Strengthen your lower abs with this unusual but beginner-friendly core exercise

We’re always on the lookout for new core exercises to add to our fitness routines, especially ones that help improve form and control. Midlife trainer Dr Won Dolegowski created the barbell back-supported knee raise with exactly this in mind, saying the movement ‘trains your lower abs without stressing your lower back’ while also teaching core control by reducing momentum and swinging.

‘A strong core goes beyond aesthetics. You need it for better posture, to protect your back and to carry you through life,’ she says.

Sarah Campus, PT, instructor, nutrition coach and founder of LDN MUMS FITNESS, explains how to perform the exercise with proper form, why it’s so effective and the key muscles it works.

• Set up a barbell on a rack so it sits at lower-back height when you’re positioned beneath it. Add a hip-thrust pad for comfort.
• Lean your lower back against the bar for support and stability, keeping your core engaged throughout.
• Raise your knees towards your chest by curling your pelvis upwards, rather than simply lifting your legs.
• Slowly lower your legs back down with control, avoiding swinging or arching through the lower back.

The movement mainly targets the core muscles, says Campus, including:

• Rectus abdominis – particularly during the lifting phase of the knee raise
• Hip flexors – which help lift the knees
• Obliques – which assist with stability and pelvic control
• Transverse abdominals – for deep core stabilisation

Other muscles involved include:

• Quadriceps – which help maintain leg position
• Forearm and grip muscles – which help support your hold on the bar
• Shoulders and upper back – which stabilise the torso against the support

Campus says the exercise offers several key benefits:

• The core stays under constant tension throughout the movement, as the back support reduces momentum and swinging.
• It helps stabilise the spine and pelvis, reducing strain on the lower back and making the exercise feel safer and more comfortable.
• Because the torso stays in a fixed position, it’s easier to perform a proper pelvic curl at the top of the movement, helping improve lower-ab engagement and control.
• It can also help strengthen grip, adds Dolegowski.

1. Reverse crunches

• Lie on your back with your legs extended and arms by your sides, palms facing down. For extra support, place your hands underneath your hips.
• Press your lower back into the floor and brace your core by pulling your belly button towards your spine.
• Engage your lower abs to lift your legs and curl your knees towards your chest, allowing your hips to lift slightly off the floor at the top of the movement.
• Slowly lower your hips back down with control before extending your legs back to the starting position.

2. Hanging knee raises

• Hang from a bar with your hands slightly wider than shoulder-width apart. Pull your shoulder blades down and brace your core.
• Bend your knees and raise them towards your chest using your core muscles, aiming to bring them up to hip height without swinging.
• Pause briefly at the top of the movement while keeping your torso stable.
• Slowly lower your legs back to the starting position with control.

3. Captain’s chair leg raises

• Position yourself in a captain’s chair with your back against the support pad and your forearms resting on the arm pads. Let your legs hang straight down.
• Brace your core and slowly raise your straight legs until they reach hip height or slightly higher.
• Pause briefly at the top while keeping your torso steady and avoiding swinging.
• Lower your legs back down slowly and with control before repeating.

Having a strong core is about far more than sporting a six-pack. Build functional mid-section strength – while also improving your power, posture, coordination and balance – with WH COLLECTIVE coach Izy George’s 4-week core challenge. Download the Women’s Health UK app to access the full training plan today.

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Sarah Campus is a highly qualified women’s PT, Nutrition Coach, Running Coach, Distance Runner, mum of 3 and founder of LDN MUMS FITNESS.

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She’s the host of the Soho House Run Club in Chiswick and a STRAVA and TOMMY’s marathon coach and ambassador. She specialises helping non-runners get into competitive distance running.

As a fitness and holistic wellness expert, Sarah regularly features on TV and in Magazines, offering tips and advice to keep the whole family healthy and active.