Guide reveals how to get the most out of your afternoon doze

While napping for half an hour makes people feel groggy when they wake A doze lasting for 20 minutes is ideal for those seeking an energy boost New graphics from Dreams reveal how long the perfect nap should be Muhammad Ali, Leonardo da Vinci and Winston Churchill all swore by a daytime doze - so why is there a stigma attached to it? Experts advise drinking coffee before taking a nap so it kicks in when dozers wake up Sleep experts recommend keeping afternoon naps to fewer than 1 and a half hours to avoid interfering with night-time sleep From improving health and productivity to having a positive impact on mood and the immune system, research shows just how beneficial a quick doze can be. Drinking coffee before a quick nap will help to boost alertness when people wake up, scientists suggest. A short sharp nap tends to be the best way of providing an energy boost in most people, while allowing them to still sleep at night Napping on the job is often frowned upon but more and more companies are beginning to change their ways Napping provides health benefits, leaving some experts wondering as to why there is a stigma surrounding the afternoon doze One sleep expert believes naps are better than coffee for providing a quick boost of energy