- Daily step counts have become a popular way to track physical activity levels.
- A recent study sought to identify the benefits of walking for longer periods in participants who were walking 8,000 steps a day or less.
- The study found that walking for longer stretches was associated with a lower risk of death and cardiovascular disease than walking for shorter stretches.
Technology is readily available to help the everyday person keep track of the number of steps they take each day. However, a recent study explored whether the length of time participants walked affected the outcomes of cardiovascular disease and all-cause mortality.
At the end of the study, people who walked for longer stretches of time had a lower risk for all-cause mortality and cardiovascular disease than those who walked for shorter lengths. These results suggest that how one reaches a step count can also affect Health outcomes.
The study and a related editorial were published in the Annals of Internal Medicine.
Participants in this prospective cohort study were part of the UK Biobank and were taking 8,000 steps a day or fewer. After recruiting participants, researchers conducted physical exams and collected some data via questionnaires.
Participants wore an accelerometer to track steps for up to one week. Researchers then focused on participants who were taking an average of less than 8,000 steps daily. They further excluded participants based on factors like missing covariate data and already having cardiovascular disease. The final analytic sample had 33,560 participants.
Researchers divided walking bouts into four ranges: less than five minutes, five to less than ten minutes, ten to less than 15 minutes, and 15 minutes or more. They then placed participants into these groups based on which walking bout length most of their daily step counts came from.
About 43% of participants fell into the less than five-minute bout group, while only 8% were in the fifteen minutes or longer group. The five-minute walking bout participants were more likely to move less and have overweight or obesity.
The average follow-up time with participants was just under eight years. Researchers kept track of mortality and incidences of cardiovascular disease. The definition of cardiovascular disease excluded lymph diseases and high blood pressure. 735 participants died, and 3,119 experienced cardiovascular disease events.
Covariates for this research included components like smoking, age, total daily steps, and the amount of time participants remained sedentary. Researchers conducted additional sensitivity analyses to “to minimize bias attributable to reverse causation.” These analyses included excluding participants who experienced an event within the first five years and accounting for factors like daily calories.
The results supported that walking for longer periods held the greatest benefit. People who got their steps from five-minute walking bouts had the highest cumulative all-cause mortality and cardiovascular disease risk. In contrast, the group with the longest walking bouts had the lowest risk.
When excluding events that occurred in the first five years, researchers found that the results were similar but more minimized.
Researchers also found that the greatest benefit was for people who were taking fewer than 5,000 steps daily.
Study author Borja Del Pozo Cruz, Senior Researcher and Associate Professor at the Faculty of Medicine, Health, and Sports, Universidad Europea de Madrid, Spain, highlighted the main findings of the research to Medical News Today:
“Our study found that among adults taking fewer than 8,000 daily steps, those who accumulated most of their steps in longer, sustained bouts—particularly 10 minutes or more—had substantially lower risks of cardiovascular disease and premature death than those whose steps were mainly taken in very short bouts.”
“This association was especially pronounced among the most sedentary individuals, suggesting that how people accumulate their steps may be particularly important for those starting from very low levels of activity,” he said.
Since it’s observational, this study can’t prove that walking longer causes specific outcomes.
The authors mention that there could be factors like remaining uncertainties and inaccuracies in how participants’ Health or behaviors were recorded due to changes between the initial assessment and subsequent data collection points, which occurred at separate times.
The researchers only collected data on step count for up to seven consecutive days, and this occurred several years after individuals were enrolled in the UK Biobank. This step count data timeframe was fairly short and might not truly show participants’ long-term habits. Because covariates were assessed only at the start of the study, it is likely that some of this information may have varied for participants over time
The authors recognize that individuals who walk for shorter durations may have undisclosed health limitations, potentially leading to a greater risk of certain outcomes. Conversely, those who walk longer may engage in muscle-strengthening activities more frequently, which may introduce unaccounted variables, as accelerometers usually do not track these activities.
Finally, the researchers note that “differences in walking intensity across bout length groups may still contribute to the observed associations.”
The UK Biobank also has noted limitations based on the study population and how data is collected. The current study relied on what participants from the UK Biobank responded to their recruitment efforts, so the sample could be limited as well. However, the researchers do not think that this impacted their results.
Some data was participant-reported, such as the use of medications for cardiovascular disease. This self-reporting of medication for cardiovascular disease also meant that researchers had trouble taking into account the effects of specific medications.
Moreover, there remains a potential risk of confusion due to inaccuracies in measurements and the chance of reverse causation.
What the editorial pointed out
The related editorial also noted limitations of the research. For one, it criticizes the age of the included participants and how the study only focused on individuals taking less than 8,000 steps. The study notes that the average age of participants was 62 years old.
The editorial further notes that the study defined sedentary as taking fewer than 5,000 steps daily, while other recent discussions suggest fewer steps equate to sedentary. It also calls out the limited clarity in the “criteria for ’bouts’ of activity,” and says there should be further examination of participants’ very similar lipid profiles.
Finally, it suggests that it may have been helpful to adjust outcomes based on obesity and therapies.
Christopher Berg, MD, board-certified cardiologist at MemorialCare Heart and Vascular Institute at Orange Coast Medical Center in Fountain Valley, CA, who was not involved in the study, noted the following:
“If this research can be confirmed with a randomized, prospective study, we may find a causative link between length of activity and cardiovascular outcomes.”
“For now, it seems accurate to say that to our best estimation, those that have sustained periods of activity greater than 10 minutes at a time have less cardiovascular disease and better survival than those that have no sustained activity. Whether it’s because of this activity or any other myriad confounders remains to be seen,” he told MNT.
The research highlights a potentially simple intervention that could help improve outcomes of cardiovascular health. Pozo noted that “Clinicians and public health professionals might use this evidence to help inactive adults gradually transition from brief, incidental movements toward more sustained walking patterns that can be integrated into daily routines.”
The editorial also suggests that the measurement of time spent walking could be incorporated into the current discussion about daily step goals. And with future research confirming, it may even lead to changes in physical activity guidelines.
Patrick Kee, a cardiologist, Vital Heart & Vein, who was also not involved in the study, emphasized:
“If you are not highly active, it is advisable to increase the duration of your daily steps by incorporating continuous walks of 10-15 minutes or longer. This simple modification in your walking pattern, even without a substantial increase in your total step count, can significantly enhance your cardiovascular Health.”
“Clinicians should not only encourage an increase in total steps but also recommend walking sessions of 10 to 15 minutes or longer. This modest change in walking pattern can yield cardiovascular health benefits beyond simply increasing total steps,” he added
