If you think you can go for some isolated exercises to lose fat from your lower belly then you are wrong. There is no specific exercise to lose lower belly fat. You have to target on decreasing your total body fat percentage. This can be done by indulging in more of aerobic exercises, which cut down the fat deposition in your body. Begin with low intensity aerobic exercises and gradually progress to higher intensity. If you are overweight then better go for low impact aerobic exercises so that your weight bearing joints are not affected much. Once the fat is strip off from your body, do some toning exercises for lower abs like reverse crunches, bridging etc. Other specific workout like kick boxing, Pilates on swiss ball, zumba dance, etc. work much better as these act as both cardio as well as toning.