Background Direct-to-consumer mHealth devices are a potential asset to behavioral research but are rarely tested as intervention tools. This trial examined the accelerometer-based Fitbit tracker and website as a basis for a low-touch physical activity intervention. Purpose To evaluate, within a randomized controlled trial, the feasibility and preliminary efficacy of integrating the Fitbit tracker and website into a physical activity intervention for postmenopausal women. Methods Fifty-one inactive, postmenopausal women with BMI≥25.0 kg/m2 were randomized to a 16-week web-based self-monitoring intervention (N=25) or a comparison group (N=26). Those in the Web-Based Tracking Group received a Fitbit, an instructional session, and a follow-up call at 4 weeks. The comparison group received a standard pedometer. All were asked to perform 150 min/week of moderate-to-vigorous physical activity (MVPA). Physical activity outcomes were measured by the ActiGraph GT3X+ accelerometer. Results Data were collected and analyzed in 2013–2014. Participants were 60±7 years old with BMI=29.2±3.5 kg/m2. Relative to baseline, the Web-Based Tracking Group increased MVPA by 62±108 min/week (p<.01), MVPA in 10-min bouts by 38±83 min/week (p=.008), and steps by 789±1,979 (p=.01), compared to non-significant increases in the Pedometer Group (between-group p-values: .11, .28 and .30, respectively). The Web-Based Tracking Group wore the tracker on 95% of intervention days; 96% reported liking the website and 100% liked the tracker. Conclusions The Fitbit was well-accepted in this sample of women and was associated with increased physical activity at 16 weeks. By leveraging direct-to-consumer mHealth technologies that align with behavior change theories, researchers can strengthen physical activity interventions.

This study is registered at ClinicalTrials.gov with clinical trial registration number NCT02188875. AbstractBackground: Studies have shown self-monitoring can modify health behaviors, including physical activity (PA). This study tested the utility of a wearable sensor/device (Fitbit Ò OneÔ;

The 2008 Physical Activity (PA) Guidelines recommend engaging in at least 2.5 hours (10 MET-hours/week) of moderate intensity PA per week (defined as 4 METs) to reduce risk of morbidity and mortality. This analysis was conducted to investigate whether this recommendation can be extended to breast cancer survivors. Data from four studies of breast cancer survivors measuring recreational PA from semi-quantitative questionnaires a median of 23 months post-diagnosis (interquartile range 18 to 32 months) were pooled in the After Breast Cancer Pooling Project (n=13,302). Delayed entry Cox proportional hazards models were applied in data analysis with adjustment for age, post-diagnosis body mass index, race/ethnicity, menopausal status, TNM stage, cancer treatment, and smoking history. Engaging in at least 10 MET-hours/week of PA was associated with a 27% reduction in all-cause mortality (n=1,468 events, Hazard Ratio (HR) = 0.73, 95% CI, 0.66–0.82) and a 25% reduction in breast cancer mortality (n=971 events, HR=0.75, 95% CI 0.65–0.85) compared to women who did not meet the PA Guidelines (< 10 MET-hours/week). Risk of breast cancer recurrence (n=1,421 events) was not associated with meeting the PA Guidelines (HR=0.96, 95% CI, 0.86–1.06). These data suggest that adhering to the PA Guidelines may be an important intervention target for reducing mortality among breast cancer survivors.

Background Returning to a healthy level of physical activity is among the most commonly discussed clinical goals for patients recovering from anterior cruciate ligament reconstruction (ACLR). However, physical activity has not been objectively measured in this population. Purpose To investigate differences in the mean time (min/d) spent in moderate-to-vigorous physical activity (MVPA) as well as the daily step count (steps/d) between patients who underwent ACLR and matched controls. A second purpose was to investigate relationships between MVPA and objective assessments of the daily step count and Tegner and Marx activity scales. Study Design Cross-sectional study; Level of evidence, 3. Methods Physical activity was assessed using ActiGraph accelerometers in 33 participants with a history of primary unilateral or bilateral ACLR (mean time from surgery, 27.8 ± 17.5 months; range, 6–67 months) as well as in 33 healthy controls (matched on age, sex, and activity level). Participants wore the accelerometer for 7 days and completed the International Knee Documentation Committee subjective form and the Tegner and Marx activity scales. Independent t tests were used to determine differences in each dependent variable per group. Results Patients who underwent ACLR spent less time in MVPA (ACLR: 79.37 ± 23.95 min/d; control: 93.12 ± 23.94 min/d; P = .02) and had a lower daily step count (ACLR: 8158 ± 2780 steps/d; control: 9769 ± 2785 steps/d; P = .02) compared with healthy matched controls. However, the Marx (ACLR median: 11.0 [interquartile range (IQR), 7–14]; control median: 12.0 [IQR, 8–13]; P = .85) and Tegner (ACLR median: 6.0 [IQR, 5–8]; control median: 7.0 [IQR, 6–8]; P = .12) scores did not differ between the groups, and no relationships were observed between objectively measured physical activity and scale measures (P > .05), except for a moderate relationship between the Tegner score and daily step count in the ACLR group (r = 0.36, P = .04). Only 24% of patients who underwent ACLR met the guideline of 10,000 steps per day compared with 42% of controls. Conclusion Patients who underwent ACLR spent less time in MVPA and had a lower daily step count compared with highly matched controls (age, sex, and activity level) with no history of knee injuries. This was true despite being similar in activity levels, which brings into question the utility of the Tegner and Marx activity scales.

BackgroundDirect-to-consumer trackers and devices have potential to enhance theory-based physical activity interventions by offering a simple and pleasant way to help participants self-monitor their behavior. A secondary benefit of these devices is the opportunity for investigators to objectively track adherence to physical activity goals across weeks or even months, rather than relying on self-report or a small number of accelerometry wear periods. The use of consumer trackers for continuous monitoring of adherence has considerable potential to enhance physical activity research, but few studies have been published in this rapidly developing area.ObjectiveThe objective of the study was to assess the trajectory of physical activity adherence across a 16-week self-monitoring intervention, as measured by the Fitbit tracker.MethodsParticipants were 25 overweight or obese, postmenopausal women enrolled in the intervention arm of a randomized controlled physical activity intervention trial. Each participant received a 16-week technology-based intervention that used the Fitbit physical activity tracker and website. The overall study goal was 150 minutes/week of moderate to vigorous intensity physical activity (MVPA) and 10,000 steps/day; however, goals were set individually for each participant and updated at Week 4 based on progress. Adherence data were collected by the Fitbit and aggregated by Fitabase. Participants also wore an ActiGraph GT3X+ accelerometer for 7 days prior to the intervention and again during Week 16.ResultsThe median participant logged 10 hours or more/day of Fitbit wear on 95% of the 112 intervention days, with no significant decline in wear over the study period. Participants averaged 7540 (SD 2373) steps/day and 82 minutes/week (SD 43) of accumulated “fairly active” and “very active” minutes during the intervention. At Week 4, 80% (20/25) of women chose to maintain/increase their individual MVPA goal and 72% (18/25) of participants chose to maintain/increase their step goal. Physical activity levels were relatively stable after peaking at 3 weeks, with only small declines of 8% for steps (P=.06) and 14% for MVPA (P=.05) by 16 weeks.ConclusionsThese data indicate that a sophisticated, direct-to-consumer activity tracker encouraged high levels of self-monitoring that were sustained over 16 weeks. Further study is needed to determine how to motivate additional gains in physical activity and evaluate the long-term utility of the Fitbit tracker as part of a strategy for chronic disease prevention.Trial RegistrationClinicaltrials.gov NCT01837147; http://clinicaltrials.gov/ct2/show/NCT01837147 (Archived by WebCite at http://www.webcitation.org/6d0VeQpvB)