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 (butt) and quadriceps (thigh) muscles.
Upward Phase: Exhale and slowly press yourself upward until your elbows are fully extended, aligning your head and spine. Avoid sagging or aching your low back, avoid the hips hiking upwards, and be sure to contract your glutes and quadriceps to maintain hip stability. Keep your feet together throughout the exercise and avoid any back and forth swinging of the TRX straps. Continue to pull your legs towards your chest. Knees must remain extended, knees and ankles in plantarflexion (toes pointed away from your shins). Keep your feet together throughout the exercise. During the movement, your hips will rise upwards and continue the movement until your hips are 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 a rigid torso, inhale and slowly lower your body towards the push-up, aligning your head and spine. 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. 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 under the anchor point of the TRX and lengthening the straps.