When do you have your first serious yawn of the day? During the Nine O'Clock News? At teatime? On the way to work? Yawning, and the coal sacks under your eyes, are two of the most telling signs that your body wishes it was tucked up in bed. But there are other, more insidious ones. These are becoming all too common among teachers, who are, frankly, knackered. Fatigue is, without doubt, a widespread problem in the teaching profession.
"Tiredness is a key factor in about 40 per cent of the casework we handle on behalf of teachers," says Alan Manasseh of the Professional Association of Teachers. "It can manifest itself as an issue of absence, competence or discipline, but tiredness is the root problem."
Constant tiredness not only makes for miserable teachers, it also has repercussions for their pupils. A tired teacher is unlikely to be as effective in the classroom and there are health and safety issues: a lapse in concentration can have serious consequences, especially for those who oversee physical activity and the use of machinery, or who drive the school minibus.
As well as being dangerous, tiredness can also lead to conflict in the classroom. Mary Howard, assistant legal secretary for the National Association of Schoolmasters Union of Women Teachers, says: "The end of every term sees a sharp rise in the number of teachers accused of assault. When people grow tired they often become irritable, patience wears thin and they may behave out of character."
Teacherline, a 24-hour telephone counselling service set up last September, has already seen a clear pattern emerge. "The majority of our calls are to do with workload, and the most obvious effect of this is fatigue," says Jason Harding of the Teachers' Benevolent Fund, which runs the helpline. "It's not surprising teachers are exhausted when you hear the hours many of them are working."
Weekends and holidays should play a key part in combating work-related fatigue. But pressure to work through holiday time is considerable - there's preparation, review, policy documents, external examination work and school trips. While most professionals can choose when they take their leave, so they can rest when they need it most, teachers' holiday periods are fixed. This can mean working through the fatigue barrier. "The first week of a holiday is always a write-off," complains Sarah Green, a chemistry teacher from Coventry. "I'm either so run-down that I get a cold, or I'm too tense to enjoy myself. By the time I've relaxed it's the end of the holiday."
In response, some local authorities are discussing a move towards a five-term academic year. This would create regular holidays at even intervals. Unions are divided on the issue. Nigel de Gruchy, NASUWT general secretary, argues that "tinkering with the structure of the holidays isn't addressing the cause of the problem. Teachers are overtired because they are overworked. Until a maximum number of working hours is agreed the problem won't go away."
Alan Manasseh favours a four-term system, but agrees that it's what goes on during term-time that matters. "One of the worst times for fatigue, and absences, is around the beginning of October," he says. "Teachers return from the summer break with their batteries recharged but then the system fails to live up to their expectations. It's like putting these newly charged batteries into a failing torch. There can be a sense of disillusionment - that's when feelings of tiredness strike. It's different from end-of-term exhaustion, and perhaps more worrying."
A positive approach can certainly increase energy levels; we all get out of bed quicker if we have something to look forward to. A recent survey by corporate support network Business Link found that employees who were content at work and felt valued reported higher energy levels than colleagues who felt dissatisfied.
But no one would suggest that tiredness is purely psychological. There are plenty of teachers who don't just feel tired; they are tired. While working long hours may be a contributory factor, it isn't necessarily the main cause of fatigue.
Nutritionists, for example, argue that the effective running of the body depends on eating the right food. Dr Alan Stewart, author of Tired all the Time, is a specialist in fatigue who, not surprisingly, numbers a high proportion of teachers among his patients. He highlights a deficiency in key minerals or vitamins as a common cause of tiredness. "Low levels of iron, magnesium and Vitamin B are all linked to fatigue. There are many reasons why a deficiency in these vital nutrients can occur. It may be the result of poor diet, or absorption of the nutrients may be affected by the consumption of tea, coffee or alcohol. In addition, more than 10 per cent of women of child-bearing age experience low levels of iron during the premenstrual phase." Dr Stewart recommends taking supplements for two months and seeing if they improve your energy levels. It goes without saying that eating regular, well-balanced meals and drinking plenty of water will also help.
When faced with the problem, most people's first port of call is their local GP. Dr Fiona Hart deals with half a dozen new cases every week at her surgery in Sheffield. "Fatigue is cumulative," she says. "If tiredness builds up over a period of time it can be difficult to shake off. Prevention is better than cure - it's important to combat tiredness on a day-to-day basis, rather than waiting until you reach a point of exhaustion."
She suggests several ways in which teachers can adjust their routines to help overcome fatigue. "Noisy environments are tiring and stressful. Building some quiet time into your day, inside or outside of the classroom, can be a real help. For many teachers, break is interrupted and lunchtime eaten away, but if amidst the duty rotas and the last-minute photo-copying you can find time for a stroll and some fresh air, you should feel better for it."
Exercise is also important. If you come home shattered at the end of a long day it's always tempting to slump on the sofa. But a feeling of physical tiredness can often be the result of tensions in the muscles caused by inactivity and poor posture. Gentle exercise can help refresh the body. Building exercise into your daily routine needn't involve anything strenuous - even 10 minutes' gentle stretching in an evening will help alleviate muscle fatigue and prevent problems building up.
Of course, the simplest remedy for tiredness is sleep. But the quality of sleep can be diminished by overtiredness. The way we spend the time just before going to bed is crucial to the quality of our night's rest. One of the potential pitfalls for teachers is that the job entails taking work home, raising the spectre of caffeine-fuelled marking sessions - a sure-fire recipe for a restless night.
Going to bed at a regular hour in a relaxed frame of mind is the key to waking refreshed; a few minutes spent unwinding can be a real benefit.
But when does tiredness stop being a case of needing a good night's sleep and become a matter for medical concern? Fatigue can be a warning sign for a range of illnesses. This leads into the sensitive area of chronic fatigue syndrome and in particular ME, a complex and debilitating condition linked to viral infection.
Jane Colby, of Action for ME, has been involved in research in schools which found a rate of ME among teachers two to three times higher than in other adult population surveys. "Teachers are exposed to a wide range of viruses," she says. "They should always be aware that excessive tiredness may be a symptom of something more serious."
Many people are reluctant to visit their GP complaining of fatigue, believing they may be wasting their doctor's time. But Dr Alan Stewart says the medical profession takes fatigue seriously. "The test is probably that if you have a completely restful weekend and feel no better for it, you should see your doctor. If you are so tired that it is changing your life or affecting your work, it's a problem."
Teacherline is run by TBF's Teachers Support Network, tel: 08000 562561. Tired all the Time by Dr Alan Stewart, Vermillion (1993). Action for ME:PO Box 268, Lewes, East Sussex BN7 2QN
* Lapses in concentration, maybe missing a turn-off on the drive home from work
* Increased irritability, snapping at colleagues or failing to see the funny side of things
* Falling asleep during the day, especially after lunch or early evenings
* Headaches, muscular aches and pains, especially in the legs
* Waking up feeling tired and reaching straight for the caffeine