Sleep your way to the top

A lack of sleep can be devastating to your career. The symptoms mimic depression and can bring your productivity to a grinding halt.

"There is a mistake in the belief that you get more out of life by cutting back on sleep. What you really do is compromise the quality of your wake time," says Professor Philippa Gander, director of Massey University's Sleep/Wake Research Centre.

Research shows we're sleeping around an hour less sleep a night than we were at the turn of the century when we averaged nine hours of sleep. Gander says this is costing us.

"If you're chronically sleepy and trying to do any kind of work you're at risk of making errors - whether it's brain work or whether physical work."

A lack of sleep causes poor concentration, impaired decision making, a lack of attention to detail, poor motivation and a lack of interest. For workers who find they haven't had enough sleep, the best thing they can do is take a power nap.

"You can top up and keep yourself going by taking short naps which I think are an effective use of time. A nap of 10 minutes will give you a few hours of better functioning. Even if you don't feel great, you will be more alert and more functional."

Gander says recent studies have found our need for sleep is so hard wired that it is a universal characteristic of all life on Earth.

"All species on the planet all the way back to blue-green algae have some kind of internal pacemaker which changes the way they function in step with the day/night cycle."

Getting up too early to go to work can not only make us less functional during the day but also lead to long-term negative health consequences such as a suppressed immune system. Gander says what's worse is that you can't make up for an early start by having an early night.

"You can't go to sleep a couple of hours earlier in the evening just because you have to get up early in the morning. It doesn't work like that. There is actually a period in the evening in the few hours before your normal sleep time where you can't go to sleep. We call it the evening wake maintenance zone."

To overcome this, a lot of people use night-time pain relievers containing antihistamine such as diphenhydramine hydrochloride (Benadryl) which Gander says is mildly sedating.

"They are generally regarded as pretty safe. That's why they're over the counter."

A recent study shows sleep deprivation may also be another reason why we're becoming so fat.

"Within a couple of nights of restricted sleep, you start changing your appetite hormones. You change your metabolism quite quickly. You get hungrier and you also start to become insulin resistant. So it looks like a pathway to type two diabetes if you keep at it for too long."

Workers who haven't had enough sleep may also find themselves hitting the candy machine and craving high fat/high carb junk food during the day. Gander says this is because sleep deprivation causes changes in two key hormones.

"Ghrelin, which is appetite enhancing, increases by about 20 per cent. Leptin, which is appetite suppressing, decreases by close to 20 per cent. So what you see is an increase in appetite even after two nights of restricted sleep."

Starting the weekend with a cumulative sleep deficit of several hours can make us feel like all we want to do on the weekends is catch up on sleep. But Gander says all hope is not lost because you don't have to make up every hour you've lost.

"Normally it takes about two nights for your sleep to get back to normal because the first night you catch up primarily on deep slow-wave sleep which is one of the types of non-rapid eye movement (REM) sleep. Then on the second night you catch up on REM sleep."

But even after a weekend of long restful nights we may not be completely restored if we've missed out on too much weekday sleep.

"Your sleep may get back to normal with two nights of unrestricted recovery sleep but maybe normal daytime functioning doesn't. At the moment it's a bit of an open question as to how many nights of recovery sleep you need to get back to your fully functional daytime level."

Gander says people experiencing ongoing problems with sleep should first talk to their GP who may then refer them to a specialist sleep clinic.

Dr Alex Bartle is the medical director of two such clinics in Christchurch and Auckland. He says by the time people come into his Sleep Well Clinics, bedtime conjures up feelings of anxiety and stress.

"Most people don't think there's anything you can do about sleep deprivation or they put up with it and don't really do much about it."

Bartle says people unfortunately continue to see sleep as a waste of time even though brain functioning during sleep is crucial.

"Most people need between seven and a half to eight and a half hours but more realistically it's seven to eight hours. Some people can cope very well with six to seven hours. Some people need nine to 10 hours."

A lack of sleep also causes increased irritability among workers and higher rates of absenteeism.

"They are things that in an office situation can lead to a lot of strife. People get snappy and short tempered."

But for 10-15 per cent of New Zealanders, getting a good night's sleep is not just a simple matter of choice. They suffer from chronic significant insomnia which has lasted for more than a month. To make sure you arrive at work feeling refreshed, there is more you can do than just have a warm glass of milk before bedtime.

Bartle calls it "sleep hygiene" which involves managing your stress, your daily routine and your pre-bedtime routine. Caffeine, tobacco and alcohol all have negative impacts on sleep. Caffeine and tobacco are obvious stimulants but alcohol can have a similar effect.

"Alcohol helps you go to sleep. It's a sedative. But the breakdown products of alcohol tend to be alerting. It's later on in the night that you tend to have a more disturbed sleep if you've had a lot of alcohol."

Bartle says having one or two drinks is alright but more could have a negative affect. A heavy meal or heavy exercise within three hours of going to bed will prevent your body from shutting down properly.

"People who play sport and have rugby tournaments that go on into the evening or train are pumping a lot of adrenaline which takes a long time to disperse. You're also heating yourself up a lot. Muscle heat tends to delay sleep onset."

Bartle also says it is particularly important for office workers to get out into the daylight while at work.

"Light boosts your serotonin levels. Serotonin at night converts to melatonin which helps you sleep better."

But not all sleep is equal and there is a definite structure to it, Bartle says. Waking up too early to go to work cuts our sleep short at the back end of the sleep cycle and can effect speed of thought processing and decision making.

To help wind down, Bartle recommends some light magazine reading but no television, no talkback and no novels. If you've got a lot on your mind and can't sleep, write down your activities for the next day.

If you wake in the night with more thoughts churning, write them down as well. Make sure you can't see the clock in the bedroom and if you can't sleep, get out of bed and wind down rather than tossing and turning.

"When you know all the amazing things that go on in sleep; all the hormonal changes, all the healing processes, all the memory processes that go on in sleep, then you might take sleep a bit more seriously. It is of vital importance for us."