What Does Running Do For Your Body?

It's no secret that exercise is essential to human health. Whether or not you identify as a runner, the human body is built for endurance running, from the shape of your feet to the length of your legs and your ability to sweat. Whether you run for fun, for competition or to enjoy time in nature, a lifestyle of regular running can transform your body, mental health and overall quality of life.

To maintain a healthy lifestyle, the CDC recommends 150 minutes of moderate physical activity per week, plus two days per week of strength training.

How could you approach this goal? We recommend a combination of running and walking, plus strength training. You can break up your weekly exercise any way you want. A great place to start could be to run or walk 30 minutes a day, 5 days a week.

If you need some extra motivation to get out the door, here are seven ways that running can improve your health from head to toe.

This article is part of our How To Start Running Guide

1. Relieve Stress

There’s a reason why the runner's high is so powerful; it’s actually your body releasing serotonin, the happy hormone, that boosts your mood and lowers other stress-related hormones in your body. According to a scientific review from 2016, endurance exercise like running boosts the levels of dopamine and serotonin in the brain. Both these hormones are important in regulating mood and stress in the body.

The review found that endurance runners have higher levels of serotonin in their brain than individuals who do not participate in aerobic exercise. This increased serotonin helps emotional processing and improves your ability to manage stress.

Another study from 2017 found the effects of running on the brain last long after your run ends. In a group of over 2,000 runners, researchers from the University of British Columbia concluded that the negative effects of stress were markedly diminished in individuals who participated in aerobic exercise every day compared to those who did not.

Translation: running helps you de-stress and stay de-stressed. While everyone responds to stress differently, running can be a great way to conquer stress and get back your peace of mind, in addition to the many other health benefits that running offers.

2. Improve Joint Health

If someone has told you, "running destroys your knees," there is evidence to prove otherwise.

We tapped “The Runner’s Mechanic,” Miriam Salloum, PT, COMT, OCS, for her thoughts on this enduring running myth. Salloum is the owner and director of The Runner’s Mechanic Physical Therapy Clinic in Asheville, North Carolina.

“This is the most common phrase I hear from new clients,” Salloum says. Many runners come in, eager to improve their running, but have friends who warn them that the sport will cause long-term knee damage.

“Overall, I think the future for most people who want to run is very bright when it comes to knee joint health,” Salloum says. “There is now a great deal of research that suggests running has no direct correlation to causing knee joint injury and actually may allow some protective factors to occur to improve joint health. Runners can also experience better longevity and general health compared to their non-running counterparts.”

Salloum says the one caveat is that runners who already present with advanced osteoarthritis should consult a medical professional to help them modify their running routine to extend the life of their knee joint and prevent further degeneration.

“Otherwise, healthy runners should go forward with their running goals with great confidence, although I would be remiss if I didn't throw in that good overall strength and sound biomechanical form is always helpful. There are some definite factors with both that can cause increased impact issues, but are correctable if identified,” she says.

Even if you’ve experienced knee pain as a runner, it may not be bad news for your long-term joint health.

“When you look at research statistics you will see that ‘knee pain’ is one of the most prevalent injuries within running populations, but these cases deal with more soft tissue disorders of the knee like patellofemoral knee pain and IT band friction syndrome,” Salloum says. “These pain syndromes really don't involve the health of the intra-articular or ‘inner joint’ of the knee. These knee conditions are usually because of hip or ankle movement impairments that irritate the soft tissues around the knee and kneecap and are fully reversible.”

For more information about running and joint health, Salloum recommends this 2023 article from Stanford University and this 2023 study.

A group of runners runs together along a sidewalk in Chicago

3. Maintain a Healthy Weight

You don’t need to be a certain size or shape to be a runner. As with any aerobic exercise though, running can be a useful tool to lose weight or maintain a healthy weight.

A 2020 study from the University of Kentucky found that individuals with BMIs (body mass index) ranging from 25 to 35 experienced significant fat loss after participating in an aerobic exercise, like running, for six days per week for 12 weeks. The study also found that maintaining a healthy fat-to-muscle ratio is important for many other aspects of well-being, like heart health, joint health and hormone regulation, to name a few.

Running can help you feel comfortable in your own skin and appreciate what your body is capable of, no matter your size or weight.

Lauren Ross, a registered dietician and trail runner from Houston, TX, shared her thoughts on body image and overcoming self-doubt as a runner in an email to Fleet Feet. “I'm not here for you to look at,” she says. “I'm here to see how far I can push my limits...What I look like doesn't impact my ability to do those things.

4. Improve Heart Health

Chronic heart disease is the leading cause of death in the United States for men and women of all age groups and ethnicities, according to the CDC, with about 655,000 Americans dying of heart disease every year.

But it’s not all doom and gloom: You can take control of your heart health by running as little as five to 10 minutes per day, according to a 2014 study. Researchers found that in a group of individuals with BMI ranging from 25 to 35, running just five to 10 minutes per day at low speed had a 45 percent lower risk of death from heart disease than non-runners. That’s right, running just a bit every day can cut your risk of death from heart disease almost in half.

5. Improve Immune System Function

In the age of pandemic, you may be more concerned than ever about keeping your immune system healthy. Luckily, forms of exercise, like running, can improve immune function by triggering anti-inflammatory responses in your body. The anti-inflammatory response gives your immune system the boost it needs to effectively fight off bacteria and viruses as you encounter them in your day to day life.

A study at UVA found that just 20 minutes of exercise per day results in an increase in white blood cells and antibodies, two important parts of our immune system that our bodies use to get rid of germs that might enter our bodies.

Another study performed in 2011 by Dr. DC Neiman, Professor and Director of the Human Performance Laboratory at Appalachian State University showed that sick days for the common cold during a 12-week period in the winter or fall is reduced by 25 to 50 percent for people who exercise most days of the week. You can read more from Dr. Neiman about how to safely maintain an active lifestyle during the COVID-19 pandemic in our interview with him.

A group of runners walk together down a hill after running a repeat

6. Age Better

Adding healthy habits to your life, like running, can help you age like a fine wine and even add years to your life.

A 2018 study from Ball State University at the Human Performance Laboratory by Dr. Scott Trapp showed that in a group of 75-year-old men and women, those who exercised regularly had the cardiovascular health of a 45 year-old. The same study also found that those same 75-year-olds had the muscular health of a 25-year-old.

This study and many others like it show that running actually makes your body seem younger. And it’s never too late to start exercising. According to cardiologist Dr. Ben Levine (UT Southwestern Medical), exercise can reverse some signs of aging in individuals up to 65 years of age.

7. Sleep Better

The Centers for Disease Control estimates that 35 percent of Americans are sleep deprived. If you struggle to get fully rested each night, running just might help.

According to the American Psychological Association a good night's sleep impacts the whole body. Proper rest leads to improved immune function and memory. It decreases the risk of negative outcomes like high blood pressure, heart disease, stroke, diabetes, obesity and depression.

A 2014 scientific review from the American Journal of Lifestyle Medicine found that aerobic exercise training in a sample of older adults with insomnia significantly improved sleep quality while also reducing daytime sleepiness and depressive symptoms.

If you add a running program into your daily routine, it can improve your sleep and your overall health as a result.