I mean I used to do a thousand sit ups a day. this will lead to a rock hard stomach, and a little deinition but I know that if I really want my six pack to show I am going to have to eat right, and by right I mean I have to watch my caloric intake, and watch how I am making that caloric intake. I know if I want a six pack i should eat about 1800 calories a day which is a caloric deficit of about 800 calories for me, for about 2 months. this will allow me to burn of the excess fat on my body, and so you know the fat on your abs is generally the last fat to go. beyond that I need to make sure that i am getting my calories in the right way. I could get 1800 calories by eatting white bread, but that is not going to help me. I have to eat lots of fruits and vegetables. I find bananas and oranges are a good way to feel full and not get alot of calories, as well as plates of brocolli. I know you are vegetarian / vegan so my other advice for what to eat wont be taken. The other thing I eat alot of is very lean protein namely chicken, this is low in calories is you eat skinless chicken breast, and a great source of protein. you could try Myoplex protein shakes in the place of chicken, they are high in protein low in fat and not to bad on the carbs. I would recommend the chocolate flavor or if you want to make them higher and calories and mix them with orange juice the strawberry is fantastic.