Question by Jesse from Pleasanton, California:

I’m in pretty good shape and I workout 4 days a week. On leg day, I do leg extensions, leg curls, and lots of calf work. I’ve been doing them for years and have noticed great leg development, but I have recently been getting a lot of pain in my knees for the past few months. I stopped running when I do cardio and just do the bike now to ease the stress off my joints. However, I still have tremendous pain in my knees. What should I do?

Answer by Jaret Grossman, Co-Founder of Muscle Prodigy:

I’m pretty sure your knee trouble is stemming from your leg routine. The leg extension has always been a topic of discussion. It’s a very useful exercise that provides great results. However, it has a lot of drawbacks. The leg extension reduces and delays the activation of the vastus medialis (VMO). The VMO is the most important muscle for keeping your knees stable. When leg extensions are performed improperly either in terms of technique, weight, or programming, they tend to strengthen every muscle in your quad except the VMO. This will lead to muscular imbalances in your knee, which will in turn, lead to injuries.

I suggest you see a doctor and get an MRI to see if you have a tear that requires surgery, but for a quick fix try doing the following. You need to expand your leg workout to make sure you strengthen your VMO. Start off with something like the bike for 5 minutes to get the blood flowing. Then move on to squats, making sure you steadily increase the weight slowly. Please perform these with a full range of motion. Then do some half squats on the Smith Machine. Also, do some dumbbell lunges. You can continue doing leg extensions, but you need to do them at the end of your workout and with much lighter loads.

Email me your question: Jaret@muscleprodigy.com