I quit sports because of a knee injury but now how do i lose the weight i gained?

About a year and a half ago, i permanently messed up my knee. Now, the slightest overrun or weight lifting puts it out. Naturally, an athlete would start to lose tone and endurance after that long without an efficient way to exercise. I quit weighing myself because I struggled with an eating disorder before, and weighing always lead to obsession, but I FEEL FLABBY! I know I'm not fat, just not as muscular as I want to be again. I about died when I jogged up some stairs because I was late for something and I was in a hurry, the other day and felt a serious cramp in my thigh. That is something that I would NEVER let happen when I ran track. Any suggestions about how to tone legs and abs with low impact on knees and other joints (my accident messed up my right shoulder and elbow too) and maybe some cardio work too. I always worked hard to be in shape, and I'm going crazy!

Man I kinda know how you feel. I just quit track. For low impact, the best advice I can give you is to do a workout in the pool. There is no impact there, and if moving your leg in the water hurts it, just let it trail behind, you don't even need it to work out the rest of your body.

http://www.workoutsforyou.com/water.htm
http://diet.ivillage.com/workouts/wcardi...

There are some websites with things you can do in the water to keep in shape. Also, just type "Pool Workouts" into google for more.

Start going to a good gym with good trainers. Some of the professionals could probably help you out.

Eat right and join a gym. Use bikes and elipticals for low resistance and if that is too much you can do simple floor excersizes, pilates, and yoga.

If necessary get one personal training class for them to teach you how to excersize without harming the injured or weak body part.

Try swimming or cycling. They're both just as good as running but put much less pressure on your knees. Walking might be also possible, depending on how severe your injury is.

As for weight lifting, your knee injury should not stop you. You can still find many exercises which do not involve your knees at all, especially when it comes to the upper body.

Methods of prevention of Knee sprain mentioned in various sources includes those listed below. This prevention information is gathered from various sources, and may be inaccurate or incomplete. None of these methods guarantee prevention of Knee sprain.
Healthy diet - keeps muscles strong.
Healthy weight
Fall prevention methods - e.g. clean up obstacles, avoid wet areas, etc.
Properly fitting shoes
Stretching exercises
Warm-up and stretch - before sports or exercise
Protective sports equipment
Avoid sports/exercise when in pain
Avoid sports/exercise when tired
Avoid running on uneven surfaces