Fit Knowledge

Cardio on Leg Day: Should You do it?

If you’re a regular weight lifter, it’s likely you won’t shy away from leaving the gym with jelly legs every now and then! And, if strength and power is your goal, then everything is as it should be!

But, many people out there think that by adding a little cardio on leg day workouts, they can get more out of it – especially those looking to burn a little extra fat.

But does this work? And are there any consequences to adding cardio after leg day? Is there a good type of leg day cardio? And is there a bad type too?

We take a look at the good and the bad of adding cardio on leg day.

Should you do cardio on leg day?

If you’re thinking of putting in a quick cardio session after leg day, then stop and consider for a moment.

If you’ve pulled in a truly challenging weights training session that leaves your leg muscles in pain, then the likelihood is your muscles are pretty damaged and sore. Therefore, it’s unlikely you’ll be able to perform anything of high intensity that will involve legs.

That pretty much removes sprints from the equation, so it’s probably not a good idea to go after that. In fact, the majority of cardio training calls on your legs!

Plus, it can really depend on the type of lifter you are. If you’re after those super heavy weights, then cardio probably shouldn’t be on your radar, especially after a legs day.

[Related Article: Best Machines for Cardio at Home]

Long, stamina based, high intensity cardio, like distance running, needs a lighter frame, and therefore promotes less muscle. So, if you’re working hard to build muscle for heavier lifts, then long runs could actually be counterproductive to what you’re aiming for.

However, if you’re a lighter lifter, you might be able to get away with this type of cardio workouts on legs day, as you won’t be lifting extremely challenging weights, are unlikely to be aiming for those bigger muscles we described above and shouldn’t be as fatigued when it comes to performing the movements.

You’re essentially more about toning than looking to become a power lifter any time soon.

But, if you are looking to build strength in your muscles, you might be thinking that all cardio is now out of the question for you.

This isn’t quite true. Keep reading.

Woman tying her shoelaces planning to do cardio on leg day

Should you avoid cardio on leg day? 

As we said above, it can depend on what your aims are. However, there’s another element that comes into play here too. The duration and type of the cardiovascular exercise.

A meta analysis in the Journal of Strength and Conditioning, found that the duration of aerobic exercise, and the use of distance running as cardio had significant detrimental effects on muscle growth[1].

This can be for a number of reasons. If you don’t give your body time to recover from weight training and head straight into this kind of cardiovascular exercise, some researchers say this can make you lose muscle mass [2].

Furthermore, endurance training kind of cancels out the work you’re doing with your weight lifting, as it requires a lighter frame, and doesn’t really need those muscles to keep going [3]. In this study, those who didn’t train in an endurance style saw much higher muscle gain[3].

So, if you’re aiming to lift heavy and build muscle, then it’s probably best to leave the long cardio sessions, and avoid endurance based exercise that will reduce your muscle gains.

What’s more, a cardio workout on leg day could actually support recovery, potentially reducing muscle soreness by a full 24 hours in a lower body workout [4]. But, of course you just need to know the type of cardio exercise to do, and the right duration.

Instead, it’s important to know that certain types of cardio can actually support muscle growth and maintenance. You just need to know which type of cardio is best for your leg training day.

[Related: 4-Week Bigger Booty Workout Plan]

Can Cardio Exercises Help With Delayed Onset Muscle Soreness?


In the study we mentioned above, doing a short cardio workout on legs day, after you’ve finished with your leg workout can really help to reduce the length of your muscle soreness and help you get back into the gym asap.

So, what kind of aerobic exercise is best?

Research suggests the following for helping with DOMS:

1. Medium intensity exercise

2. 20 minutes max

After finishing your leg day workout routine, aim to hit the stationary bike, or go for a short, really gentle job to help clear your leg muscles of lactic acid and promote muscle growth.

woman on a stationary bike doing cardio after leg day

What cardio should I do on leg day? 

If you’re focussing on building muscle instead of preventing soreness, we’d recommend the following.

Leave it a day or two and add the right kind of cardio that will help to support your efforts on the squat rack.

So what type of cardio will help you maintain muscle and help you burn fat too?

A recent study has found that there’s two key rules to cardio that helps to support muscle and therefore will help to promote your efforts on legs day:

1. Keep it to less than 20 minutes

2. Ensure the intensity is high

This study found that muscle loss was minimal as long as the workout was 20 minutes long or less and the intensity was super high, like 20 second max sprints for example [4].

The study suggests that high intensity training like this could even be anabolic! Which could potentially even improve your strength and muscle growth in a more efficient way than long duration training.

If you’re looking for some sprint training inspiration, we’ve written up three workouts to get you going. 

Why is leg day hard? 

If you’re like us, you have a kind of love hate relationship with leg day. While it’s one of the most challenging and rewarding days of the workout week, it’s also one of the most difficult. It can really take it out of you!

That’s one of the reasons we can’t do leg day cardio, as it really reduces your glycogen stores, so you feel the energy loss for the rest of the day.

But what is it about leg day that makes it more challenging than others? Let’s take a look at the two main reasons!

Woman doing a leg workout

Leg muscles are big muscle groups! 

When we say leg day, it’s an all encompassing term for a big selection of muscles and a large muscle group.

When we say leg day, it’s likely we’re thinking about the following muscles:

  • Quads
  • Hamstrings
  • Calves
  • Glutes
  • Even lower back!

What’s more, these muscles are all large, with the glutes being the largest in the body! So, if you’re working all of these on legs day, it goes without saying you’re working a big portion of your body, which requires a lot of energy from those glycogen stores.

That’s why, if you decided to do a cardio workout on leg day, it’s likely you’ll find it very challenging and your body will struggle to recover, as you won’t have the optimum amount of energy to do both.

Leg day uses compound movements 

On top of the different muscles you’ll be using, an effective leg day will use compound movements. This means movements that recruit multiple muscle groups and joints.

For example, a squat recruits just about all muscles in your lower body, along with your hip, knee and ankles too.

And, with movements like the squat and lunge as your foundations of a truly challenging leg day, you’ll recruit a huge amount of muscles in each movement, which requires a larger amount of energy than say, arms day.

In comparison, arms day recruits much smaller muscles over a smaller area of your body. This will require a lot less energy than your lower body workouts.

What leg day exercises should I do? 

If you’re looking to start building strength in your lower body, then there are some key exercises you should consider as part of your normal routine.

As we mentioned above, some lower body exercises (compound movements) recruit a range of muscles. This is key to a legs day workout for a number of reasons.

By recruiting more muscles within a movement such as a squat, you’re making them work together, which promotes a stronger, more well rounded physique. Furthermore, the more muscles you use in a movement, the more energy you need and the more calories you burn!

So, with that in mind check out these key leg day exercises, and click on the links to see a step-by-step tutorial of how to do each movement:

1. Back Squat

2. Front Squat

3. Lunge

4. Hip Thrusts

5. Sumo Deadlift

6. Split Squat

7. Deadlift

With these movements in your leg day workout, you’ll find you’re using a range of muscles and achieving an all round lower body burn!

What’s more, you can use the leg machines in the gym, such as hamstring curl and leg extension, to focus on certain areas more. This allows you to target specific areas really effectively and work on any weaknesses you may have.

Cardio Exercise on Leg Day: Should you do it? 

We’ve learnt that no, you shouldn’t do cardio on leg day. Not only will it max out your energy supplies and potentially disrupt your recovery, certain types of cardio can be really detrimental to your muscle building efforts.

To prevent DOMS after a big leg workout, aim to do a 20 minutes, medium intensity cardio session right after your legs day, so you can get back in the gym hitting the squat rack as soon as possible.

If you’re aiming to put on muscle mass give yourself time to recover from your leg workout, then pick a short, high intensity workout that lasts no longer than 20 minutes, and you should see the best results from your leg workout.

So, why not try the cardio exercise options we outlined after your leg workout and let us know how you get on! Leave your results in the comments below, we love to see them!


gymgirlfit was created by health and fitness enthusiasts, with backgrounds in powerlifting and writing. We've written for a number of well-known fitness publishing companies.

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