What Running Does for Your Body: The Surprising Details

Chances are you know that running is good for you. But are you doing it? That likelihood is a bit lower. Why? In large part, people are reluctant to run because they don't understand just how far-reaching the benefits of this simple human movement are. To give you insight into your body—and maybe some extra motivation—here's an overview of precisely what running does for your body. You might be surprised by how useful those regular bouts of cardio can be.

Your Body on the Road

Before delving into what running does for your body, it's helpful to understand what your body is doing, both mechanically and chemically, when you head out for a basic run. From there, you'll have a deeper appreciation for some less obvious benefits of running.

  • Zero to Two Minutes: As your muscles start to work, they require energy. To keep them fueled, your body taps into the glycogen that it has tucked away, and converts that sugar into its primary fuel: adenosine triphosphate (ATP). This substance is then broken down further into ADP, which is continuously recycled back to ATP. If there isn't enough glucose stored in your muscles, your body will take some from your blood as well. Lactic acid is released as a byproduct of the reaction, which is also used for fuel. In this initial stage, your body is getting primed and this fuel cycle is revving up for more activity.
  • Two to Ten Minutes: At this point, you're likely starting to hit your stride. Now that you're moving at a comfortable working pace, your heart is beating faster to make sure that sufficient oxygen and nutrients are getting to where they're needed most. To support this, blood is diverted away from non-running-related systems, like digestion. Your energy demands are starting to rise here and since oxygen is vital for that fuel cycle, you start to breathe more heavily. To keep you balanced and moving forward efficiently, the muscles of your legs and core start firing along with the largest muscle you have—your glutes (buttocks). This increased muscle activity from such large muscle groups burns an incredible amount of calories. The rising demands for fuel and oxygen result in an increase in body temperature, usually resulting in a healthy sweat.
  • Ten to Thirty Minutes: How you feel during this phase depends largely on your fitness level, diet, and running experience. Seasoned runners have plenty of ATP stored away to keep them energized for extended periods. Their bodies are also trained to use that fuel and oxygen more efficiently. Newer runners, however, start to run low on ATP around this time and have difficulty breathing in enough oxygen to keep the cycle running correctly. As a result, energy levels drop as lactic acid levels rise, leading to burning, exhausted muscles.

Muscles, Bones, and Joints

Several major muscle groups are hard at work when you run. That challenge causes each of the involved muscles to become stronger, faster, and more efficient at both moving and using fuel.

Surprisingly, bones respond to exercise in a similar way to muscles. In response to feeling stressed, they get stronger, denser, and are better prepared for future challenges. In fact, researchers at the University of Missouri found that high-impact activities like running are even more effective than resistance training when it comes to building stronger bones.

But your muscles and bones aren't the only parts of your body that benefit from all the jostling—your joints are learning and growing, too. The cartilage and various cushions that support your knees, ankles, and hips are challenged and stimulated into improvements each time you run. The small muscles that wrap around these joints, which are often missed during other activities, are strengthened when you hit the road. This results in better support of the joints, better balance, and more efficient movement patterns.

Heart, Lungs, and Brain

In the same way that your joints, bones, and muscles improve to keep up with the demands of your run, your heart and lungs start to make some changes. Your heart, responsible for moving huge quantities of blood through your body, gets stronger and develops the ability to push more blood with each pump. At the same time, your blood vessels become more efficient carriers and open wider to allow for a better flow of traffic. In response, your blood pressure drops. Your lungs also become stronger and learn to move and process more oxygen at faster rates.

Those neurochemicals also stimulate lasting changes in your brain that may improve your memory and overall thinking ability, even warding off signs of aging, notes Harvard Health Publications.

Metabolism, Self-Esteem, and Mood

Remember how newer runners hit a wall at around ten to thirty minutes when they start to exhaust their fuel supplies? The more you run, the more efficient your body becomes at using fuel. But the benefits of this extend way beyond your runs. Now that you've developed those big running muscles, they'll demand more calories even when they aren't working, giving you a higher metabolism all day, every day.

The act of setting and achieving a goal, something that is a regular feature of running, can provide you with a massive boost of confidence, according to a 2010 study published in Health Education Research. Interestingly, a study in the International Journal of Environmental Health Research found that people who regularly run outdoors have noticeable boosts of self-esteem after their workouts.

During your run, your brain is also pumping out numerous substances that are designed to keep your mood and energy elevated. Fortunately, this effect doesn't wear off when you stop running. In fact, exercise in general has been shown to be extremely useful for combating depression and anxiety, according to the Archives of Physical Medicine and Rehabilitation.

Many benefits of running are well-known, but others are often overlooked. Do you feel like heading out for a run yet?