In the era of smartwatches, tracking step counts has become incredibly convenient. However, existing physical activity guidelines do not prescribe specific step counts for optimal health.

A recent investigation conducted by researchers at Brigham and Women’s Hospital, a key member of Mass General Brigham, indicates that both time-based and step-based exercise goals are equally linked to reduced risks of premature mortality and cardiovascular disease. Hence, the choice between a time or step goal may not be crucial; instead, selecting a goal that aligns with individual preferences is paramount. These findings have been published in JAMA Internal Medicine (1^✔ ✔Trusted Source
Research finds step-count and time are equally valid in reducing health risks

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Exploring Step-Based vs. Time-Based Exercise Goals

Regular physical activity diminishes the likelihood of developing chronic ailments and infections while enhancing lifespan. The latest U.S. guidelines, updated in 2018, advocate for adults to partake in a minimum of 150 minutes of moderate to vigorous physical activity weekly (e.g., brisk walking) or 75 minutes of vigorous activity (e.g., jogging).

Historically, much of the evidence supporting health benefits stemmed from studies reliant on self-reported physical activity. However, with the widespread use of wearables, step counts have emerged as a popular metric in numerous fitness tracking platforms. Now, in light of this shift, researchers are investigating the comparative effectiveness of time-based versus step-based exercise goals.

“We recognized that existing physical activity guidelines focus primarily on activity duration and intensity but lack step-based recommendations,” said lead author Rikuta Hamaya, MD, PhD, MS, a researcher in the Division of Preventive Medicine at BWH. “With more people using smartwatches to measure their steps and overall health, we saw the importance of ascertaining how step-based measurements compare to time-based targets in their association with health outcomes – is one better than the other?”

For this study, investigators collected data from 14,399 women who participated in the Women’s Health Study, and who were healthy (free from cardiovascular disease and cancer). Between 2011 and 2015, participants aged 62 years and older were asked to wear research grade wearables for seven consecutive days to record their physical activity levels, only removing the devices for sleep or water-related activities. Throughout the study period, annual questionnaires were administered to ascertain health outcomes of interest, in particular, death from any cause and cardiovascular disease. Investigators followed up with participants through the end of 2022.

The Impact of Physical Activity Metrics on Health Outcomes

At the time of device wear, researchers found that participants engaged in a median of 62 minutes of moderate-to-vigorous intensity physical activity per week and accumulated a median of 5,183 steps per day. During a median follow-up of 9 years, approximately 9% of participants had passed and roughly 4% developed cardiovascular disease. Higher levels of physical activity (whether assessed as step counts or time in moderate-to-vigorous activity) were associated with large risk reductions in death or cardiovascular disease – the most active quarter of women had 30-40% risk reductions compared with the least active quarter. And, individuals in the top three quartiles of physical activity outlived those in the bottom quartile by an average of 2.22 and 2.36 months respectively, based on time and step-based measurements, at nine years of follow-up. This survival advantage persisted regardless of differences in body mass index (BMI).

While both metrics are useful in portraying health status, Hamaya explained that each has its advantages and downsides. For one, step counts may not account for differences in fitness levels. For example, if a 20-year-old and 80-year-old both walk for 30 minutes at moderate intensity, their step counts may differ significantly. Conversely, steps are straightforward to measure and less subject to interpretation compared to exercise intensity. Additionally, steps capture even sporadic movements of everyday life, not just exercise, and these kinds of daily life activities likely are those carried out by older individuals.

“For some, especially for younger individuals, exercise may involve activities like tennis, soccer, walking, or jogging, all of which can be easily tracked with steps. However, for others, it may consist of bike rides or swimming, where monitoring the duration of exercise is simpler. That’s why it’s important for physical activity guidelines to offer multiple ways to reach goals. Movement looks different for everyone, and nearly all forms of movement are beneficial to our health,” said Hamaya.

Reference:

1. Research finds step-count and time are equally valid in reducing health risks – (https://news.harvard.edu/gazette/story/2024/05/should-we-measure-exercise-in-minutes-or-steps/)

Source-Medindia