I have been following a conditioning heavy fitness plan in order to cut some weight and lose some body fat over the last three weeks. I am exercising six days a week, and two sessions involve sprints (hill sprinting and normal). On these sessions it has got to the point where I can't finish them because my knees hurt quite a bit. When not doing anything my knees just sort of have a mild discomfort but sometimes when the leg completely straightens it is really painful and feels like the knee will just give way, and I often buckle when this happens, but it doesn't happen often maybe three times in the last few days. I am not sure if this is because I am actively preventing it from happening or not as I am being more careful in day to day activity because of the pain.
The pain feels like it is beneath the kneecap but in a sort of "U" shape around the kneecap. I am able to walk and do day to day things ok and I was able to perform a squatting session, with a mild weight for me without any discomfort, in fact normally I get a popping sound in my knee when I squat which was absent for this session.
I believe the pain has probably been caused by an overuse of the knees in activities they are not used too, as I stopped exercising around April and didn't really do anything until a few weeks ago. Last weekend I also completed the three peaks challenge with no extra training and it wasn't until after this I noticed the problem with straightening my legs, but the mild discomfort was present prior.
I am making good progress exercising and I would like some alternative exercise suggestions to sprinting as I do not wish to stop if at all possible. I tried swimming tonight and that doesn't seem to have aggravated my knees but it is expensive and commuting to the pool takes time therefore I couldn't afford to do it more than once a week. Advice on treating this type of knee pain as well would be appreciated if possible, additionally any insight into why my knees normally make a "clicking" sound when squatting would be helpful.
