Sit ups
 

I have previously spent many years doing power lifting, which I have since moved away from for my training. However, due to my power lifting I have a lot of trouble with sit ups. My quads always severely overpowered my hip flexor, so the became almost useless.

I am trying to increase my sit up count, but need some accessory movements to activate my hip flexor more. I have a strong core, was able to stabilize 500+lbs on my back to squat, yet struggle to crack out more than 50 sit ups.

Saw your intro also. The best way is knock them out at your stage.
Best of luck and your stubbornness will help you.

I agree with Joker, do lots of them. :lifter

Stubborn or too stupid to quit - either works. :lifter

Will do. Appreciate the input.

Now included at the end of my leg day, thank you!

You have learned the lesson of bulk- Not good for much of anything other than NFL interior lineman and power lifting. Much better off leaning down. If you need to lift, use light weights, lots of reps...

GHD sit ups will increase your hip-flexor strength/ endurance.:lifter
Put them in the same workout you do box jumps and you will double-work the flexors.

I have since backed off the weight training, and drastically increased my "athletic" training. Pushing my way down below 200 in the next 2-3 weeks. I am trying to piece together a new routine, however I think I should just do the Selected program since that is what seems to be recommended by all.

Selected programs are good but you know your body. Look at what works for you to get to the desired end state. Sometimes it is different.