Bent-Knee Hip Raise: Lower Abs Form, Sets, Tips & FAQ

Learn the Bent-Knee Hip Raise to train lower abs with controlled pelvic lift technique, step-by-step form, sets, mistakes, FAQs, and gear.

Bent-Knee Hip Raise: Lower Abs Form, Sets, Tips & FAQ

Core Strength

Bent-Knee Hip Raise

Beginner No Equipment Lower Abs / Pelvic Control

The Bent-Knee Hip Raise is a controlled floor-based core exercise that trains the lower abs through a small posterior pelvic tilt and hip lift. Instead of swinging the legs, the goal is to curl the pelvis upward, lift the hips slightly from the floor, and lower back down with steady abdominal control. Because the knees stay bent, this variation is easier to control than many straight-leg lower-ab exercises.

This exercise works best when the movement stays small, smooth, and deliberate. The upper body remains stable, the arms press lightly into the floor, and the knees stay bent as the pelvis curls upward. As a result, the abs create the lift instead of momentum from the legs. For better results, focus on rolling the hips off the floor rather than kicking the knees toward the chest.

Safety tip: Stop if you feel sharp lower-back pain, hip pinching, neck strain, dizziness, or discomfort that increases with each rep. Keep the lift compact and controlled, especially if you are still learning lower-ab coordination.

Quick Overview

Body Part	Core
Primary Muscle	Rectus abdominis, especially the lower abdominal region
Secondary Muscle	Obliques, transverse abdominis, hip flexors as light stabilizers
Equipment	No equipment required; optional exercise mat
Difficulty	Beginner to intermediate, depending on control and tempo

Sets & Reps (By Goal)

Beginner core control: 2–3 sets × 8–10 reps with slow, clean reps
Lower-ab strength: 3–4 sets × 10–15 reps with a controlled hip lift
Core endurance: 2–4 sets × 12–20 reps while avoiding leg swing
Warm-up activation: 1–2 sets × 8–12 reps before ab training or lower-body sessions

Progression rule: First improve control, then add reps. Once every rep stays smooth, increase the pause at the top or slow the lowering phase before choosing a harder variation.

Setup / Starting Position

Lie on your back: Set your body flat on the floor or on an exercise mat.
Place your arms beside you: Keep the arms down with the palms pressing lightly into the floor for balance.
Lift and bend the knees: Bring both knees up with roughly a 90-degree bend.
Stack the knees over the hips: Keep the thighs close to vertical before starting the rep.
Brace gently: Pull the ribs down slightly and keep the lower back controlled without forcing tension.
Keep the neck relaxed: Let the head stay down and avoid looking up or crunching the neck forward.

The setup should feel stable before the hips move. Therefore, if your legs swing before the rep starts, reset your knees over your hips and reduce the range.

Execution (Step-by-Step)

Start from the bent-knee position: Keep the knees lifted, the feet relaxed, and the arms steady beside the body.
Brace your abs: Exhale gently and prepare to curl the pelvis rather than swing the legs.
Lift the hips: Roll the tailbone upward and raise the hips slightly off the floor.
Keep the movement compact: Allow the knees to move slightly toward the chest, but do not kick or throw the legs.
Pause briefly at the top: Squeeze the lower abs for a short moment while keeping the upper body quiet.
Lower slowly: Roll the spine and hips back to the floor with control.
Reset without relaxing completely: Return to the starting position and repeat with the same smooth rhythm.

Form checkpoint: The hips should lift because the pelvis curls, not because the legs swing. If the feet or knees create momentum, slow down and make the lift smaller.

Pro Tips & Common Mistakes

Use your abs first: Start the rep by curling the pelvis, not by pulling with the hip flexors.
Keep the knees bent: A consistent knee angle helps reduce momentum and keeps the exercise focused.
Avoid kicking upward: The lift should be short and controlled rather than explosive.
Press the arms lightly: Use your hands for balance, but do not push so hard that the upper body does the work.
Lower with control: Dropping the hips reduces tension and may irritate the lower back.
Do not chase height: A small, clean hip raise is usually more effective than a large, sloppy lift.
Keep the head down: Neck tension is unnecessary, so let the abs handle the movement.
Breathe through the rep: Exhale during the hip lift and inhale as you return with control.

FAQ

What muscles does the Bent-Knee Hip Raise work?

The Bent-Knee Hip Raise mainly targets the rectus abdominis, especially the lower-ab region. In addition, the obliques and deep core muscles help stabilize the pelvis while the hip flexors assist lightly as the legs stay lifted.

Is the Bent-Knee Hip Raise the same as a reverse crunch?

It is very similar to a reverse crunch variation. However, this version emphasizes a compact hip lift with bent knees and controlled pelvic curling rather than a large knee-to-chest motion.

Should my lower back come off the floor?

Yes, but only slightly. The hips and lower back should peel up as the pelvis curls. However, the lift should remain controlled and should not turn into a forceful swing.

Why do I feel this in my hip flexors?

Some hip flexor involvement is normal because the legs are lifted. Still, if the hip flexors dominate, reduce the range, slow the tempo, and focus on curling the tailbone upward with your abs.

Is this exercise good for beginners?

Yes. Since the knees stay bent, the Bent-Knee Hip Raise is usually more beginner-friendly than straight-leg lower-ab movements. Nevertheless, beginners should start with fewer reps and prioritize control.

How can I make the Bent-Knee Hip Raise harder?

First, slow down the lowering phase. Next, add a short pause at the top. After that, you can progress to longer lever variations, such as a reverse crunch with less knee bend, only if your lower back stays comfortable.

Recommended Equipment

Exercise Mat — adds cushioning for the spine and hips during floor-based core training
Thick Yoga Mat — helpful if a standard mat feels too thin for repeated hip raises
Core Sliders — useful for progressing into other controlled ab and pelvic stability drills
Resistance Bands Set — supports additional core and hip stability exercises after mastering bodyweight reps
Ab Workout Bench — optional tool for advanced reverse-crunch and hip-raise variations

Tip: You only need a comfortable floor surface to perform this exercise well. Therefore, equipment should improve comfort or progression, not replace proper form.