Chapter 1: The Power of Walking

In today's fast-paced world, many individuals become overly enthusiastic about their fitness routines. One such individual is I-Min Lee, an avid walker who prefers walking over driving and incorporates running into her routine. She tracks her daily steps with a pedometer, demonstrating how even small daily activities can accumulate to a substantial step count. "This helps me see how the little things we do each day can add up," says the 59-year-old. Lee acknowledges her unique motivation, noting, "Would you trust a researcher who doesn't engage in what they study?"

As an epidemiologist at Brigham and Women's Hospital in Massachusetts, Lee investigates how physical activity can enhance health and prevent chronic diseases. Her recent research focuses on the daily step requirements for older adults to enjoy substantial health benefits.

Along with other studies published this year, her findings highlight the remarkable advantages of merely participating in an activity that humans have practiced for millennia. Notably, Lee's research challenges the long-standing belief that a daily goal of 10,000 steps is essential for health—a target that originated from 1960s Japanese pedometers called manpo-kei, or "10,000 steps meter."

Lee questioned whether this figure truly represented a magical threshold for health.

Determining the correct step count is a complex task. Most research on the long-term benefits of physical activity relies on self-reported data, which can often be unreliable. To address this, Lee and her colleagues analyzed data from 16,741 women aged 62 to 101, who wore accelerometers over a week-long period as part of a multi-year health study.

Throughout a four-year follow-up, 504 of the participants passed away. Remarkably, over half of these individuals—275 women—averaged only 2,700 steps per day during the testing phase. Those who achieved a slightly higher daily count of 4,400 steps experienced a 41% lower risk of premature death. The risk continued to decline with increased steps, peaking at 7,500 steps per day, after which it plateaued.

Interestingly, the pace at which participants walked—slow or fast—did not significantly influence outcomes.

"For many seniors or those who are less active, aiming for 10,000 steps can be intimidating," Lee explains via email. Based on her findings, she recommends that those who are inactive should strive to increase their daily step count modestly—suggesting an additional 2,000 steps can greatly enhance health. Lee emphasizes that these steps do not have to be viewed as formal exercise; simple activities, like parking further away from store entrances, can suffice.

The results of this study were published in JAMA Internal Medicine on May 29.

Oh, and men, take note: Walking is just as beneficial for you.

"I believe these results are applicable to men of similar ages," Lee asserts, "since previous studies, primarily based on self-reported activity, have shown no significant differences in the benefits of physical activity between genders."

She also believes these findings hold true for individuals in their fifties.

Though Lee's study is groundbreaking, it does not definitively establish causation. While it's possible that walking enhances health, it could also be that healthier individuals tend to walk more. Nonetheless, Lee and her team argue that the evidence suggests a likely causal relationship, particularly as they excluded participants with conditions like heart disease, cancer, and diabetes, as well as those who rated their health poorly.

"This study significantly contributes to the existing literature on moderate physical activity," remarks Tom Yates, a researcher at the University of Leicester who specializes in the health implications of physical exercise.

"I anticipate a shift away from the 'more is better' mindset that has dominated public health discussions, particularly concerning overall mortality," Yates, who was not involved in Lee's research, adds. "Conversely, there’s growing evidence indicating that excessive exercise can harm heart health and lead to long-term damage."

In May, Yates and his team discovered something intriguing about walking that contrasted with Lee's findings: individuals who identified as brisk walkers tend to live significantly longer, according to a study published in Mayo Clinic Proceedings. This research involved 474,919 participants over seven years, and while it relied on self-reported data, the outcomes remained consistent across all body mass categories.

"Fast walkers enjoy longer life expectancy, regardless of their obesity status," Yates explains.

While this study establishes a correlation, it does not confirm causation. Healthier individuals may simply be more inclined to walk briskly. Yates is currently engaged in research that will replicate Lee's methodology using objective measurement tools.

The U.S. Centers for Disease Control and Prevention defines brisk walking as the ability to converse but not sing while walking, typically about 100 steps per minute for most people. According to Lee's research, this translates to roughly 44 minutes of walking daily to achieve the health benefits associated with 4,400 steps.

Federal health guidelines recommend that adults engage in at least 2.5 hours of moderate physical activity each week (approximately 21 minutes per day) or partake in 75 minutes of vigorous exercise, alongside muscle-strengthening activities. Children and teenagers should aim for at least one hour of daily moderate-to-vigorous physical activity. Such activities enhance mood, energy levels, sleep quality, cognitive function, and various physical health metrics, as reported by the American Heart Association.

Unfortunately, a large majority of Americans, both young and old, fail to meet these minimum activity standards.

Acknowledging this issue, health officials are increasingly promoting physical activity as a more approachable alternative to rigorous exercise. In fact, in the latest federal guidelines from the Department of Health & Human Services, the term "exercise" appears only once, while "physical activity" is mentioned 40 times.

Moreover, with research indicating that inactivity among youth can create lasting habits, the government now emphasizes the importance of walking for children as well. As video games replace outdoor activities and physical education classes are eliminated, inactivity has become the norm, contributing to rising obesity rates. Nearly half of adolescents aged 12 to 21 are not sufficiently active, according to the Surgeon General's report, and by high school, only one in four students meets the recommended activity levels.

The Surgeon General has a message for youth and their guardians:

"Physical activity doesn't need to be strenuous to provide benefits. A moderate amount of daily activity is recommended for individuals of all ages. This can include longer sessions of moderate-intensity activities, like brisk walking for 30 minutes, or shorter bursts of more intense exercises, such as jogging or playing basketball for 15-20 minutes."

The Surgeon General's "Step it Up!" initiative advocates for schools to establish policies that encourage walking to school and throughout the day.

While studies show that a sedentary lifestyle during youth can set a lifelong pattern, research also indicates that it’s never too late to become active. Sedentary individuals who start exercising in midlife can reduce their mortality risk by 30 to 35%.

Walking and other forms of moderate physical activity not only benefit the body but also enhance cognitive function, as numerous studies have demonstrated.

Columbia University researcher Yaakov Stern conducted an experiment with 132 participants, aged 20 to 67, who were not previously active. They were divided into two groups: one engaged in stretching and toning for six months, while the other participated in moderate aerobic exercise four times weekly, including walking on a treadmill and cycling. Afterward, all participants underwent tests measuring executive function, such as attention, organization, and goal achievement.

"The individuals who exercised performed as if they were about a decade younger at age 40 and two decades younger at age 60," Stern reports. These findings were presented in January in the journal Neurology.

While scientists are still uncovering the precise mechanisms by which physical activity benefits the brain, it has been shown to elevate mood, reduce stress, and improve sleep—factors that are known to enhance cognitive abilities. Exercise triggers the release of chemicals in the brain that support cell health and promote the growth of new blood vessels, according to Harvard Medical School.

A review of 14 controlled trials examining the impact of aerobic exercise on the hippocampus—a brain region critical for verbal memory and learning—revealed "significant positive effects on left hippocampal volume" compared to non-exercisers.

Moderate physical activity can also help counteract depression and boost happiness.

Research published in JAMA Psychiatry in January utilized accelerometers to measure activity alongside DNA analysis. "Using genetic data, we found that higher physical activity levels may causally reduce depression risk," states Karmel Choi, lead author and researcher at Massachusetts General Hospital. "Even small amounts of activity seem better than none."

This is not to undermine the value of intense exercise. The health benefits of vigorous physical activity, even short yet intense workouts or challenging weightlifting sessions lasting just 13 minutes, are well-documented. If that's your preference, continue with it, but be cautious not to overdo it. As the CDC advises: "Greater amounts of physical activity are generally more beneficial, but excessive activity can lead to injuries, menstrual irregularities, and weakened bones."

If the term "exercise" makes you anxious, you can skip the high-tech gear, expensive shoes, and unused gym memberships. Instead, why not simply take a walk?

I'm the author of Make Sleep Your Superpower: A Guide to Greater Health, Happiness & Productivity (available in paperback or Kindle). Your support allows me to continue my health writing. You can subscribe for updates on my publications on Medium, or join Medium to support my work directly and gain access to all stories. Connect with me on YouTube, Instagram, Twitter, and LinkedIn. — Rob

The first video, "Suit Case Walk," provides insights into the benefits of walking and how to incorporate it into your daily routine.

The second video, "Case Study 4 - Walking (Anterior-Posterior)," explores walking's impact on health from a scientific perspective.