Posture and stability are essential in all sports.
Once a client said to me “This is like when we teach snowboarding – we always talk about alignment”. As we do in riding, cycling, running.
Core stability is an “overused” phrase, but it explains everything. Hold yourself up, no leaning or resting or slouching. No hanging in the ligaments of the joints – which often shows up when planking or bridging – all about engaging the muscles to hold the body strong and straight.