As a former PE teacher, sport was Cherry Protheroe's life.
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.