Starting Position: Place your feet securely into the foot cradles positioned directly under the anchor point. Apply downward pressure with the tops of your feet by pointing your toes. Lie flat on your stomach with your hands placed shoulder-width apart, under your shoulders and fingers facing forward. Brace your torso by engaging your core/abdominal muscles. Keep the glutes (butt) and quadriceps (thigh) muscles engaged and strong.
Upward Phase: Exhale and slowly press your body off the floor until your elbows are straight (plank position) Keep your head and spine aligned. Do not allow the low back or ribcage to sag or arch. Do not allow the hips to hike upward. Keep the glutes and quadriceps contracted to maintain hip stability. Your feet should be together throughout the exercise and avoid any back and forth swinging of the TRX straps. Pull your legs towards your chest with your knees straight and toes pointed. During this movement, your hips will rise upward. Continue the movement until your hips are directly over your shoulders in an inverted shoulder press position. Maintain strong arms and shoulders, rigid torso and flat spine, preventing any arching or bowing in the back.
Downward Phase: Bring your body back to plank position. Keeping the torso rigid, and head and spine aligned, inhale and slowly lower your body into a push-up. Continue to slowly lower your body, touching your chin or upper chest to the floor. Again, avoid any arching or sagging in your low back or ribcage. Contract your glutes and quadriceps to help maintain stability.
Exercise Variation: The intensity of this exercise can be increased by positioning your body further away from the anchor point of the TRX and lengthening the straps.
Using the TRX certainly enhances the appeal of many exercises; however, trainers and individuals should not participate in these advanced exercises until they demonstrate they can effectively stabilize their lumber spine (low back) using their core muscles.