conclusion - considering that there's currently no known way to objectively measure biological age. Best thing that any researcher can do right now is just measure everything, and that's what they're doing.

I came to that conclusion because, if they have a definition, they're almost certainly measuring things they can easily measure and perhaps influence, which aren't really the things people speak about when they talk about age. I don't care how fit this guy is, he's not living to 140 by doing the stuff he's doing.