Doesnt the TVA anti rotation? Why do I see all the demonstration for working on the TVA to lie on the ground and draw in your stomach a little? Its the same thing for so many exercises where it seems like an exercise for the elderly.
Legit vacuums are hardly sissy exercises for the elderly. It’s like planks being easy if you just use your joints and hang out vs an RKC plank where you actively create tension. Really focus on getting your belly button into your spine, blow out all your air, brace down and hold that thing - that’s tough.