Steps or minutes: what is the best way to measure an exercise?

With the popularity of using smartwatches during physical activity, it has become easier to monitor the amount of physical exercise performed per day, whether by steps or by minutes . However, a new study sought to answer which of these is the best way to set physical activity goals to reduce the risk of cardiovascular disease and early death.

The conclusion of BWH researchers (Brigham and Women's Hospital) is that Both forms offer health benefits . Additionally, the study suggests that choosing a time or steps goal may not be as important as setting a goal that aligns with personal preferences and goals. The findings were published Monday (20), in the scientific journal JAMA Internal Medicine.

Current WHO (World Health Organization) guidelines recommend practicing 150 to 300 minutes of moderate physical activity per week for adults and 60 minutes per week for children. Furthermore, recent studies have shown that, to stay healthy, a person must reach the mark of 10,000 steps daily, a value that can represent a 39% lower risk of death and cardiovascular diseases .

Given this, researchers sought to understand which type of daily physical exercise goal could be most beneficial for health. “With more people using smartwatches to measure their steps and overall health, we’ve seen the importance of looking at how step-based measurements compare to time-based goals in their association with health outcomes – is one better than the other?” , pondered Rikuta Hamaya, researcher at the Division of Preventive Medicine at BWH.

How was the study carried out?

To answer their questions, researchers collected data from 14,399 women who participated in the Women's Health Study and who were healthy, that is, they did not have cardiovascular disease or cancer.

Between 2011 and 2015, researchers asked participants aged 62 and over to wear devices such as smartwatches for seven consecutive days to record their physical activity levels. They were only able to remove the device when sleeping or to carry out activities that had contact with water.

Throughout the study, annual questionnaires were administered to assess the health of the participants, mainly the development of cardiovascular diseases or death from any cause. Participants were evaluated until the end of 2022.

What were the results found?

The researchers found that while using the device, participants engaged in an average of 62 minutes of moderate to vigorous intensity physical activity per week and accumulated an average of 5,183 steps per day.

During follow-up, around 4% developed cardiovascular disease. According to the study, higher levels of physical activity were associated the greatest reduction in the risk of death or cardiovascular disease . The most active women had a 30% to 40% reduction in cardiovascular health risk compared to the least active women.

Additionally, participants with the best physical activity time and step count lived 2.22 and 2.36 months longer than the least active women, respectively. This survival advantage remained the same regardless of differences in BMI (Body Mass Index).

Therefore, the researchers concluded that both metrics are useful in portraying a person's health status and establish physical activity goals. However, for the study authors, each of them has advantages and disadvantages.

According to researchers, step counts may not take into account differences in fitness levels. For example, if a 20-year-old and an 80-year-old walk for 30 minutes at a moderate intensity, their step counts may differ significantly.

On the other hand, steps are simple to measure and less subject to different interpretations compared to the intensity of the exercise, in addition to being able to be captured with everyday movements.

“For some, especially younger people, exercise may involve activities such as tennis, football, walking or running, which can be easily tracked with steps. However, for others, it may consist of bike rides or swimming, where monitoring exercise duration is simpler. That's why it's important that physical activity guidelines offer multiple ways to achieve goals. Movement looks different for everyone and almost all forms of movement are beneficial to our health,” says Hamaya.

The study authors also note that the work incorporates only a single assessment of physical activity metrics based on times and steps. Furthermore, the majority of women included in the study were white and of higher socioeconomic status.

It is also worth remembering that the study was only observational, that is, it only indicates a relationship and not proof. Therefore, the research team intends to collect more data in the future through a randomized clinical trial to better understand the relationship between time and step-based exercise metrics and their effects on health.