I notice that when I plank, I can do a few different things.
First of all, when I plank my elbows are together and slightly in front of my shoulders.
I could choose to strongly engage my core (abs), and also engage what I will refer to as my "upper glutes" not sure if that makes sense or not.
Contrarily, what I was doing yesterday was really focusing on contracting my glutes (entire). This activated a lot of muscles in the backs of my upper legs aswell.
Which form of the exercise is the proper one? I feel more burn in my abs when doing the second one, and I find it harder to contract my abs as much when doing the second option, perhaps though the abs are getting worked just as hard, I just don't notice it as much because I'm focused on the other sensation aswell