PURPOSE: Wearable activity monitors (wearables) are increasingly used in the US and can help encourage physical activity participation through step counts. Understanding whether wearable users track daily step counts and how they set step goals can help ensure wearables are designed and used to maximize their public health impact. This study examined the proportion of US adults who use wearables, and among users whether wearables are used to track daily step counts and how they determine their daily step count goals. | | METHODS: Data from a nationwide sample of US adults (SummerStyles, 2020) were analyzed (N = 3661). Participants were asked if they have ever used a wearable and were categorized as a current, past, or never user. Current users were asked if they use their wearable to track their daily step count. Those who responded yes were asked if they determine their daily step goal by using the default goal, a personal goal, no goal, or that they gradually increase their step goal. Prevalence of wearable users, use of wearable to track daily step counts, and how users determine daily step count goals were calculated overall and by demographic characteristics. Pairwise t tests were used to identify significant differences between subgroups (p < .05). | | RESULTS: Overall, 31.4% of US adults currently use a wearable activity monitor. Among current users (n = 1219), 88.3% reported using their device to track their daily step count with a greater prevalence among females (91.2%) compared to males (84.6%) and among Hispanics (95.2%) compared to Whites (87.1%). Current wearable users reported determining their step count goal by using the default goal (41.7%), their own personal goal (32.9%), not having a daily goal (17.4%), and gradually increasing their daily goal (8.0%). | | CONCLUSION: Nearly 9 in 10 wearable users track their daily step count on their devices. Most users set step goals based on default settings or personal goals, so establishing evidence-based steps per day guidelines may help wearable users achieve levels of health enhancing physical activity.

PURPOSE: Inadequate pre-enlistment physical activity is a risk factor for musculoskeletal injury during and discharge from basic military training. We estimated the prevalence of physical activity (PA) participation among the US population eligible to enter the armed forces based on age and body mass index (BMI) overall and by selected characteristics. | | METHODS: Data on non-pregnant, age-eligible respondents (aged 17-42 years) were analyzed from the January 2015 - March 2020 National Health and Nutrition Examination Survey (unweighted n = 5964). In accordance with Department of Defense policy, BMI eligibility was defined as 19.0-27.5 kg/m2; BMI was calculated from measured weight and height. Based on guidance from the US Army Pre-Basic Combat Training Physical Training Program and the Physical Activity Guidelines for Americans, 2nd edition, we characterized inadequate PA participation as < 300 minutes/week of equivalent moderate-intensity PA from all domains. We calculated PA overall and compared PA by gender, age, race/ethnicity, education, and family income using the Satterthwaite adjusted F-test. | | RESULTS: Of the age-eligible population, 47.3% were BMI eligible. Among those eligible by age and BMI, 27.5% had an inadequate PA level. Prevalence of inadequate PA was lower among males than females (P = .001) and non-Hispanic white persons versus other racial/ethnic groups (P < .001); no significant differences were evident by age, education, or family income. Among those with BMI < 19.0 kg/m2 and > 27.5 kg/m2, respective prevalence of inadequate PA was 36.3% and 36.5%. | | CONCLUSIONS: Less than half of the military age-eligible US population has an eligible BMI for entering the US armed forces. Over a quarter of these report PA that may be inadequate for basic military training. Promotion of healthy weight status and participation in PA in young adults could help improve readiness to enter the armed forces.