I have a question about my knees and below my knees hurting. I have been doing two types of lunges everyday and I am now feeling pain in my knees and right below the knees. They actually feel weak during the day...I was wondering what should be the max number of lunges and what could be some other reasons to why they are hurting? Thanks.
Lots of stuff can go wrong with your knees, but the reason that they are probably hurting is poor form. Make sure that your front knee doesn't go past your foot or you are adding too much stress to your knee. If you are following a video look at the instructor and then do the lunge yourself in front of a mirror. If you use a gym talk to a trainer or check out a book from the library like body for life.
Lunges are notoriously hard on the knees. As the previous poster said, form is very important. Also, you might want to consider not doing any more lunges until the pain is completely cleared up. In the meantime, work on strengthening the muscles that hold the knee in place, with quad sets and straight leg lifts. You can find these exercises at http://www.hughston.com/hha/a.11.2.2.htm .