And I would do the weighted back extension exercise at higher reps. If you go too low reps, then you're going to lift too much weight, and that could be a problem.

How to Do a Glute Extension/Hyperextension If you’re adding the glute extension to your workout, consider doing so later in your leg workout, Arent says.

How to do tricep extensions How to: Stand with feet hip-width apart, holding one dumbbell in your hands. Bring the weight overhead, extending your arms straight so the dumbbell is above your head.