Sedentary Time and Physical Activity in Older Women Undergoing Exercise Training

Area of Science:

• Gerontology
• Exercise Physiology
• Public Health

Background:

• Older adults exhibit low adherence to physical activity (PA) guidelines and high sedentary behavior.
• Low PA and excessive sedentary time are associated with adverse health outcomes.
• The impact of exercise interventions on sedentary time and PA intensity in older adults requires further investigation.

Purpose of the Study:

• To investigate the effects of a 16-week aerobic exercise program on sedentary time, light-intensity PA (LPA), moderate- to vigorous-intensity PA (MVPA), and daily step counts in older women.

Main Methods:

• Sixty-one inactive women (mean age 65.5 years) were randomized into low- or moderate-dose moderate-intensity walking groups.
• Objective measures of sedentary time, LPA, MVPA, and step counts were collected using wearable sensors at baseline and post-intervention.

Main Results:

• Overall, sedentary time decreased by approximately 39 minutes/day, and LPA increased by 19 minutes/day.
• MVPA time increased, primarily due to the supervised exercise sessions.
• Daily step counts increased significantly more in the moderate-dose group (33.6% median increase) compared to the low-dose group (19.8% median increase).

Conclusions:

• Aerobic exercise training can effectively reduce sedentary time and increase LPA in older women.
• While exercise training did not increase sedentary time, the dose of exercise may influence the increase in daily step counts.
• Individual responses to exercise interventions for PA and sedentary behavior vary.