This one bodyweight exercise builds serious core strength and improves grip — trust me, I’ve been using it for weeks

We talk a lot about core strength on the fitness side of Tom’s Guide, so you might assume my abs are carved from steel thanks to all the workouts and expert advice I try. The truth is, I have always found core exercises a bit boring. But to stay strong for the activities I actually enjoy, like running marathons, strength training and hiking, a solid core is essential.

That is why I was thrilled when I discovered an exercise I actually enjoy, and that feels like it is making a real difference: hanging knee raises. You hang from a pull-up bar and lift your knees up and down for a set of reps or a timed set. Sounds simple on paper, right?

I thought so too until I realized how much strength it takes just to keep your body from swinging and how much it challenges your grip. It's one of those moves that makes you feel your whole body work in ways you don't expect, and I have quickly become hooked.

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How to do hanging knee raises

If you have a pull-up bar at home or in your garage, you can do this exercise without going to the gym. Otherwise, you’ll need access to a pull-up bar, either at a local park or in the gym.

• Grab a pull-up bar with both hands and hang with your arms straight.
• Let your legs hang down and keep your body still.
• Brace your core as if you are about to be lightly punched in the stomach.
• Slowly lift your knees toward your chest.
• Pause briefly at the top, then lower your legs back down with control.
• Reset your position and repeat.

To get that good form, try to keep your shoulders pulled down away from your ears and move slowly rather than relying on momentum. Brace your core throughout each rep, exhaling as you lift your knees and inhaling as you lower them with control.

If your body starts swinging, touch your toes to the floor between reps to steady yourself, or use a step or box if your feet don’t reach. I was surprised at how much strength and stability this exercise requires to stay controlled, but I actually enjoyed the challenge. Unlike the typical ab burn from crunches or sit-ups, hanging knee raises make you engage multiple muscles at once to maintain proper form.

I found the grip strength aspect humbling at first, but it’s also very satisfying to feel improvement over time.

Benefits of hanging knee raises

First of all, this move forces you to stabilize your entire torso while lifting your legs, which engages not just your abs but also your hip flexors, lower back and your obliques. The constant tension required to keep your body from swinging teaches your core to work as a unit rather than in isolation, which translates to better overall core stability.

Another major benefit is grip strength. Hanging from a bar might seem secondary to lifting your knees, but your forearms and hands work hard to hold your weight throughout each rep. Over time, this builds grip endurance, which helps in other lifts like pull-ups, deadlifts, or even carrying heavy groceries.

One of the main reasons I really rate this core exercise is that it challenges coordination and body awareness. As a beginner, momentum can easily take over, but learning to lift your knees slowly and with control forces you to connect your mind and muscles.

More from Tom's Guide

• ‘This standing abs sequence challenges your core through rotation, balance, and controlled strength’ — and it's demanding, effective and easy to do at home, according to a personal trainer
• 'People assume their spinal health is determined entirely by what happens in the gym': spinal expert shares 3 key habits you need to build now
• Stiff shoulders? A mobility and strength coach says, 'Try these 4 moves today'

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