Muscles worked
The back extension trains the back of your body. Your spinal erectors, which run along your spine, work hard to keep your back straight throughout. Much of the lift itself happens at the hip, where your glutes and hamstrings do a large share of the work. How you hold your arms changes how hard it is. Crossing your arms over your chest is easiest. With your hands at your temples, the weight of your arms sits further from your hips, which makes it harder. A plate held against your chest makes it harder still.
Common mistakes
- The pad is set too high. If it sits against your stomach, you cannot hinge at the hip, and the movement becomes short and stiff. Adjust the bench so the top of the pad sits just below your hip bones.
- Throwing yourself up. A quick bounce at the bottom lets momentum do the lifting instead of your muscles. Rise at an even pace and pause briefly when your body is straight.
- Adding weight too soon. Wait until you can manage around 15 controlled reps without weight, then start with a light plate held close to your chest.
Variations and alternatives
- The Superman is done lying face down on the floor and is an easier option at home.
- The Romanian deadlift is the same hip hinge with a barbell, for heavy work on the back of your body.
- The good morning is done standing with the bar across your back, a harder version that needs sound technique.
- The glute ham raise is often done on a similar bench but puts far more of the work on your hamstrings.
Sets and reps
Back extensions suit building muscle and endurance best. Without extra weight, 10 to 15 reps over two to four sets works for most people, and 15 to 20 reps is fine for endurance. With a plate against your chest, 8 to 12 reps suits a muscle-building goal. Heavy sets of a few reps add little here; deadlifts build that kind of strength better. The guide to sets and reps explains more.
Make it harder in small steps: more reps first, then hands at your temples, and finally a light plate that you swap for a heavier one once you reach the top of your range in every set. That is progressive overload, even without a barbell. If your back hurts, rather than just feeling tired, stop the exercise and have it looked at by a doctor or physiotherapist.