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Rating of perceived exertion (RPE) and respiratory exchange ratio (RER) have previously been associated with acute exercise compensation. This study examined adaptations in the RPE and RER with long-term exercise training in individuals who did (noncompensators) and did not (compensators) lose the expected amount of weight. Participants ( n = 110, 71.8% women, means ± SD; age 49 ± 12 yr) completed 24 wk of supervised exercise training at 65-85% V̇o 2peak to achieve a prescribed dose of 8 kcal·kg body wt -1 ·wk -1 (8 KKW) or 20 KKW. Participants were categorized as noncompensators ( n = 55) or compensators ( n = 55) based on the percent of expected weight loss (%EWL) achieved. Changes in RPE and RER during exercise over time (baseline, week 12 , week 24 ) were compared by weight compensation category. Individual %EWL in relation to RPE, RER, and training intensity (%V̇o 2peak ) was evaluated over the same time period. RPE and RER for a given workload decreased from baseline to week 12 and stabilized through week 24 , regardless of weight compensation (time P < 0.0001). Noncompensators had a higher RPE relative to heart rate, which was partly explained by higher %V̇o 2peak . RPE and %V̇o 2peak both positively predicted %EWL, independent of age, sex, and exercise dose. Training intensity and RPE were positively associated with weight loss on the individual level, warranting further investigation into self-selection in exercise-based programs. Understanding individual heterogeneity in training intensity and behavioral responses may improve future weight management efforts that involve exercise. NEW & NOTEWORTHY In sedentary individuals with overweight and obesity, achievement of expected weight loss from long-term exercise training was associated with individual adaptations in perceived exertion. Contrary to our hypothesis, those with higher relative perceived exertion achieved a larger proportion of their expected weight loss, which was partly explained by a higher self-selected exercise training intensity.

Background: Step-counting interventions with discrepant intensity emphases may elicit different effects., Methods: A total of 120 sedentary/low-active, postmenopausal women were randomly assigned to one of the following 3 groups: (1) 10,000 steps per day (with no emphasis on walking intensity/speed/cadence; basic intervention, 49 completers), (2) 10,000 steps per day and at least 30 minutes in moderate intensity (ie, at a cadence of at least 100 steps per minute; enhanced intervention, 47 completers), or (3) a control group (19 completers). NL-1000-determined steps and active minutes (a device-specific indicator of time at moderate+ intensity) were collected as process variables during the 12-week intervention. Outcome variables included systolic and diastolic blood pressure, anthropometric measurements, fasting blood glucose and insulin, flow-mediated dilation, gait speed, and ActiGraph GT3X+-determined physical activity and sedentary behavior., Results: The "basic group" increased 5173 to 9602 steps per day and 9.2 to 30.2 active minutes per day. The "enhanced group" similarly increased 5061 to 10,508 steps per day and 8.7 to 38.8 active minutes per day. The only significant change over time for clinical variables was body mass index., Conclusions: Interventions that use simple step-counters can achieve elevated volume and intensity of daily physical activity, regardless of emphasis on intensity. Despite this, few clinical outcomes were apparent in this sample of postmenopausal women with generally normal or controlled hypertension.

Background: Exercise is recommended for weight management, yet exercise produces less weight loss than expected, which is called weight compensation. The mechanisms for weight compensation are unclear., Objective: The aim of this study was to identify the mechanisms responsible for compensation., Methods: In a randomized controlled trial conducted at an academic research center, adults (n = 198) with overweight or obesity were randomized for 24 wk to a no-exercise control group or 1 of 2 supervised exercise groups: 8 kcal/kg of body weight/wk (KKW) or 20 KKW. Outcome assessment occurred at weeks 0 and 24. Energy intake, activity, and resting metabolic rate (RMR) were measured with doubly labeled water (DLW; with and without adjustments for change in RMR), armband accelerometers, and indirect calorimetry, respectively. Appetite and compensatory health beliefs were measured by self-report., Results: A per-protocol analysis included 171 participants (72.5% women; mean ± SD baseline body mass index: 31.5 ± 4.7 kg/m2). Significant (P < 0.01) compensation occurred in the 8 KKW (mean: 1.5 kg; 95% CI: 0.9, 2.2 kg) and 20 KKW (mean: 2.7 kg; 95% CI: 2.0, 3.5 kg) groups, and compensation differed significantly between the exercise groups (P = 0.01). Energy intake by adjusted DLW increased significantly (P < 0.05) in the 8 KKW (mean: 90.7 kcal/d; 95% CI: 35.1, 146.4 kcal/d) and 20 KKW (mean: 123.6 kcal/d; 95% CI: 64.5, 182.7 kcal/d) groups compared with control (mean: -2.3 kcal/d; 95% CI: -58.0, 53.5 kcal/d). Results were similar without DLW adjustment. RMR and physical activity (excluding structured exercise) did not differentially change among the 3 groups. Participants with higher compared with lower compensation reported increased appetite ratings and beliefs that healthy behaviors can compensate for unhealthy behaviors. Furthermore, they increased craving for sweet foods, increased sleep disturbance, and had worsening bodily pain., Conclusions: Compensation resulted from increased energy intake and concomitant increases in appetite, which can be treated with dietary or pharmacological interventions. Compensation was not due to activity or metabolic changes. This trial was registered at clinicaltrials.gov as NCT01264406., (Copyright © American Society for Nutrition 2019.)

Underserved and minority populations suffer from a disproportionately high prevalence of obesity and related comorbidities. Effective obesity treatment programs delivered in primary care that produce significant weight loss are currently lacking. The purpose of this trial is to test the effectiveness of a pragmatic, high intensity lifestyle-based obesity treatment program delivered within primary care among an underserved population. We hypothesize that, relative to patients who receive usual care, patients who receive a high-intensity, health literacy- and culturally-appropriate lifestyle intervention will have greater percent reductions in body weight over 24 months. Eighteen clinics (N = 803 patients) serving low income populations with a high proportion of African Americans in Louisiana were randomized to the intervention or usual car. Patients in the intervention participate in a high-intensity lifestyle program delivered by health coaches employed by an academic health center and embedded in the primary care clinics. The program consists of weekly (16 in-person/6 telephone) sessions in the first six months, followed by sessions held at least monthly for the remaining 18 months. Primary care practitioners in usual care receive information on weight management and the current Centers for Medicare and Medicaid Services reimbursement for obesity treatment. The primary outcome is percent weight loss at 24 months. Secondary outcomes include absolute 24-month changes in body weight, waist circumference, blood pressure, fasting glucose and lipids, health-related quality of life, and weight-related quality of life. The results will provide evidence on the effectiveness of implementing high-intensity lifestyle and obesity counseling in primary care settings among underserved populations., Trial Registration: ClinicalTrials.gov Identifier NCT02561221., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: To examine the joint association of birth weight and physical activity/sedentary time with childhood obesity in 12 countries., Methods: A cross-sectional study of 5,088 children aged 9 to 11 years was conducted. Birth weight was recalled by parents or guardians. Moderate-to-vigorous physical activity (MVPA) and sedentary behavior were objectively measured using accelerometry., Results: The association of birth weight with the odds of obesity, central obesity, and high body fat was significant among children with either low MVPA or high sedentary time but not among children with either high MVPA or low sedentary time. In comparison with children with normal birth weight and high MVPA, children with high birth weight and low MVPA showed 4.48- to 5.18-fold higher odds of obesity, central obesity, and high body fat; children with normal birth weight and low MVPA showed 3.00- to 3.30-fold higher odds of obesity, central obesity, and high body fat, and children with high birth weight and high MVPA showed 1.16- to 1.68-fold higher odds of obesity, central obesity, and high body fat., Conclusions: High MVPA is more important than high birth weight as a correlate of obesity in children., (© 2017 The Obesity Society.)

Purpose: This study aimed to catalog the relationships between step-based accelerometer metrics indicative of physical activity volume (steps per day, adjusted to a pedometer scale), intensity (mean steps per minute from the highest, not necessarily consecutive, minutes in a day; peak 30-min cadence), and sedentary behavior (percent time at zero cadence relative to wear time; %TZC) and cardiometabolic risk factors., Methods: We analyzed data from 3388 participants, 20+ yr old, in the 2005-2006 National Health and Nutrition Examination Survey with ≥1 valid day of accelerometer data and at least some data on weight, body mass index, waist circumference, systolic and diastolic blood pressure, glucose, insulin, HDL cholesterol, triglycerides, and/or glycohemoglobin. Linear trends were evaluated for cardiometabolic variables, adjusted for age and race, across quintiles of steps per day, peak 30-min cadence, and %TZC., Results: Median steps per day ranged from 2247 to 12,334 steps per day for men and from 1755 to 9824 steps per day for women, and median peak 30-min cadence ranged from 48.1 to 96.0 steps per minute for men and from 40.8 to 96.2 steps per minute for women for the first and fifth quintiles, respectively. Linear trends were statistically significant (all P < 0.001), with increasing quintiles of steps per day and peak 30-min cadence inversely associated with waist circumference, weight, body mass index, and insulin for both men and women. Median %TZC ranged from 17.6% to 51.0% for men and from 19.9% to 47.6% for women for the first and fifth quintiles, respectively. Linear trends were statistically significant (all P < 0.05), with increasing quintiles of %TZC associated with increased waist circumference, weight and insulin for men, and insulin for women., Conclusions: This analysis identified strong linear relationships between step-based movement/nonmovement dimensions and cardiometabolic risk factors. These data offer a set of quantified access points for studying the potential dose-response effects of each of these dimensions separately or collectively in longitudinal observational or intervention study designs.

Background: Energy expenditure (EE) estimates for a broad age range of youth performing a variety of activities are needed., Methods: 106 participants (6-18 years) completed 6 free-living activities (seated rest, movie watching, coloring, stair climbing, basketball dribbling, jumping jacks) and up to 9 treadmill walking bouts (13.4 to 120.7 m/min; 13.4 m/min increments). Breath-by-breath oxygen uptake (VO2) was measured using the COSMED K4b2 and EE was quantified as youth metabolic equivalents (METy1:VO2/measured resting VO2, METy2:VO2/estimated resting VO2). Age trends were evaluated with ANOVA., Results: Seated movie watching produced the lowest mean METy1 (6- to 9-year-olds: 0.94 ± 0.13) and METy2 values (13- to 15-year-olds: 1.10 ± 0.19), and jumping jacks produced the highest mean METy1 (13- to 15-year-olds: 6.89 ± 1.47) and METy2 values (16- to 18-year-olds: 8.61 ± 2.03). Significant age-related variability in METy1 and METy2 were noted for 8 and 2 of the 15 evaluated activities, respectively., Conclusions: Descriptive EE data presented herein will augment the Youth Compendium of Physical Activities.

Objective: The aim was to assess associations between lifestyle behaviors and obesity in a multinational study of children from 12 countries representing a wide range of human development., Methods: The sample included 6,025 children 9-11 years of age. Behavioral risk factors included nocturnal sleep duration, moderate to vigorous physical activity (MVPA), television viewing (TV time), and healthy and unhealthy diet pattern scores. Multilevel analyses were used to obtain odds ratios for obesity expressed per standard deviation of each behavioral risk factor., Results: The odds ratios (95% confidence intervals) for obesity from multilevel, multivariable models were 0.79 (0.71-0.90) for nocturnal sleep duration, 0.52 (0.45-0.60) for MVPA, 1.15 (1.05-1.27) for TV time, 1.08 (0.96-1.20) for healthy diet score, and 0.93 (0.83-1.04) for unhealthy diet score in boys and 0.71 (0.63-0.80) for nocturnal sleep duration, 0.43 (0.35-0.53) for MVPA, 1.07 (0.96-1.19) for TV time, 1.05 (0.93-1.19) for healthy diet score, and 0.96 (0.82-1.11) for unhealthy diet score in girls., Conclusions: Behavioral risk factors are important correlates of obesity in children, particularly low MVPA, short sleep duration, and high TV viewing., (© 2015 The Obesity Society.)

Background: Lack of regular physical activity at prescribed intensity levels is a modifiable risk factor for insulin resistance and the development of diabetes. African American men are at increased risk for developing diabetes and most African American men are not meeting the current recommended levels of physical activity. The primary objective of the Aerobic Plus Resistance Training and Insulin Resistance in African American Men (ARTIIS) study is to determine the effectiveness of an exercise training intervention aimed at reducing diabetes risk factors in African American men at risk for developing diabetes., Methods: Insufficiently active 35-70 year old African American men with a family history of diabetes were eligible for the study. The 5-month randomized controlled trial assigns 116 men to an exercise training or healthy living control arm. The exercise training arm combines aerobic and resistance training according to the current national physical activity recommendations and is conducted in community (YMCA) facilities. The healthy living arm receives information promoting healthy lifestyle changes., Outcomes: Insulin response to an oral glucose load is the primary outcome measure, and changes in physiological parameters, cardiorespiratory fitness, strength, body composition, and psychological well-being comprise the secondary outcomes., Conclusions: The ARTIIS study is one of the first adequately powered, rigorously designed studies to investigate the effects of an aerobic plus resistance exercise training program and to assess adherence to exercise training in community facilities, in African American men., (Copyright © 2015 Elsevier Inc. All rights reserved.)

We report experiences, observations, and general lessons learned, specifically with regards to participant recruitment and adherence, while implementing a 6-month randomized controlled treadmill desk intervention (the WorkStation Pilot Study) in a real-world office-based health insurance workplace. Despite support from the company's upper administration, relatively few employees responded to the company-generated e-mail to participate in the study. Ultimately only 41 overweight/obese participants were deemed eligible and enrolled from a recruitment pool of 728 workers. Participants allocated to the Treadmill Desk Group found the treadmill desk difficult to use for 45 min twice a day as scheduled. Overall attendance averaged 45%-50% of all possible scheduled sessions. The most frequently reported reasons for missing sessions included work conflict (35%), out of office (30%), and illness/injury/drop-out (20%). Although focus groups indicated consistently positive comments about treadmill desks, an apparent challenge was fitting a rigid schedule of shared use to an equally rigid and demanding work schedule punctuated with numerous tasks and obligations that could not easily be interrupted. Regardless, we documented that sedentary office workers average ∼43 min of light-intensity (∼2 METs) treadmill walking daily in response to a scheduled, facilitated, and shared access workplace intervention. Workstation alternatives that combine computer-based work with light-intensity physical activity are a potential solution to health problems associated with excessive sedentary behavior; however, there are numerous administrative, capital, and human resource challenges confronting employers considering providing treadmill desks to workers in a cost-effective and equitable manner.

Background: Weight loss induced only by exercise is frequently less than expected, possibly because of compensatory changes in energy intake and/or energy expenditure. The purpose of the Examination of Mechanisms (E-MECHANIC) of Exercise-Induced Weight Compensation trial is to examine whether increased energy intake and/or reduced spontaneous activity or energy expenditure (outside of structured exercise) account for the less than expected, exercise-associated weight loss., Methods/design: E-MECHANIC is a three-arm, 6-month randomized (1:1:1) controlled trial. The two intervention arms are exercise doses that reflect current recommendations for (1) general health (8 kcal/kg body weight per week (8 KKW), about 900 kcal/wk) and (2) weight loss (20 KKW, about 2,250 kcal/wk). The third arm, a nonexercise control group, will receive health information only. The sample will include a combined total of 198sedentary, overweight or obese (body mass index: ≥25 kg/m² to ≤45 kg/m²) men and women ages 18 to 65 years. The exercise dose will be supervised and tightly controlled in an exercise training laboratory. The primary outcome variables are energy intake, which will be measured using doubly labeled water (adjusted for change in energy stores) and laboratory-based food intake tests, and the discrepancy between expected weight loss and observed weight loss. Secondary outcomes include changes in resting metabolic rate (adjusted for change in body mass), activity levels (excluding structured exercise) and body composition. In an effort to guide the development of future interventions, the participants will be behaviorally phenotyped and defined as those who do compensate (that is, fail to lose the amount of weight expected) or do not compensate (that is, lose the amount of weight expected or more)., Discussion: In this study, we will attempt to identify underlying mechanisms to explain why exercise elicits less weight loss than expected. This information will guide the development of interventions to increase exercise-induced weight loss and maximize weight loss retention and related health benefits., Trial Registration: ClinicalTrials.gov ID: NCT01264406 (registration date: 20 December 2010).

Objective: To establish whether exercise improves quality of life (QOL) in individuals with type 2 diabetes and which exercise modalities are involved., Research Design and Methods: Health Benefits of Aerobic and Resistance Training in individuals with type 2 Diabetes (HART-D; n = 262) was a 9-month exercise study comparing the effects of aerobic training, resistance training, or a combination of resistance and aerobic training versus a nonexercise control group on hemoglobin A1c (HbA1c) in sedentary individuals with type 2 diabetes. This study is an ancillary analysis that examined changes in QOL after exercise training using the Short Form-36 Health Survey questionnaire compared across treatment groups and with U.S. national norms., Results: The ancillary sample (n = 173) had high baseline QOL compared with U.S. national norms. The QOL physical component subscale (PCS) and the general health (GH) subscale were improved by all three exercise training conditions compared with the control group condition (resistance: PCS, P = 0.005; GH, P = 0.003; aerobic: PCS, P = 0.001; GH, P = 0.024; combined: PCS, P = 0.015; GH, P = 0.024). The resistance training group had the most beneficial changes in bodily pain (P = 0.026), whereas physical functioning was most improved in the aerobic and combined condition groups (P = 0.025 and P = 0.03, respectively). The changes in the mental component score did not differ between the control group and any of the exercise groups (all P > 0.05). The combined training condition group had greater gains than the aerobic training condition group in the mental component score (P = 0.004), vitality (P = 0.031), and mental health (P = 0.008) and greater gains in vitality compared with the control group (P = 0.021)., Conclusions: Exercise improves QOL in individuals with type 2 diabetes. Combined aerobic/resistance exercise produces greater benefit in some QOL domains.

African American (AA) women have an elevated risk of cardiovascular disease and have been reported to have lower cardiorespiratory fitness (CRF) compared with Caucasian American (CA) women. However, little data exist that evaluate racial differences in the change in CRF following aerobic exercise training. CA (n = 264) and AA (n = 122) postmenopausal women from the Dose-Response to Exercise in Women study were randomized to 4, 8, and 12 kcal·kg body wt(-1)·wk(-13) (KKW) of aerobic training or the control group for 6 mo. CRF was evaluated using a cycle ergometer. A greater increase in relative CRF was observed in CA compared with AA women in the 4 (CA: 1.00 vs. AA: 0.35 ml O2·kg(-1)·min (-1), P = 0.034), 8 (CA: 1.59 vs. AA: 0.82 ml O2·kg(-1)·min (-1), P = 0.041), and 12 (CA: 1.98 vs. AA: 0.50 ml O2·kg(-1)·min (-1), P = 0.001) KKW groups. Similar effects were found in absolute CRF, with the exception of the 4-KKW (CA: 0.04 vs. AA: 0.02 l O2/min, P = 0.147) group. However, in categorical analyses, the percentages of women who improved in both relative (>0 ml O2·kg(-1)·min (-1)) and absolute (>0 l O2/min) CRF were not significantly different for CA and AA women in all exercise groups (all P > 0.05). AA postmenopausal women, in general, had an attenuated increase in CRF (both relative and absolute) following exercise training, but had similar response rates compared with CA women. Future studies should investigate the physiologic mechanisms responsible for this attenuated response.

Background: Exercise training reduces adiposity and risk of cardiovascular disease. However, the combined effects of habitual free-living physical activity and aerobic training on waist circumference, weight, fitness, and blood pressure in postmenopausal women are unknown., Purpose: To evaluate the effects of habitual physical activity levels during aerobic training on weight, waist circumference, fitness, and blood pressure., Design: Secondary analysis of an RCT. Original data collected April 2001 to June 2005 and analyzed in 2012., Setting/participants: Postmenopausal women in a supervised exercise trial., Intervention: Women (n=325) were randomized to 4, 8, or 12 kcal/kg per week of aerobic training or a control group for 6 months. All outcome measures were collected at baseline and follow-up. Changes in dependent variables within each training group were evaluated across tertiles of pedometer-determined habitual physical activity outside exercise training sessions., Main Outcome Measures: Changes in waist circumference and weight., Results: Reductions in waist circumference were significantly greater with higher steps/day accumulated outside exercise training compared to lower levels in the 4 (high: -4.8 cm vs low: -1.4 cm, p=0.03); 8 (high: -4.2 cm vs low: -0.4 cm, p=0.03), and 12 kcal/kg per week groups (high: -4.1 cm vs low: -0.7 cm, p=0.05). For all groups, p-trend≤0.03. A trend was observed for greater weight reduction with higher steps/day in the 4 kcal/kg per week group (p-trend=0.04) but not for the other exercise doses. No effects were observed for blood pressure or fitness measures (all p>0.05)., Conclusions: In postmenopausal women, higher habitual physical activity while participating in aerobic training was associated with greater reductions in central adiposity, and was supportive of weight loss compared to lower levels., (Copyright © 2012 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.)

Background: Elevated total white blood cell (WBC) count is associated with an increased risk of coronary heart disease and death. Aerobic exercise is associated with lower total WBC, neutrophil, and monocyte counts. However, no studies have evaluated the effect of the amount of aerobic exercise (dose) on total WBC and WBC subfraction counts., Purpose: To examine the effects of 3 different doses of aerobic exercise on changes in total WBC and WBC subfraction counts and independent effects of changes in fitness, adiposity, markers of inflammation (IL-6, TNF-α, C-reactive protein), fasting glucose metabolism, and adiponectin., Methods: Data from 390 sedentary, overweight/obese postmenopausal women from the DREW study were used in these analyses. Women were randomized to a non-exercise control group or one of 3 exercise groups: energy expenditure of 4, 8, or 12 kcal kg(-1)⋅week(-1) (KKW) for 6 months at an intensity of 50% VO2peak., Results: A dose-dependent decrease in total WBC counts (trend P = 0.002) was observed with a significant decrease in the 12KKW group (-163.1±140.0 cells/µL; mean±95%CI) compared with the control (138.6±144.7 cells/µL). A similar response was seen in the neutrophil subfraction (trend P = 0.001) with a significant decrease in the 12KKW group (-152.6±115.1 cells/µL) compared with both the control and 4KKW groups (96.4±119.0 and 21.9±95.3 cells/µL, respectively) and in the 8KKW group (-102.4±125.0 cells/µL) compared with the control. When divided into high/low baseline WBC categories (median split), a dose-dependent decrease in both total WBCs (P = 0.003) and neutrophils (P<0.001) was observed in women with high baseline WBC counts. The effects of exercise dose on total WBC and neutrophil counts persisted after accounting for significant independent effects of change in waist circumference and IL-6., Conclusion: Aerobic exercise training reduces total WBC and neutrophil counts, in a dose-dependent manner, in overweight/obese postmenopausal women and is especially beneficial for those with systemic low grade inflammation., Clinical Trials Identifier: NCT00011193.

Background: We examined the effects of wear time on a population profile of time-stamped accelerometer outputs using the 2005-2006 National Health and Nutrition Examination Survey (NHANES) data representing 3744 adults ≥ 20 years of age., Methods: Outputs included activity counts, steps, and time variables: nonwear (macro-determined), sedentary behavior (<100 activity counts/minute), and time in low (100-499 activity counts/minute), light (500-2019 activity counts/minute), and moderate-to-vigorous physical activity (MVPA; ≥2020 activity counts/minute) intensities. We describe mean values according to a 24-hour clock. Analysis was repeated in a reduced data set with only those who wore the accelerometer for 60 minutes within each considered hour of the day., Results: Between 12:00 and 17:00, U.S. adults spend approximately 31 minutes each hour in sedentary behaviors, and approximately 14 minutes, 10 minutes, and 2 minutes in low, light, and MVPA intensity activity, respectively. Removing the effect of nonwear time, sedentary behaviors are reduced in the morning hours and increase in the evening hours., Conclusion: At either end of the day, nonwear time appears to distort population estimates of all accelerometer time and physical activity volume indicators, but its effects are particularly clear on population estimates of time spent in sedentary behavior.

Background: Objective physical activity data analyses focus on moderate-to-vigorous physical activity (MVPA) without considering lower intensity lifestyle-type activities (LA). We describe 1) quantity of LA (minutes and steps per day) across demographic groups, 2) proportion of LA to total physical activity, and 3) relationships between LA and MVPA using NHANES 2005-2006 accelerometer adult data (n = 3744)., Methods: LA was defined as 760 to 2019 counts per minute (cpm) and MVPA as ≥2020 cpm. LA was compared within gender, ethnicity, age, and BMI groups. Regression analyses examined independent effects. Correlations were evaluated between LA and MVPA. All analyses incorporated sampling weights to represent national estimates., Results: Adults spent 110.4 ± 1.6 minutes and took 3476 ± 54 steps per day in LA. Similar to MVPA, LA was highest in men, Mexican Americans, and lowest in adults ≥60 years or obese. When LA was held constant, ethnic differences no longer predicted MVPA minutes, and age no longer predicted MVPA steps. LA and MVPA minutes (r = .84) and steps per day (r = .72) were significantly correlated, but attenuated with MVPA modified bouts (≥10 minutes sustained activity)., Conclusions: LA accumulation differs between demographic subgroups and is related to MVPA: adults who spend more minutes and steps in MVPA also spend them in LA.

Background: The purpose of this study was to compare steps/day detected by the YAMAX SW-200 pedometer versus the Actigraph GT3X accelerometer in free-living adults. Methods: Daily YAMAX and GT3X steps were collected from a sample of 23 overweight and obese participants (78% female; age = 52.6 ± 8.4 yr.; BMI = 31.0 ± 3.7 m·kg-2). Because a pedometer is more likely to be used in a community-based intervention program, it was used as the standard for comparison. Percent difference (PD) and absolute percent difference (APD) were calculated to examine between-instrument agreement. In addition, days were categorized based on PD: a) under-counting (> -10 PD), b) acceptable counting (-10 to 10 PD), and c) over-counting (> 10 PD). Results: The YAMAX and GT3X detected 8,025 ± 3,967 and 7131 ± 3066 steps/day, respectively, and the outputs were highly correlated (r = .87). Average PD was -3.1% ± 30.7% and average APD was 23.9% ± 19.4%. Relative to the YAMAX, 53% of the days detected by the GT3X were classified as under-counting, 25% acceptable counting, and 23% over-counting. Conclusion: Although the output of these 2 instruments is highly correlated, caution is advised when directly comparing or using their output interchangeably. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to examine the relationship between 2005-2006 National Health and Nutrition Examination Survey (NHANES) accelerometer-determined steps/day and activity counts/day, and between steps/day and estimates of nonwear time (as an indicator of the unmonitored day) and time spent in sedentary behaviors as well as a range of physical activity intensities. Methods: Linear regression models were used to characterize the relationship between steps/day, activity counts/day, estimates of wear time, and intensity categories. Results: 1781 males (mean age = 46.5 years) and 1963 females (mean age = 47.7 years) wore accelerometers 14.0 ± SEM0.06 hours/day. The relationship between steps/day and activity counts/day was positive and strong (R² = .87). The relationship between steps/day and time spent in sedentary behaviors was inverse and moderate (R² = .25). Stronger and positive relationships were apparent between steps/day and time in light (R² = .69) and moderate (R² = .63) intensity activities. There was no discernable relationship between steps/day and time spent in low or vigorous intensity activities or with wear time. Conclusions: Assessed by accelerometer, steps/day explains 87% of the variation in activity counts/day, 25% of the variation in time in sedentary behaviors, 69% of time in light intensity, and 63% of time in moderate intensity. [ABSTRACT FROM AUTHOR]

Background Lack of regular physical activity at prescribed intensity levels is a modifiable risk factor for insulin resistance and the development of diabetes. African American men are at increased risk for developing diabetes and most African American men are not meeting the current recommended levels of physical activity. The primary objective of the Aerobic Plus Resistance Training and Insulin Resistance in African American Men (ARTIIS) study is to determine the effectiveness of an exercise training intervention aimed at reducing diabetes risk factors in African American men at risk for developing diabetes. Methods Insufficiently active 35–70 year old African American men with a family history of diabetes were eligible for the study. The 5-month randomized controlled trial assigns 116 men to an exercise training or healthy living control arm. The exercise training arm combines aerobic and resistance training according to the current national physical activity recommendations and is conducted in community (YMCA) facilities. The healthy living arm receives information promoting healthy lifestyle changes. Outcomes Insulin response to an oral glucose load is the primary outcome measure, and changes in physiological parameters, cardiorespiratory fitness, strength, body composition, and psychological well-being comprise the secondary outcomes. Conclusions The ARTIIS study is one of the first adequately powered, rigorously designed studies to investigate the effects of an aerobic plus resistance exercise training program and to assess adherence to exercise training in community facilities, in African American men. [ABSTRACT FROM AUTHOR]

Objectives: We used linked existing data from the 2006–2008 American Time Use Survey (ATUS), the Current Population Survey (CPS, a federal survey that provides on-going U.S. vital statistics, including employment rates) and self-reported body mass index (BMI) to answer: How does BMI vary across full time occupations dichotomized as sedentary/non-sedentary, accounting for time spent in sleep, other sedentary behaviors, and light, moderate, and vigorous intensity activities? Methods: We classified time spent engaged at a primary job (sedentary or non-sedentary), sleep, and other non-work, non-sleep intensity-defined behaviors, specifically, sedentary behavior, light, moderate, and vigorous intensity activities. Age groups were defined by 20–29, 30–39, 40–49, and 50–64 years. BMI groups were defined by 18.5–24.9, 25.0–27.4, 27.5–29.9, 30.0–34.9, and ≥35.0 kg/m2. Logistic and linear regression were used to examine the association between BMI and employment in a sedentary occupation, considering time spent in sleep, other non-work time spent in sedentary behaviors, and light, moderate, and vigorous intensity activities, sex, age race/ethnicity, and household income. Results: The analysis data set comprised 4,092 non-pregnant, non-underweight individuals 20–64 years of age who also reported working more than 7 hours at their primary jobs on their designated time use reporting day. Logistic and linear regression analyses failed to reveal any associations between BMI and the sedentary/non-sedentary occupation dichotomy considering time spent in sleep, other non-work time spent in sedentary behaviors, and light, moderate, and vigorous intensity activities, sex, age, race/ethnicity, and household income. Conclusions: We found no evidence of a relationship between self-reported full time sedentary occupation classification and BMI after accounting for sex, age, race/ethnicity, and household income and 24-hours of time use including non-work related physical activity and sedentary behaviors. The various sources of error associated with self-report methods and assignment of generalized activity and occupational intensity categories could compound to obscure any real relationships. [ABSTRACT FROM AUTHOR]

Background Pedometer-based programs have elicited increased walking behaviors associated with improvements in blood pressure in sedentary/low active postmenopausal women, a population at increased risk of cardiovascular disease. Such programs typically encourage increasing the volume of physical activity with little regard for its intensity. Recent advances in commercially available pedometer technology now permit tracking of both steps/day and time in moderate (or greater) intensity physical activity on a daily basis. It is not known whether the dual message to increase steps/day while also increasing time spent at higher intensity walking will elicit additional improvements in blood pressure relative to a message to only focus on increasing steps/day. The purpose of this paper is to present the rationale, study design, and protocols employed in WalkMore, a 3-arm 3-month blinded and randomized controlled trial (RCT) designed to compare the effects of two community pedometer-based walking interventions (reflecting these separate and combined messages) relative to a control group on blood pressure in sedentary/low active post-menopausal women, a population at increased risk of cardiovascular disease. Methods/design 120 sedentary/low active post-menopausal women (45-74 years of age) will be randomly assigned (computer-generated) to 1 of 3 groups: A) 10,000 steps/day (with no guidance on walking intensity/speed/cadence; BASIC intervention, n = 50); B) 10,000 steps/day and at least 30 minutes in moderate intensity (i.e., a cadence of at least 100 steps/min; ENHANCED intervention, n = 50); or a Control group (n = 20). An important strength of the study is the strict control and quantification of the pedometer-based physical activity interventions. The primary outcome is systolic blood pressure. Secondary outcomes include diastolic blood pressure, anthropometric measurements, fasting blood glucose and insulin, flow mediated dilation, gait speed, and accelerometer-determined physical activity and sedentary behavior. Discussion This study can make important contributions to our understanding of the relative benefits that walking volume and/or intensity may have on blood pressure in a population at risk of cardiovascular disease. Trial registration ClinicalTrials.gov Record NCT01519583, January 18, 2012 [ABSTRACT FROM AUTHOR]

Background. Pedometers are more likely than accelerometers to be used in walking interventions and other applications, including wide spread adoption by lay people. The purpose of this article is to provide older adults’ sex-and-age-specific normative values for accelerometer-determined steps/day, adjusted to a pedometer-based scale. Methods. The data source was accelerometer data collected over multiple valid days (defined as ≥ 10 h/day; mean 5.8 ± SE 0.1 valid days) from 1,196 60+ year olds participating in the 2005–2006 National Health and Nutrition Examination Survey. Accelerometer data were adjusted to a pedometer scale using an established process of censoring steps counted during those minutes where activity counts totaled <500. Quintile-defined categories of adjusted steps/day (lowest, below average, average, above average, and highest) for six age groups (60–64, 65–69, 70–74, 75–79, 80–84, and 85+ years) were computed for the entire sample and separately for each sex. LMSChartmakerPro was used to create smoothed percentile curves corresponding to the 5th, 25th, 50th, 75th, and 95th percentiles. Results. Men aged 65–69 years defined the highest single category (>9,126 steps/day) and women aged 85+ years of age defined the lowest single category (<276 steps/day). In general, steps/day tended to decrease within each quintile-defined category as age increased. Similar patterns were apparent in the more detailed LMSChartmakerPro percentiles. Conclusions. These data represent the first presentation of a detailed population distribution of normative accelerometer-determined steps/day adjusted to pedometer scaling, an instrument more likely to be used in clinical and public health applications. [ABSTRACT FROM PUBLISHER]

Background: An evidence-based steps/day translation of U.S. federal guidelines for youth to engage in ≥60 minutes/day of moderate-to-vigorous physical activity (MVPA) would help health researchers, practitioners, and lay professionals charged with increasing youth's physical activity (PA). The purpose of this study was to determine the number of free-living steps/day (both raw and adjusted to a pedometer scale) that correctly classified children (6-11 years) and adolescents (12-17 years) as meeting the 60-minute MVPA guideline using the 2005-2006 National Health and Nutrition Examination Survey (NHANES) accelerometer data, and to evaluate the 12,000 steps/day recommendation recently adopted by the President's Challenge Physical Activity and Fitness Awards Program. Methods: Analyses were conducted among children (n = 915) and adolescents (n = 1,302) in 2011 and 2012. Receiver Operating Characteristic (ROC) curve plots and classification statistics revealed candidate steps/day cut points that discriminated meeting/not meeting the MVPA threshold by age group, gender and different accelerometer activity cut points. The Evenson and two Freedson age-specific (3 and 4 METs) cut points were used to define minimum MVPA, and optimal steps/day were examined for raw steps and adjusted to a pedometer-scale to facilitate translation to lay populations. Results: For boys and girls (6-11 years) with ≥ 60 minutes/day of MVPA, a range of 11,500-13,500 uncensored steps/day for children was the optimal range that balanced classification errors. For adolescent boys and girls (12-17) with ≥60 minutes/day of MVPA, 11,500-14,000 uncensored steps/day was optimal. Translation to a pedometer-scaling reduced these minimum values by 2,500 step/day to 9,000 steps/day. Area under the curve was ≥84% in all analyses. Conclusions: No single study has definitively identified a precise and unyielding steps/day value for youth. Considering the other evidence to date, we propose a reasonable 'rule of thumb' value of ≥ 11,500 accelerometer-determined steps/day for both children and adolescents (and both genders), accepting that more is better. For practical applications, 9,000 steps/day appears to be a more pedometer-friendly value. [ABSTRACT FROM AUTHOR]

The article presents a study on the accelerometer-determined steps of children and youth in the U.S., which aims to detect the low-force steps of the research-quality pedometers. It offers a descriptive epidemiology of an accelerometer-determined steps of children and youth. The study was conducted to 2610 children and youth who have an uncensored accelerometer-determined steps. It also mentions that the U.S. data has shown that a consistent decline of steps per day throughout childhood and youth.

The article presents a study which examines the steps per day of 3,774 participants with the use of ActiGraph AM-7164 accelerometer-defined step data revealed by the 2005-2006 U.S. National Health and Nutrition Examination Survey (NHANES). It states that the data analysis provides the epidemiology of accelerometer-determined steps per day of adults in the U.S. with and without censoring steps. Results reveal that U.S. adults approximately have 10,000 uncensored accelerometer-determined steps per day. It notes that the accelerometer model has a step counter function used to measure the physical activity. It also categorizes the gathered data by sex wherein the difference between men and women are determined.

Background: Evidence of the effectiveness of treatment for obesity delivered in primary care settings in underserved populations is lacking.Methods: We conducted a cluster-randomized trial to test the effectiveness of a high-intensity, lifestyle-based program for obesity treatment delivered in primary care clinics in which a high percentage of the patients were from low-income populations. We randomly assigned 18 clinics to provide patients with either an intensive lifestyle intervention, which focused on reduced caloric intake and increased physical activity, or usual care. Patients in the intensive-lifestyle group participated in a high-intensity program delivered by health coaches embedded in the clinics. The program consisted of weekly sessions for the first 6 months, followed by monthly sessions for the remaining 18 months. Patients in the usual-care group received standard care from their primary care team. The primary outcome was the percent change from baseline in body weight at 24 months.Results: All 18 clinics (9 assigned to the intensive program and 9 assigned to usual care) completed 24 months of participation; a median of 40.5 patients were enrolled at each clinic. A total of 803 adults with obesity were enrolled: 452 were assigned to the intensive-lifestyle group, and 351 were assigned to the usual-care group; 67.2% of the patients were Black, and 65.5% had an annual household income of less than $40,000. Of the enrolled patients, 83.4% completed the 24-month trial. The percent weight loss at 24 months was significantly greater in the intensive-lifestyle group (change in body weight, -4.99%; 95% confidence interval [CI], -6.02 to -3.96) than in the usual-care group (-0.48%; 95% CI, -1.57 to 0.61), with a mean between-group difference of -4.51 percentage points (95% CI, -5.93 to -3.10) (P<0.001). There were no significant between-group differences in serious adverse events.Conclusions: A high-intensity, lifestyle-based treatment program for obesity delivered in an underserved primary care population resulted in clinically significant weight loss at 24 months. (Funded by the Patient-Centered Outcomes Research Institute and others; PROPEL ClinicalTrials.gov number, NCT02561221.). [ABSTRACT FROM AUTHOR]

Physical activity (PA) guidelines are typically communicated in terms of duration, frequency and intensity, e.g., 30min/day of moderate-to-vigorous physical activity (MVPA) on at least 5days/week. Step counters can be used to collect objective PA expressed as steps/day, however the association between steps/day and recommended PA levels is unclear. Objective: We determined a direct steps/day translation of 30min/day accumulated MVPA, using concurrently detected ActiGraph accelerometer-defined step and activity count data collected as part of the 2005–2006 National Health and Nutrition Examination Survey (NHANES). Method: We employed statistical models to analyze data from 3523 participants 20+years of age who wore the accelerometer for at least one valid day (i.e., at least 10/24h) over 7days. Results: 30min/day of MVPA translated to approximately 7900steps/day for males and 8300steps/day for females. In a subsample of participants (n=1197) with valid data on all 7days, we found 150min/week of MVPA translated to approximately 7000steps/day (or 49,000steps/week). Conclusion: Accumulating approximately 8000steps/day is a good proxy for 30min of daily MVPA, while accumulating 7000steps/day every day of the week is consistent with obtaining 150min of weekly MVPA. [Copyright &y& Elsevier]

Objective: Laboratory studies of adult walking behavior have consistently found that a cadence of 100 steps/min is a reasonable threshold for moderate intensity. The purpose of this study was to determine cadence patterns in free-living adults, and in particular, time spent at increasing cadence increments including 100 steps/min and beyond. Method: 3744 adults ≥20 years provided at least one valid day (minimally 10/24h of wear) of minute-by-minute accelerometer-determined step data during the 2005–2006 U.S. National Health and Nutrition Examination Survey (NHANES). Means for time spent (min/day) and steps/day were calculated for 8 cadence categories including zero and each incremental cadence band thereafter beginning with 1–19 through 100–119, and beyond to 120+steps/min. Results: U.S. adults accumulate ≅4.8h/day of zero cadence during wearing time, ≅8.7h between 1 and 59 steps/min, ≅16 min/day at cadences of 60–79 steps/min, ≅8 min at 80–99 steps/min, ≅5 min at 100–119 steps/min, and ≅2 min at 120+steps/min. Conclusion: Self-selected walking at 100+steps/min was a rare phenomenon in this large free-living sample of the U.S. population, but study participants did accumulate ≅30 min/day at cadences of 60+steps/min. [Copyright &y& Elsevier]