It started gradually. I was running with a group of friends in the woods, enjoying the fresh air and challenging myself to keep up, when I noticed a slight stiffness in my right knee. Slightly annoying – not serious.
The next time I ran, it was there again. Not immediately, but after about 2km, the same niggling feeling. Again I kept running…
A few weeks later I set off to do my regular 5km Park Run one Saturday at 9am – a timed run in a nearby park which I was running almost five minutes faster than when I’d first started.