[robbedpeter]

Your assertion depends on his evening meal being deleterious.

https://naturallystrong.me/david-sinclair/

He's got an excellent diet. He's also got very solid reasoning behind metformin supplementation, having done years of research and investigation. He's a smart and respectable guy, operating in good faith with his research, so if you find yourself disagreeing with him over something trivial, it's unlikely you're right and he's wrong.

Implying that metformin is useful only to mitigate hypothetical harms from nutrition (a trivial dispute) is probably wrong.

Across various interviews, he's recommended metformin for exactly the mitochondrial effects you're talking about. He doesn't supplement on workout days to prevent disruption of the healing and recovery. Metformin isn't something that anyone should start taking blindly or blithely, as it can amplify damage from other circumstances, but it's got a clear place in Sinclair's regimen for very good reasons.

Metformin's longevity effects work on a lot of species. It's got solid science recommending it for life extension, like the other things Sinclair uses, but unless you're a doctor, or work with one to create a comprehensive life extension, health, nutrition, and fitness plan, metformin probably isn't a great idea. Sinclair is doing something similar to juggling chainsaws - it's really cool that he can do that, but it's dangerous for amateurs. Too many unknowable factors can blow up in your face.

Then again, maybe it'll be part of a standard regimen in the next decade, and the immortals are living among us.