I quite like counter-intuitive advice like this.
We have long been told that we tend to slump in the afternoon due to the time of day (and our lack of will power)
Turns out this is all wrong
The key is to work in batches of 50 mins with frequent breaks. Also, never work on more than four items - they call it "chunking". Have a read.
The stereotype is that we suddenly capitulate to our chocolate craving once 3pm hits, struggle to work well in the afternoon or evening, and smash the chardies after work because our will has been weakened from exercising self-control all day. This model – that we have finite self-control that, once depleted, leaves us vulnerable to our automatic impulses and desires (as well as leaving us with the attention span of a gnat) – is one many psychologists have subscribed to.