Does running build muscle?
A combination of the right conditions and type of running can build muscle. We break down the ins and outs of muscle growth for runners and how to optimise it.
Whether you can effectively build muscle through running alone is a question most runners have probably wondered.
Granted, runners at the pointy end of the sport are not known for having muscular frames. That doesn’t mean that you should rule out running completely though when it comes to finding ways to build muscle.
Running is great for working the muscles, just why, how, and how to best optimise your running for muscle gain is what we’ll cover in this article.
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- What muscles does cycling use?
- What muscles does walking use and tone?
- Does swimming build muscle?
Can you gain muscle through running?
The short answer is yes, you can absolutely build muscle from running. What kind of running, the duration, and the distance, plays a big part in muscle gain though.
A 2017 study found that high-intensity, short-duration running (like sprints or hill repeats) can stimulate muscle growth, particularly in the lower body. Long-distance running, on the other hand, can sometimes lead to muscle breakdown.
This is because prolonged endurance efforts can cause muscle protein breakdown (MPB) at a faster rate than muscle protein synthesis (MPS). This could counteract any potential muscle growth, especially if there’s inadequate fuelling. This is why endurance runners tend to be lean yet powerful, with efficient muscles that are optimised for sustained run effort rather than maximum run power output.
You only need to compare the typical stature of a professional sprinter and that of a pro endurance runner to see this in action. Hence why it’s important to understand the nuances of the impact of running on the body, and how you can use these to achieve your goals.
How does running build muscle?
High-intensity running, like sprinting, tempo workouts, and high-intensity interval training (HIIT), all employ your fast-twitch muscle fibres, which have a greater potential for hypertrophy (muscle growth).
This high-intensity kind of running creates a high metabolic demand, which in turn stimulates the release of growth hormones in the body that promote MPS, leading to muscle adaptation and growth.
Running, especially high-intensity, creates micro-tears in muscle fibres, but don’t worry, the body then repairs and strengthens the muscle, thus leading to muscle growth. The main muscles affected are those most used for running in the lower body, including the calves, hamstrings, and quadriceps.
It’s essentially very simple and logical when you think about it: muscle growth occurs when MPS exceeds MPB (muscle creation exceeds muscle breakdown).
This comes with a caveat though, as if you want to tip the scales in favour of muscle growth, you need to also be fuelling with the right and enough nutrition, factor in adequate recovery, and hit the right training volume.
The rumours are true, you do need a certain amount of protein for muscle repair and growth (see how much the experts recommend below). Along with this, you must be consuming enough calories to support energy expenditure, recovery from running, and your muscle-building goals.
Proper rest and recovery is essential for muscle adaptation and growth. Be sure to leave enough time in between your hardest sessions of the week, and avoid overtraining which can lead to muscle breakdown and overall burnout. If you fail to do so, you’ll effectively be sabotaging any potential muscle-growing results from your sessions.
The best way to maximise muscle growth as a runner is to first incorporate high-intensity run sessions into your program, but also to combine these with strength training for the most effective approach.
Strength training, in the gym or at home, provides additional stimulus for hypertrophy, which complements and accelerates the muscle-building effects of high-intensity running. One key rule to remember – consistency is crucial for achieving muscle growth.
How much should I run if I want to build muscle?
How much you should run if you want to build muscle depends on what you’re currently used to in training. If you don’t already do much intensity and resistance training, slowly incorporate these into your training program.
Keep these sessions short in duration. Be sure to disperse intense sessions with rest days and with consuming nutritious and balanced, protein-rich meals.
To begin with, add to your weekly program two high-intensity run sessions of either sprints, hill repeats, or short tempo efforts.
An example session could be: 5-10 minutes warm-up jog with dynamic stretching to prepare the muscles, followed by high-intensity intervals of near-maximal effort of 6 x 20s sprints with 60s jog/walk recovery after each, finish with a 5-10 minutes cool-down to gradually lower the heart rate.
Progress this session by reducing the rest as you get used to high-intensity work. Give yourself at least two days of rest between these, during which you can do low-intensity activity or complete rest.
Eventually once your body is used to the additional load, you can increase this to three sessions, and/or supplement it with strength training. Aim to include 2-3 strength training sessions into your program per week, focusing on compound exercises like squats, lunges, and deadlifts.
If you’re doing both strength training and high-intensity running, avoid doing too much as this will counteract potential muscle-building results. Pay attention to your body’s signals and adjust your training accordingly.
Combine running and nutrition to build muscle
To fully optimise any muscle gain from your run training, it’s key to consume adequate protein to support muscle protein synthesis (MPS).
In a single meal, studies show that the optimal amount of protein is 20-25g, any more and the excess will be used for energy or elsewhere in the body. (J. Physiol, 2013). This is called the ‘muscle full’ concept.
Recommendations vary, but the British Heart Foundation cites that the best quantity of protein to consume to build muscle as 0.75g of protein per kilogram of body weight. For example, a 70kg person would therefore need to eat 52.5g of protein.
This advice is most suited to sedentary individuals, with active people like runners who are looking to build muscle advised to eat 1.2-1.7g of protein per kilogram of bodyweight. For our 70kg example, that’s pretty much double a sedentary person’s quota, at 84-119g (Mayo Clinic).
Though there’s dispute as to whether the 30-minute ‘anabolic window’ truly exists, it’s still a good idea to consume around 15-30g of protein post-exercises to aid muscle synthesis.
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Some known good sources of protein include: lean meats, poultry, fish, eggs, beans, and dairy products like milk and yogurt. If you struggle to get in enough protein, you may want to consider supplementing your fuelling with protein bars or protein powder.
Don’t make the mistake of having tunnel vision for protein only, carbohydrates are essential for fuelling your workouts and replenishing glycogen stores. It’s key for performance and recovery.
Eating your protein with a good carbohydrate source will also help to replenish energy levels and ensure you’re consuming a balanced diet, along with other food groups, essential nutrients and minerals. Remember – a calorie deficit can severely hinder muscle growth. In fact, building muscle is incredibly difficult without a calorie surplus.
We recommend you seek the support of a professional nutritionist or doctor before starting a new diet or exercise program, they will be able to provide more tailored advice for your body and goals. Don’t forget, individual responses to training and nutrition can vary, there is no one-size-fits-all.
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Kate Milsom
Freelance sports journalist 
