Background: Published accelerometer cut-points have limited accuracy in measuring sedentary (SED) and stationary time (STA) despite hip or wrist placement. Few studies have evaluated established cut-points to measure SED and STA in free-living settings. Methods: This study evaluated published uniaxial and triaxial cut-points of accelerometers and identified optimal cut-points to measure SED and STA. Twenty participants, ages 18–65, wore three ActiGraph GT3X+ (one on each wrist and the waist) and two GENEActiv accelerometers (one on each wrist) for one weekday and one weekend day during simultaneous direct observation of movement. ActiGraph uniaxial cut-points (50, 100, 150, and 500 counts per minute [cpm]) and GENEActiv vector magnitude cut-points (VMCP; 217 and 386 cpm) were compared against the criterion measure of direct observation. As compared to the criterion, accuracy was determined with mean percent error, Bland-Altman plots, kappa coefficient, sensitivity, and specificity. Receiver operating characteristic curves identified cut-points with greatest discrimination to detect SED and STA. Results: For the GENEActiv, the 217 VMCP was most accurate for measuring SED and STA regardless of which arm wore the monitor. The ActiGraph was most accurate worn on the right hip using 100 and 150 uniaxial cpm to measure STA and 50 cpm to measure SED. Optimal ActiGraph VMCP cut-points to classify SED and STA were ActiGraph 2,000 cpm (left-wrist) and 63 cpm (right hip), respectively. Conclusion: Accuracy of ActiGraph uniaxial cut-points and GENEActiv VMCP is limited in assessing SED in free-living settings. Newer cut-points may increase the accuracy of measuring SED and STA from monitors in free-living settings.
Alberto Flórez-Pregonero, Matthew S. Buman and Barbara E. Ainsworth
Diane K. Ehlers, Jennifer Huberty, Matthew Buman, Steven Hooker, Michael Todd and Gert-Jan de Vreede
Commercially available mobile and Internet technologies present a promising opportunity to feasibly conduct ecological momentary assessment (EMA). The purpose of this study was to describe a novel EMA protocol administered on middle-aged women’s smartphones via text messaging and mobile Internet.
Women (N = 9; mean age = 46.2 ± 8.2 y) received 35 text message prompts to a mobile survey assessing activity, self-worth, and self-efficacy over 14 days. Prompts were scheduled and surveys were administered using commercial, Internet-based programs. Prompting was tailored to each woman’s daily wake/sleep schedule. Women concurrently wore a wrist-worn accelerometer. Feasibility was assessed via survey completion, accelerometer wear, participant feedback, and researcher notes.
Of 315 prompted surveys, 287 responses were valid (91.1%). Average completion time was 1.52 ± 1.03 minutes. One participant’s activity data were excluded due to accelerometer malfunction, resulting in complete data from 8 participants (n = 252 [80.0%] valid observations). Women reported the survey was easily and quickly read/completed. However, most thought the accelerometer was inconvenient.
High completion rates and perceived usability suggest capitalizing on widely available technology and tailoring prompting schedules may optimize EMA in middle-aged women. However, researchers may need to carefully select objective monitors to maintain data validity while limiting participant burden.
Eduardo Salazar, Mayank Gupta, Meynard Toledo, Qiao Wang, Pavan Turaga, James M. Parish and Matthew P. Buman
Obstructive sleep apnea (OSA) is an under-diagnosed risk factor for several adverse health outcomes. The gold standard diagnostic test for OSA is laboratory-based polysomnography (PSG). Portable sleep monitoring has been studied as an alternative for patients lacking access to PSG. This study aimed to assess the validity of the Zephyr BioHarness 3 (BH3), a chest-worn activity monitor that records movement, electrocardiography, and respiratory parameters, to identify apnea events in patients suspected of OSA. Patients (N = 18) underwent single-night laboratory-based PSG while wearing the BH3. PSG data were scored in 30-second epochs by PSG technicians. PSG and BH3 data were sampled and analyzed using three sets of features with a radial basis function support vector machine and three-layer neural networks: (1) apnea events were identified second by second using 5-second windows of raw BH3 data (sensitivity = 48.0 ± 8.7%, specificity = 75.6 ± 3.0%, accuracy = 74.4 ± 2.7%); (2) apnea events were identified second by second using mean, median, and variance values of 5-second windows of BH3 data (sensitivity = 54.7 ± 17.3%, specificity = 66.5 ± 12.1%, accuracy = 66.0 ± 10.9%); and (3) apnea events were identified second by second using phase-space transformation of BH3 data (sensitivity = 68.4 ± 9.0%, specificity = 81.5 ± 2.7%, accuracy = 80.9 ±2.5% for τ = 60; sensitivity = 64.0 ± 7.9%, specificity = 81.8 ± 2.5%, accuracy = 81.0 ± 2.3% for τ = 70). The BH3 may be useful for patients suspected of OSA without timely access to PSG.
Peter R. Giacobbi Jr., Matthew P. Buman, Kimberly J. Romney, Monica R. Klatt and Mari J. Stoddard
The purpose of this review was to evaluate the scope, impact, and methods of research funded by the National Institutes of Health (NIH) in kinesiology departments. Information was obtained from university websites, the Research Portfolio Online Reporting Tool (RePORT), PubMed, Google Scholar, and Journal Citation Reports (JCR) from the Institute of Scientific Information (ISI) Web of Knowledge. Abstracts from 2,227 published studies funded by the NIH were reviewed. The National Institute on Aging funded the largest portion of grants. Metabolic functioning, the nervous system, pathology, and cardiovascular diseases were the major foci. Human and animal studies were predominantly discovery-oriented (e.g., comparative studies, clinical research) with a large percentage of translational approaches. Recommendations for interdisciplinary research are provided.
Jennifer L. Huberty, Jeni L. Matthews, Meynard Toledo, Lindsay Smith, Catherine L. Jarrett, Benjamin Duncan and Matthew P. Buman
Purpose: To estimate the energy expenditure (EE) of Vinyasa Flow and validate the Actigraph (AG) and GENEActiv (GA) for measuring EE in Vinyasa Flow. Methods: Participants (N = 22) were fitted to a mask attached to the Oxycon. An AG was placed on the left hip and a GA was placed on the non-dominant wrist. Participants were randomized to an initial resting activity before completing a 30-minute Vinyasa Flow video. AG data was scored using the Freedson VM3 (2011) and the Freedson Adult (1998) algorithms in the Actilife software platform. EE from GA were derived using cut points from a previous study. Date and time filters were added corresponding to the time stamps recorded by the tablet video files of each yoga session. Kcals and METs expended by participants were calculated using bodyweight measured during their visit. Data was analyzed using SPSS. A dependent samples t-test, an intraclass correlation coefficient (ICC), and mean absolute difference were used to determine agreement between variables. Results: According to the Oxycon, participation in Vinyasa Flow required an average EE of 3.2 ± 0.4 METs. The absolute agreement between the Oxycon, AG, or GA was poor (ICC < .20). The mean difference in METs for the AG was −2.1 ± 0.6 and GA was −1.4 ± 0.6 (all p < .01). Conclusion: According to the Oxycon, participation in Vinyasa Flow met the criteria for moderate-intensity physical activity. The AG and GA consistently underestimated EE. More research is needed to determine an accurate measurement for EE during yoga using a wearable device appropriate for free-living environments.
Matthew P. Buman, Peter R. Giacobbi Jr., Joseph M. Dzierzewski, Adrienne Aiken Morgan, Christina S. McCrae, Beverly L. Roberts and Michael Marsiske
Using peer volunteers as delivery agents may improve translation of evidence-based physical activity promotion programs for older adults. This study examined whether tailored support from older peer volunteers could improve initiation and long-term maintenance of physical activity behavior.
Participants were randomized to 2 16-week, group-based programs: (1) peer-delivered, theory-based support for physical activity behavior change; or (2) an intervention typically available in community settings (basic education, gym membership, and pedometer for self-monitoring), attention-matched with health education. Moderate-to-vigorous physical activity (MVPA) was assessed via daily self-report logs at baseline, at the end of the intervention (16 weeks), and at follow-up (18 months), with accelerometry validation (RT3) in a random subsample.
Seven peer volunteers and 81 sedentary adults were recruited. Retention at the end of the trial was 85% and follow-up at 18 months was 61%. Using intent-to-treat analyses, at 16 weeks, both groups had similar significant improvements in MVPA. At 18 months, the group supplemented with peer support had significantly more MVPA.
Trained peer volunteers may enhance long-term maintenance of physical activity gains from a community-based intervention. This approach has great potential to be adapted and delivered inexpensively in community settings.
Eric B. Hekler, Matthew P. Buman, William L. Haskell, Terry L. Conway, Kelli L. Cain, James F. Sallis, Brian E. Saelens, Lawrence D. Frank, Jacqueline Kerr and Abby C. King
Recent research highlights the potential value of differentiating between categories of physical activity intensities as predictors of health and well-being. This study sought to assess reliability and concurrent validity of sedentary (ie, 1 METs), low-light (ie, >1 and ≤2 METs; eg, playing cards), high-light (ie, >2 and <3 METs; eg, light walking), moderate-to-vigorous physical activity (MVPA, ≥3 METs), and “total activity” (≥2 METs) from the CHAMPS survey. Further, this study explored over-reporting and double-reporting.
CHAMPS data were gathered from the Seniors Neighborhood Quality of Life Study, an observational study of adults aged 65+ years conducted in 2 US regions.
Participants (N = 870) were 75.3 ± 6.8 years old, with 56% women and 71% white. The CHAMPS sedentary, low-light, high-light, total activity, and MVPA variables had acceptable test-retest reliability (ICCs 0.56−0.70). The CHAMPS high-light (ρ = 0.27), total activity (ρ = 0.34), and MVPA (ρ = 0.37) duration scales were moderately associated with accelerometry minutes of corresponding intensity, and the sedentary scale (ρ = 0.12) had a lower, but significant correlation. Results suggested that several CHAMPS items may be susceptible to over-reporting (eg, walking, housework).
CHAMPS items effectively measured high-light, total activity, and MVPA in seniors, but further refinement is needed for sedentary and low-light activity.