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 plantarflexing your ankles (toes point away from your shins). Gently lie flat on your stomach with your hands placed shoulder-width apart, under your shoulders and facing forward. Stiffen your torso by contracting your core/abdominal muscles ("bracing"), and your glutes and quadriceps (butt and thigh muscles).
Exhale and slowly press yourself upward until your elbows are fully extended, aligning your head and spine (avoid any sagging or aching in your low back or hips hiking upwards). Keep your feet together throughout the exercise and avoid any back and forth swinging of the TRX straps.
Upward Phase: Exhale, contract your abdominal muscles and slowly pull your legs towards your chest. Knees must remain extended knees and ankles in plantarflexion (toes pointed away from your shins). Keep you feet together throughout the exercise. During the movement your hips will rise upwards (your glutes should move towards the ceiling). Continue the movement until your hips move directly over your shoulders in an inverted shoulder press position. Maintain a rigid torso and flat spine, preventing any arching or bowing in the back.
Downward Phase: While maintaining your rigid torso, inhale and slowly lower your body towards the starting push-up position, maintaining your head and spine alignment.
Exercise Variation: The intensity of this exercise can be increased by lengthening the straps and positioning your body further away from the anchor point of the TRX.