Does running build muscle? What you need to know before lacing up

Hands up if you hate leg day? We thought so. The bad news is: you do have to work out your lower body. But, the good news is, there’s more than one way to do it.  Running is a great way to keep fit and build muscle. Plus, there’s no expensive gym membership or equipment required. 

Whether you’re an avid runner looking to brush up on technique or a newbie seeking guidance, here’s everything you should know about running to build muscle.

How running affects your body

Research shows that aerobic exercise, like running, can improve multiple bodily functions, including [1][2]:

• Heart function
• Muscle function
• Balance
• Endurance
• Metabolism

While all of these are great, endurance is an important one to note. The more endurance you have, the longer you are able to work out for. This is a key factor in the muscle building process that we’ll explain later on.

Running can also reduce your risks of various health issues and diseases [2], and new research is also pointing to aerobic exercise as a key factor in muscle protein synthesis [1].

It’s early days, so we can’t say anything for sure yet, but results suggest that aerobic exercise helps improve blood flow. The better your blood flow, the more amino acids (the building blocks of protein) can be delivered to your muscles. 

The effects seem to be highest for older adults and people who don’t exercise often. Though, some researchers believe it could be beneficial for young adults too.

Can you gain muscle from running?

Everyone knows that cardio burns fat and weights build muscle, right? Just because it’s common knowledge doesn’t mean it’s the absolute truth.

Since the 1990s, researchers have had access to high-resolution imaging techniques that allow them to take a closer look at muscles after exercise [1].

They’ve been exploring a range of aerobic exercises — from running to walking and cycling. In nearly every study, people did build strength from aerobic exercise; on average, a 7% increase in their muscle mass.

One study directly compared strength training and aerobic exercise on the quadriceps, which are the upper thigh muscles. After 12 weeks, there was a comparable 8-9% increase in muscle mass for both groups.

We do want to add a note here that every person’s body is different. While some body types respond well to any exercise, others are more suited to certain types of exercise.

A lot of the studies we mentioned above had mixed results. Not everyone gained muscle from running. But, even if your body type doesn’t respond directly to running, it can still help you build muscle in other ways. 

How running supports muscle growth 

We mentioned earlier that endurance is an important part of muscle growth. But, how does running help with endurance? Here’s what you need to know.

First, let’s start with how running helps build endurance. It comes back to blood flow again. Aerobic exercise helps increase the small blood vessels in your leg muscles [7].

The more blood vessels you have, the more oxygen your muscles receive. The more oxygen your muscles have to work with, the better endurance you have, meaning you can work out for longer or push your body harder.

Endurance is important for all types of exercise. When it comes to strength training, having a higher level of endurance often means you can lift heavier weights.

To put it all together now: running helps build endurance, endurance helps you train harder, and training harder helps with muscle growth.

Does running for 30 minutes build muscle?

Even 30 minutes of running can be effective for muscle building. But, it’s not just about timing. There are 3 key factors in building muscle during aerobic exercise [1]:

• High-intensity: Getting your heart rate to 70-80% of its maximum intensity
• Duration: A minimum of 30-45 minutes is recommended per session
• Frequency: You need to be getting active on 4-5 days per week

This combination of intensity, duration and frequency creates a similar environment to resistance training, which is the gold standard for muscle building.

But, what if getting out on a run each day is not practical? Can you still benefit from 30 minutes of exercise? To state the obvious, doing any amount of exercise each week is better than none. While 30 minutes alone may not be the ideal amount to build muscle, it does have other benefits.

Research shows that just 30 minutes of running per week is enough for weight loss, helping reduce body weight, body fat percentage and waist circumference [5].

Another study found that 1 session of running for 50 minutes per week can improve your longevity by reducing the risk of many diseases [2].

How long should I run to build muscle?

It’s hard to give an exact time limit, since everyone’s running pace is different. So, rather than focus on duration, let’s turn to distance.

There is evidence that long runs (10km, 21km or 42km) can negatively impact muscle growth. This is because long distance running can increase the levels of 2 enzymes: creatine kinase and lactate dehydrogenase [9].

High levels of these enzymes in your body are a sign of significant muscle damage. While some damage is necessary for repair and growth, too much can mean your body is unable to repair itself effectively.

Running for a shorter distance or at a lower intensity can protect against this. So, to build muscle while running, you can focus on:

• Running at a high intensity for a short distance
• Running at a low intensity for a longer distance

How will you know if you’ve overdone it? Recovery time is a good indicator. In the study we’re referring to, the long-distance runners had muscle recovery times of up to 7 days.

Ideally, you’ll be ready to go again in only a few days’ time – giving your body time to rest, while still maintaining a consistent training schedule.

What physique does running give you?

In general, the muscles that you train are the ones that will grow. So, for running, this is the lower body muscles, including [4]:

• Glutes
• Hamstrings
• Quadriceps
• Calf muscles

If you focus only on running, then you would expect to have a sculpted lower body and legs. Balancing out your upper body will likely require a different type of exercise. For example, many men are seeking a broader chest which provides a more athletic physique. To achieve this, you might work on your shoulder muscles [4].

There is one caveat to mention — exercise can’t change the fundamental shape of your body. Things like your bone structure, height and proportions are pretty much set once you reach adulthood.

So, rather than hoping a certain type of exercise will change your body type, focus on using it to enhance your best features.

There’s also a common myth that running will make you lose muscle [7]. While running can help you drop weight, which may include both fat and muscle, you can protect against muscle loss with a mixed training routine.

Multiple studies have found that combining aerobic exercise with strength training is effective for maintaining muscle gains [7].

It’s not easy to find the right diet and exercise for your particular body type, but you don’t have to do it alone. You can work with a personal trainer, dietitian, your doctor or consider a programme like Compound.

Compound combines medical treatments, diagnostics, prescriber support, and personalised nutrition and exercise plans for an effective programme that helps men unlock body recomposition. 

• Up to 15% weight loss with clinically-backed treatments
• Lose fat and gain muscle with customised diet and movement plans
• Track metrics and progress within the Compound app

We’re in the middle of building something special for UK men. In the meantime, register your interest and we’ll keep you updated.

Does running help with weight loss?

Many forms of cardio training are known to be effective for weight loss — from running to cycling, boxing and skipping (or jump rope) [4].

A key factor in cardio for weight loss is the intensity of your exercise. Moderate-to-high intensity training is most effective for reducing body weight and body fat percentage [6].

How to find your maximum intensity

In general, the more you huff and puff during exercise, the higher the intensity will be. But in scientific terms, intensity refers to how high your heart rate is:

• Low: 40-50% of your max heart rate
• Moderate: 50-70% of your max heart rate
• High: 70-80% of your max heart rate 

These levels are known as your target heart rate zone [10]. Your maximum heart rate is equal to about 220 minus your age. For example, a 30-year-old male has a maximum heart rate of 190 beats per minute (bpm). Their target heart rate zone from 50-85% is equal to 95-162bpm.

A lot of fitness watches and gym equipment will help you track your heart rate during exercise. These can help you reach the maximum level so that you’re training effectively for your goals. 

But, if you don’t have access to these types of technology, you can also use the conversation method. According to the NHS, during moderate-intensity exercise, you should be able to hold a conversation, but not sing.

During high-intensity exercise, you would struggle to say more than a few words without needing to take a breath [11].

How to build muscle while running 

Whether you’re a trail runner, a beach runner or a city street runner – every step you take has the power to build up your leg muscles. 

But, there are a few extra tips to get greater muscle gains from going on a run.

Vary your speed and direction

We know it’s not what you want to hear, but making your run more difficult will help your muscles grow. Compared to running on a flat surface, varying your speed and direction makes your muscles work harder.

That might mean incorporating short sprints into your training or finding an uphill running spot, which brings us to our next tip.

Running uphill and downhill

The simplest way to maximise your muscle gains from running is to find a steep hill. Uphill running activates the quad muscles, making them work harder than they would on a flat surface [7][8].

Downhill running is great for your lower legs — think calf and shin muscles. But, be careful of your balance here. It’s often helpful to adjust your speed when running downhill. 

Get into team sports

If heading out on a long run is your idea of hell, then you might benefit from some incidental running through sports. Research shows that team sports, like football, have a better effect on your muscles than standard low-impact training, like running [3]. 

Actions like turns, jumps, and short sprints make your muscles work harder, which in turn helps them grow larger.