How to Do a Dead Bug
A dead bug is a core exercise done on your back. Start with your arms pointing at the ceiling and your knees over your hips, then lower one arm and the opposite leg toward the floor without letting your lower back arch. It trains the abs and obliques. Most people do 3 sets of 8 to 12 reps per side.
How to do a dead bug
- Lie on your back on a mat. Reach your arms straight up over your shoulders and lift your legs so your knees are over your hips, bent 90 degrees.
- Breathe out and brace your abs, so your ribs come down and your lower back rests lightly on the floor. It stays there for the whole set.
- Over 2 to 3 seconds, reach one arm back over your head while you straighten the opposite leg toward the floor.
- Stop with your hand and heel just above the floor, or sooner if your lower back starts to lift.
- Bring both back to the start and repeat with the other arm and leg. Breathe out as you lower, in as you return.
How far to lower your leg
The lower your leg goes and the straighter it gets, the harder it pulls on your pelvis, and that pull is what arches your lower back. At the bottom of a full dead bug, the moving leg pulls about 4 times as hard as at the start, so the last part of the rep is where your back lifts. The curves are modelled from standard body segment weights and show the pull of the moving leg only.
Lower only as far as your lower back stays down. If it lifts before your heel is near the floor, stop higher or keep the knee bent, and add range over the weeks.
From heel taps to weighted dead bugs
Keep the other leg up in tabletop. Lifting one leg with the other on the floor did not need ab activity, and lifting both legs did (Andersson 1997), which is why the resting leg stays up. In 10 healthy men, harder levels of the dead bug and three other stability exercises raised trunk muscle activity (Kim 2016). Move up a step when you can do 3 sets of 12 slow reps per side with your lower back down.
Muscles worked
Dead bug claims the research does not back
Four claims that most dead bug guides repeat:
- The dead bug is the best exercise for your deep core. It came out on top for transverse abdominis thickness among 5 Pilates exercises in 44 women (Tsartsapakis 2023). In 44 young adults, the bird dog and side plank thickened the deep abs more (Tsartsapakis 2024), and in another study transverse abdominis thickness did not differ between the dead bug, plank, bird dog and side plank (Bini 2021). It trains the deep abs about as much as other stability exercises.
- Draw your belly button in toward your spine. Hollowing made the deep abs thicker on ultrasound than bracing (Tsartsapakis 2024), but thicker is not more stable. In a lab model, a full brace made the spine 32% more stable than a hollow (Grenier and McGill 2007). Brace all the way around your waist instead.
- Dead bugs fix back pain. Core stability exercise reduced pain more than general exercise in the short term, but by 6 and 12 months there was no difference (Wang 2012, 5 trials, 414 people). Dead bugs are an easy way to train your core if your back is sore, not a cure.
- Dead bugs burn belly fat. Six weeks of ab exercise, 5 days a week, did not reduce belly fat or waist size (Vispute 2011). Visible abs come from lower body fat.
Dead bug vs bird dog vs plank
| Attribute | Dead bug | Bird dog | Plank |
|---|---|---|---|
| Position | On your back | On your hands and knees | On your forearms and toes |
| Resists | Your back arching as your limbs move | Your trunk twisting and sagging as your limbs move | Your back arching |
| Works most | Abs, obliques, hip flexors | Lower back, glutes, deep abs | Abs, shoulders |
| Make it harder | Straighter legs, a weight in your hands | A pause at full reach, a band | Elbows forward, a plate on your back |
Do the dead bug and the bird dog together, since they train the front and back of your trunk. Making the bird dog harder raised activity in the lower back muscles in one EMG study (Kim 2016), and it thickened the deep abs more than the dead bug in another (Tsartsapakis 2024). The plank holds you still. The dead bug trains you to stay still while your arms and legs move, with nothing on your wrists or shoulders.
Sets, reps and progression
Do dead bugs 2 to 3 times a week, as part of your warm-up or at the end of a session. Lower over 2 to 3 seconds and end the set when your lower back starts to lift, not when you reach a number.
When every set reaches 12 slow reps per side with your back down, move one step up the progression and drop back to 8. Speed makes the rep easier, not harder, because momentum carries your leg through the bottom.
Common mistakes
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Lower back lifting off the floorYour leg went lower than your abs can hold. Stop higher, or keep the knee bent.
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Moving too fastMomentum carries the leg through the hardest part. Take 2 to 3 seconds to lower.
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Ribs flaring upYour brace has gone. Breathe out and pull your ribs down toward your hips before the next rep.
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Holding your breathBreathe out as your arm and leg lower and in as they come back, without losing the brace.
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Same arm and same legMove the opposite arm and leg together. Right arm with left leg, then left arm with right leg.
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Knees drifting toward your chestThis shortens the lever and makes the rep easier. Keep the resting knee over your hip.
Dead bug variations
Questions people ask
How many dead bugs should I do?
Start with 2 to 3 sets of 8 to 12 slow reps per side, and end each set when your lower back starts to lift. On Gravitus, as of September 2026, the median best set logged is 15 reps for men and 16 for women, and the top 10% have done 30 or more (1,600+ men, 1,100+ women). Logs do not say whether one rep means one side or both.
Should I press my low back into the floor?
Lightly. Keep your lower back resting on the floor by bracing your abs and bringing your ribs down, not by flattening it as hard as you can. If you cannot breathe or your back lifts as your leg lowers, shorten the range.
Why do dead bugs hurt my lower back?
Your lower back is arching as your leg lowers, so it takes the load your abs should. Stop the leg higher or keep the knee bent, and move slower. If it still hurts, do heel taps.
Why do dead bugs hurt my hips?
Your hip flexors hold the weight of your legs for the whole set, so you will feel them. If the front of your hip cramps or pinches, keep the knee more bent and lower the leg less far.
Are dead bugs good for abs?
They train your abs and obliques to stop your back from arching while your limbs move, which carries over to lifting and running. They do not load the abs heavily. To build them, add a crunch you can load, such as the kneeling cable crunch, and make dead bugs harder with a weight.
Are dead bugs and bird dogs the same?
No. Both move the opposite arm and leg, but the dead bug is on your back and resists arching, and the bird dog is on your hands and knees and resists twisting and sagging. The bird dog also works your lower back and glutes. Do both.
Are dead bugs better than crunches?
They do different jobs. The dead bug trains your abs to keep your spine still. The crunch trains them to bend it, under a load you can keep adding to. Use both.
Can dead bugs give you abs?
Not on their own. Six weeks of ab exercise, 5 days a week, did not reduce belly fat or waist size (Vispute 2011). Dead bugs strengthen the muscles under the fat, and lower body fat is what makes them visible.
Log every set and Gravitus charts your reps, times and records from week to week.
Get GravitusRelated exercises
- Andersson et al. 1997. Eur J Appl Physiol 75(2):115-123.
- Kim et al. 2016. PM R 8(10):979-989.
- Pereira et al. 2017. J Manipulative Physiol Ther 40(5):350-357.
- Tsartsapakis et al. 2023. J Funct Morphol Kinesiol 8(3):110.
- Tsartsapakis et al. 2024. J Funct Morphol Kinesiol 9(2):70.
- Bini and Bini 2021. J Bodyw Mov Ther 28:131-137.
- Grenier and McGill 2007. Arch Phys Med Rehabil 88(1):54-62.
- Wang et al. 2012. PLoS One 7(12):e52082.
- Vispute et al. 2011. J Strength Cond Res 25(9):2559-2564.