The Side Rotation is working your core with focus on your external obliques. It also engages the whole body stability.

Stand in upright position with your knees slightly bent with your body sideways.
Adjust resistance band a little below shoulder height.
Grab the band with the hand that has the longer way first.
Make sure your arm is almost straight and then grab with your other hand.
Keep the leading arm straight when pushing towards the other side.

Tip:

• Make sure to keep your face straight and only rotate your upper body a little bit