Lying leg raise form: leg height and straight legs

Leg raises are much harder with straight legs, which is why people start bending their knees as they tire. The camera checks how high your legs go and calls it out when your knees bend.

How to do it

1. Lie flat on the floor or a bench, legs straight, hands under your hips or holding the bench.
2. Press your lower back into the floor.
3. Lift your legs, keeping them straight, until they're close to vertical.
4. Lower them slowly without letting your lower back arch.

What counts as a full rep

Lying flat, the angle at your hips has to close from about 160° to 100° or less, so your legs end up close to vertical. Bent-knee reps still count, but they get flagged.

What the camera calls out

You hear a short cue mid-set when something's off. After the set, the report card gives you one line on whichever fault came up most.

Setting up your phone

Put the phone on the floor side-on to you, about 2 m away, so your head and feet both fit.

Lie flat with your legs straight. Only full reps count.

Muscles worked

Mostly your abs, with your hip flexors helping.

Exercises this check works on

• Lying leg raise
• Flat bench leg raise
• Leg lift

A tip from the coach

If your lower back lifts off the floor, don't lower your legs as far. The range comes back as you get stronger.

Other exercises

• Squat
• Push-up
• Lunge
• Romanian deadlift
• Overhead press
• Biceps curl
• Plank
• Glute bridge
• Sit-up
• Lateral raise
• Bent-over row
• Jumping jacks
• Pull-up
• Wall sit
• Side plank

Updated 11 October 2026. General fitness and nutrition guidance, not medical advice.