- Physical activity is a key component of a healthy lifestyle.
- One way to measure physical activity is to look at the number of steps a person takes each day.
- New research suggests that people who take 7,000 steps or more each day may have a lower mortality risk than those who take fewer steps.
Lifestyle recommendations from public health officials continually change as new data emerges. Still, the benefits of certain activities are well documented.
Research confirms that being physically active has various health benefits, including reducing the risk of mortality. A recent study published in JAMAfound that taking at least 7,000 steps a day may decrease this risk by 50–70%.
The benefits of physical activity
As the Centers for Disease Control and Prevention (CDC) note, being physically active benefits physical and mental health. Regular physical activity can:
- help keep thinking and learning skills sharp
- improve sleep quality
- strengthen bones and muscles
- reduce the risks of depression and anxiety
- decrease the risks of cardiovascular disease and type 2 diabetes
- reduce the risks of certain cancers
Specific recommendations about physical activity vary, and scientists continue to collect data on the topic. One area of interest concerns the health benefits of taking a certain number of steps each day.
For example, a study published in 2020 found that the associated mortality risk for people who took 8,000 steps a day was much lower than the risk for people who took 4,000 steps a day.
Another study, from the same year, found that a higher step count for 70-year-olds was associated with lower incidence rates of diabetes. As more data emerge, researchers seek to adapt physical exercise guidelines.
This most recent study contributes to mounting evidence of the importance of increased physical activity.
Increased step count and decreased mortality
The research was part of the Coronary Artery Risk Development in Young Adults prospective cohort study, which recruited participants from four states in the United States.
In this secondary study, the team recruited a subset of 2,110 participants between 38 and 50 years old, 1,205 of whom were women and 888 of whom were Black.
The authors write, “Our study extends research by examining a prospective cohort of middle-aged men and women of Black and white race and the association of steps with premature mortality, considered deaths earlier than U.S. population mean life expectancy.”
Between 2005 and 2006, the participants wore an accelerometer for 7 days to measure their average step counts. They only removed the device during sleep an any water-based activities. The researchers followed up with the participants an average of 10.8 years later. During the follow-up period, 72 (3.4%) of the participants had died.
The team classified the daily step counts into three categories:
- Low: Fewer than 7,000 steps per day
- Moderate: 7,000–9,999 steps per day
- High: 10,000 steps or more per day
In addition to calculating the participants’ average daily step counts, the researchers also accounted for their average step intensity. They measured participants’ highest number of steps per minute in any 30 minutes. They also kept track of the amount of time each day participants were taking 100 steps a minute or more.
Also, the team took into account several factors related to health, including:
- a history of smoking
- body mass index
- cholesterol and fasting blood glucose levels
- alcohol intake
- blood pressure
- any use of medications for high blood pressure, high cholesterol, or diabetes
- cardiovascular disease
Using multivariable adjusted Cox proportional hazards models, the researchers calculated the mortality risk of the participants.
The team found that participants who took 7,000 steps a day or more had approximately 50–70% lower mortality risks than those who took fewer than 7,000 steps a day. However, taking more than 10,000 steps a day was not associated with a greater reduction in mortality risk.
The analysis did not show an association between step intensity and mortality risk, suggesting that the number of steps matters more than their intensity. But the participants who had the greatest step intensity also tended to take the highest number of steps, making it difficult to draw a firm conclusion about the effects of step intensity, the researchers note.
Study strengths and limitations
This study provides more insight into the benefits of increased physical activity via step count among middle-aged adults.
In an interview with Medical News Today, Prof. Juan Franco, a primary care expert and the editor-in-chief of BMJ Evidence-Based Medicine, identified the following strengths of the study:
“The study identified that participants with a higher step count per day had lower mortality rates than those with a lower step count. They considered other risk-important factors associated with death and had a long follow-up (over 10 years), which is a big strength of the study. Moreover, this fits with previous research that shows that people who do more physical activity have a lower incidence of cardiovascular disease, cancer, and other diseases.”
While the analysis gives important insights, the lack of findings about an association between step intensity and mortality warrants further research, the study authors note.
They also acknowledged the following limitations:
- The study could not establish causality, due to the nature of the research.
- There was a risk of errors in data collection, analysis, and other health factors that the researchers may not have accounted for.
- The researchers were unable to accurately measure mortality risk for participants taking 12,000 steps a day or more.
- Because it was part of a longer study, there was risk of selection bias.
- Due to the low death rate, the team could not thoroughly explore specific causes of mortality among groups of different races and sexes.
- The analysis of the accelerometer may not have captured periods of walking that lasted under 1 minute.
- The intensity metrics might not reflect step intensity and patterns that are typical in everyday situations.
- The accelerometer in the study differs from devices that people commonly use to count their steps, indicating that the results are not fully applicable to all other devices.
It is also critical to consider other health factors, Prof. Franco told MNT:
“People with a higher daily step count may be healthier by other unmeasured factors in their lifestyle, which might have also contributed to this difference. That means that step count is part of a bigger picture of differences in a physically active lifestyle that can explain what makes people have lower mortality. This is important, since we do not want to give the general public the impression that getting a Fitbit and achieving more than 7,000 steps, in itself, will lower their mortality.”
Recommendations moving forward
Overall, the study does provide evidence that an increased step count is associated with a reduced mortality rate. This is helpful, and future studies may investigate other potential health benefits of an increased step count.
Dr. Nicole L. Spartano, of the Boston University School of Medicine, emphasized in an invited commentary article that further research should focus on areas other than mortality risk.
“Mortality is not the only matter of concern, when it comes to developing a guideline for health promotion, and we also need to expand our study beyond cardiovascular and metabolic diseases. It is critical to focus our investigations on other health outcomes, such as quality of life, years of healthy life, mobility, mental health, and dementia and Alzheimer disease.”
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