Lower Back Exercises: Strengthen Your Erectors Safely

If your back hurts right now

This guide covers lower back exercises for healthy lifters who want stronger erector spinae muscles. It is not a treatment plan and cannot tell you why your back hurts. UK NHS guidance on back pain sorts the warning signs into three levels.

Call emergency services or go to an emergency department now if back pain comes with:

• numbness or loss of feeling around your genitals or anus
• new trouble peeing, or loss of control of your bladder or bowels
• pain, tingling, weakness or numbness in both legs
• new changes in sexual function, such as trouble getting an erection
• chest pain
• pain that started after a serious accident or fall

Get an urgent appointment the same day if you feel feverish, shivery or generally unwell, or the pain is severe, started suddenly or is getting worse quickly.

See a doctor or physical therapist before you train if the pain has not improved after a few weeks, stops your day-to-day activities, comes with weight loss you cannot explain or a lump or change in the shape of your back, does not ease with rest or is worse at night, or gets worse when you cough, sneeze or poo.

UK clinical guidance, NICE NG59, tells clinicians to rule out serious causes such as cancer, infection, trauma or inflammatory disease, and to encourage people to keep up normal activities. Never train through sharp pain. If an exercise sends symptoms down a leg, stop it and get it checked.

What your lower back muscles do

The erector spinae run along both sides of the spine, from the pelvis to the ribs and neck. In the lower back they extend the spine and, more often in the gym, stop it bending forward under a load. A hinge loads the erectors isometrically, holding one length under heavy load, while a back extension that lets the spine round slightly and straighten trains them through a range of motion.

A dissection and modeling study of 5 cadavers estimated the lat's contribution to extending the lower back as trivial, so lat work does not replace erector work. For the rest of the back, see what the research says about the best back exercises and the back exercise hub.

The lower back exercises worth your sets

The 45° back extension, the classic back extension exercise, ranks first on mechanism: it loads the erectors directly and in small steps. A crossover study in 15 resistance-trained women measured similar erector activity in a barbell RDL, a 45° back extension and a back-extension machine. The 45° version also produced the most hamstring activity, so it is not a pure lower back exercise.

In an EMG study of young, healthy adults, prone floor back extensions, including a resisted version and the Superman, and a resisted seated extension reached about 77–92% of a maximal lower-back contraction, while bridges, side bridges and bird-dog-type limb raises stayed under 50%. It did not test the 45° bench, and EMG measures electrical activity, not growth.

Bird dogs and side bridges earn a place as erector spinae exercises for control. A lab modeling study of 13 young men estimated that extending one leg with the spine held still put little load on the lumbar spine, and adding the opposite arm raised the challenge.

A no-equipment starter routine

No gym? These four moves build strength and control in a healthy back; they are not a treatment for back pain. Do them 2–3 times a week and end each set while your form is still clean.

When 15 controlled floor back extensions feel easy, hold a weight at your chest or move to a 45° bench.

What reviews say about exercise and back pain

Many people search for lower back strengthening exercises because their back hurts; the evidence for exercise is real but modest.

A 2021 Cochrane review of 249 trials covered adults with chronic non-specific low back pain. Compared with no treatment, usual care or placebo, exercise probably reduced pain by 15.2 points on a 0–100 scale at the earliest follow-up (moderate certainty), which the review judged clinically important. The effect on function, 6.8 points, fell below the 10-point threshold, and gains over other treatments were too small to matter clinically. Side effects were mostly minor.

A network meta-analysis of 89 studies ranked Pilates highest for pain, and resistance training and motor-control exercise among the most effective options for physical function, while stretching and McKenzie exercise did not differ from a true control. The authors graded this evidence low quality, and other researchers disputed its methods, so the ranking could change.

In a randomized trial of 70 people with mechanical low back pain, 8 weeks of supervised deadlifts gave pain and disability results similar to low-load motor-control exercise, with follow-up to 24 months. Both groups also received pain education, and there was no group without exercise, so it does not mean everyone with back pain should deadlift.

Lumbar extension machines fit the same pattern: a narrative review of machine training linked it with meaningful improvements in pain and disability, with only limited evidence that it beats other exercise. That is why UK guidance suggests considering a group exercise programme chosen around the person's needs, preferences and capabilities, not a specific exercise.

Do deadlifts and RDLs train the lower back enough?

They train it hard, but mostly as a holding job. A 10-week randomized trial in 36 trained men compared RDL training, lumbar extension machine training and no training. RDL strength rose in both training groups (143.3 to 166.3 kg in the RDL group), but lumbar extension torque rose only in the machine group, at 6 of 7 joint angles. Torque was tested on that group's own machine, and only strength was measured.

A systematic review of deadlift EMG studies found the RDL works the hamstrings relatively more than the erectors. A review of lumbar extensor exercises adds that all of them can activate the lower back, but long-term strengthening evidence is weaker than for machines that lock the pelvis. A 2017 review of single- and multi-joint training noted the lumbar extensors may benefit from isolation work.

So keep your hinges and add one direct extension exercise: a lumbar extension machine with a pelvic strap if your gym has one, otherwise the 45° back extension, though no trial has compared the two. If floor pulls do not suit you, see the deadlift alternatives guide.

Sets, reps and weekly volume

No study has set a weekly set target for the lumbar erectors, so these are coaching starting points. If you already do 4–8 hard hinge sets a week, add 2–4 sets of back extensions; if you do none, build toward 6–10 total sets of hinges and extensions. Once or twice a week is enough for most lifters, and in chronic low back pain the machine training review reported that once-weekly sessions to failure appeared sufficient.

For effort, a 2024 meta-regression estimated that growth tends to rise as sets end closer to failure, while strength gains were similar across a wide range of reps in reserve; the authors call the exact relationship unclear. The RPE and RIR guide and the RPE calculator help you judge and apply this.

Technique cues and progressions

45° back extension

• Set the pad below your hip crease so your hips can fold.
• Lower until your hamstrings stretch, then rise to a straight line from head to heels. Do not arch past it.
• To bias the erectors, use a light load and let your spine round a little at the bottom, then straighten it on the way up. Skip this version while your back is sore.
• Start with bodyweight: the lab modeling study estimated the highest lumbar forces in trunk-extension exercises, a reason to load gradually, not a sign of harm.

Romanian deadlift

• Start standing with knees soft, then push your hips back and let the bar slide down your legs, keeping your spine position fixed.
• End the descent when your hips stop moving back, then drive them forward to stand.
• See the RDL guide for setup and the warm-up calculator for ramp-up sets.

Deadlift

• Bar over mid-foot, shins close, slack out of the bar.
• Brace your trunk before the bar leaves the floor, and keep your back position the same from start to lockout.
• Push the floor away so your hips and shoulders rise together.
• Stand tall at the top; do not lean back past straight.
• If your lower back rounds more as the set goes on, end the set.

Bird dog and side bridge

• Bird dog: reach one arm and the opposite leg long without your lower back sagging or twisting. Hold 5–10 seconds.
• Side bridge: elbow under shoulder, body straight, hips high.
• Brace lightly; in an EMG study of 8 healthy men, bracing raised oblique activity.

Easier and harder versions

In the same EMG study, muscle activity supported stepwise progressions within each exercise, including drawing small squares with the hand or foot in the bird dog. Add reps until every set hits the top of the range, then add the smallest load available.

A sample lower back session

Run this once a week on a lower-body or pull day, two or more days away from heavy deadlifts and not right before squats or bent-over rows, which also tire the erectors.

Trainer logs each set, suggests your next weight and tracks weekly sets per muscle. Pair this session with upper back exercises on a pull day, or use the dumbbell back exercises guide at home.

Common mistakes

• Arching hard at the top of a back extension. Stop at a straight body line.
• Treating bird dogs and side bridges as strength work; they are control drills.
• Rounding more on each RDL rep to reach the floor.
• Expecting one exercise to fix back pain. No trial supports a single best exercise.

What the research cannot tell you yet

• Few trials have measured lower back muscle size, and none has compared gym exercises for erector growth. The training data here mostly measure strength, and EMG records electrical activity, not growth.
• The clearest growth data come from an 18-month randomized trial in 180 men aged 50 to 79: resistance training plus impact exercise produced a net 2.6% gain in paraspinal and psoas muscle size versus no exercise. It tested a whole programme in older men, not single exercises.
• For chronic low back pain, exercise helps modestly, but no exercise type is clearly best, and the network ranking rests on low-quality evidence.
• Lumbar extension machines with a pelvic strap have the best strength evidence, mostly from one research group, and few gyms have them.
• Most EMG and modeling studies tested small groups of young, healthy adults.