Can’t squat? Try this knee-friendly exercise instead to build stronger legs

This squat substitute is ideal for anyone with bad knees

A smiling woman in sports wear sits on a yoga mat in her plant-filled living room. She is leaning back slightly, with her hands on the floor behind her, and her legs straight out in front of her.
(Image credit: Getty Images)

Squats are a great compound move that strengthen your legs and back. But if you struggle to do them because of bad knees or limited mobility, I recommend this alternative.

The seated leg lift is a knee-friendly exercise that works your hip flexors, core and quads (thigh muscles), without putting strain on the joints.

I'm a personal trainer and find that many of my clients struggle with squats, so I recommend they do the seated leg lift instead. To increase the intensity, we add ankle weights or dumbbells for resistance.

How to do the seated leg lift

  • Sit up straight on a mat with your legs out straight in front of you. Put your arms behind you for support.
  • Brace your core as you slowly lift your left leg off the floor, then lower it again to the starting position.
  • Repeat this move on your right leg. Aim for 8-10 reps on each leg, building up to 10-12.

You don’t need any equipment to do this exercise, but you can add some resistance if you want to progress it. Add ankle weights or gently press 3kg dumbbells on your thighs as you lift your legs.

How it works

This move primarily targets muscles in your hips, upper thighs and core.

It's particularly good for strengthening your hip flexors, located at the top of your thighs. The main function of these muscles is to pull your legs and knees towards your trunk, for example when you walk or run. They can become weakened by excess sitting but this move helps to rebuild them.

The exercise will also target the front-thigh quad muscles, which will have to contract to stay stable during the exercise. As you have to maintain a stable, upright posture throughout the move, it also challenges your core and helps to build abdominal strength.

Why are strong legs important?

Strong legs provide a solid foundation for everyday activities like walking, running, climbing and standing. When you build leg strength, it helps with balance and stability. By contrast, when you lose strength in your legs—which naturally happens with age—it can affect your ability to walk and stand, putting you at greater risk of falls and injury.

Maddy Biddulph

Maddy Biddulph is a freelance journalist specializing in fitness, health and wellbeing content. With 26 years in consumer media, she has worked as a writer and editor for some of the bestselling newspapers, magazines and websites in the US and UK. 

She is also a qualified L3 personal trainer and weight loss advisor, and helps women over 40 navigate menopause by improving their physical and mental strength. At Maddy Biddulph Personal Training, she runs one-to-one and small group training for menopausal women who want to get fit to ease symptoms and feel like themselves again.