By Jane Elliott
Health reporter, BBC News
As a former PE teacher, sport was Cherry Protheroe's life.
Cherry is enjoying exercise again
If she was not teaching it, she was taking part, training every spare minute and very fit and active.
But a bout of psoriasis as a teenager led her to develop psoriatic arthropathy at the age of 28 - this causes pain and swelling in joints and tissue, accompanied by associated stiffness, particularly in the morning.
Doctors told Cherry, now 60 from North Bedfordshire, that she had to give up sport or face life in a wheelchair.
So for nearly 30 years Cherry, who later also developed severe osteoarthritis, did no sport.
Her health deteriorated and four years ago she was forced to take early retirement from her post as deputy head of a large comprehensive school.
Then her doctor wrote her a very special prescription - for exercise.
On her GP's advice she joined a local gym and started using the treadmill, cross trainer, rower and bikes.
"And I started to feel much better. I have got more mobility back," she said.
"Before it was so bad I could do very little. At one stage I had to walk with a stick.
"I would not have gone to the gym had it not been for the doctor, because I had been told that exercise was wrong for me. But it was really the intensity of the exercise I was doing that was the problem.
Cherry regularly rides her bike
"Now I go to the gym twice a week and I try to cycle round the village as well."
Cherry's doctor supplied the gym instructors with pertinent medical details.
They started her off with a gentle half-hour programme and within a year she had regained much mobility and reduced her pain levels.
Within two years she had increased her gym time to an hour's stretch and has been able to reduce her medication.
Now a new medical trial hopes to offer chronic pain sufferers similar benefits.
Gary Macfarlane, professor of epidemiology at the University of Aberdeen's department of public health, plans to recruit 500 people, aged between 25-60, to a trial.
The patients will be split into groups, one doing exercise programmes, one cognitive behaviour therapy (CBT) and the third a combination of both.
Patients doing the exercise part will be offered free exercise on prescription at their local gym and will be expected to use the gym twice a week for nine months as well as getting their own personal trainer.
Cherry exercises regularly
Those using the phone CBT will get an hour long assessment, followed by seven weekly half-hour session and then two more at three and six months. This hopes to help them manage their pain by identifying and evaluating thoughts and behaviour.
There will also be a control group receiving the usual GP based care, which may be painkillers.
Dr Macfarlane said: "What we believe happens is that people get these symptoms and pain, so do less exercise. Their bodies then become deconditioned."
He said it was hoped an increase in exercise could change this pattern.
A spokeswoman for Arthritis Research Campaign, which is funding the trial, said: "Chronic widespread pain is a massive problem but currently there is little effective treatment. We hope many people will benefit as a result of this trial.
"Cherry is setting a fantastic example to other people with arthritis, and is living proof that exercise can really help to reduce pain and stiffness without having to rely to drugs."