William L. Haskell
William L. Haskell
For the scientific domain of physical activity and public health research to advance its agenda of health promotion and disease prevention continued development of measurement methodologies is essential. Over the past 50 years most data supporting a favorable relationship between habitual physical activity and chronic disease morbidity and mortality have been obtained using self-report methods, including questionnaires, logs, recalls, and diaries. Many of these instruments have been shown to have reasonable validity and reliability for determining general type, amount, intensity, and bout duration, but typically do better for groups than individuals with some instruments lacking the sensitivity to detect change in activity. During the past decade the objective assessment of physical activity using accelerometer-based devices has demonstrated substantial potential, especially in documenting the pattern of light-, moderate-, and vigorous-intensity activity throughout the day. However, these devices do not provide information on activity type, location or context. Research that combines the strengths of both self-report and objective measures has the potential to provide new insights into the benefits of physical activity and how to implement successful interventions.
William L. Haskell
This symposium addressed the ongoing development of new technologies for the objective measurement of physical activity and diet and efforts to provide best practice guidelines for scientists developing, evaluating and using existing and new technologies for the objective measurement of physical activity. The research projects discussed and the workshop overview presented are components of the Genes, Environment, and Health Initiative (GEI) of the National Institutes of Health. The rationale, plans and progress of the GEI physical activity and diet initiative were presented. Detailed presentations described 2 projects focused on the use of mobile phone based systems designed to collect, process and store data; 1 uses multiple wireless accelerometers to detect body movement and the other uses a camera built into a mobile phone and advanced software to quantify dietary intake. Given the rapid development of new accelerometer-based physical activity measurement devices and analytical approaches, it is important that best practices be used by scientists and practitioners using theses devices. An overview of a “best practices” workshop held in July 2009 was presented. The presentations and discussions during this symposium made evident the progress, potential and challenges of implementing advanced technologies to enhance the measurement of physical activity and diet.
Wayne T. Phillips and William L. Haskell
The U.S. Department of Health and Human Services (1990) has specified as a key objective the reduction of disability in the performance of activities of daily living (ADL) for persons over the age of 65 years. Many ADL involve combinations of muscular strength, muscular endurance, and flexibility, three components that together have been referred to as "muscular fitness." The capacity of the elderly to remain functionally independent, therefore, may depend less on cardiovascular fitness, which has traditionally been the focus of health related fitness research, than on these components of muscular fitness. This review addresses the issue of muscular fitness and disability in the elderly by considering three questions: Is muscular fitness associated with ADL performance? Can muscular fitness be improved with exercise training? Do improvements in muscular fitness improve ADL performance? Answers to these questions will have important implications for future research and program implementation. Although initial findings are promising, more data are needed on the effect of muscular fitness on functional independence and quality of life in the elderly.
Miriam E. Nelson, William L. Haskell and Mary Kennedy
Ralph S. Paffenbarger Jr., Jeremy N. Morris, William L. Haskell, Paul D. Thompson and I-Min Lee
Ruth E. Taylor-Piliae, Kathryn A. Newell, Rise Cherin, Martin J. Lee, Abby C. King and William L. Haskell
To compare the effects of Tai Chi (TC, n = 37) and Western exercise (WE, n = 39) with an attention-control group (C, n = 56) on physical and cognitive functioning in healthy adults age 69 ± 5.8 yr, in a 2-phase randomized trial.
TC and WE involved combined class and home-based protocols. Physical functioning included balance, strength, flexibility, and cardiorespiratory endurance. Cognitive functioning included semantic fluency and digit-span tests. Data were analyzed using intention-to-treat analysis.
At 6 mo, WE had greater improvements in upper body flexibility (F = 4.67, p = .01) than TC and C. TC had greater improvements in balance (F = 3.36, p = .04) and a cognitive-function measure (F = 7.75, p < .001) than WE and C. The differential cognitive-function improvements observed in TC were maintained through 12 mo.
The TC and WE interventions resulted in differential improvements in physical functioning among generally healthy older adults. TC led to improvement in an indicator of cognitive functioning that was maintained through 12 mo.
Leslie A. Pruitt, Nancy W. Glynn, Abby C. King, Jack M. Guralnik, Erin K. Aiken, Gary Miller and William L. Haskell
The authors explored using the ActiGraph accelerometer to differentiate activity levels between participants in a physical activity (PA, n = 54) or “successful aging” (SA) program (n = 52). The relationship between a PA questionnaire for older adults (CHAMPS) and accelerometry variables was also determined. Individualized accelerometry-count thresholds (ThreshIND) measured during a 400-m walk were used to identify “meaningful activity.” Participants then wore the ActiGraph for 7 days. Results indicated more activity bouts/day ≥10 min above ThreshIND in the PA group than in the SA group (1.1 ± 2.0 vs 0.5 ± 0.8, p = .05) and more activity counts/day above ThreshIND for the PA group (28,101 ± 27,521) than for the SA group (17,234 ± 15,620, p = .02). Correlations between activity counts/hr and CHAMPS ranged from .27 to .42, p < .01. The ActiGraph and ThreshIND might be useful for differentiating PA levels in older adults at risk for mobility disability.
Leslie A. Pruitt, Abby C. King, Eva Obarzanek, Michael Miller, Mary O’Toole, William L. Haskell, Laura Fast, Sheila Reynolds and for the Activity Counseling Trial Research Group
Physical activity recall (PAR) reliability was estimated in a three-site sample of African American and white adults. The sample was sedentary at baseline and more varied in physical activity 24 months later. Intraclass correlation coefficients (ICCs) were used to estimate the number of PAR assessments necessary to obtain a reliability of 0.70 at both timepoints.
The PAR was administered ≤ 30 d apart at baseline (n = 547) and 24 months (n = 648). Energy expenditure ICC was calculated by race, gender, and age.
Baseline reliability was low for all groups with 4–16 PARs estimated to attain reliable data. ICCs at 24 months were similar (ICC = 0.54–0.55) for race and age group, with 2–3 PARs estimated to reach acceptable reliability. At 24 months, women were more reliable reporters than men.
Low sample variability in activity reduced reliability, highlighting the importance of evaluating diverse groups. Despite evaluating a sample with greater physical activity variability, an estimated 2–3 PARs were necessary to obtain acceptable reliability.
Ruth E. Taylor-Piliae, Joan M. Fair, William L. Haskell, Ann N. Varady, Carlos Iribarren, Mark A. Hlatky, Alan S. Go and Stephen P. Fortmann
This study examined the construct validity and reliability of the new 2-item Stanford Brief Activity Survey (SBAS).
Secondary analysis was conducted using data collected from the healthy older controls (n = 1023) enrolled in the Atherosclerotic Disease Vascular Function and Genetic Epidemiology (ADVANCE) study. Construct validity was examined by regression analyses to evaluate significant trends (P ≤ .05) across the SBAS activity categories for the selected psychological health factors measured at baseline and year 2, adjusted for gender, ethnicity and education level. Test-retest reliability was performed using Spearman’s rank correlation.
At baseline, subjects were 66 ± 2.8 years old, 38% female, 77% married, 61% retired, 24% college graduate, and 68% Caucasian. At baseline, lower self-reported stress, anxiety, depression, and cynical distrust, and higher self-reported mental and physical well-being were significantly associated with higher levels of physical activity (p trend ≤ 0.01). These associations held at year 2. The test-retest reliability of the SBAS was statistically significant (rs= 0.62, P < .001).
These results provide evidence of the construct validity and reliability of the SBAS in older adults. We also found a strong dose-response relationship between regular physical activity and psychological health in older adults, independent of gender, education level and ethnicity.