Single Arm Sit-Up

  1. Lay on your back with your knees bent, feet flat on the floor.
  2. Reach one arm straight up towards the ceiling, while the other arm is relaxed across your chest.
  3. Sit-Up just far enough so that your shoulder blade of your extended arm comes off of the ground.
  4. Alternate with the other arm every 5 reps

Muscles: Upper abs, rectus abdominis, internal obliques, external obliques

Make it Harder: Hold a dumbbell in the extended arm.