Exercises that are easy on the knees

I know from experience that the knee is one of the more vulnerable joints on the body -- especially for active people who spend lots of time running and walking. So it's important that we learn to look after our knees, and take measures to not only treat injury but to prevent it as well. eDiets has come up with a series of easy knee-friendly exercises that can help build muscle in the joint without straining it.

If you already have trouble with your knees like I do, I find it's a good idea to find exercises that don't put too much pressure on them. Using the elliptical trainer and swimming are two of my favourites.

What do you do for you knees?