A Side Plank is a key core exercise that targets the oblique abdominal muscles, helping to improve your balance and protect your spine. The Side Plank with Hip Flexor Resistance is a great adaptation that will also improve your hip flexor strength.
This exercise starts by getting into your side plank position - lying on your side, push yourself up on to one of your forearms with your elbow directly below your shoulder and your legs extended out in a straight line. If this is a struggle then begin by holding the side plank from the knees. In either position, lift your hips up high and away from the floor and keep a straight line - don't let your hips dip too low or arch up too high! Keep your gaze straight ahead. The top arm can be held straight up towards the ceiling or flat against your side body. Drive the knee of the upper leg towards your hip whilst maintaining stiffness in the trunk. Don't let your upper body rotate inwards. To develop this exercise further, you can place a light resistance band around your feet so you are pulling some tension when driving that knee up towards your hips.
Focus on nailing your form before adding a resistance band.