A leg raise is a core move where you lift your legs with control to train your abs, hip flexors, and trunk stability.
A leg raise sounds simple. You lie down, lift your legs, and lower them back. That’s the shape of it. What makes the move worth doing is the way your trunk stays braced while your legs try to pull your pelvis out of position.
That’s why a clean rep feels harder than it looks. The real job isn’t just getting your feet up. It’s keeping your low back steady, your ribs down, and the lowering phase slow instead of letting gravity take over.
Done well, leg raises can fit into a home workout, a gym session, or a short core block at the end of training. Done poorly, they turn into a hip-flexor swing with your back doing work it didn’t ask for. The difference comes down to form, range, and pacing.
What Is A Leg Raise Exercise? Form, Range, And Control
A leg raise exercise is a bodyweight movement where the legs lift away from the floor while the trunk stays firm. You’ll usually see it done on the floor, on a bench, on a captain’s chair, or hanging from a bar.
The floor version is the starting point for most people. You lie on your back, brace your midsection, lift your legs, then lower them without letting your low back pop off the floor. That last part is the whole game.
The move trains your trunk to resist extension. In plain terms, your abs work to stop your back from arching as your legs move. Your hip flexors also join in because they drive the leg lift. According to HSS on core muscles, the core includes the abdomen, back, and hips, which is why leg raises feel like more than an “ab” exercise.
Main Muscles A Leg Raise Hits
Leg raises are usually tagged as a lower-ab move. That label is common, though the work is shared across several areas.
- Rectus abdominis: keeps the trunk steady and resists back arching.
- Hip flexors: lift the legs during each rep.
- Obliques: keep the torso from shifting or twisting.
- Deep trunk muscles: hold the pelvis and spine in a cleaner position.
If you feel only the front of your hips, your setup likely needs work. A small knee bend, a shorter lowering range, or a firmer brace usually fixes that fast.
Why The Lowering Phase Matters More Than The Lift
Plenty of people can fling their legs up. Fewer can lower them with the same control. The lowering phase is where your trunk has to stay locked in while the lever gets harder.
That’s why beginners often get more from bent-knee raises than straight-leg raises. The shorter lever lets you keep better shape. The rep feels smoother, and your low back stays quieter.
Leg Raise Exercise Benefits For Strength And Control
Leg raises earn their place because they train body control, not just fatigue. They teach you to move your legs while your torso stays organized, which carries over to lifts, sprinting, and day-to-day movement.
What You Get From Doing Them Well
- Stronger trunk bracing under motion
- Better awareness of pelvic position
- More tension through the front of the torso
- A clear way to progress from basic to hard variations
Leg raises also fit neatly into broader training habits. The CDC adult activity advice calls for muscle-strengthening work at least two days per week. A leg raise won’t replace full-body training, but it can be a smart part of that mix.
Who Usually Gets The Most From Them
This move works well for people who want a bodyweight core drill with a clear path from easy to hard. It also suits lifters who need more trunk control without adding loaded spinal flexion work.
If you already feel back strain during floor leg raises, step back a notch. Bent-knee raises, dead bugs, or reverse crunches may fit better while you build control.
| Variation | How It Feels | Best Fit |
|---|---|---|
| Bent-knee floor raise | Shortest lever, easier to brace | New lifters learning pelvic control |
| Straight-leg floor raise | More demand on abs and hip flexors | People who can keep low back down |
| Alternating single-leg raise | Less strain per side, steady rhythm | Warm-ups and form practice |
| Reverse crunch to leg raise | More pelvic motion, more trunk tension | Intermediate home workouts |
| Bench leg raise | Extra range, less floor feedback | Lifters wanting more range |
| Captain’s chair raise | Upright setup, less grip demand | Gym users who want a hanging-style feel |
| Hanging knee raise | Grip and trunk work together | Intermediate trainees |
| Hanging straight-leg raise | Long lever, high control demand | Advanced trainees with clean form |
How To Do A Floor Leg Raise Without Wrecking The Rep
Start on your back with your legs straight or slightly bent. Put your hands by your sides or slide them under your hips if that lets you stay flatter through the low back. Pull your ribs down and brace as if you’re about to cough.
- Lift your legs with a smooth tempo.
- Stop before your pelvis tips hard off the floor.
- Lower with control until you’re close to the point where your back wants to arch.
- Repeat from that clean range.
If your back lifts, shorten the range. That’s not a cheat. That’s good training. The rep only counts while you can keep the shape you want.
Common Mistakes That Change The Exercise
The most common slip is lowering too far for your current strength. The next one is rushing the top and bottom of the rep. You may also see people yank on their neck, swing their legs, or hold their breath until the set turns messy.
- Don’t chase floor contact if your back pops up first.
- Don’t turn each rep into a bounce.
- Don’t force straight legs if bent knees give cleaner form.
- Don’t count speed as progress.
If you want a rehab-style cue for cleaner leg lifting, the AAOS bent leg raises page shows the same broad idea: brace the abdominals, keep the back stable, and move the leg under control.
| Problem | What It Usually Means | Easy Fix |
|---|---|---|
| Low back arches off the floor | Range is too big for your control | Lower less and bend the knees |
| Front of hips burn first | Brace is weak or reps are too fast | Slow down and tuck pelvis slightly |
| Neck gets tense | Upper body is straining for balance | Relax shoulders and press arms down |
| Legs swing at the top | Momentum is doing the work | Pause briefly before lowering |
Best Progressions, Reps, And Placement In A Workout
If you’re new to the move, start with 2 to 3 sets of 6 to 10 clean reps. Stop the set when your low back starts to peel off the floor or the lowering phase gets jerky.
Once that feels steady, move through this order:
- Bent-knee floor raises
- Straight-leg floor raises
- Reverse crunch plus raise
- Hanging knee raises
- Hanging straight-leg raises
You can place leg raises after your main lifts, inside a core circuit, or on a short bodyweight day. They pair well with planks, carries, and anti-rotation drills because each one trains trunk stiffness from a different angle.
When To Skip Them
If leg raises trigger sharp back pain, groin pain, or pinching in the front of the hip, stop and swap the move out. Dead bugs, heel taps, or bent-knee reverse crunches usually give you a cleaner starting point.
So, what is a leg raise exercise in plain language? It’s a controlled leg-lifting drill that trains your core to hold position while your hips move. That mix of motion and restraint is what makes it useful.
References & Sources
- Hospital for Special Surgery (HSS).“A Guide to Your Core Muscles, from a PT.”Explains what the core includes and why core strength helps stabilize the spine during movement.
- Centers for Disease Control and Prevention (CDC).“Adult Activity: An Overview.”States weekly activity targets, including muscle-strengthening work at least two days each week.
- American Academy of Orthopaedic Surgeons (AAOS).“Low Back Surgery Exercise Guide.”Shows bent leg raises with cues on abdominal bracing and keeping the low back stable during the movement.