study reveals best way to measure exercise

Just for good measure, researchers at a Boston hospital have determined whether it’s better to measure exercise goals in minutes or steps.

“We recognized that existing physical activity guidelines focus primarily on activity duration and intensity but lack step-based recommendations,” said lead study author Dr. Rikuta Hamaya, who works in the Division of Preventive Medicine at Brigham and Women’s Hospital.

“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?” Hamaya continued.

According to the Physical Activity Guidelines for Americans, adults should aim for 150 minutes of moderate-intensity physical activity and two days of muscle strengthening a week. Step recommendations from experts, meanwhile, have varied based on research.

For the latest analysis, published Monday in JAMA Internal Medicine, 14,399 healthy women 62 years and older wore devices to record their physical activity for seven consecutive days between 2011 and 2015.

Researchers found that participants typically engaged in 62 minutes of moderate-to-vigorous physical activity per week, accumulating 5,183 steps a day.

During the nine-year follow-up period, some 9% of participants had died and about 4% had developed cardiovascular disease.

The most active 25% of participants — by step counts or time — reduced their risk for death or cardiovascular disease by 30% to 40% compared with the least active quarter.

And those in the top 75% of physical activity outlived those in the bottom quartile by about two months.

Ultimately, researchers found that choosing between steps or minutes may not be as important as setting a fitness goal that fits into your lifestyle.

“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,” Hamaya said. “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,” Hamaya added.

He aims to collect more data on time- and step-based metrics and expand the sample size, which was mostly white women of higher socioeconomic status.

Hamaya’s team notes that the next iteration of the federal physical activity guidelines is planned for 2028.

“Our findings further establish the importance of adding step-based targets, in order to accommodate flexibility of goals that work for individuals with differing preferences, abilities and lifestyles,” said senior study author I-Min Lee, an epidemiologist in the Division of Preventive Medicine at Brigham and Women’s Hospital.