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Scott Strath, Raymond Isaacs and Michael J. Greenwald

This qualitative study describes environmental supports and barriers to physical activity in an older adult sample drawn from low- and high-walkable neighborhoods. Thirty-seven individuals age 55 and over were recruited and answered open-ended survey questions, with a subsample invited back to partake in a semistructured interview. Content analysis identified categories and themes linking perceptions of neighborhood-environment characteristics to activity. Emerging categories and themes did not differ across neighborhood walkability, so results are presented for both groups combined. Infrastructure was the most common category identified to encourage activity, specifically, well-maintained sidewalks, bike paths or lanes, and traffic control. Other categories of land use, landscape, and aesthetics were reported. Poorly maintained or missing sidewalks, crosswalks, bike paths or lanes, and traffic safety were categories that discouraged activity. In conclusion, the information obtained is helpful in solidifying which environmental characteristics are important to measure as they relate to activity behavior in an older adult population.

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Sarah J. Parker, Scott J. Strath and Ann M. Swartz

This study examined the relationship between physical activity (PA) and mental health among older adults as measured by objective and subjective PA-assessment instruments. Pedometers (PED), accelerometers (ACC), and the Physical Activity Scale for the Elderly (PASE) were administered to measure 1 week of PA among 84 adults age 55–87 (mean = 71) years. General mental health was measured using the Positive and Negative Affect Scale (PANAS) and the Satisfaction With Life Scale (SWL). Linear regressions revealed that PA estimated by PED significantly predicted 18.1%, 8.3%, and 12.3% of variance in SWL and positive and negative affect, respectively, whereas PA estimated by the PASE did not predict any mental health variables. Results from ACC data were mixed. Hotelling–William tests between correlation coefficients revealed that the relationship between PED and SWL was significantly stronger than the relationship between PASE and SWL. Relationships between PA and mental health might depend on the PA measure used.

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Hotaka Maeda, Chris C. Cho, Young Cho and Scott J. Strath

When processing free-living accelerometer data, invalid days are typically discarded, potentially resulting in loss of valuable information. The purpose of this semi-simulation study was to compare the accuracy of the conventional method of calculating free-living physical activity (PA) in average counts per day to three methods that can utilize all accelerometer data, including the invalid days (<10 hours per day). National Health and Nutrition Examination Survey data from 2003 to 2006 were used. Age and sample size were included as study conditions. Artificial missing data were created among the participants with 7 days of valid accelerometer data by imposing missing data patterns from a donor matched on age and gender. Results showed that the conventional method of calculating PA levels discarded 26.0% to 28.6% of the data. In most conditions, the within-minute average and day-level imputation method were able to recover the artificially deleted accelerometer counts better than the conventional method. As an exception, the within-minute average method overestimated PA among young people with ≥3 valid days. In conclusion, practitioners are suggested to use the within-minute average method for adults ≥18 years of age, and the day-level imputation method for children and teenagers. To note, the day-level imputation method may be unstable for sample sizes of <50. These methods are particularly useful when the number of valid days is ≤3. Potentially, these methods can allow some participants with insufficient number of valid days to be included in the final analysis.

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Scott J. Strath, Ann M. Swartz and Susan E. Cashin

This study examined objectively determined walking profiles of older adults across a wide range of sociocultural backgrounds. All individuals (N = 415; 131 men age 70.5 ± 9.2 yr and 284 women age 71.5 ± 9.0 yr) underwent physiological measurements, completed pen-and-paper surveys, and wore a pedometer for 7 consecutive days. The total sample accumulated a mean of 3,987 ± 2,680 steps/day. Age (r = –.485, p < .001) and body-mass index (BMI; r = –.353, p < .001) were negatively associated with steps per day. Multivariate analysis revealed that race/ethnic category (F = 3.15, df = 3), gender (F = 2.46, df = 1), BMI (F = 6.23, df = 2), income (F = 9.86, df = 1), education (F = 43.3, df = 1), and retirement status (F = 52.3, df = 1) were significantly associated with steps per day. Collectively these categories accounted for 56% of the variance in walking activity in this independently living, community-dwelling older adult sample. Sedentary characteristics highlighted within, and step-per-day values specific to, older adults have implications for planning targeted physical activity interventions related to walking activity in this population.

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Ann M. Swartz, Scott J. Strath, Sarah J. Parker and Nora E. Miller

The purpose of this study was to investigate the combined impact of obesity and physical activity (PA) on the health of older adults. Pedometer-determined steps/d, body-mass index (BMI), resting blood pressure, and fasting glucose (FG) were assessed in 137 older adults (69.0 ± 8.9 yr). The active group (>4,227 steps/d) had lower systolic blood pressure (SBP; p = .001), diastolic blood pressure (DBP; p = .028), and FG (p < .001) than the inactive group (≤4,227 steps/d). The normal-BMI group (18.5-24.9 kg/m2) had lower SBP (p < .001) and DBP (p = .01) than the obese group (≤30 kg/m2). There were no differences in SBP (p = .963) or DBP (p = 1.0) between active obese and inactive normal-BMI groups. The active obese group, however, had a more favorable FG than the inactive normal-BMI group (χ2 = 18.9, df = 3, p = .001). Efforts to increase PA of older adults should receive the same priority as reducing obesity to improve BP and FG levels.

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Nicholas L. Lerma, Ann M. Swartz, Taylor W. Rowley, Hotaka Maeda and Scott J. Strath

Background:

The ill-health effects of sedentary behavior are becoming well-documented, yet older adults spend 70–80% of waking hours sedentary.

Purpose:

To determine if a portable elliptical device increases energy expenditure (EE) while performing popular seated activities.

Methods:

Twenty older adults (68.1 ± 1.4 years) participated to compare the measured EE between seated rest and three randomized seated pedaling activities: computer use, reading, TV viewing. Each pedaling activity included 5-min of self-selected paced/no resistance (SSP) and externally paced/added resistance pedaling (Paced).

Results:

A significant increase in EE existed during SSP (+1.44 ± 0.12 kcal/min) and Paced (+2.19 ± 0.09 kcal/min) pedaling relative to Seated Rest (p < .001). EE during the Paced activities was significantly greater than all SSP activities (p <.01).

Conclusion:

Extrapolating these results, pedaling at a SSP for an hour while performing seated activities is equivalent to the net EE of walking 1.6 miles. Future home-based effectiveness and feasibility should be explored.

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Whitney A. Welch, Ann M. Swartz, Chi C. Cho and Scott J. Strath

The purpose of the study was to evaluate the accuracy of direct observation (DO) to estimate MET level and intensity category during laboratory-based and free-living activity in older adults. Older adults engaged in unstructured laboratory and free-living activity. Participants wore a portable metabolic system to measure energy expenditure and were directly observed. DO recorded MET-level point estimates. 32,401 in-laboratory and 87,715 free-living data points (9 participants, 67% male, 71.0 ± 6.9 years, 27.1 ± 4.3 kg·m–2) were included in final analysis. Results revealed 45.4% of in-laboratory and 61.1% of free-living mean DO activities fell within 0.5 METs of the measured MET values. DO accurately classified intensity category 45.0% of the time in-laboratory and 50.9% of free-living observations. DO-estimated activity cost resulted in low point estimate accuracy however there was low variability between the mean measured and estimated METs. This suggests, dependent on the desired outcome, DO could provide a viable option for activity assessment, however, the low point estimate accuracy presents a need for further research to continue to refine the approach to increase accuracy.

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Elizabeth K. Grimm, Ann M. Swartz, Teresa Hart, Nora E. Miller and Scott J. Strath

Older adult physical activity (PA) levels obtained from the International Physical Activity Questionnaire–Short Form (IPAQ) and accelerometry (ACC) were compared. Mean difference scores between accumulated or bout ACC PA and the IPAQ were computed. Spearman rank-order correlations were used to assess relations between time spent in PA measured from ACC and self-reported form of the IPAQ, and percentage agreement across measures was used to classify meeting or not meeting PA recommendations. The IPAQ significantly underestimated sitting and overestimated time spent in almost all PA intensities. Group associations across measures revealed significant relations in walking, total PA, and sitting for the whole group (r = .29–.36, p < .05). Significant relationships between bout ACC and IPAQ walking (r = .28–.39, p < .05) were found. There was 40–46% agreement between measures for meeting PA recommendations. The IPAQ appears not to be a good indicator of individual older adult PA behavior but is better suited for larger population-based samples.

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Keith P. Gennuso, Kathryn Zalewski, Susan E. Cashin and Scott J. Strath

Background:

To examine the effectiveness of the American College of Sports Medicine (ACSM) and the American Heart Association (AHA) resistance training (RT) guidelines to improve physical function and functional classification in older adults with reduced physical abilities.

Methods:

Twenty-five at-risk older adults were randomized to a control (CON = 13) or 8-week resistance training intervention arm (RT = 12). Progressive RT included 8 exercises for 1 set of 10 repetitions at a perceived exertion of 5–6 performed twice a week. Individuals were assessed for physical function and functional classification change (low, moderate or high) by the short physical performance battery (SPPB) and muscle strength measures.

Results:

Postintervention, significant differences were found between groups for SPPB—Chair Stand [F(1,22) = 9.14, P < .01, η = .29] and SPPB—Total Score [F(1,22) = 7.40, P < .05, η = .25]. Functional classification was improved as a result of the intervention with 83% of participants in the RT group improving from low to moderate functioning or moderate to high functioning. Strength significantly improved on all exercises in the RT compared with the CON group.

Conclusions:

A RT program congruent with the current ASCM and AHA guidelines is effective to improve overall physical function, functional classification, and muscle strength for older adults with reduced physical abilities.

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Nora E. Miller, Scott J. Strath, Ann M. Swartz and Susan E. Cashin

This study examined the predictive validity of accelerometers (ACC) to estimate physical activity intensity (PAI) across age and differences in intensity predictions when expressed in relative and absolute PAI terms. Ninety adults categorized into 3 age groups (20–29, 40–49, and 60–69 yr) completed a treadmill calibration study with simultaneous ACC (7164 Actigraph) and oxygen-consumption assessment. Results revealed strong linear relations between ACC output and measured PAI (R 2 = .62–.89) across age and similar ACC cut-point ranges across age delineating absolute PAI ranges compared with previous findings. Comparing measured metabolic equivalents (METs) with estimated METs derived from previously published regression equations revealed that age did not affect predictive validity of ACC estimates of absolute PAI. Comparing ACC output expressed in relative vs. absolute terms across age revealed substantial differences in PAI ACC count ranges. Further work is warranted to increase the applicability of ACC use relative to PAI differences associated with physiological changes with age.