What's better doing a higher number of halfway push-ups (where I only go halfway down), or a lower number of full push-ups (where I go all the way down)?
Great question! My answer is, essentially, both always perform as many reps of an exercise with proper form. In this instance, do as many full push-ups as you can with your core engaged (this means with no break or sway in the back). If you feel you are beginning to lose your form, that is the time to start going halfway. When halfway starts to suffer, it's time to go to your knees.
Sara Haley (SaraFitness.com) is a Fitness DVD Personality, Master Trainer and Creative Consultant for Reebok.