The 4 Best Isolation Exercises for Leg Day

Build Size With More Than Just the Big Lifts

Isolate your legs like a pro. Use these exercises in addition to the big lifts and you’ll make leg day far more effective.


Machine Isolation Lifts: The Advantages

Machines that isolate your muscles don’t get much respect these days. They’re not “hardcore,” but they sure are effective if you want to look good naked.

They can target the muscles you want to build the most, add size to your lagging areas, and complement the big lifts. You can safely push them a bit closer to failure, and they can help you work around injuries.

Here’s how to get the most from these go-to isolation lifts:

1. Leg Extension Machine

While squats do a great job at activating three out of the four quadriceps muscles, they fall a little short when it comes to activating your rectus femoris. Why? Because, unlike your other quad muscles, your rectus femoris acts as both a knee extensor and hip flexor.

Studies show that leg extensions activate this area greater than squats (1). If you want more “complete” quad growth, leg extensions are the perfect addition to your workouts.

Common Mistakes

  • Not paying attention to the degree of hip flexion or remaining upright throughout.
  • Using too much momentum and too much weight.
  • Not squeezing at the top or controlling the weight.
  • Not getting enough range of motion at the bottom of the lift.
  • Not locking yourself down into the seat hard enough.

For that last one, try using grip supports like Versa Gripps to anchor yourself down using the handles. Game changer!

2. Seated Calf Raise Machine

Adding size to puny calves is more complex than you might think. Those who do usually adopt a strategy combining standing and seated calf raise variations. Then, by simply doing more volume and frequency, they see some growth, but it usually stops short of their expectations. That’s when you need to take a look at how you’re actually doing your calf raises.

Focus on pushing through your big toe. This will put you at a mechanical disadvantage since you’re pressing down more with the insides of your feet.

This prevents your body from taking the path of least resistance (pressure outside of your foot) and forces your calves to work harder. It’s easiest to make this mistake when doing seated calf raises. This calf-building article goes more in-depth on using your big toe to build stubborn calves.

Common Mistakes

  • Positioning yourself wrong from the get-go.
  • Going too heavy.
  • Going too fast.
  • Bouncing at the bottom.
  • Not focusing on the hard contraction at the top.
  • Pressing through the wrong parts of your feet.

3. Hip Abduction Machine

Lifters often use it to target the gluteus medius, or the upper part of the glutes. One thing to look at when determining its effectiveness is not just how well it activates your glute medius, but its ratio of activation compared to another muscle that contributes to hip abduction: the tensor fascia latae (TFL).

Overuse of the TFL is linked with glute medius weakness. This imbalance in lower limb mechanics is linked to several conditions and injuries. Exercises that allow you to target the glute medius the most – while also minimizing activation of the TFL – will, in the long run, stop other muscles from compensating and prevent your glutes from getting lazy.

There aren’t many studies examining the hip abduction machine. However, in a 2022 study comparing it with side-lying hip abductions and clam shells (both credible exercises), researchers concluded that the hip abduction machine was the winner. It showed the best ratio of activation between glute medius and TFL (2).

Common Mistakes

  • Going so heavy that you lose the tension on the target area and other muscles kick in to move the weight.
  • Using a machine with cables that are too slack, and/or there’s a loss of loading as your thighs meet in the middle. This causes you to miss out on the full benefits of the stretched position.
  • Thinking there’s only one way – the textbook way – to do them. Explore different positions and angles at your hips to find what feels best for you.

4. Seated Hamstring Curl Machine

Isolate your hamstrings if you want to keep your knees healthy and develop better-looking legs. And if you’re after bigger quads, then having strong hamstrings is essential. To build them, do two types of exercises:

  1. Deadlifts (barbell, dumbbell, Romanian, stiff-legged, etc.) and other hip hinges.
  2. Knee flexion exercises like ham curl variations.

The musculature in your hamstrings (except for the short head of your biceps femoris) acts as both hip extensors and knee flexors. Training both of these functions will activate your hamstrings a little differently. They can also be manipulated to target your hamstrings at different muscle lengths.

The lying ham curl is the most common hamstring machine. It’s hard to do wrong as long as you’re positioned on the machine correctly and your hips remain braced down hard into the pad.

But it’s easier to do seated hamstring curls in a way that fails to maximize their effectiveness. Do them right and they’ll have an advantage over the lying variant. Why? Because they target your hamstrings at longer muscle lengths since your hips are more flexed.

When your muscles are applying force at longer muscle lengths, it creates a powerful growth stimulus. (Albeit, there are benefits to training at shorter muscle lengths, too.) Let’s make those seated hamstring curls work even better!

Common Mistakes

  • Not aligning your knees with the axis of rotation of the machine.
  • Hips should be flexed and torso upright.
  • Not locking yourself down hard or getting a good grip on the knee pad in front.
  • Not extending your knees far enough to maximize the active stretch of your hamstrings.
  • Thinking seated hamstring curls are just about the stretch at the top and forgetting to fully flex your knees and contract hard at the bottom.
References

References

  1. Ebben WP et al. Muscle activation during lower body resistance training. Int J Sports Med. 2009 Jan;30(1):1-8. PubMed.
  2. de Almeida Paz I et al. Hip abduction machine is better than free weights to target the gluteus medius while minimizing tensor fascia latae activation. J Bodyw Mov Ther. 2022 Apr;30:160-167. PubMed.

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6 Likes

I need to know more about the extra padding Gareth is using in the video. I might want to steal that idea!

1 Like

My wife has a pad that would work really well for that!

Perille Grade’s “The Balancer”, can be found on insta.

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Thank you! I’ll have to check that out! I’m wanting to see what the advantages are for them on isolation machines like these because I have a hunch (which could be totally wrong). But someone made a comment about them on YouTube, and it got my wheels turning.

For the abductor machine at least, it looks like the pads he’s using end up pressing your legs closer together, which seems like it could increase tension earlier on in the exercise… maybe?

With the abductor machine at my gym, the first half of the range of motion has almost no tension, so I kinda want to try adding pads like he did!

1 Like

For the leg extensions then an airex balance pad works great. Or foam cushion. For the abduction machine then the same, or some softer yoga blocks :slight_smile:

2 Likes

Thanks so much!