This exercise is something to add into your core workout. Initially it may feel quite easy but just a few reps into it you will start to really feel it.
Start in the full press up position, arms shoulder width apart with shoulders, hips and ankles all in alignment.
Engage your core by contracting your TVA ensuring neutral pelvis position. Contract your rhomboids and middle trapezius to pull your shoulder blades together and down. Head position should be neutral with eyes looking towards the floor.
Whilst keeping your core engaged, slightly lift one foot off the floor. Keeping your hips and shoulders square bring the knee towards your chin. Contract your hip flexors as hard as possible to bring the knee as far towards your chin as possible. Ensure the core is constantly engaged. Slowly return the foot back to the start position without it touching the floor at any point. Ensure hips and shoulders stay square at all times. Repeat for 8-10 repetitions and then perform on the other leg.#
To progress this exercise place the feet on a roller or medicine ball to add an element of instability or internally rotate the hip in the top position to challenge the obliques.