Your lower back should never hurt during exercise. If it is, it means you are not activating your core properly. Please stop what you are doing and get in touch.  Your back muscles (that run down the sides of you spine) may be sore from exercise and activation. This is normal, especially if you have not activated them in some time. This type of sore should feel the same as when we do glute bridges and our bottom hurts. It should feel like your muscles have worked.  If your lower back is hurting you may be using it instead of your core during exercises. This can often happen in the clams and leg lifts. Your torso should be still and there should be no crunching in the lower back. If you’re concerned about your technique please get in touch. We can arrange a one-to-one session to ensure you are doing it correctly.