fbpx
scroll down icon
legs getting bigger from running

I get a lot of complaints from women who have found their legs getting bigger from running, which isn’t the desired results for most of us. So let me explain why this is happening.

WHY ARE MY LEGS GETTING BIGGER FROM RUNNING? 

Running uses your glutes, quadriceps, hamstring and calves constantly, meaning that your leg muscles are working and this will cause them to develop and get bigger in size.

Any form of exercise that engages your muscles will cause them to grow in size. However, some exercises cause more muscle growth than others.

Running will not build as much muscle as weightlifting, sprinting and high-intensity interval training.

LET’S TALK ABOUT SPRINTING

We all know that sprinters have very muscular physiques, especially compared to distance runners. Sprinting engages your muscles more and focuses on muscular power. Therefore, sprinting will build more muscle than just steady state running.

Doing a lot of sprint training and plyometric type exercises will develop a more muscular look, but will also help you get lean. If you don’t mind this look, then this is probably a great style of workout for you. If not, it might be best to avoid these style of workouts.

When I was training for a triathlon, I used fast past interval runs (not a full on sprint) to help me develop my cardio fitness quicker. It definitely did this, but what I found was that it actually helped me lean out my legs quicker too.

If you still want to include some cardio interval training, have a read of this blog post which explains how to do the fast past runs.

why are my legs getting bigger from running

IT DEPENDS ON YOUR BODY TYPE 

Your ability to get bulky muscle from running depends on your body type. If you don’t know your body type, click here to find out.

Ectomorphs find it very difficult to gain muscle and will probably never get bulky even if they do lots of weight lifting. Mesomorphs build muscle easily but can also lose muscle and fat quickly too. Some mesomorphs may get bulky legs whereas others might not.

And finally, endomorphs probably already have naturally muscular legs so find it easy to bulk up.

Running does burn a lot of calories and will help you lose weight all over your body. It may help you lose weight in your legs too. But at the end of the day, it will still build muscle in your legs. I have mentioned this before, but if you are a shorter endomorph build, I would avoid running as it can make your legs bigger.

IT ALSO DEPENDS ON YOUR MUSCLE FIBERS 

There are 2 basic types of muscle fibers. Slow twitch fibers are those used for longer endurance style workouts; and fast twitch fibers are those used for short bursts of energy such as sprinting, HIIT and plyometric workouts.

Everyone has different amounts of these fibers, and the amount and type you have will determine whether or not your legs get bigger from running. Someone with lots of fast twitch fibers might have muscular legs, even though they don’t do any type of weight lifting or sprinting. They may even build muscle just from walking.

On the other end of the scale, someone with lots of slow twitch fibers might do lots of sprinting and HIIT and find it difficult to gain muscle.

As you can see, genetics play a huge factor in whether or not your legs will get bigger from running. Some people will run all their life and their legs will stay slim and toned, while others will get bigger legs from running after just a month or so.

You need to adjust your running (and exercise program) to suit your body type and your goals.

legs getting bigger from running
Both women are long-distance runners. The difference is their genetics

OTHER FACTORS THAT CAN CAUSE YOUR LEGS TO GET BIGGER FROM RUNNING 

Running on an incline will also use your muscles more (especially your quads and glutes) and will build them. This is due to the pushdown and jumps motion. If you want a leaner look, always try to run on a flat surface.

Another factor that might cause your legs to get bigger from running is your exercise experience. If you haven’t done much exercise and have very little muscle in your legs, then you start running, you are going to build muscle and this is going to be a significant difference.

But if you already exercise and have muscle in your legs, the change caused by running might not appear as significant. What is considered significantly bigger depends on your preference.

Another thing to keep in mind is that your legs can also swell after a run. This is short-term and the swelling will reduce. So try not to judge your progress based on what your legs look like immediately after a run.

SUMMARY

The takeaway points from this are:

  • Running builds muscle in your legs, but doesn’t build as much as sprinting, HIIT and weightlifting;
  • Your body type and muscle fibers (i.e. genetics) will determine whether your legs will get significantly bigger from running. But “significantly bigger” is determined by YOU and what you think is too big;
  • You need to adjust your running (and exercise program) to suit your body type and your goals; and
  • Run on a flat surface and at a steady pace to avoid building more muscle from running.

3 STEPS TO LEAN LEGS PROGRAM

If running has made your legs bulkier and you would like to lean them out, I should also mention my 3 Steps to Lean Legs Program which is designed to help you get lean legs without the bulkiness :)

There are 3 different versions fo my program, one for each body type. Each version combines the right type of cardio and resistance training for one particular body type so you can be sure you’re going to get the best possible results. 

And of course, since you cannot train and be on a crappy diet, I included a complete 8-week meal plan in my program.

Also, the resistance training part of my program now has FULL-LENGTH videos that you can follow from warm up to cool down.

To find out more about my 3 Steps to Lean Legs Program click the link below:

https://www.rachaelattard.com/skinny-legs-ebook/

To find out more about my FULL-LENGTH VIDEOS, follow this link: 

https://www.rachaelattard.com/lean-legs-video-course/

And as always, if you have any questions, please feel free to ask! 

Love Rachael xx

Picture of Rachael

Rachael is an Australian born certified personal trainer and nutritionist who holds a Bachelor degree in Science.

After struggling for years to find an exercise and diet program that is tailored to women striving for lean and toned body with no bulk she designed her Lean Legs Program. This program is tailored to each body type and focused on helping women get toned but feminine bodies, without getting bulky.

Her mission is to empower women and help them stay in shape in a healthy and balanced way.

25 comments on “Why Are My Legs Getting Bigger From Running?”

    Frustrated says:

    Not only have my legs gotten bigger, but so has my butt, and with continued running, I am not going down on the scale at all. I gained about 20 lbs from running this year! I’m done with this. I finally lost weight when I started modifying diet, but my huge legs remain!! There’s so much muscle built on them. At this point I’m going to do walking instead.

      Diana - Lean Legs Support says:

      Hi lovely,
      It sounds like you were probably eating at a calorie surplus which is why your weight has increased so much. If you find that running makes your legs bulky, power walking is the best substitute. Also, make sure you’re eating less calories than you burn. :)
      For more helpful tips on how to calculate your ideal calorie intake please have a read of this blog post.

      Love,
      Diana
      xx

    Jolie says:

    Hi, I was happy with my legs…then decided to try walking to get them a little more leaner. Yesterday, I walked 10km, but today they are even bigger! Is this just after-day swelling since I’m not used to walking that much?

    Natalya says:

    The first picture is the wrong comparison for showing the difference between sprinter and marathon runner. As you can see between those women is a huge age difference. The right one is at least 25 years older from the left one. Maybe back then she had muscles like the girl from the left.

      Diana - Lean Legs Support says:

      Hi lovely,
      You have a point, this could’ve been true. You can find another sprinter VS marathon runner image here. These athletes are about the same age. However, the pic was only posted as an example to show the effects that different types of cardio can have on your body. You can find more similar images using Google search! xx

      Love,
      Diana

      Lance says:

      Not so. The women on the right is of similar age but her East African heritage makes her look older. That tends to be the case with East African heritage.

Leave a Reply

Your email address will not be published. Required fields are marked *

*

This site uses Akismet to reduce spam. Learn how your comment data is processed.

WANT TO FIND OUT MORE? SIGN UP TO RECEIVE

LATEST NEWS & FREE 7 DAY MEAL PLAN

Privacy Preference Center

Necessary

Necessary cookies for the website to function.

Non-Necessary

These cookies are used to provide an enhanced experience for website visitors, and to collect analytics data.

_ga,_gid,fbp,_omappvp,_om,_omSeem