Prone Bridge

when I do these I just hold for a minute, about 3 times

a little harder than you might expect it to be. but still very very doable to do 3X30

what muscles does this work?

The whole of your core, its for strength and stability.

My training buddy and I used to do a circuit of these:
1) Normal prone bridge with weight on the back
2) Elevated prone bridge (one side, then switch over to the other side)
3) Elevated 'normal' prone bridge with weight on the back

You do them all after each other.
We first did them all at 30s each and eventually got to 1 minute each.
We accomplished this within a month.
Your core will feel fantastic!

m8 if my only work out is prone brdge will i get a 6 pac

Everyone has a sixpack but it is covered by fat. The only way to get a 6 pack is to cut your fat. However, you can change the way they look. Doing these exercises (and doing them longer/with more weight everytime) will really help you give a solid core (stomach + lower back) and if you flex it, the girls have something way better to touch than an untrained 6 pack ;)! Be sure to use correct techniques though and I can tell you they are NOT easy to do ;)! Forgot to tell; we did 3 rounds of 1+2+3!

you'll get stronger abs but a visible six pack is only maybe 20 percent big abs it's mostly bodyfat. Some people can't show a six-pack without dangerous water cutting - it's partially genetic. Worry about being fit first and the looks will follow.

what

yup me too. i can knock out 3x30, but its not as easy as i thought it would be.