Power nap

Bought 2 Sudoku books the other day and one proved to be too tough for me so now I am on the second one. Its quite ok for but I almost fell asleep doing it during lunch so decided to take a small nap. It was a good nap as I woke up feeling abit more refreshed. Read before somewhere that says napping for 10-15 mins during lunch is power nap as it refreshes the body and brain to get rid of some tireness. Lucky I got a few mini pillows here!