For ages I always thought that by doing heaps and heaps of sit ups every night I will be able to show off a six pack during summer. I found that my abdominal muscles were increasing if I touched them but I could not get that perfect definition. Working out your abdominal area will increase the muscles but if they are covered by a layer of fat they will not be seen. Therefore it is essential to be on a low fat diet to achieve the definition you are after.
It will take time and dedication to reach a six pack. Regular abdominal training and a healthy low fat diet will have you seeing toned and defined abs. You should aim to eat 5 smaller sized meals a day. For example, breakfast, snack, lunch, snack, dinner. You have to make sure that your diet consists of plenty of protein so your body will not break down your muscles for fuel and shrink your abs.
Many gyms have machines that you can use to train your abs however most abdominal exercises can also be done at home. I would try to include the following exercises in your ab workout:
Crunches: Lie on the floor and cross your arms in front of your chest placing your finger tips behind your ears. Bend your knees up as far as they go. Flex your abs while lifting your shoulders off the floor towards your knees. Hold for one second at the top and exhale until your shoulder blades touch the ground. Repeat.
Sit-ups: Lie on the floor with your knees up and arm in front of your chest. Lift your lower back off the floor with your should blades. Lower yourself and repeat. To increase the resistance of the exercise you can hold a weight on your chest while performing the manoeuvrer.
Leg raises: Lie on the floor with your legs straight out and hands by your sides. Lift your legs straight up until they are close to a 90 degree angle. Do not bend at the knees. Lower your legs and repeat.
You can also exercise your oblique muscles which are on the side of your stomach by twisting your upper body in all of the exercises described above. You can do all this fitness training but if you are not eating a healthy low fat diet then there is no way your abs can be defined.