And, it is important not to overlook the implementation of effort-saving or -reducing strategies: that is, shortcuts. I know, for example, that once I've marked a stack of tests once, and the average comes in too low, I don't need to remark them. I can adjust the grades in my spreadsheet -- as long as I do it consistently across the board, the relative rankings don't change significantly. So, I might give everyone who got a 4.5/5 a 5. Similarly, if I'm writing a paper on a narrow problem, I won't necessarily read an entire book -- I'll only read the chapters I need.
Obsessive overwork is fun and all, but I don't think it's necessary to succeed in your endeavours, whatever they may be. I also don't think that you ever really "run out" of self-discipline. But, apart from that, the article's a decent little read.