There are many ways to reduce weight, brisk walking being one of them. Since you are having pain in the legs, I suggest that you walk rather than jog on the treadmill. It may not seem like much but there are other variables you can play with: You can increase the time that you spend on the treadmill; that means that the distance will also increase. You can do a simple test to know whether you are walking fast enough. If you can sing while you are walking, you should try and go a little faster! By using your arms, bent at the elbows and moving them back and forward, you can increase your pace without much difficulty.