Mecanim Animate Physics - When to use?

I was wondering when one should use Animate Physics on an animator? I consider myself a beginner, and I recently switched from Animate Physics to Normal Mode on my main character's Animator, since running it's shooting animation on Physics step would delay it by about one frame, and I didn't want that. After that I started wondering if I did the right thing, and in which scenarios one should use Animate Physics? I've already searched for this, only to find information on animation.AnimatePhysics which, at least for me, was vague. Thanks.