Why feel guilty because you don't go to the gym? Teachers are well-placed to keep fit on the job - at no expense, says a leading physiotherapist.
"Child contact time is relatively short and broken up, with constant chances to move around," says Chris McCarthy, chairman of the Manipulation Association of Chartered Physiotherapists (MACP). "The people we see with real problems are stuck in call centres from 8am to 6pm and can't move."
But, he adds hastily, he knows the teacher's job doesn't end with classroom contact. Like other professionals, teachers are spending more and more time peering at screens, as well as reading and marking at their desks. Even in the classroom, things are not arranged for the good of the teacher's spine and knees. Primary teachers especially are constantly bending over low tables or squatting to get down to the level of their charges. But perhaps the biggest single factor affecting teachers' well-being is stress, he says - the kind that makes you hunch your shoulders when the level of disruption is rising in class. That tension is the strongest predictor of chronic neck and back problems.
The 1,000 members of the MACP specialise in musculo-skeletal disorders (Dr McCarthy's research was on different exercise approaches to osteoarthritis of the knee). And they are keen to get physiotherapy out of the home and into the workplace.
"Our problem," he explains, "is compliance. If people are given boring exercises to do at home, they won't bother, whereas exercises specifically tailored to fit into your working day, either during the work itself or during breaks, are far more likely to be effective. When the bell goes, you can do your exercises."
A recent pilot study with lecturers at Warwick university, where he is an assistant professor in the school of medicine, found that workplace tips and exercises are nearly as effective in combating neck and shoulder pain as sessions with a trainer in the gym.
Thirty lecturers were given an ergonomic advice session on how their workstation (computer and desk) should be set up, as well as some simple stretches and exercises. Their fitness was then compared with that of 30 others, who had attended the university gym for 12 weekly sessions of progressive resistance training. The gym-goers were fitter, but not by much.
What should teachers avoid above all? "The poking chin," says Dr McCarthy, sticking his neck out like a chicken. "If we could stop people doing that, it would have a huge impact on neck and back pain"