Comparison of the IPAQ-Short Form and accelerometry predictions of physical activity in older adults.

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.

Prediction of body fat in older adults by time spent in sedentary behavior.

The purpose of the study was to determine the relationship between sedentary behavior (SB), physical activity (PA), and body fat (total, abdominal) or body size (body-mass index [BMI], waist circumference [WC]) in community-dwelling adults 50 yr old and over. This study included 232 ambulatory adults (50-87 yr, 37.4% ± 9.6% body fat [BF]). Average daily time spent in SB (<100 counts/min) and light (100-759 counts/min), lifestyle-moderate (760-1,951 counts/min), walking-moderate (1,952-5,724 cts/min), and vigorous-intensity (≥ 5,725 counts/min) PA were determined by accelerometer and corrected for wear time. BF was measured with dual-energy X-ray absorptiometry. SB was positively related to measures of BF. Measures of SB, PA, and gender accounted for 55.6% of the variance in total BF, 32.4% of the variance in abdominal fat, and 28.0% of the variance in WC. SB, PA, and age accounted for 27.1% of the variance in BMI. Time spent in SB should be considered when designing obesity interventions for adults 50 yr old and over.

A pilot randomized controlled trial evaluating motivationally matched pedometer feedback to increase physical activity behavior in older adults.

BACKGROUND: Increasing physical activity (PA) levels in older adults represents an important public health challenge. The purpose of this study was to evaluate the feasibility of combining individualized motivational messaging with pedometer walking step targets to increase PA in previously inactive and insufficiently active older adults. METHODS: In this 12-week intervention study older adults were randomized to 1 of 4 study arms: Group 1--control; Group 2--pedometer 10,000 step goal; Group 3--pedometer step goal plus individualized motivational feedback; or Group 4--everything in Group 3 augmented with biweekly telephone feedback. RESULTS: 81 participants were randomized into the study, 61 participants completed the study with an average age of 63.8 ± 6.0 years. Group 1 did not differ in accumulated steps/day following the 12-week intervention compared with participants in Group 2. Participants in Groups 3 and 4 took on average 2159 (P < .001) and 2488 (P < .001) more steps/day, respectively, than those in Group 1 after the 12-week intervention. CONCLUSION: In this 12-week pilot randomized control trial, a pedometer feedback intervention partnered with individually matched motivational messaging was an effective intervention strategy to significantly increase PA behavior in previously inactive and insufficiently active older adults.

A Pilot Randomized Controlled Trial Evaluating Motivationally Matched Pedometer Feedback to Increase Physical Activity Behavior in Older Adults.

BACKGROUND: Increasing physical activity (PA) levels in older adults represents an important public health challenge. The purpose of this study was to evaluate the feasibility of combining individualized motivational messaging with pedometer walking step targets to increase PA in previously inactive and insufficiently active older adults. METHODS: In this 12-week intervention study older adults were randomized to 1 of 4 study arms: Group 1-control; Group 2-pedometer 10,000 step goal; Group 3-pedometer step goal plus individualized motivational feedback; or Group 4-everything in Group 3 augmented with biweekly telephone feedback. RESULTS: 81 participants were randomized into the study, 61 participants completed the study with an average age of 63.8 ± 6.0 years. Group 1 did not differ in accumulated steps/day following the 12-week intervention compared with participants in Group 2. Participants in Groups 3 and 4 took on average 2159 (P < .001) and 2488 (P < .001) more steps/day, respectively, than those in Group 1 after the 12-week intervention. CONCLUSION: In this 12-week pilot randomized control trial, a pedometer feedback intervention partnered with individually matched motivational messaging was an effective intervention strategy to significantly increase PA behavior in previously inactive and insufficiently active older adults.

Validity of Physical Activity Monitors in Assessing Energy Expenditure in Normal, Overweight, and Obese Adults.

A comparison of the validity of downloadable motion sensors, which use either a glass-enclosed magnetic reed proximity switch technology, a piezo-electric sensor accelerometer with a horizontal beam technology, or an internal pendulum based mechanism to determine energy expenditure (EE), across different body sizes does not exist. Therefore, the purpose of this study was to determine the validity of three different downloadable motion sensors to estimate EE during walking activity in normal weight, overweight and obese volunteers. Forty-eight participants completed this study. Each participant had their body height and mass measured and completed a treadmill walking protocol. Body mass index (BMI) was calculated. The treadmill walking protocol included six 5-minute stages starting at 1.5 mph and increasing by 0.5 mph, up to 4.0 mph while grade was constant at 0% for the duration of the test. The Kenz Life-Corder EX (LC), the Omron HJ-700IT (OM) and the Sportbrain iStep X1 (SB) were worn during the treadmill walking protocol. Heart rate, oxygen consumption, carbon dioxide production and EE estimated from the motion sensors were monitored throughout the walking protocol. Results showed the OM overestimated net EE in normal, overweight and obese participants. The LC underestimated gross EE in all groups. The SB overestimated net EE in normal BMI participants, was not significantly different from the criterion measure of net EE in overweight participants and underestimated net EE in obese individuals. This study demonstrates that these devices do not offer the accuracy needed to provide precise feedback on EE for individuals with varying BMI levels.