Does Running Build Muscle?

In recent years, running has gained popularity not just as a form of aerobic exercise but also as a way to support overall well-being and physical resilience.

Like many others, I often find myself lacing up my shoes for a casual light jogging in the morning.

I do that not necessarily to build endurance or hit my personal best, but to clear my mind, lift my mood, and enjoy some fresh air. For me, running has always been more about mental clarity than physical transformation.

However, during one of these runs, a question crossed my mind: can running help build muscle mass like lifting weights? I realized I didn’t have a clear answer.

That moment of curiosity sparked my inner researcher, and after returning home, I dove into the scientific literature to find out what current evidence says about the relationship between running, muscle development, and overall body composition.

So, can a daily jog build muscle? Read on to discover the facts.

Understanding muscle growth

Before we dig deeper into how specifically running affects muscles, let’s get an understanding of how muscles grow.

When you engage in activities like lifting weights or doing bodyweight exercises, also known as resistance exercises, you create tiny tears in your muscle fibers. Due to this muscle stress, the body repairs the damaged fibers and adds new muscle proteins to reinforce the structure. This is how muscle building occurs.

The cycle of damage (muscle protein breakdown) and repair (muscle protein synthesis) leads to muscle gain. However, greater muscle gains only happen when muscle protein synthesis exceeds muscle protein breakdown. To put it simply, you will gain muscle only when the amount of muscle your body rebuilds after getting damaged is greater than the amount that gets damaged in the first place.

Various forms of exercise and workouts, nutrition practices, and other factors may impact muscle breakdown and repair. For example, resistance training may support the overall body muscles, while running may stimulate muscle adaptation in the leg muscles.

Moreover, growth hormones are key players in muscle development. Demanding workouts and exercises stimulate a growth hormone spike, meaning that muscles are most likely to grow when the routine includes maximum-intensity workouts.

How running impacts muscle

While resistance training, such as lifting weights, is usually associated with helping to build muscle, running may also impact certain muscles depending on run intensity and duration.

Some research suggests that running, like strength training, may impact a process in which the muscles experience stress. In response, the body repairs and rebuilds those stressed fibers, making them thicker and stronger. This is especially noticeable in people who haven’t been physically active before.

One literature review explained a study in which authors looked at whether younger and older men were able to build muscle when walking or jogging five times a week for six months. The workout plan became more challenging every two weeks.

The authors noted that running mainly affected the lower body muscles (leg muscles) in older men, whereas younger men did not see the same benefit.

For me, as an occasional runner, the question of whether muscles grow when practicing running has a short answer: yes, but only when it comes to lower body muscles. There are even more nuances when digging deeper, so let’s explore those.

Sprint vs. marathon

Running is usually divided into high-intensity, short-duration running, such as sprinting or high-intensity interval training (HIIT), and long-distance running, such as marathons. These types of running impact muscles differently.

High-intensity, short-duration running and muscles

Interval training is a type of running workout that involves brief bursts of maximum-intensity running followed by light and restful recovery. The most commonly used type of interval training is HIIT. While HIIT usually includes a variety of exercises, it often involves periods of short sprints.

One study assessed people with overweight and obesity to see whether HIIT exercise can help build muscle. Participants were randomized into two groups and one control group and performed 5 x 2-min bouts or 10 x 1-min bouts for nine sessions over three weeks. The authors concluded that such exercises helped build muscle in people with overweight or obesity.

Moreover, we can take some insights from another national-level sprinters study, in which the authors found that targeted sprint training not only helped increase the runners' speed over time but also contributed to muscle development.

I personally quite enjoy HIIT exercises. Even if they are pretty challenging, these exercises help me keep my engagement on point while working out, and often, after such exercises, I feel my leg muscles especially have had a good workout.

However, it’s important to keep in mind that while high-intensity running or HIIT exercises may help support muscle building over time in some body areas, a well-rounded approach to growing the muscles is needed to maintain the general muscle tone of the whole body.

Long-distance running and muscles

While long-distance running is often associated more with cardiovascular health than muscle growth, it does impact muscles in specific ways, however, differently from short-duration and high-intensity running.

Endurance training or long-distance running often leads to physiological adaptations as increases happen in muscle efficiency rather than size. Long-distance running focuses on low intensity and repetition rather than high mechanical muscle tension, which often leads to muscle growth.

In one of his LinkedIn posts, Greg Morrone, an ACE-certified personal trainer, explained to his followers that it is essential to combine cardio workouts such as running with strength training to ensure comprehensive health benefits.

Morrone highlighted: “Cardio remains essential. It strengthens your heart and lungs, but integrating strength training into your routine is a smart move for transforming your body composition.”

With that being said, since long-distance training may potentially hinder muscle growth in some instances, strength training and exercises that help build muscles are of special importance for those who often participate in such distance runs.

Effective running workouts for building muscle

Multiple running workouts may be incorporated into your routine, but before any exercise, always consider a thorough body warm-up.

In one of his LinkedIn posts, Ofir Malamud, MSc, shared the importance of a warm-up before running: “A warm-up routine supports running performance. Physiologically, a warm-up increases the body’s core temperature and muscle temperature, which leads to improved muscle elasticity and reduced stiffness.”

To warm up before the run, try light jogging or brisk walking for 5–7 minutes. Dynamic stretches, such as leg swings, walking lunges, and high knees, could be a few that you may want to include.

When your body and muscles are warmed up, try some HIIT exercises for your muscle mass support:

Remember that active rest is still encouraged during the cool down to prevent injuries and support recovery after the workout.

Also, modify your workouts and physical activity routine according to your individual needs. If needed, adjust rest periods or the number of sets to your preference. If you are new to running or HIIT, try introducing the exercises slowly, starting with shorter intervals or fewer sets to allow your body to adapt safely and reduce the risk of injury.

Nutrition for building muscle

As a nutritionist myself, I always try to highlight that a healthy diet plays a role in muscle building, and training alone is not enough. Poorly planned nutrition practices may also inhibit muscle growth. The body needs appropriate energy and adequate nutrients to repair and grow muscle tissue, especially after a workout.

Here are some nutritional guidelines that may help you support your muscle-building process:

• Energy. An appropriate energy (calorie) intake is essential for supporting overall health and muscle maintenance. Providing your body with enough fuel ensures it can carry out key processes like muscle protein synthesis, while a higher caloric deficit may inhibit muscle growth over time.
• Protein. Dietary protein is necessary for tissue repair and support. Generally, the daily protein recommendations for physically active people range between 1.2–2 g per kilogram of body weight. More protein is required for those who practice running or work out intensely. The body also requires more protein after exercise.

Sports dietitian Aashee Shah shared some nutrition strategies post-workout in one of her LinkedIn posts. She highlighted that protein stimulates muscle repair and growth. In her post, Shah said, “Aim for 20–30 g of high-quality protein post-workout.”

• Carbohydrates and healthy fats. A balanced carbohydrate and fat intake is essential for replenishing muscle glycogen stores, which is vital for recovery and reducing muscle breakdown. Meanwhile, fats help to better absorb certain micronutrients that participate in muscle function and recovery.

While some forms of running can help engage and strengthen lower body muscles, increasing muscle size typically requires a combination of strength training and supportive nutrition. Eating well plays a key role in maintaining and gradually building more muscle throughout the body.

The bottom line

All things considered, running, especially when combined with strength training and the right nutrition, may help you build muscle, particularly in the lower body.

While light jogging supports overall health, more intense workouts and structured training routines, such as HIIT, are more active in building muscle.

To build more muscle, it’s important to balance your workouts with resistance exercises, allow for proper recovery, and fuel your body with adequate nutrients.