7 Ways Your Body and Mind Change When You Start Running Every Day

There’s a mountain of research to back up all the ways in which running can better your physical and mental health. These payoffs provide motivation, which is why so many people turn to running as their preferred method of exercise. But what happens when running becomes a daily habit? Can you overdo it if you run day after day?The short answer is yes, it is possible to run too much—the correct dose varies from runner to runner and depends on a variety of factors. But as long as you’re listening to your body and not overdoing it, you’ll gain some serious health advantages from clocking miles on the regular.“If running or exercise were a pill, it would be the most widely prescribed drug in the world for all of the benefits for your health that it has,” Todd Buckingham, PhD, a professor of exercise science at Grand Valley State University, tells Runner’s World. “Exercise really is medicine, and running is medicine,” he says.If you’re wondering about the effects of your daily dose, here’s a list of all the benefits that you can gain when you make running every day a regular habit. Let this list give you the drive to keep putting in those miles.1. Better Heart HealthAs a new runner, those first couple of runs can be brutal. Your breathing is labored, and your heart feels like it’s pounding against your chest. Meanwhile, your legs are barely moving. But a couple of weeks into your training, breathing becomes easier, and that heart-pounding sensation lessens as your feet pick up the pace.If you wear a fitness tracker, you may even notice a dip in your heart rate while you hit the same paces. “The heart is a muscle, just like every other muscle in the body. The more that you train it, the stronger it’s going to get,” Buckingham says.He explains that running every day strengthens cardiac muscle tissue and causes the heart’s left ventricle—the chamber that forces oxygenated blood into the aorta (the artery that carries blood from the heart to the body)—to increase in size. “There’s more space in that left ventricle to fill up with blood,” he says. “So not only is there more blood to be pumped out, but the heart is also stronger, so it can pump more blood out with each beat.”As a result, your heart doesn’t have to work as hard to deliver oxygenated blood to your muscles. This is a boon for both your daily runs and your overall heart health, and you benefit the most when you run consistently.2. Stronger MusclesWhen you pound the pavement, treadmill, or trail day after day, your muscles—specifically, the glutes, quadriceps, hamstrings, soleus, and gastrocnemius (those last two are your calf muscles)—respond to the stimulus being imposed upon them.“The muscle is damaged, and that means that the body has to repair the damaged muscles so that the same run doesn’t have the same effect that it did last time,” Buckingham says. Essentially, the muscles are rebuilt bigger and stronger.But unless your workouts consist of sprint intervals paired with resistance training, don’t expect to bulk up. Running long distances (even just a mile or more) at a sustainable pace primarily engages type I muscle fibers, which are good at resisting fatigue but are smaller in size. (Type II fibers, which are quick to fatigue but generate more force and power, are generally responsible for visible muscle growth.)“You might see a little bit of increase in [muscle] size with distance running, but it’s not going to be as pronounced. Type I muscle fibers can get bigger, but not to the same extent as those type II fibers,” Buckingham explains.Just keep in mind that building type II fibers—via those hill runs and sprints, along with strength workouts—can not only help build and maintain healthy muscle but can also improve your running performance.3. More Resilient Tendons and LigamentsYour body’s connective tissues, namely the tendons and ligaments, will also adapt to withstand the daily stress of running—probably even more than our muscles, just not as quickly. “The reason for this is because tendons and ligaments don’t have the same amount of blood flow that the muscles do, so it takes them longer to adapt,” Buckingham says.While your muscles may begin to change a couple of weeks into a daily running streak, it could take three to four months for your tendons and ligaments to catch up, he says.To prevent overuse injuries, it’s best to begin a streak with a conservative goal (a mile a day is a good place to start, says Buckingham) and gradually build upon that foundation. The general rule of thumb is to increase your mileage by no more than 10 percent each week, but Buckingham notes that this can vary depending on the athlete, their experience, and their mileage. If you’re new to running, you might want to make it even more conservative than that.Avoiding long breaks is helpful for your connective tissues, says RRCA-certified run coach and physical therapist assistant Alison Staples. “Tendons need to be loaded consistently to learn how to accept the impact of running,” she says. “Running sporadically often leads to injury because we haven’t practiced loading our tendons enough before tacking on mileage.”4. More Efficient Nervous SystemBuckingham compares the nervous system to a maze. “The first time you do it, you’re going to take a lot of wrong turns and end up doing extra work,” he says. But over time, you learn the most direct path from point A to point B.Similarly, the first few times you go out for a run, your neuromuscular connections will fire inefficiently, as one nerve fiber connects to multiple muscle fibers. Muscle fibers that don’t need to contract will be stimulated, resulting in wasted energy. However, with consistent running, your nervous system eventually adapts and learns the optimal route so everything works more efficiently—and you sidestep aches and pains.Research backs this up, too, suggesting that consistent running trains your central nervous system to adapt to the demands of running and become more efficient over time.“The more you run, the more efficient you’re going to become [at running] because you’re teaching the body which muscle fibers should be firing and which shouldn’t,” Buckingham says.5. Sharper MindRunning boosts circulation, increasing blood flow to the brain and delivering the nutrients you need to think and function. But exercise has also been shown to promote the expression of brain-derived neurotrophic factor (BDNF), a protein important to brain function and memory.“BDNF actually increases the brain’s ability to form new synapses, or connections, in the brain,” Buckingham says. “This helps with learning and memory. It makes it easier to absorb information and form long-term memories. The more BDNF that somebody has, the more the memory improves in function and capacity.”According to Buckingham, the effects of increased BDNF are cumulative, but you may feel mentally sharper and more alert after just a few days of running. You might even experience the effects during a run, when you reach a meditative state or problem-solve an issue that’s been bothering you.6. Improved Mental HealthBDNF can also help mitigate stress. “It doesn’t decrease stress hormones, but it does decrease the number of stress receptors,” Buckingham says. “And this could minimize the effect of those stress hormones in the brain.”Add that to an exercise-induced endorphin release, and you have a recipe for an improved mood. In fact, research shows just 10 minutes of running can enhance your happiness.When Staples does a run streak, she says she can notice the difference in her headspace: “Running a mile every day has been a huge boost in my mood and motivation,” she explains. “My one mile a day is my own form of non-negotiable self-care.”7. Better Body AwarenessSpending more time on your feet can raise your body awareness, particularly to how your body is responding to running every day as opposed to every other day, five days a week, or only on weekends.Regardless of your experience level, it is possible to take on too much too soon. Low energy, a high resting heart rate, and slower run paces are all indications you could be clocking too many miles per day. Keep in mind that when you change your running routine, some soreness is to be expected as your body begins to adapt to running every day (see above on the advantages to your nervous system). However, you should be able to press along the muscles in your back and legs with virtually no discomfort.Also, overtraining symptoms can vary, but fatigue, sleep disruption, decreased motivation, poor mood, and overuse injuries are common symptoms. Bad runs happen, but taking time to reflect and figure out what went wrong—and most importantly, taking a few days off when you need it—can help you stick with your running routine in the long term. Don’t push through pain to maintain a daily habit.John Vasudevan, M.D. is an associate professor at the University of Pennsylvania. He is board-certified in Physical Medicine & Rehabilitation and Sports Medicine. He is a Team Physician for UPenn Athletics and medical director of the Broad Street Run and Philadelphia Distance Run, and previously for the Rock 'n' Roll Half-Marathon and Tri-Rock Triathlon in Philadelphia. He is a director of the running and endurance Sports Medicine Program at Penn Medicine. Dr. Vasudevan provides non-operative management of musculoskeletal conditions affecting athletes and active individuals of all levels, and combines injury rehabilitation with injury prevention. He utilizes a variety of ultrasound-guided procedures and regenerative approaches such as platelet-rich plasma and percutaneous ultrasonic tenotomy. He sees patients at the Penn Medicine and the Philadelphia Veterans Administration hospital. Dr. Vasudevan attended medical school at the University of Wisconsin School of Medicine and Public Health in Madison. After his Transitional Year in Tucson, Arizona, he went to residency in PM&R at Thomas Jefferson University in Philadelphia and onwards to Stanford University for his fellowship in Sports Medicine. He has been in practice at the University of Pennsylvania since 2012.