Now perform a regular sit-up, keeping your legs turned to the right with your right knee on the floor, so that you are doing a regular sit-up from the waist up while your bottom half is twisted to the right. After 25 of these, move your lower body to the left and repeat 25 more working the other side.
Set 4: Ceiling Sit-Ups
Lie on your back but elevate your legs at a right angle as if you were sitting in a chair. With your hands behind your head, focus on a place above you (a mark on the ceiling, for instance) and slowly raise your nose towards that spot, lifting your head and upper back off the ground.
You should feel your upper abdominals strain if you do this exercise correctly, which is a good thing because this small group of muscles (the top two of your six-pack) are most often neglected and forgotten.
Set 5: Bicycles
On your back, begin pedaling with your legs as if you are on an invisible bicycle. With your hands behind your head, alternate bringing your right elbow towards your left knee and vice versa (much like in the right/left sit-ups).
This exercise requires some dexterity and coordination, so be patient as you get the hang of it. It is also the main set, meaning it is the most difficult of the lot and the most all-encompassing, working every major abdominal muscle group.
Set 6: Final Set
I like to leave the last set open for repeating any of the above sit-ups that you prefer. You may want to repeat the first set of regulars, maintaining the same slow speed and control as you did the first time. Or you may choose to really challenge yourself with another set of bicycles.
Regardless, it is essential that you keep your form and technique throughout the session; it is easy to get sloppy as you get tired, but the key to building great abs is slow, concentrated repetitive movement.
Doing sit-ups is a great warm-up if you have the luxury of a half hour before your swimming workout. It is also a good way to warm up before beginning a workout in the weight room.
The push-ups are meant to stimulate blood flow to the upper body and warm up your arms while giving your abdominals a little break. However, you will notice that they are still contracted during the push-ups, so they aren't entirely getting a break!
Finally, if you get a chance to swim immediately after an ab routine, you will really notice how important your stomach muscles are in the water. You should feel them flexing during your swim if you worked them properly on dry land.
As your stomach gets tighter and more conditioned, you'll start executing your flip turns faster and snappier. Your body should also feel more balanced as you rotate through your stroke.
A former swimmer at Stanford University, Alex Kostich has stayed strong in the sport at the elite level even while maintaining a day job. The three-time Pan-American Games gold medalist still competes in—and wins—numerous open-water races around the world each year, as well as competing in the occasional triathlon and running race.