You work out at home by doing sit ups and crunches, change you eating habits and do cardio exercise (such as brisk walking, running or jogging) to remove any extra body fat from around your abdomen.
If you mean the stomach/abs six pack, then you have to do heaps of crunches and sit ups, at least 100 crunches a day for a month or more. Swimming is extremely good for toning abs, the stroke butterfly in particular. it also depends on the person.
There are two requirements to get a six-pack:
You have to lose any extra fat covering over your abdominal muscles. So, to do this change your eating habits and do cardio exercise such as brisk walking, running, joggling, etc. These will burn fat.
You have to strengthen your abdominal muscles so that they get bigger. For this you do sit-ups, crunches, and sit-ups on an inclined bench, hanging on a bar and raise knees to chest.
