The purpose of this Position Stand is to provide an overview of issues critical to understanding the importance of exercise and physical activity in older adult populations. The Position Stand is divided into three sections: Section 1 briefly reviews the structural and functional changes that characterize normal human aging, Section 2 considers the extent to which exercise and physical activity can influence the aging process, and Section 3 summarizes the benefits of both long-term exercise and physical activity and shorter-duration exercise programs on health and functional capacity. Although no amount of physical activity can stop the biological aging process, there is evidence that regular exercise can minimize the physiological effects of an otherwise sedentary lifestyle and increase active life expectancy by limiting the development and progression of chronic disease and disabling conditions. There is also emerging evidence for significant psychological and cognitive benefits accruing from regular exercise participation by older adults. Ideally, exercise prescription for older adults should include aerobic exercise, muscle strengthening exercises, and flexibility exercises. The evidence reviewed in this Position Stand is generally consistent with prior American College of Sports Medicine statements on the types and amounts of physical activity recommended for older adults as well as the recently published 2008 Physical Activity Guidelines for Americans. All older adults should engage in regular physical activity and avoid an inactive lifestyle.

Exercise and physical activity for older adults

Overweight and obesity affects more than 66% of the adult population and is associated with a variety of chronic diseases. Weight reduction reduces health risks associated with chronic diseases and is therefore encouraged by major health agencies. Guidelines of the National Heart, Lung, and Blood Institute (NHLBI) encourage a 10% reduction in weight, although considerable literature indicates reduction in health risk with 3% to 5% reduction in weight. Physical activity (PA) is recommended as a component of weight management for prevention of weight gain, for weight loss, and for prevention of weight regain after weight loss. In 2001, the American College of Sports Medicine (ACSM) published a Position Stand that recommended a minimum of 150 min wk(-1) of moderate-intensity PA for overweight and obese adults to improve health; however, 200-300 min wk(-1) was recommended for long-term weight loss. More recent evidence has supported this recommendation and has indicated more PA may be necessary to prevent weight regain after weight loss. To this end, we have reexamined the evidence from 1999 to determine whether there is a level at which PA is effective for prevention of weight gain, for weight loss, and prevention of weight regain. Evidence supports moderate-intensity PA between 150 and 250 min wk(-1) to be effective to prevent weight gain. Moderate-intensity PA between 150 and 250 min wk(-1) will provide only modest weight loss. Greater amounts of PA (>250 min wk(-1)) have been associated with clinically significant weight loss. Moderate-intensity PA between 150 and 250 min wk(-1) will improve weight loss in studies that use moderate diet restriction but not severe diet restriction. Cross-sectional and prospective studies indicate that after weight loss, weight maintenance is improved with PA >250 min wk(-1). However, no evidence from well-designed randomized controlled trials exists to judge the effectiveness of PA for prevention of weight regain after weight loss. Resistance training does not enhance weight loss but may increase fat-free mass and increase loss of fat mass and is associated with reductions in health risk. Existing evidence indicates that endurance PA or resistance training without weight loss improves health risk. There is inadequate evidence to determine whether PA prevents or attenuates detrimental changes in chronic disease risk during weight gain.

Appropriate Physical Activity Intervention Strategies for Weight Loss and Prevention of Weight Regain for Adults

Accurate assessment is required to assess current and changing physical activity levels, and to evaluate the effectiveness of interventions designed to increase activity levels. This study systematically reviewed the literature to determine the extent of agreement between subjectively (self-report e.g. questionnaire, diary) and objectively (directly measured; e.g. accelerometry, doubly labeled water) assessed physical activity in adults. Eight electronic databases were searched to identify observational and experimental studies of adult populations. Searching identified 4,463 potential articles. Initial screening found that 293 examined the relationship between self-reported and directly measured physical activity and met the eligibility criteria. Data abstraction was completed for 187 articles, which described comparable data and/or comparisons, while 76 articles lacked comparable data or comparisons, and a further 30 did not meet the review's eligibility requirements. A risk of bias assessment was conducted for all articles from which data was abstracted. Correlations between self-report and direct measures were generally low-to-moderate and ranged from -0.71 to 0.96. No clear pattern emerged for the mean differences between self-report and direct measures of physical activity. Trends differed by measure of physical activity employed, level of physical activity measured, and the gender of participants. Results of the risk of bias assessment indicated that 38% of the studies had lower quality scores. The findings suggest that the measurement method may have a significant impact on the observed levels of physical activity. Self-report measures of physical activity were both higher and lower than directly measured levels of physical activity, which poses a problem for both reliance on self-report measures and for attempts to correct for self-report – direct measure differences. This review reveals the need for valid, accurate and reliable measures of physical activity in evaluating current and changing physical activity levels, physical activity interventions, and the relationships between physical activity and health outcomes.

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A comparison of direct versus self-report measures for assessing physical activity in adults: a systematic review

ContextWithout detailed evidence of their effectiveness, pedometers have recently become popular as a tool for motivating physical activity.ObjectiveTo evaluate the association of pedometer use with physical activity and health outcomes among outpatient adults.Data SourcesEnglish-language articles from MEDLINE, EMBASE, Sport Discus, PsychINFO, Cochrane Library, Thompson Scientific (formerly known as Thompson ISI), and ERIC (1966-2007); bibliographies of retrieved articles; and conference proceedings.Study SelectionStudies were eligible for inclusion if they reported an assessment of pedometer use among adult outpatients, reported a change in steps per day, and included more than 5 participants.Data Extraction and Data SynthesisTwo investigators independently abstracted data about the intervention; participants; number of steps per day; and presence or absence of obesity, diabetes, hypertension, or hyperlipidemia. Data were pooled using random-effects calculations, and meta-regression was performed.ResultsOur searches identified 2246 citations; 26 studies with a total of 2767 participants met inclusion criteria (8 randomized controlled trials [RCTs] and 18 observational studies). The participants' mean (SD) age was 49 (9) years and 85% were women. The mean intervention duration was 18 weeks. In the RCTs, pedometer users significantly increased their physical activity by 2491 steps per day more than control participants (95% confidence interval [CI], 1098-3885 steps per day, P < .001). Among the observational studies, pedometer users significantly increased their physical activity by 2183 steps per day over baseline (95% CI, 1571-2796 steps per day, P < .0001). Overall, pedometer users increased their physical activity by 26.9% over baseline. An important predictor of increased physical activity was having a step goal such as 10 000 steps per day (P = .001). When data from all studies were combined, pedometer users significantly decreased their body mass index by 0.38 (95% CI, 0.05-0.72; P = .03). This decrease was associated with older age (P = .001) and having a step goal (P = .04). Intervention participants significantly decreased their systolic blood pressure by 3.8 mm Hg (95% CI, 1.7-5.9 mm Hg, P < .001). This decrease was associated with greater baseline systolic blood pressure (P = .009) and change in steps per day (P = .08).ConclusionsThe results suggest that the use of a pedometer is associated with significant increases in physical activity and significant decreases in body mass index and blood pressure. Whether these changes are durable over the long term is undetermined.

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Using Pedometers to Increase Physical Activity and Improve Health: A Systematic Review

Purpose: The purpose of this review is to address important methodological issues related to conducting accelerometer-based assessments of physical activity in free-living individuals. Methods: We review the extant scientific literature for empirical information related to the following issues: product selection, number of accelerometers needed, placement of accelerometers, epoch length, and days of monitoring required to estimate habitual physical activity. We also discuss the various options related to distributing and collecting monitors and strategies to enhance compliance with the monitoring protocol. Results: No definitive evidence exists currently to indicate that one make and model of accelerometer is more valid and reliable than another. Selection of accelerometer therefore remains primarily an issue of practicality, technical support, and comparability with other studies. Studies employing multiple accelerometers to estimate energy expenditure report only marginal improvements in explanatory power. Accelerometers are best placed on hip or the lower back. Although the issue of epoch length has not been studied in adults, the use of count cut points based on 1-min time intervals maybe inappropriate in children and may result in underestimation of physical activity. Among adults, 3-5 d of monitoring is required to reliably estimate habitual physical activity. Among children and adolescents, the number of monitoring days required ranges from 4 to 9 d, making it difficult to draw a definitive conclusion for this population. Face-to-face distribution and collection of accelerometers is probably the best option in field-based research, but delivery and return by express carrier or registered mail is a viable option. Conclusion: Accelerometer-based activity assessments requires careful planning and the use of appropriate strategies to increase compliance.

Conducting accelerometer-based activity assessments in field-based research.

CROUTER, S. E., P. L. SCHNEIDER, M. KARABULUT, and D. R. BASSETT, JR. Validity of 10 Electronic Pedometers for Measuring Steps, Distance, and Energy Cost. Med. Sci. Sports Exerc., Vol. 35, No. 8, pp. 1455–1460, 2003.PurposeThis study examined the effects of walking speed on the accuracy and

Validity of 10 electronic pedometers for measuring steps, distance, and energy cost.

PATRICK L. SCHNEIDER, SCOTT E. CROUTER, and DAVID R. BASSETT, JR. Pedometer Measures of Free-Living Physical Activity: Comparison of 13 Models. Med. Sci. Sports Exerc., Vol. 36, No. 2, pp. 331–335, 2004.PurposeThe purpose of this study was to compare the step values of multiple brands of ped

Pedometer measures of free-living physical activity: comparison of 13 models.

SCHNEIDER, P. L., S. E. CROUTER, O. LUKAJIC, and D. R. BASSETT, JR. Accuracy and Reliability of 10 Pedometers for Measuring Steps over a 400-m Walk. Med. Sci. Sports Exerc., Vol. 35, No. 10, pp. 1779–1784, 2003.PurposeThe purpose of this study was to determine the accuracy and reliability of

Accuracy and reliability of 10 pedometers for measuring steps over a 400-m walk.

Purpose: The purpose of this study was to examine the effects of BMI, waist circumference, and pedometer tilt on the accuracy of a spring-levered pedometer (Yamax Digiwalker SW-200 (SW)) and a piezo-electric pedometer (New Lifestyles NL-2000 (NL)) during treadmill walking and over a 24-h period in overweight and obese adults.

Methods: Forty participants (40 +/- 13.0 yr, 32.6 +/- 4.8 kg[middle dot]m-2) walked on a treadmill at various speeds (54, 67, 80, 94, and 107 m[middle dot]min-1) for 3-min stages. Simultaneously, an investigator determined actual steps by a hand counter. For all walking trials the SW and NL were positioned on the right and left waistband, respectively. Height, weight, pedometer tilt angle and circumference measures of the hip and waist were also measured. Thirty-six participants wore the pedometers for a 24-h period in the same position as during the treadmill walking trials.

Results: In general, the SW became less accurate with increasing BMI, increasing waist circumference, and greater pedometer tilt, whereas the NL was not affected by these variables. The SW error scores were significantly correlated with the absolute pedometer tilt angle at all walking speeds (P < 0.05), but the NL error scores were not. On average the NL recorded 1030 +/- 1414 (16.5 +/- 22.7%) more steps that the SW during the 24-h trial.

Conclusion: In overweight and obese individuals, a piezo-electric pedometer (NL) is more accurate than a spring-levered pedometer (SW), especially at slower walking speeds. In addition, it appears that pedometer tilt; more so than waist circumference and BMI, was the most important factor influencing the accuracy of the SW. The NL accuracy was not affected by pedometer tilt, waist circumference, or BMI.

Spring-Levered versus Piezo-Electric Pedometer Accuracy in Overweight and Obese Adults

BASSETT, JR., D. R., P. L. SCHNEIDER, and G. E. HUNTINGTON. Physical Activity in an Old Order Amish Community.Med. Sci. Sports Exerc., Vol. 36, No. 1, pp. 79 – 85, 2004. One method to assess the impact of modern technology on physical activity is to examine a group whose lifestyle has not changed markedly in the last 150 yr. The Old Order Amish refrain from driving automobiles, using electrical appliances, and employing other modern conveniences. Labor-intensive farming is still the preferred occupation. Purpose: The purposes of this study were to characterize the physical activity (PA) levels in an Old Order Amish farming community and to examine measures of adiposity in this group. Methods: Ninety-eight Amish adults (18 –75 yr of age) in southern Ontario were studied. Anthropometric variables included height, weight, body mass index (BMI), and percent body fat (% BF). Participants were asked to wear an electronic pedometer for 7 d and to fill out a log sheet on which they recorded steps per day and physical activities. After 1 wk, they returned the pedometers and log sheets and filled out the International Physical Activity Questionnaire. Results: The average number of steps per day was 18,425 for men versus 14,196 for women (P 0.05). Men reported 10.0 h·wk 1 of vigorous PA, 42.8 h·wk 1 of moderate PA, and 12.0 h·wk 1 of walking. Women reported 3.4 h·wk 1 of vigorous PA, 39.2 h·wk 1 of moderate PA, and 5.7 h·wk 1 of walking. Men had higher levels of energy expenditure than women (P 0.001). A total of 25% of the men and 27% of the women were overweight (BMI 25), and 0% of the men and 9% of the women were obese (BMI 30). Conclusions: The Amish we studied had very high levels of physical activity, which may contribute to their low prevalence of obesity. This group probably represents an upper extreme for “lifestyle PA” in North America today. Key Words: FARMING, LIFESTYLE ACTIVITY, PEDOMETER, QUESTIONNAIRE, OBESITY, OVERWEIGHT

Patrick L. Schneider

Papers

Validity of 10 electronic pedometers for measuring steps, distance, and energy cost.

Pedometer measures of free-living physical activity: comparison of 13 models.

Accuracy and reliability of 10 pedometers for measuring steps over a 400-m walk.

Spring-Levered versus Piezo-Electric Pedometer Accuracy in Overweight and Obese Adults

Physical Activity in an Old Order Amish Community