There are certain exercises that benefit from the use of light weight and solid form rather than super-heavy weights. The hip thrust is one of them.

Hip Thrust

Similar to a deadlift, the hip thrust involves many muscles of the posterior chain. But consider the true intention of people who add hip thrusts to their workouts. They're wanting better, stronger glutes. Not hamstrings, not quads, and not lower back. Just glutes.

A 405-pound hip thrust for 5 reps can't help you develop that muscle group if you already have an issue engaging the glutes... and most people do. Are your glutes really that strong or are your quads, hams, and low back really doing most of the work?

If you want to make the glutes strong and well developed, and you want to make sure they rightfully fire first in the posterior chain's firing sequence, drop a couple of plates and look for some isolation on every rep.

Bret Contreras recommends doing "frog pumps" or using a duck-footed stance. This can be a great step in the right direction for teaching the glutes how to fire.

Frog Pumps

Once you're able to effectively fire the glutes, keep things light on your barbell hip thrusts. You probably don't need to exceed one plate on each side. Add a significant pause at the top of each rep and slow the eccentric (negative) down too. Do 10-12 reps per set.

Related:  The Flat Butt Fix

Related:  Build Great Glutes and Lats With Light Weight