Lie on your back with your hands behind your head. Contract abdominals to go into a quarter or half situp.
Extend your right leg straight out and let it hover 2 to 4 inches off the ground; tuck your left leg in so that the left knee is at a 90° angle and directly above the hip joint.
Crunch upward and twist your right elbow in towards your left knee. Get as close as you can without letting your knee come in past your hip joint.
Switch leg positions; extend your left leg straight out while simultaneously bringing your right knee in over your hip joint. This time, crunch your left elbow up towards the right knee.
Alternate back and forth for a set number of repetitions or a set time period. Pulling in towards each knee makes one repetition
The Crisscross Crunch is a deceptively difficult core workout. The key to making this abdominal move effective is not letting the knees come in past the hip joint. Focusing on this detail forces abdominals to contract continuously, which further challenges the abs muscles and burns more calories. This situp variation tones and flattens the abdominal muscles quickly and effectively making it a perfect exercise for a core routine. It is also a great abdominal exercise to add into an intense boot camp routine.