The back extension is the most versatile of the posterior chain (hams, glutes and low back) assistance lifts. Once you master the basic version, here are two ways to ramp it up and increase the difficulty.
1 – Dumbbell/Chain/Weighted-Vest Back Extension
After mastering the basic back extension, it's time to add resistance via external loading. You can hold a dumbbell at chest level, use a chain draped over the neck, or wear a weighted vest. Strong lifters can do around 15 reps while holding onto a 150-pound dumbbell.
2 – Band Back Extension
The band back extension is very challenging. The accommodating resistance makes the exercise increasingly difficult throughout the range of motion and you'll find that the erectors take a beating, but in a good way.