That looks like something Kelly Starrett does in his mobs, I think it was actually his 4th video or something. It's more of a stretch than an activation exercise.
For those, I do Lying Psoas Match with a resistance band:
https://www.t-nation.com/img/photos/2008/08-015-feature/image030.jpg[/IMG
Or if I don't have a band with me, I sit on a low bench/chair, and with my knees bent I just lift each knee as high as possible while keeping my back straight and hold it for a second. My psoas get lit on fire that way, especially my left one which is certainly weaker in comparison.
The psoas doesn't primarily activate and become the prime mover until your knee passes 90 degrees flexion. So if you sit with your thighs parallel to the floor, then just lift your legs a couple inches the psoas will be doing mostly all of the work. Below 90 degrees and other hip flexors are sharing the load.[/QUOTE]
That sounds like an awesome thing to do while I'm sitting at my desk at work. Thanks dude.
[QUOTE=MjFrancis]Yesterday at the gym I had the misfortune of witnessing my first professional poser. Most people will flex their biceps here and there or lift their shirt up for a brief moment. Usually in between sets. That's amateur stuff. This guy took this seriously.
He walks back near the squat racks where I'm pressing, and he starts busting out cheesy bodybuilding photoshoot flexes. Lifting up his shirt, flexing his abs seven different ways, striking arm poses like Johnny Bravo. When recounted to my wife, she asked how I didn't bust up laughing. Truthfully, it was awkward. So, he does this for about a minute and a half, and just walks away to workout in some other part of the gym. There are mirrors all over the place but he felt compelled to bust this stuff out right next to me.
I'm sure other people have seen worse, but since I go to the gym in the early afternoon, it's mostly a bunch of regulars and it's pretty low key 90% of the time.[/QUOTE]
I ran into a friend at the gym last week (she just started working out), and she points over to some guy that's near some of the machines. She asks if it's normal for guys to show up, just stand around and not even do anything while loudly talking on their phone and talk about the girl they fucked last night and how "she was alright I guess".
I said, "yep, that dude is definitely a bro".
I think that's far worse than the flexing. He expanded more energy talking than working out.