Step- and time-based exercises equally beneficial in reducing CVD, mortality risks

Key takeaways:

• The most active women outlived the least active women by more than 2 months for both step- and time-based measurements.
• This finding persisted after the researchers adjusted for differences in BMI.

Both step counts and time-based physical activity reduced the risks of death and CVD among women aged 62 years and older, a study in JAMA Internal Medicine showed.

WHO guidelines currently recommend that adults complete 150 to 300 minutes of moderate physical activity or 75 to 150 minutes of vigorous intensity per week and muscle strengthening activities 2 days per week.

According to Rikuta Hamaya, MD, PhD, MS, a researcher at Brigham and Women’s Hospital, existing guidelines primarily focus on moderate-to-vigorous physical activity, or MVPA, “but lack a clear step-based recommendation.”

“Our study thus aimed to explore whether step counts could be as effective as MVPA time in predicting health outcomes, particularly in an older female population,” she told Healio.

In the cohort study, Hamaya and colleagues analyzed data on 14,399 women aged 62 years and older from the Women’s Health Study who were free of CVD and cancer at baseline.

Between 2011 and 2015, participants wore an accelerometer for several consecutive days and completed annual questionnaires. They were followed until the end of 2022.

During a median follow-up of 9 years, 9.2% of participants died and 4.1% developed CVD.

Participants’ median duration of MVPA was 62 minutes per week, and they had a median step count of 5,183 per day.

Hamaya and colleagues reported that HRs per standard deviation (SD) of MVPA time were:

• 0.82 (95% CI, 0.75-0.9) for all-cause mortality; and
• 0.81 (95% CI, 0.72-0.91) for CVD.

Meanwhile, HRs per SD of step counts were:

• 0.74 (95% CI, 0.69-0.8) for all-cause mortality; and
• 0.82 (95% CI, 0.73-0.91) for CVD.

The most active women had 30% to 40% reduced risks for CVD and mortality compared with the least active women, according to the press release.

Additionally, women in the top three quartiles of MVPA and step counts outlived those in the bottom quartiles by an average of 2.22 (95% CI, 1.58-2.85) and 2.36 (95% CI, 1.73-2.99) months, respectively, at 9 years follow-up. This finding persisted after researchers adjusted for BMI.

After further investigating all-cause mortality outcomes, researchers reported that both MVPA and step counts were associated with an area under the curve of 0.55 (95% CI, 0.52-0.57).

“The key takeaway is that both MVPA and walking measured by steps are beneficial,” Hamaya said. “People should aim to be active in ways that fit their lifestyle and preferences, whether that’s structured exercise or simply walking more throughout the day.”

The researchers pointed out that it is important to understand the distinctiveness of each physical activity metric, like how step counts may not account for differences in fitness levels.

“For example, if a 20-year-old patient and an 80-year-old patient both walk for 30 minutes at a moderate intensity, relative to each individual’s cardiovascular fitness, they will not record the same step count,” they wrote.

Because the study was observational, researchers could not determine cause and effect. Additionally, there was only a single assessment of step counts and MVPA, which could have changed over time.

Still, “our findings support the inclusion of step counts as an alternative metric in physical activity guidelines, particularly for older adults,” Hamaya said. “This could allow for more personalized approaches to meeting physical activity recommendations, accommodating personal preferences and capabilities.”

For more information:

Ryan Jaslow can be reached at rjaslow@mgb.org.

References:

• Hamaya R, et al. JAMA Intern Med. 2024;doi:10.1001/jamainternmed.2024.0892.
• Should your exercise goals be in minutes or steps? Study suggests they are equally beneficial. https://sph.unc.edu/sph-news/should-your-exercise-goals-be-in-minutes-or-steps-study-suggests-they-are-equally-beneficial/. Published May 20, 2024. Accessed May 20, 2024.