He will not be tired at work because of this; minds don't tire, they only need change and sleep. [...]
You're not tired after work. You can and do push yourself for particular events. Every other weekday evening, spend an hour and a half doing something important. You'll soon want more. Make that a priority; take the social cost. [...]
If you are young and energetic, push yourself full time. But on average, six days a week of striving are enough. If you want more, sure, but going back is okay.
While it's probably true that the average person could push themselves to do more, personal experience suggests that taking advice like this literally will quickly lead to burnout.
I can think of no better way to spend my karma than on encouraging people to read this 19th century self-help book. It's free and online in full.
The guidelines on what makes an appropriate front-page article be damned, or, if necessary, enforced by official censorship.
Thanks to User:sfb for the quote that led me here, although the decision to post is entirely my own.
http://www.gutenberg.org/files/2274/2274-h/2274-h.htm