Lie on the floor, on your left side, supporting your bodyweight on your left elbow. Your elbow should be directly under your shoulder.
Place the inside of your right foot on a bench and lift your hip off the floor a little by pushing your foot down onto the bench.
Straighten your body and legs. At this point, your bodyweight should be being supported by your left elbow and right foot, and your left foot should be under the bench.
Exhale as you slowly raise your hip by both pushing the inside of your right foot down onto the bench and laterally flexing your waist.
Hold for a count of two.
Inhale as you slowly lower your hip to the starting position.
Repeat for the prescribed number of repetitions.
Repeat the exercise on your right side.
Comments and tips
The side plank hip adduction is a decent exercise that you can use at home or at the gym to strengthen your core, work your inner thighs, and strengthen the lateral flexion movement pattern of your spine.
Make sure you get full hip adduction and lateral flexion of your spine.
Make the exercise easier by resting your knee instead of your foot on the bench.
Make it more difficult by holding a weight plate on your hip.