
Perform:
3 x 5 heavy weighted Deck Squats
3 x 5 heavy weighted single leg arch-ups
Finish with 3 x 10 Hip Extensions
notes
Add enough weight to the Deck Squats that they are quite challenging for the 3-5 reps.
Outside of gymnastics circles, single leg arch-ups are usually called back hyper-extensions. As the name implies, the single leg variation is only anchored by one leg.
As noted in the essay referenced above, the first set of hip extensions is forward, the second is sideward and the third is circular.