Why napping is the best way to catch up on sleep

Thanks to our over-caffeinated, never-switched-off society, we're in the midst of a sleep deprivation epidemic. Researchers from Oxford, Cambridge, Harvard, Manchester and Surrey universities recently found we are sleeping almost two fewer hours a night than we were in the 1960s - and we're paying the price with our health. In the short term, studies show just one bad night's sleep suppresses immunity and quadruples our risk of catching a cold. Regularly skipping sleep makes us less motivated, slows down reaction time and reduces concentration.

It can also cause weight gain. Researchers from Pennsylvania State University say too little sleep makes our levels of ghrelin, a hunger hormone, go up and levels of leptin, a satiety hormone, decline. In other words - when we're tired we feel hungrier than normal and rarely full. Long term, the consequences of poor sleep include an increased risk of certain cancers, diabetes, heart disease, obesity, cognitive decline and depression.

So, what's the answer?

'Sleep cycles', says Nick Littlehales, sleep coach to sports stars including Sir Bradley Wiggins and Christiano Ronaldo. 'For a long time, athletic training focused on diet and exercise, but nothing was mentioned about the forgotten but equally important pillar - sleep. It's vital for performance and recovery.'

Littlehales' theory, which he explains in his best-selling book Sleep, is based around his R90 Recovery Programme referring to the 90-minute sleep cycle he says it takes to recover under clinical conditions. It shakes the view long-held by many that we need eight hours of solid sleep a night - which is just as well, given the average person in the UK gets just six hours and 19 minutes.

So, rather than thinking of sleep in nightly eight-hour chunks, we should meet our sleep needs throughout the day and, while the average person needs around 35 sleep cycles a week, there's no need to get it all during the night.

The power of ZZZs

Midday, late afternoon and early evening snoozing - or just taking time out to yourself - is key, but Littlehales describes it as controlled recovery periods (CRP) rather than napping. 'It doesn't even matter if you don't fall asleep, you just need to catch that place when you're on the verge of dropping off,' says Littlehales. 'It's just as refreshing, and I'll often book an hour-long meeting for myself at 5pm, where I won't be contactable. I'll even drive home, pull up outside my house and have a half-hour rest in my car before going in.'

Owl or lark?

According to Littlehales the other key to good sleep is to know what kind of sleeper you are. 'Chronotypes or AMers are morning people, and PMers are night owls. AMers tend to wake easily and early and go to bed earlier. Night owls, on the other hand, can feel more alert and productive in the evening and naturally want to go to bed later, but struggle to wake up in the mornings. Some people may fall between the two,' says Littlehales, 'although most people lean more heavily towards one type.'

Night owls should get a dawn-wake stimulator to mimic sunrise to help wake them up. 'Also, avoid weekend lie-ins because this will cause your body clock to drift back towards its natural state, which makes it harder to wake up for work in the week. But otherwise, you should make your sleep type work for you - early birds are more productive in the early part of the day whereas night owls are more productive later on.'

So, work-wise, early birds should plan important meetings or complete important tasks first thing. Whereas night owls will be more productive after lunch and can take on more of the household chores, like cooking dinner, later on when early birds will be getting tired.

Lastly, fretting about sleep is counterproductive: 'Chasing or worrying about sleep is the one thing guaranteed to make you sleep less,' says Littlehales.

Sleep better

Have more magnesium: It maintains good levels of GABA, a neurotransmitter that promotes sleep. Good sources include wholegrain bread and pasta, spinach, bananas, nuts and black beans.

Top-up on cherry: Sour or tart cherries are a rich source of melatonin - your natural sleep-inducing hormone - and drinking cherry juice before bedtime can help to improve sleep quality and quantity. Look out too for supplements containing concentrated cherry juice.

Go king-sized: 'Most so-called double beds are actually smaller than two singles put together,' says Littlehales. 'If your children or grandchildren climb into bed with you at night, your sleep will suffer further. So buy the biggest mattress you can'.

Less is more: Littlehales sees bedrooms as recovery rooms, and advises they're kept cool (16 - 18C is ideal, he says), dark and calming. Say yes to black out blinds and soothing paint shades, and no to TVs and clutter.

Do it right: If you're right-handed sleep on the right side of the bed: 'If you're on the left side of the bed you'll naturally turn more onto your right side and the mattress will create more pressure on your dominant side, causing you to move around more than you should, which means you sleep less,' says Littlehales.