Step 1: Standing on one leg, facing away from the TRX anchor, place other foot in both the TRX stirrups (combined); toes and hips are facing forward.
Step 2: Begin the movement by bending the supporting leg as you lunge back, bring the TRX supported knee back and towards the floor, until you feel a stretch in the hip flexors. Hands can rest on hips for support, or they can mimic a running motion with the split squat.
Step 3: Push back up with the supporting leg, and drive the TRX knee forward past the supporting leg.
Step 4: Repeat the movement several times before changing legs and repeating.
How to progress the exercise
This is the base exercise that is required in order to progress to other, more advanced exercises, such as Body Saw (#24), Kneeling Fallout, and Sprinter Start. The Plank performed on the forearms can be progressed to the hands for a greater challenge before attempting the other exercises. Placing your hands on a stability ball or even a BOSU will add more of a core/balance/stability challenge!
Even when moving on to more advanced exercises that require a solid plank as the foundation, it’s always good to revisit the basic plank from time to time to work on improving it, as our movement biomechanics can change slowly over time, without realizing it.