Does Running Make Your Butt Bigger? It Depends

“Running builds muscle, but not in the way we traditionally think about building muscle,” says Todd Buckingham, PhD, an exercise physiologist at Mary Free Bed Sports Rehabilitation Performance Lab.

A lot comes down to muscle fiber types, and more specifically, type I or slow-twitch fibers, and type II or fast-twitch muscle fibers (1).

According to Buckingham, distance runners use type I muscle fibers, which are smaller and better for endurance.

“These smaller fibers can endure fatigue but do not produce much output, so even though you might not get ‘muscular’ with big muscles, distance running will build type I muscle fibers,” he explains.

Because type I fibers don’t get very big, Buckingham says you may not see an increase in glute size, but the glutes will become stronger even if they aren’t getting larger.

Sprinting, however, uses type II fibers, which are larger and suited for short bursts of speed. Buckingham says they can contract more forcefully because of their size, allowing you to have more power and run faster.

When you sprint, type II muscle fibers will hypertrophy and cause an increase in muscle size. And because the glutes are heavily utilized in sprinting, Buckingham says you can expect to see your glutes get bigger due to the increased size of type II muscle fibers.

Summary

Yes, running builds muscles in the glutes, but it depends on the type of running. Sprinting activates type II fibers, which are larger and more able to increase muscle size, whereas distance running uses smaller type I fibers that are better for endurance.

The largest and strongest muscle in your body is the gluteus maximus (2).

However, your glutes consist of three different muscles:

• gluteus maximus
• gluteus medius
• gluteus minimus

After a grueling run, there’s a good chance your glutes, along with your quads, hamstrings, and calf muscles are burning. You may also notice fatigue in other parts of your body.

“The legs are most definitely working with running; however, the abdominal muscles and arms are working, too,” says Max Chee, PT, a physical therapist at Providence Saint John’s Health Center’s Performance Therapy Center.

“The abs are working to keep your upper body stable, and the arms move to help with coordination, while the glutes provide the power to push your body forward,” he says.

Summary

Although running specifically targets lower body muscles like the quadriceps, glutes, hamstrings, and calves, you also use your upper body and core to help with balance, coordination, and forward movement.

Yes, running burns fat, but in a specific way.

Just like any type of physical activity, running requires energy, which comes in the form of calories, which you get from fat, carbs, and protein. Since your body has a lot of stored fat, Buckingham says you can use it as energy.

In other words, your body can use fat as fuel when running. That said, to use fat (or “burn fat”), Buckingham says the fat must be converted from its storage form of triglycerides into a usable energy source, which is adenosine triphosphate (ATP).

Although this requires a long and slow process, there are a few things to note. Because fat takes a long time to break down, Buckingham says the body’s preferred energy source for any activity above a moderate intensity is carbohydrates.

“Carbs are much easier to break down and can be used as energy more quickly. Therefore, if you are running faster than approximately 50% of your maximum heart rate (HR), you will burn a greater percentage of carbs than fat,” he explains.

Because lipolysis is such a slow process, Buckingham says it takes time for it to really kick in after exercise begins. “If working at a submaximal intensity, it can take upwards of 30 minutes for fat to become the predominant fuel source over carbohydrates.”

However, even if you run faster than 50 percent of your maximum HR, Buckingham says you will still burn fat, and the rate at which you burn the fat will be higher than when running at slower speeds.

“It’s the percentage of fat that will be lower if you run faster, so if you want to burn a greater percentage of fat, run slower. If you want to burn a greater total amount of fat, run faster,” he says.

Summary

As an aerobic activity that requires energy from calories, running burns fat. High intensity, shorter duration exercise relies more on carb calories. Longer duration, lower intensity activities typically lasting longer than 30 minutes use carbs and fat.

If boosting your glutes and improving speed and power are your top priorities, sprinting is the way to go.

However, if you’re more concerned with cardiovascular endurance and making it across the half-marathon finish line, stick with long-distance running. Just don’t expect to build your booty in the process.

And while distance running and sprinting do have some of the same effects on the body, such as improved cardiovascular health, Buckingham says they also have some key differences.

First, they train different muscle types — long-distance running trains type I muscle fibers and sprints train type II.

Buckingham also points out that sprints increase your anaerobic capacity to a much greater extent than distance running. “On the other hand, distance running will improve your aerobic capacity (V̇O₂max) to a much greater extent than sprints.

Summary

Both sprinting and distance running improve the cardiovascular system and recruit your lower body muscles. Higher intensity exercises like sprinting rely on the larger type II fibers, and slower, distance running recruits the smaller type I fibers.

When it comes to sculpting the glutes, strength training, bodyweight exercises, and aerobic exercise like running should be your go-to activities.

Here are some of Chee’s favorite glute-friendly moves:

• Clamshells: resisted side-lying external hip rotation
• Side-lying hip abduction: side leg lifts
• Quadruped hydrants: hip extension with external rotation
• Squats: both with and without weights

To target the glutes, make sure to include resistance training exercises that specifically target this area.

One review found that while glute activation varied among lower body exercises, step-ups, squats, the barbell hip thruster, and deadlift required a high level of gluteus maximums activation. Still, step-ups, and more specifically, lateral step-ups, required the most glute activation (3).

Another method of exercise that recruits the glutes, builds power, and burns calories is plyometric training.

Plyometric exercises like jump squats, box jumps, step-ups, and jumping lunges all activate the larger type II fibers in the lower body muscles.

And while all of these exercises can reduce overall fat levels in the body, Chee says it’s very difficult to train to reduce fat in one specific area.

In fact, Buckingham says the best way to reduce fat is by eating fewer calories than you’re burning. “This will cause a reduction in body weight, but if you don’t exercise, some of this weight could be lost through muscle,” he says.

To preserve muscle and sculpt the glutes, Buckingham says it’s important to follow a reduced calorie diet while incorporating cardiovascular exercise like running and strength training into your fitness routine.

Moreover, when designing a running routine that targets glute building, Buckingham recommends combining sprints and distance runs.

Summary

To sculpt the glutes, incorporate cardiovascular and resistance training. Lower body exercises like squats and lunges activate the glutes. Also, add bodyweight moves like clamshells and side-lying hip abductions to target the glute medius and minimus.

Running is an excellent form of aerobic exercise that burns calories, improves the cardiovascular system, and tones the lower body muscles.

Long-distance running targets type I muscle fibers in the glutes. As such, it’s not as effective at building muscle size as sprinting, which targets larger type II fibers that are better at increasing muscle size in the glutes.

If you want a workout that challenges both muscle fiber types and your anaerobic and aerobic systems, combine short duration, higher intensity runs with longer, lower intensity jogs.

Make sure to follow a healthy diet and incorporate strength training exercises like squats, lunges, and step-ups to sculpt and tone the glutes.