Once you are in good shape (or in a good weight loss track) it's time to move on the next level but keep in mind that this is not just a one day project: "it will take dedication, time and patience to get your abs noticed". You get to this second task by adopting a consistent abs workout philosophy consistently. This blog will discuss the was in which you can accomplish this second goals.
1. Do sit ups. Lie on the floor, feet on the floor, knees up and hands crossed on your chest or behind your head. Have someone hold your feet down, or wedge them underneath something heavy. Sit all the way up, lifting your lower back off the floor along with your shoulder blades. Keep your back straight (no hunching). Lower yourself down. REPEAT
2. Do crunches. Lie on the floor with your arms in front of your chest or with your hands lightly touching your temples or behind your head. Bend your knees. Raise your shoulders (upper torso) towards your knees, using strictly your abdominal muscles. As soon as you begin lifting off the floor, exhale through your mouth, ending with a gasp once your shoulders are off the floor. Pause for a second once you are at the top of the crunch and exhale the last bit of air from your diaphragm while flexing your abs. Lower back down slowly and controlled while inhaling through your nose, just until your shoulder blades touch the ground. Do not let your head touch the ground. REPEAT
3. Do leg lifts. Lie on the floor, legs straight out, hands at your sides. Lift your legs straight up (not bending your knees at all) until they're at a 90 degree angle (or close). Lower your legs and repeat without letting your legs touch the floor. REPEAT
4. Train your oblique muscles. These are the muscles on either side of your stomach. It's not as important to work on your oblique muscles at first, but eventually you'll want to start working these too. There are multiple ways to do this work out. There are twisting machines at gyms; you can twist while you do sit-ups; you can do side bends; you can twist side to side with a medicine ball in hand, etc. Lift your feet off the ground while doing the crunches by alternating each leg in the air. Bring your left knee up toward your right shoulder and then your right knee toward your left shoulder. REPEAT
5. Do pull-ups hanging from a horizontal bar (optional). You will be amazed at the number of muscles around your stomach working with pull-ups. Do 5 to 10 pull-ups with your palms facing away from you and 5 to 10 pull-ups with your palms facing towards you. This will also build your lats and biceps at the same time. REPEAT
Finally this picture gives you an idea of the type of exercises and the abs muscles you will be working out. Ideally for having well-packed abs you should be able to alternate all these workouts.
It is never too late to get your abs noticed. I am already on my 50s and I managed to get it ;-)