The Plank to Push-Up is an excellent exercise for core stability and muscular endurance.  Start in a modified plank position; lie prone with only your toes and forearms on the ground.  Your elbows should be directly under your shoulders, shoulder blades pinched back, glutes and abdominals strongly contracted.  
Push off of your right forearm to propel yourself slightly upwards and place your left hand on the ground and straighten your left arm.  Push off your left hand to propel yourself up slightly and place your right hand on the ground and straighten your right arm to put your self in a push-up position.  Place your forearms back on the ground one at a time to get back into the starting position.  That's 1 repetition.
Repeat this as quickly as you can for 30 seconds while keeping your core tight to prevent yourself from twisting to either side.  Next round begin by pushing off of your left forearm to work both sides of your body evenly.  
Tip: For an added cardiovascular challenge, perform this exercise immediately after a run.  We do this with many of our weight loss clients to simultaneously burn fat and keep their heart rates elevated.

If you have any questions about this exercise or any of our techniques, feel free to contact us:  info@emergeathletics.com

The partner sit-up and twist is a great exercise to spike your metabolism and keep your heart rate sprinting during a workout.   It challenges the muscles of the abdominal wall as well as the obliques to help you carve a solid core.  To perform this exercise grab a partner and sit on the ground facing each other with knees bent.  Next, hook your feet together, place your fingertips behind your ears, and lay back.  Then simultaneously sit up and rotate your torso until your elbow touches your partner's coinciding elbow.  Sit back and then sit up again turning in the other direction (Rep 1- right elbow to right elbow.  Rep 2 - left elbow to left elbow).  Perform this exercise for 30 repetitions at home, at the gym, or come to a bootcamp class at Battery Park as Shermaine and Melissa pictured above did!