We all know that exercise is good for your health. But, the other side of this equation is often overlooked: a lack of exercise, or physical inactivity, is a major health risk.
One of the first landmark studies that recognized this fact was conducted more than 70 years ago. In the 1950s, epidemiologist Jeremy Morris studied more than 30,000 employees of the London transportation system. He observed that bus drivers who sat all day behind the wheel had a higher risk of developing coronary heart disease than conductors who walked up and down the aisles and stairs collecting fares. This natural experiment fundamentally changed how we think about activity for the prevention of heart disease.
Since then, the evidence to support physical activity for better cardiovascular health has grown substantially. Regular physical activity lowers the risk of heart disease, stroke, and diabetes, and has been linked to longer lives and healthier aging. These data are strong enough that the American Heart Association names physical activity one of the eight key things you can do for better cardiovascular health. That group, and the federal physical activity guidelines, both recommend at least 150 minutes each week of moderate intensity exercise, along with at least two days per week of muscle-strengthening activities.
Despite the accumulation of decades of evidence, physical inactivity remains one of our greatest public-health challenges. According to the American Heart Association’s 2026 Heart Disease and Stroke Statistics report, which my colleagues and I recently published in Circulation, fewer than half of U.S. adults achieve the recommended amount of aerobic activity, and only one in five achieve recommended targets for combining aerobic and muscle-strength training activities.
As we have modernized our lives and jobs with screens and desks, the “bus driver” problem that Morris identified several decades ago has become even more common. Physical inactivity now contributes to millions of deaths worldwide each year.
So why don’t we, as clinicians, approach physical inactivity the way we do other major cardiovascular risk factors?
When someone has high blood pressure or high cholesterol or is at high cardiovascular risk, we identify it and develop a treatment plan. Although physical inactivity is rarely addressed in this way, there are a few select conditions where we in fact do prescribe exercise. For people recovering from a heart attack or for anyone who has recently had a coronary stent placement, bypass surgery, or heart valve surgery, guidelines recommend a supervised exercise program called cardiac rehabilitation. However, even after a cardiac event, less than one-third of patients participate, despite strong evidence that cardiac rehabilitation programs reduce hospitalizations and risk of dying.
The value of structured exercise extends well beyond heart disease. A recent randomized trial published in the New England Journal of Medicine found that patients with colon cancer who participated in a three-year structured exercise program were 30% more likely to live longer and without cancer compared with the group that only received advice to exercise.
But why do we wait until after someone develops heart disease, or cancer, to prescribe exercise as part of the treatment plan? Why aren’t we investing in the tools and programs to help people become more active years or even decades earlier, before disease develops? Exercise, after all, can prevent disease.
Today, we have the opportunity to change our collective approach to physical inactivity. Millions of people now have smartphones, watches, and digital tools to track daily movement. These wearable devices have the potential to help us measure, modify, and monitor our movement behaviors. But as health monitors have gotten more popular, the sheer volume of health advice for how to use them has increased exponentially. As a result, it can sometimes be overwhelming to know where to start.
Step counts are an intuitive, universally understood, and easily tracked place to begin. They have the potential to be a powerful public-health tool. Moreover, walking is an accessible form of activity that doesn’t require equipment and can be a great place to start an exercise program.
So, what’s a good goal for daily steps? Most people may think that 10,000 steps a day is the right target. But this number originated from a marketing campaign—not from science—because it was easy to remember. Ten thousand steps per day was never based on hard evidence. In fact, when researchers examined daily step counts in large population studies, the health benefits for walking begin well before 10,000 steps.
Even more encouraging is that people who moved from very low levels of activity to modest activity had significant gains in health outcomes. This is particularly important when we think about defining achievable goals to set people up for success rather than discourage them. As a preventive cardiologist, I focus on the message that every step, and every movement, matters. Even parking a little farther away, walking while doing a video call, or taking the stairs instead of the escalator add up.
To address the 10,000 steps misperception, we should retire that arbitrary target as a one-size-fits-all prescription and replace it with a message grounded in evidence: start where you are, and do a little more. If you're currently taking 3,000 steps a day, aim for 4,000. If you're at 5,000, try for 6,000.
Exercise isn't only good for improving heart health. Regular walking is linked to better sleep, improved mood, healthier brain aging, and lower risk of dementia.
At the same time, we cannot ignore that the choice to exercise is not solely an individual one. It is also shaped by a person’s surroundings. In order to be able to make walking an exercise habit, there need to be safe sidewalks, neighborhood parks, and green spaces in the communities in which we live and work. We must prioritize policies that enable and support a healthy environment and healthy activity choices.
Perhaps our greatest missed opportunity comes from not starting earlier. By adolescence, physical inactivity is already common, with only 20-26% of teens reporting meeting physical activity guidelines. This means by adulthood, we are already working backwards.
The science is remarkably reassuring: you don’t need to become an athlete to improve your health. Spending more minutes walking today can improve the health of your heart and your brain for years to come. The goal is not to reach an arbitrary number. It is to keep moving.