Bottoms Up
Bottoms up is a bodyweight ab exercise where you lie on your back, extend your legs straight toward the ceiling, and lift your hips off the floor using your abdominals rather than momentum. It targets the lower portion of the rectus abdominis through a small but demanding range of motion. It suits anyone who has the basic reverse crunch down and wants a straighter-leg version that asks more of the abs and less of the hip flexors.
Why it works
Keeping the legs straight and vertical during the lift removes the mechanical advantage that bent knees give the hip flexors, so the abdominals end up doing more of the work of curling the pelvis off the floor. The actual range of hip movement is small, but because the legs act as a long lever, that small lift demands real tension through the entire lower abdominal wall to control it. The floor also gives the upper back and shoulders a stable base, which keeps the exercise focused on the pelvis and abs rather than turning into a balance challenge.
Set up
- Lie on your back with your legs extended straight up, perpendicular to the floor.
- Rest your arms flat on the floor at your sides, palms down, for stability.
- Press your lower back gently into the floor before you start the first rep.
- Keep your head and shoulders relaxed on the floor throughout.
How to do it
- Contract your abdominals to lift your hips a few inches off the floor, driving your legs and heels toward the ceiling.
- Keep your legs straight and close to vertical as your hips rise.
- Pause briefly at the top of the lift, feeling the contraction in your lower abs.
- Lower your hips back to the floor with control rather than dropping them.
- Reset your lower back against the floor between reps before starting the next one.
Form cues
- Lift the hips, not the legs, the legs just travel with them.
- Small range, real squeeze, don't chase height.
- Press the palms down for a stable base.
- Lower with control, don't let gravity do the work.
Breathing: Exhale as you lift your hips off the floor, inhale as you lower them back down.
Common mistakes
Using the arms and lower back to rock the hips up instead of contracting the abs.
Fix: Keep your palms flat and passive on the floor, and initiate the lift from your abdominals, not from pushing with your hands.
Letting the legs swing forward and backward for momentum.
Fix: Slow the tempo down so the legs stay nearly vertical and the movement comes purely from the hips lifting.
Dropping the hips back to the floor instead of lowering with control.
Fix: Take at least two full seconds to lower your hips back down, keeping the abs engaged the whole way.
Letting the lower back arch off the floor before or after the lift.
Fix: Keep your lower back gently pressed down throughout the set; if it lifts, shorten the range of the hip raise.
How to program it
- Three sets of 10 to 15 controlled reps is a reasonable target once the movement feels smooth and pain-free.
- This exercise pairs well with an upper-ab movement like a standard crunch, since together they cover the abdominal wall from both ends.
- Being a bodyweight, single-joint movement with a small range, it tolerates being trained most days you train your core without needing extra rest between sessions.
- If the hips barely leave the floor, that's fine at first; the range grows as lower-ab control improves.
Safety notes
- Stop if your lower back arches or you feel strain there rather than in your abs; that usually means the range is too large for your current control.
- Keep the movement slow and small rather than using a fast swinging motion to throw the hips up.
Exercise profile
- Force
- Pull
- Mechanics
- Compound
- Category
- Strength
Frequently asked questions
How many reps of bottoms up should I do?
Three sets of 10 to 15 controlled reps is a good starting point. Focus on a small, deliberate lift rather than chasing a high rep count with momentum.
Can I do bottoms up without any equipment?
Yes, it's a pure bodyweight exercise done lying on the floor. All you need is enough space to lie flat with your legs extended toward the ceiling.
What's the difference between bottoms up and a reverse crunch?
A reverse crunch bends the knees toward the chest, which shares some of the work with the hip flexors. Bottoms up keeps the legs straight, which shifts more of the demand onto the lower abdominals.
Why does my lower back hurt during bottoms up?
That usually means the hips are lifting past the range your abs can control, letting the lower back arch to compensate. Shorten the lift and keep your lower back pressed toward the floor.