I recently met with my trainer and she suggested that to start losing weight (I have been working out for nearly 2 years at a gym and have lost only 10 pounds. I work out 4 times a week with cardio and weight training), I should work up to jogging for 30 minutes. She suggested that I take 1 week to build up my walking speed and then gradually add minutes of jogging to my walking. This sounds like a good way to challenge myself; however, I am more than 100 pounds overweight and it just seems wrong to further stress my joints by pounding on them. I am decently in shape, but I am wondering if this is really feasable. Does anyone have experience with this or any suggestions for me???

Should I really try to do this, or is my trainer nuts?