Dumbbell Leg Extension – How to Perform, Benefits and Muscles Worked

Dumbbell Leg Extension

As one of the largest muscles in the body, our quads are a key player in the demands of daily life and a huge array of sporting activities.

By targeting the quads, dumbbell leg extensions are a strength training exercise that help to build the vital force for any activity that requires strength in our legs; think football, cycling, deadlifting and day-to-day movements such as lifting, climbing stairs and simply walking. With little equipment required, they are a great option for an at-home workout.

Before we get started, the clue is in the name in terms of equipment, so you’ll need your dumbbells at the ready (we’ve written a handy guide to some of our favourite dumbbells, you can find it here).

Follow the steps below to make this exercise a part of your fitness regime today.

How to Perform Dumbbell Leg Extension

  • Step 1. Sit on a bench or stable chair and engage your core to straighten your back.
  • Step 2. Place a dumbbell between your feet so that you can hold it there, and position your legs so that there is a 90. degree at your knees, between your upper and lower legs. The angle is important – any less than 90 degrees, where your ankles fall behind your knees can place too much stress on the knee joint.
  • Step 3. With your hands firmly placed either side of your body, grip the edge of the bench or chair.
  • Step 4. Engage your quads, maintaining a stable core and straight back, and extend your knees to lift your lower legs as far as you are able without causing any pain. Do not allow your knees to lock.
  • Step 5. Hold the position briefly before slowly returning your lower legs back towards the starting position. The movement should be smooth and controlled. Tip: try not to let your legs fall all the way down into the 90 degree angle between repetitions. This ensures your muscles stay contracted and work harder through each set.
  • Step 6. Repeat the movement for 10-15 repetitions, and 2 to 3 sets making sure you pause between each set. Tip – If you’re struggling to make it to 10 repititions, swap to a lesser weight as it may mean you are putting too much stress on your knees.

Dumbbell Leg Extension Variations

Decrease the challenge

Without dumbbells – practise the movement initially without holding the dumbbell between your feet. This will help you to understand the correct posture and how to maintain a smooth movement between reps without allowing your legs to fully relax back into the starting position.

Increase the challenge

Increased weights or repetitions – a common misconception might be to think that performing the exercise with a heavier dumbbell is the best way to progress. Whilst this is definitely an option, you want to make sure the you are able to complete a decent number of repetitions, so work on the principle of lower weights and higher repetitions rather than the other way round. Of course, once you are able, you can then begin to increase the weight.

Benefits of Dumbbell Leg Extensions

Beginner and advanced friendly

By choosing the most appropriate weight for you, dumbbell leg extensions are appropriate for both beginners and those who already have good strength in their quads but want to improve this further.

Core stability

Your core needs to be engaged throughout the exercise which helps to improve core stability, linked with good posture and balance.

Less tension on knee tendon

In comparison to using a machine for leg extensions, the exercise can be a gentler on the knee tendon providing you use an appropriate weight and are able to maintain the correct form.


With minimal equipment required, dumbbell knee extensions can be done almost anywhere.

Leg Definition

By isolating the quads, with regular and consistent practise of the exercise, you’ll tone your upper-legs and increase the muscle definition.

Quad strength

As one of the largest muscles in the body and with vital role to play in allowing you to extend your knees as well as being essential for movement in the hips, strength here is beneficial to so many other disciplines; football, cycling, deadlifting, squats, even simply walking and so much more.

Balance leg muscles

It may be that your previous training has focused on your hamstrings or glutes, so targeting the quads is a great way to help balance out the muscles in your legs

Muscles Worked During Dumbbell Leg Extensions

Dumbbell leg extensions are a lower body exercise that are often referred to as an open-chain kinetic exercise. This means they specifically target an isolated muscle, in this case the quads. That said, your core will be also be engaged to maintain the correct posture throughout the exercise.

It’s important to understand by isolating such a specific set of muscles, dumbbell leg extensions may not be appropriate for anyone who has injury to their quads or knee joints. Seek professional guidance before trying them if this is the case.

When you’re ready to give them a go, they are an awesome way to target the quads without the need heavy duty resistance machines. For a full leg workout, consider incorporating dumbbell leg extensions with squats and lunges, also perfect for at home fitness!

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