[Lazare]

That might be true for some physical/mechanical skills, such as sports. However, some quick googling shows that even professional athletes rarely average more than 40 hours a week practising over the course of a year, so even that's questionable.

And as for things like programming or any mental/intellectual skill like that? I highly doubt it.

As a general rule, you're going to see heavy diminishing returns on time invested. By the time you've spent 40 hours doing it, a few more hours on the weekend is unlikely to have any real benefit, and to the extent it causes burn out or takes the place of something that helps you stay healthy, it's likely to be a net negative.