Right. Some of these potential longevity interventions seem to have a catabolic effect. Not a problem if you're a mouse living in a safe, flat lab cage. But problematic for an elderly human at risk of falling down the stairs and breaking a hip due to sarcopenia.

Is it strong enough to actually cause that, or is it the kind of thing nonathletes won't notice?

Or is the life extension effect too subtle to be relevant at all outside a flat mousecage?

It's just a general trend. The strength of the catabolic effect will depend on the specific intervention and dose. The risk is greatest for non-athletes because they tend to be weaker to start with and more likely to experience disabling falls as they age.

That is really interesting. I hadn't heard that, but it makes a lot of sense.