ABS ON FIRE!
I do abs but only 2-3 times a week with cardio and it's a short set. I only use my body weight because like any other muscle when you add weight you will build muscle and well, I don't know about you but I'm always trying to tone the belly rather than make it look bulky and muscular. Now If you want deep lines then adding weight is to your benefit! I sometimes add weight to my oblique exercises to give my stomach the sexy V shape on the sides! I love that look!
To show you which exercises you are working here is a full diagram of the abdominal wall:
I'm going to show you how to work each of these muscles. I tell all of my clients, you can work out your abs everyday and won't look cut, toned, or defined unless you look at your eating habits. When training for my bikini competition, I noticed the biggest difference in my muscle definition by how much water I drank, and my diet. The killer was sodium and sugar intake. Too much of it will just cover up all your hard work!
Alright, enough talk! Keep your abs tight and engaged throughout the entire workout to protect the back. Now let's tone and define!
1) SWISS BALL KNEE IN'S (15 Reps)
*modification: mountain climbers (15 each side)

Muscles Worked: transverse abdominis, rectus abdominis, internal and external obliques
2) BENCH V-UPS (notice he kicks them down at an angle) (15 Reps)

Muscles Worked: transverse abdominis, rectus abdominis.
3)INCLINE SWISS BALL PLANK (30 seconds to 1 min)
*modification: put ball into a corner or eliminate the ball.

Muscles Worked: transverse abdominis, rectus abdominis
4)SWISS BALL LEG LIFTS (15 reps) every time you open up is 1 rep.
*modification: keep knees bent

Muscles worked: Rectus Abdominis.
5) OBLIQUE SIDE DIPS (15 reps each side)
*modification: lower knees or hold side plank

Muscles worked: Internal and external obliques and adductors (inner thigh)
6)PLANK WALKS (8 reps each side...Go down 8 times with the right hand first then switch for 8 more with the left hand first)
*modification: lower knees but keep shoulders over wrists.

Muscles worked: Strengthens abdominals, spine extensors, chest, shoulders, triceps; buttocks and all leg muscles as stabilizers.
7)STRAIGHT LEG ALTERNATING SCISSORS WITH ARMS (30 Reps total or 15 reps each side)

Muscles worked: Entire abdominal wall, especially rectus abdominis.
8)OBLIQUE CRUNCH (15 reps each side)
*modification, bend your knees or just lift upper body
