Be patient! I had been running for 10+ years without any serious injuries. But then I was sidelined by knee pain, ITBS and recurring muscle cramps for almost 8 years. I had to stop running completely for several months over and over again in the process. Doctors found nothing as a real cause. I also love running, and this is why I never gave up overcoming this.
I am 33 now and have been back to regular training and racing for a year, even winning small races again. I am still far from my PRs (1:08/2:26), but I enjoy running again.
The most likely cause for my problems were severe muscular imbalances.
Here's what helped me after trying many things:
- weekly cross-friction massage sessions, for one year; needed several tries to find a skilled physio
- switching from heel-striking to mid-foot running
- daily mobility routine with foam roller and all sort of tools; I found the exercises from Kelly Starrett most helpful
- almost daily strength/core routine, especially focusing on the glutes and movement patterns; see James Dunne‘s videos and programs. I also found Mark Verstegen’s book really useful
- using only lightweight running shoes with standard orthotics that provide only little support (tried custom-made as well, but they are too heavy)
- focusing on running form, following the advice from James Dunne (YouTube)
- doing running form video analyses to see where there is still room for improvement
I have to do the core/mobility routine regularly to prevent the muscle cramps from returning. But my knee pain seems to be gone once and for all.
Strangely, I feel like I am better runner now, although I am slower.
All the best for you!