I went on a run yesterday and within 20 minutes I fest a very sharp pain below my left knee it has happened before but I didn't think much of it. Can anyone advise me on stretches or exercises to stop it?
I'd begin by Googling 'pre-run stretching' as it will deliver a wealth of suggestions with illustrations.
Also, perhaps try some body weight squats to get your knees 'warmed up' and moving.
If you're not accustomed to running (particularly on hard surfaces) it can take a while for one's body to get into the swing of things. Hopefully others will chip in with their own suggestions and comments.
It might be runners knee which is what I got a few years ago. About 2 weeks off and doing this stretch (icing also for up to 20mins a time) helped:
To stretch the area, Andy recommends lying on your side with your bad leg on top.
Bend your top leg so your foot goes back towards your bottom, then hold it there with your hand and keep both knees touching.
Hold the stretch for at least 45 seconds, breathing deeply and feeling the stretch in the thigh. Repeat this around 6 times a day.
If the pain's severe or the knee's swollen, see your GP straight away.
If your knee pain isn't severe, stop running and get it checked by a GP or physiotherapist if the pain doesn't go away after a week.