Kettlebell training, specifically double front squats or goblet squats with elbows inside the knees, effectively teaches proper core tightness and squat form.

“with a kettle bell for example you take uh you start doing double front squats with a pair of kettle bells it's going to be like zerchers you're going to your abdominal wall is going to light up you suddenly learn exactly oh this is what it means to get tight or you stick your elbows inside the knees and do goblet squat oh this is what the proper proper squat feels like and just very easy to uh very easy to integrate uh integrate all your body in one lift”