Ok so I'm very overweight. Wii fit said my BMI is 39.8. Yikes! That's pretty scary. I want to lose weight and get fit but I have a bulging disk in my lower lumbar region. The doctor said I should avoid squats and jogging. Other than walking what can I do for exercise? I use an exercise ball to do stomach crunches. If I try to use a mat to do them, my disks pop. Not fun. So... recommendations anyone?