For most healthy adults, 30 to 72 leg raises in a session — 3 to 4 sets of 10 to 18 reps — is a reasonable benchmark for hip-flexor and lower-ab strength, done 3 to 4 days a week rather than every day. Beginners should keep the knees softly bent and the lower back pressed flat against the floor; more advanced trainees straighten the leg and slow the tempo. Leg raises put most of the work on the hip flexors, with the lower rectus abdominis bracing isometrically to keep the pelvis from tilting — which makes lower-back position, not rep count, the real marker of whether you’re doing them well. Below are leg raise benchmarks by level, the lower-back guidance this exercise genuinely needs, and how it fits alongside sit-ups and russian twists in a core routine.
How Many Leg Raises Should You Do? Quick Benchmarks
| Level | Per-Session Target | Suggested Structure |
|---|---|---|
| Complete beginner | 12-24 total | 2-3 sets of 6-8, knees bent, small range of motion |
| Beginner (1-3 months) | 30-45 total | 3 sets of 10-15, knees slightly bent |
| Intermediate | 36-72 total | 3-4 sets of 12-18, straight leg |
| Advanced | 72-100 total | 4 sets of 18-25, straight leg, slow tempo, optional ankle weights |
| Older adults (65+) | 16-24 total | 2 sets of 8-12, knees bent, reduced range |
These are per-session numbers for a leg raise day, not a total to hit every day of the week — the frequency guidance further down explains why the lower back wants rest days between sessions. They also assume a controlled raise that lowers the legs only as far as your lower back can stay flat against the floor, not a fast swing that bounces off the ground between reps. Leg raises punish momentum more than most ab exercises do: a set of 10 slow, controlled reps beats 20 fast ones that let the lower back arch, and any pulling sensation in the lower back rather than the hip flexors or lower abs is a signal to bend the knees and shrink the range, not push through.
How Many Leg Raises Should You Be Able to Do?
Leg raises don’t have standardized age-based fitness-test norms the way push-ups and sit-ups do — no military or school fitness battery scores them, partly because “leg raise” covers a wide range of difficulty depending on knee bend, leg speed, and whether the lower back is allowed to arch. What trainers use instead are capability benchmarks built around control, not just count:
| Level | Consecutive Controlled Reps | What It Reflects |
|---|---|---|
| Untrained | 0-6 | Normal starting point; lower back usually lifts before hip flexors fatigue |
| Novice | 7-12 | Baseline hip-flexor and lower-ab endurance established |
| Intermediate | 13-20 | Lower back stays flat through a full straight-leg set |
| Advanced | 21-30, straight leg, slow tempo | Strong hip-flexor and lower-ab control under a longer lever arm |
| Elite | 31+, weighted or hanging | Competitive-athlete or dedicated-lifter territory |
Losing lower-back contact with the floor before rep 6 is an ordinary starting point, not a red flag — most people’s hip flexors are tighter and weaker than their lower abs at first, which is exactly the imbalance this exercise is meant to correct. Build the habit of stopping a set the instant your lower back arches off the floor rather than chasing a bigger number with poor form.
What Do Leg Raises Actually Work?
Leg raises primarily train the hip flexors — the muscles at the front of your hip, led by the iliopsoas, that lift your thigh toward your torso — with the lower portion of the rectus abdominis working isometrically to stop your pelvis from tilting forward as your legs lower. There’s no separate “lower ab” muscle; the rectus abdominis is one continuous sheet, but leg raises bias its lower fibers more than a standard crunch or sit-up does, which is why the two exercises feel different even though they share a muscle.
How much the hip flexors versus the lower abs do depends on range and speed. A small, controlled range where the lower back never leaves the floor keeps the lower abs doing real stabilizing work, while a full-range, faster raise shifts more of the load onto the hip flexors and reduces how much the abs actually contribute. That’s exactly why range control, not leg straightness, is the detail that determines whether this is an ab exercise or a hip-flexor exercise on any given rep.
Is It Safe to Do Leg Raises Every Day?
For most people, daily leg raises at a real training volume ask more of the lower back than it gets to recover from. The mechanism is specific: as your legs lower, your hip flexors pull on the front of your pelvis, and if your lower abs can’t hold the pelvis in place, your lower back arches to compensate. Repeating that daily, especially at higher reps or a full range, is a common route to lower-back irritation.
A more sensible pattern is 3 to 4 leg raise sessions a week, with other core work — a plank, dead bug, or sit-ups — filling the other days. If you want to train your core daily, alternate: leg raises one day, a plank or dead bug the next, russian twists or sit-ups on a third, so the lower back isn’t loaded the same way two days running. Stop each set the moment your lower back lifts off the floor, and treat any sharp or radiating lower-back sensation as a stop signal, not something to work through. Anyone with a history of lower-back injury or disc issues should start with bent-knee raises and a small range, and check with a professional before progressing to straight-leg or weighted versions.
How to Do a Proper Leg Raise
Lie on your back with your legs extended and your hands flat on the floor by your hips, or tucked under your lower back for extra support. Press your lower back into the floor before you move — that contact is what you’re protecting for the whole set. Keeping a slight bend in your knees if you’re new to the movement, lift both legs together until they’re roughly vertical, then lower them slowly, stopping the instant your lower back starts to arch off the floor. That’s one rep.
Exhale as you lift, and keep the movement slow on the way down — the lowering phase is where most of the hip-flexor and lower-ab work happens. Never let momentum carry your legs past the point where your lower back stays flat. If you can’t keep your lower back down through even a small range, shrink the range further or bend your knees more; a smaller, controlled leg raise trains the same muscles with far less lower-back risk than a full-range one done with an arched back.
Common Form Mistakes
The frequent errors are letting the lower back arch off the floor to chase a bigger range, using momentum to swing the legs up instead of lifting with control, dropping the legs too fast on the way down, and holding your breath through the set. Rushing reps to inflate a rep count is the other side of the same coin — it trains speed more than it trains the hip flexors and lower abs. A slower tempo with a genuine pause at the top is worth more than a higher number done with an arched back.
Leg Raise Variations to Progress (or Regress)
| Variation | Difficulty | Why Use It |
|---|---|---|
| Bent-knee leg raise | Easiest | Shortens the lever arm and reduces lower-back demand |
| Reverse crunch | Beginner | Lifts the hips off the floor, shifting more load onto the lower abs directly |
| Lying straight-leg raise | Intermediate | Standard version, full hip-flexor and lower-ab range |
| Flutter kicks | Intermediate | Keeps the legs low and moving, longer time under tension |
| Hanging knee raise | Advanced | Removes the floor’s support and adds a grip and shoulder demand |
| Ankle-weighted leg raise | Advanced | Adds resistance without changing the pattern |
| Hanging straight-leg raise | Advanced | Longest lever arm; the hardest common hip-flexor and lower-ab combination |
The reverse crunch deserves a specific mention for anyone whose lower back struggles with a standard leg raise: lifting the hips instead of lowering straight legs removes most of the hip-flexor lever arm and puts the work more directly on the lower abs, which is a genuinely easier entry point rather than a lesser exercise. The two hanging variations need a pull-up bar or a sturdy overhead bar to hang from, and the weighted version needs a pair of ankle weights; everything else on this list needs nothing but the floor.
A 30-Day Leg Raise Progression Plan
Week 1: 2-3 sets of 6-8, knees bent, small range of motion, three days that week. Week 2: 3 sets of 10-12, knees only slightly bent, keeping the lower back flat through the full set, again three days that week. Week 3: 3 sets of 12-15, straightening the leg for the first half of each set and bending the knee again if your lower back starts to lift, three to four days that week. Week 4: 3-4 sets of 12-18, straight leg, slow tempo, resting 45-60 seconds between sets, three to four days that week. The frequency is part of the plan, not a detail — every week leaves a rest day between leg raise sessions for the same reason the safety guidance above does, and doing week 4 daily would undo most of what the four weeks built. By day 30, a beginner who started at 8 reps can commonly hold clean form through 12-18 straight-leg reps, which puts a full session in the intermediate band of the table above — a real jump in hip-flexor and lower-ab control, not just a bigger number. If you’d rather follow trainer-led sessions than assemble a progression yourself, Daily Burn’s core and full-body programs build controlled lower-ab work like this into complete workouts — and you can try Daily Burn risk-free, backed by a money-back guarantee.
Leg Raises vs. Sit-Ups vs. Russian Twists: Which Should You Actually Do?
These three train the core through different regions and planes, and a well-rounded routine uses all three rather than picking one. Sit-ups train straight-ahead spinal flexion through the whole abdomen and are the accessible everyday core movement most people start with; our guide to how many sit-ups you should do a day covers those benchmarks. Russian twists add a rotational demand through the obliques that neither sit-ups nor leg raises train directly; see how many russian twists you should do a day for that side. Leg raises are the hip-flexor and lower-ab specialist — the one of the three that most directly targets the lower portion of the abdominal wall and the muscles that lift your thigh.
A simple default: sit-ups or a plank variation as your everyday core volume, leg raises 3 to 4 times a week once your lower back tolerates the pattern, and russian twists on separate days so rotation and hip-flexor loading aren’t stacked back to back.
Do Leg Raises Give You Lower-Ab Definition Specifically?
Leg raises strengthen and can add some muscle tone to the lower portion of your abs, but they won’t reduce fat specifically in your lower belly — spot reduction isn’t how fat loss works, regardless of how targeted an exercise feels there. There’s also no separate “lower ab” muscle to isolate: the rectus abdominis is one continuous sheet from your ribs to your pelvis, and leg raises simply bias its lower fibers more than a crunch does. Visible definition anywhere on the abdomen comes from lowering overall body fat through a sustained calorie deficit and consistent training, with leg raises contributing strength and control underneath rather than melting fat off that one area.
FAQ: Leg Raises
How many leg raises should a beginner do?
Start with 12-24 total in a session, split into 2-3 sets of 6-8, knees bent and the range small enough that your lower back stays flat on the floor. Straighten the leg and add reps only once that feels controlled.
Is 100 leg raises a day too many?
A hundred reps is the very top of the advanced per-session range, so it’s only appropriate for someone who has built up to a 4-set straight-leg session with clean form. Doing that volume every day is the actual problem rather than the number itself — the lower back needs rest days between sessions that load it this way, so even an advanced trainee should keep it to 3 or 4 days a week.
Why does my lower back hurt when I do leg raises?
It usually means your lower abs aren’t yet strong enough to hold your pelvis in place as your hip flexors pull on it, so your lower back arches to take over. Bend your knees, shrink the range, and stop each rep the instant your lower back lifts off the floor rather than pushing through a bigger range.
Should my knees be bent or straight?
Bent knees are the easier, lower-back-friendlier version and a reasonable place for most beginners to stay for several weeks. Straightening the legs lengthens the lever arm and adds real hip-flexor and lower-ab demand, and is worth progressing to once the bent-knee version feels controlled and easy.
Are leg raises better than sit-ups?
Neither is better outright — they target different parts of the same muscle and different supporting muscles. Sit-ups build overall abdominal flexion strength and are gentler on most people’s lower backs at higher frequency; leg raises bias the lower abs and hip flexors but ask more of lower-back control. Most people benefit from both rather than choosing one.
Do I need equipment to do leg raises?
No. Lying leg raises on the floor are a complete beginner-to-intermediate exercise on their own. A pull-up bar for hanging leg raises, or ankle weights for added resistance, are optional additions once the floor version feels easy and controlled.
Can I do leg raises every day if I keep the volume low?
A short, low-range, bent-knee set most days is lower-risk than a heavy straight-leg session every day, but the safer default is still 3 to 4 dedicated sessions a week with other core work filling the gaps, since even light daily hip-flexor loading adds up for a lower back that isn’t fully recovered.