Association of step counts with cognitive function in apparently healthy middle-aged and older Japanese men

Background

Increasing physical activity may prevent cognitive decline. Previous studies primarily focused on older adults and used self-reported questionnaires to assess physical activity. We examined the relationship between step count, an objective measure of physical activity, and cognitive function in community-based middle-aged and older Japanese men.

Methods

The Shiga Epidemiological Study of Subclinical Atherosclerosis randomly recruited community-dwelling healthy men aged 40-79 years from Shiga, Japan, and measured their step counts over 7 consecutive days using a pedometer at baseline (2006-2008). Among men who returned for follow-up (2009-2014), we assessed their cognitive function using the Cognitive Abilities Screening Instrument (CASI) score. We restricted our analyses to those with valid 7-day average step counts at baseline and those who remained free of stroke at follow-up (n = 676). Using analysis of covariance, we calculated the adjusted means of the CASI score according to the quartiles of the average step counts.

Results

The mean (standard deviation) of age and unadjusted CASI score were 63.8 (9.1) years and 90.8 (5.8), respectively. The CASI score was elevated in higher quartiles of step counts (90.2, 90.4, 90.6, and 91.8 from the lowest to the highest quartile, respectively, [p for trend = 0.004]) in a model adjusted for age and education. Further adjustment for smoking, drinking, and other cardiovascular risk factors resulted in a similar pattern of association (p for trend = 0.005).

Conclusion

In apparently healthy middle-aged and older Japanese men, a greater 7-day average step count at baseline was associated with significantly higher cognitive function score.

Associations of pedometer-measured ambulatory activity with incidence of atherosclerotic cardiovascular diseases: Strong heart family study

OBJECTIVE

Coronary heart disease has several risk factors that require a multifactorial community intervention approach in prevention efforts. Prevalence of coronary heart disease and its risk factors have been disproportionately high among American Indians. The objective of this study is to evaluate the impact of ambulatory activity levels on the development of coronary heart disease in this population.

METHODS

Using pedometer data and other lifestyle and clinical factors from 2492 participants in the Strong Heart Family Study, we examined the associations of average daily step counts with incident coronary heart disease during an 18 to 20 year follow-up.

RESULTS

After adjusting for potential confounders, participants with daily step counts in the 4th quartile (>7282 steps per day) had significantly lower odds of developing coronary heart disease compared to those in the 1st quartile (<3010 steps per day) (p = 0.035).

CONCLUSIONS

Higher daily step count (over 7282 steps per day) is significantly associated with lower incidence of coronary heart disease among American Indian participants of the Strong Heart Family Study in a 20-year follow-up period.

Daily physical activity monitoring in older adults with metastatic prostate cancer on active treatment: Feasibility and associations with toxicity

INTRODUCTION

Physical activity may be associated with cancer treatment toxicity, but generalizability to geriatric oncology is unclear. As many older adults have low levels of physical activity and technology use, this area needs further exploration. We evaluated the feasibility of daily step count monitoring and the association between step counts and treatment-emergent symptoms.

MATERIALS AND METHODS

Adults aged 65+ starting treatment (chemotherapy, enzalutamide/abiraterone, or radium-223) for metastatic prostate cancer were enrolled in a prospective cohort study. Participants reported step counts (measured via smartphone) and symptoms (Edmonton Symptom Assessment Scale) daily for one treatment cycle (i.e., 3-4 weeks). Embedded semi-structured interviews were performed upon completion of the study. The feasibility of daily monitoring was evaluated with descriptive statistics and thematic analysis. The predictive validity of a decline in daily steps (compared to pre-treatment baseline) for the emergence of symptoms was examined using sensitivity and positive predictive value (PPV). Associations between a 15% decline in steps and the emergence of moderate (4-6/10) to severe (7-10/10) symptoms and pain in the next 24 h were assessed using logistic regression.

RESULTS

Of 90 participants, 47 engaged in step count monitoring (median age = 75, range = 65-88; 52.2% participation rate). Daily physical activity monitoring was found to be feasible (94% retention rate; 90.5% median response rate) with multiple patient-reported benefits including increased self-awareness and motivation to engage in physical activity. During the first treatment cycle, instances of a 15% decline in steps were common (n = 37, 78.7%), as was the emergence of moderate to severe symptoms overall (n = 40, 85.1%) and pain (n = 26, 55.3%). The predictive validity of a 15% decline in steps on the emergence of moderate to severe symptoms was good (sensitivity = 81.8%, 95% confidence interval [CI] = 68.7-95.0; PPV = 73.0%, 95% CI = 58.7-87.3), although the PPV for pain was poor (sensitivity = 77.8%, 95% CI = 58.6-97.0; PPV = 37.8%, 95% CI = 22.2-53.5). In the regression models, changes in daily physical activity were not associated with symptoms or pain.

DISCUSSION

Changes in physical activity had modest ability to predict moderate to severe symptoms overall. Although participation was suboptimal, daily activity monitoring in older adults with cancer appears feasible and may have other uses such as improving physical activity levels. Further studies are warranted.

Interrupting bedtime to reverse frailty levels in acute care: a study protocol for the Breaking Bad Rest randomized controlled trial

BACKGROUND

Hospitalized older patients spend most of the waking hours in bed, even if they can walk independently. Excessive bedrest contributes to the development of frailty and worse hospital outcomes. We describe the study protocol for the Breaking Bad Rest Study, a randomized clinical trial aimed to promoting more movement in acute care using a novel device-based approach that could mitigate the impact of too much bedrest on frailty.

METHODS

Fifty patients in a geriatric unit will be randomized into an intervention or usual care control group. Both groups will be equipped with an activPAL (a measure of posture) and StepWatch (a measure of step counts) to wear throughout their entire hospital stay to capture their physical activity levels and posture. Frailty will be assessed via a multi-item questionnaire assessing health deficits at admission, weekly for the first month, then monthly thereafter, and at 1-month post-discharge. Secondary measures including geriatric assessments, cognitive function, falls, and hospital re-admissions will be assessed. Mixed models for repeated measures will determine whether daily activity differed between groups, changed over the course of their hospital stay, and impacted frailty levels.

DISCUSSION

This randomized clinical trial will add to the evidence base on addressing frailty in older adults in acute care settings through a devices-based movement intervention. The findings of this trial may inform guidelines for limiting time spent sedentary or in bed during a patient's stay in geriatric units, with the intention of scaling up this study model to other acute care sites if successful.

TRIAL REGISTRATION

The protocol has been registered at clinicaltrials.gov (identifier: NCT03682523).

Accuracy and precision of wrist-worn actigraphy for measuring steps taken during over-ground and treadmill walking in adults with Parkinson's disease

INTRODUCTION

Step counts represent a straight-forward method of measuring physical activity in adults with Parkinson's disease (PD). The present study examined the absolute and relative accuracy and precision of a wrist-worn research-grade accelerometer (i.e., ActiGraph GT3X+) for measuring step counts during over-ground and treadmill walking in adults with PD and controls without PD.

METHODS

Participants (PD: n = 29; controls: n = 31) wore two ActiGraph GT3X + accelerometers, one on each wrist, and completed an over-ground walking bout followed by a treadmill walking bout at the same speed. Step counts were measured manually using a hand-held tally counter. Accuracy and precision were based on absolute and relative metrics.

RESULTS

The ActiGraph GT3X + underestimated step counts in both participants with PD (4.7-11% error) and controls without PD (8.8-17% error), with a greater discrepancy in controls. The ActiGraph GT3X + provided more accurate and precise estimates of step counts when placed on the more affected wrist and non-dominant wrist for participants with PD and controls, respectively, and was more accurate and precise during over-ground walking compared with treadmill walking for both groups.

CONCLUSIONS

Our results suggest that placement of the device (i.e., dominant vs. non-dominant), type of activity (i.e., over-ground vs. treadmill walking), and presence of clinical conditions may impact the accuracy and precision of data when using the research-grade ActiGraph GT3X + accelerometer for measuring step counts.

Early effects of the COVID-19 pandemic on physical activity locations and behaviors in adults living in the United States

COVID-19 restrictions and social-distancing may inhibit adults from attaining recommended levels of physical activity. This study examined early impact of COVID-19 pandemic on physical activity in adults during the first two months of restrictions in the U.S. and how physical activity locations were associated with physical activity levels during this period. Adults (N = 268) completed an online survey between April 10-May 25, 2020. Participants reported minutes of vigorous, moderate, and walking physical activity for past 7 days (early-COVID-19) and for a typical week in February 2020 (pre-COVID-19). Adults reported locations (e.g., home/garage, parks/trails) were they were active over the past 7 days. Past 12-month step count data were extracted from participants' personal smartphones. Participants (18-74 years old, 22% Hispanic/Latino, 81% female) showed reductions in vigorous (M _diff  = -66.9 min/week), moderate (M _diff  = -92.4 min/week), walking (M _diff -70.8 min/week), and step counts (M _diff  = -2232 steps/day) from the pre- to early-COVID19 periods. Reductions in walking and steps were larger for low-income and Hispanic/Latino adults. During early-COVID19, more vigorous and moderate activity were reported by those who were active in their home/garage or driveway/yard, and more steps were recorded by those who were active on the roads in their neighborhood or at parks/trails. We observed a decline in adults' physical activity during the first two months of the COVID-19 pandemic based on retrospective self-report and device-based measures. Although these restrictions were necessary to slow the spread of the virus, data indicate that there may be unintended consequences on health-related behaviors.

REGO-ACT: assessment of physical activity during treatment with regorafenib for metastatic colorectal cancer

BACKGROUND

A frequent side effect of the multikinase inhibitor regorafenib is fatigue. Physical activity has shown potential in reducing cancer-related fatigue.

METHODS

This non-interventional pilot study assessed physical activity levels of metastatic colorectal cancer (mCRC) patients treated with regorafenib based on median daily step counts measured at 1‑week intervals using a pedometer. The study further evaluated relations between physical activity levels and fatigue, quality of life (QoL) and progression-free survival.

RESULTS

Pedometer data were available for 22 out of 25 enrolled patients. The numbers of days with available pedometer data ranged from 6 to 100 days. The overall median daily step count was 2357 (range 10-14,931), with substantial interindividual and intraindividual variations. Interindividual median weekly step counts were in the range of 5000-7000 in some, 2000-3000 in others, and several hundreds or less in a few patients. Intraindividual daily step counts also varied by several thousands of steps. Step counts in weeks in which patients reported fatigue were well within the range of or even higher than step counts in adjacent weeks, indicating a lack of correlation. The risk of disease progression was also independent of median weekly step counts; however, significant correlations were seen between QoL and step counts.

CONCLUSION

Despite the severity of their disease patients showed remarkable levels of walking activity. In view of the highly individual activity levels, exercise prescriptions for seriously ill patient populations should be personalized to the specific needs and preferences of each individual patient.

Excessive body weight of children and adolescents in the spotlight of their parents' overweight and obesity, physical activity, and screen time

OBJECTIVES

The main aim of this study was to bridge the research gap in the countries of Central Europe using the family dyad approach to examine the associations of parents' overweight/obesity, physical activity (PA), and screen time (ST) with excessive body weight in their offspring.

METHODS

The cross-sectional study included 1101 parent-child dyads (648/453 mother/father-child aged 4-16) selected by two-stage stratified random sampling with complete data on body weight categories, weekly PA (Yamax pedometer), ST (family logbook) collected over a regular school/working week during the spring and autumn seasons between 2013 and 2019. Binary logistic regression analyses were used to identify which of parents' lifestyle indicators were associated with the overweight/obesity of their offspring.

RESULTS

The mother's overweight/obesity significantly increases her children's odds of overweight/obesity. Concerning fathers, active participation in organized leisure-time PA and reaching 10,000 steps per day significantly reduce the odds of overweight/obesity in their children and adolescent offspring.

CONCLUSIONS

The cumulative effect of parental participation in organized leisure-time PA with their own family-related PA can be a natural means of preventing the development of overweight/obesity in their offspring.

Psychological factors are associated with return to pre-injury levels of sport and physical activity after ACL reconstruction

PURPOSE

The impetus of anterior cruciate ligament reconstruction (ACLR) is to allow patients to return to sport and to remain engaged in physical activity. Many patients exhibit deficits in psychological domains of health-related quality of life which may impede return to sport and physical activity participation. Therefore, the purpose of this study was to examine the association of patient-based, specifically psychological, and functional outcomes with return to sport and physical activity.

METHODS

Forty participants, a minimum of 1-year post-ACLR, reported to the laboratory for one-testing session. Participants completed a series of patient-based and functional outcome assessments. Participants were also instructed to wear a pedometer for 1 week to monitor their daily steps.

RESULTS

Twenty-five participants (62%) did not return to sport and 29 participants (72%) did not average 10,000 steps per day. Individuals with elevated levels of self-reported kinesiophobia were 17% less likely to return to sport. Self-reported knee self-efficacy and knee-related quality of life accounted for 27.1% of the variance of average daily step counts.

CONCLUSIONS

Psychological factors, specifically injury-related fear and self-efficacy, were associated more significantly than functional outcomes with return to sport and physical activity levels. Clinicians should examine psychological factors throughout rehabilitation in patients after ACLR. Future research should explore the effectiveness of psychoeducation techniques to decrease injury-related fear and enhance self-efficacy in this population.

LEVEL OF EVIDENCE

III.

Meeting physical activity recommendations is associated with health-related quality of life in women before and after Roux-en-Y gastric bypass surgery

PURPOSE

Meeting physical activity (PA) recommendations is positively associated with health-related quality of life (HRQoL), but it is still unclear whether PA (specifically objectively measured) is associated with HRQoL in bariatric surgery candidates, both before and after surgery. Thus, the aim of this study was to examine the cross-sectional association between meeting objectively measured PA recommendations and HRQoL before and after Roux-en-Y gastric bypass (RYGB) surgery.

METHODS

Sixty-six women undergoing RYGB with pre-surgery and 62 women with post-surgery valid PA and HRQoL data were included from the control group of a RCT study aiming at improving HRQoL and PA post-RYGB surgery. Measures before and 12 months after RYGB included the Short Form Health Survey (SF-36) and objectively measured PA, sedentary time (ST), and step counts with GT3X+ accelerometers. Multiple linear regression models were used to analyze the associations between PA and HRQoL.

RESULTS

Participants who engaged in more than 150 min of moderate to vigorous PA (MVPA)/week (PA recommendations) had considerably higher SF-36 scores (HRQoL) than those who did not, both pre and 12-month post-surgery, with greatest difference in the subscale bodily pain, 15.5 (p = 0.021) higher score (higher scores means less pain) pre-surgery and a 19.7 (p = 0.004) higher score post-surgery. Higher LPA and step counts and lower ST also showed positive associations in some of the subscales of SF-36.

CONCLUSIONS

Meeting the PA recommendations and overall engaging in more PA was associated with higher HRQoL, pre-, and post-RYGB surgery, highlighting the importance of PA both pre- and post-surgery.

Health-related parental indicators and their association with healthy weight and overweight/obese children's physical activity

Background

Although it is accepted that parents play a key role in forming children’s health behaviours, differences in parent-child physical activity (PA) have not previously been analysed simultaneously in random samples of families with non-overweight and overweight to obese preschool and school-aged children. This study answers the question which of the health-related parental indicators (daily step count (SC), screen time (ST), and weight status and participation in organized leisure-time PA) help their children achieve the step count recommendations.

Methods

A nationally representative sample comprising 834 families including 1564 parent-child dyads who wore the Yamax Digiwalker SW-200 pedometer for at least 8 h a day on at least four weekdays and both weekend days and completed a family log book (anthropometric parameters, SC, and ST). Logistic regression analyses were used to investigate whether parental achievement of the daily SC recommendation (10,000 SC/day), non-excessive ST (< 2 h/day), weight status, and active participation in organized PA were associated with children’s achievement of their daily SC (11,500 SC/day for pre-schoolers and 13,000/11,000 SC/day for school-aged boys/girls).

Results

While living in a family with non-overweight parents helps children achieve the daily SC recommendation (mothers in the model: OR = 3.50, 95% CI = 2.29–5.34, p < 0.001; fathers in the model: OR = 2.41, 95% CI = 1.37–4.26, p < 0.01) regardless of their age category, gender, or ST, for families with overweight/obese children, only the mother’s achievement of the SC recommendations and non-excessive ST significantly (p < 0.05) increase the odds of their children reaching the daily SC recommendation. The active participation of children in organized leisure-time PA increases the odds of all children achieving the daily SC recommendations (OR = 1.80–2.85); however, for overweight/obese children this remains non-significant. The participation of parents in organized leisure-time PA does not have a significant relationship to the odds of their overweight/obese or non-overweight children achieving the daily SC recommendations.

Conclusions

The mother’s health-related behaviours (PA and ST) significantly affect the level of PA of overweight/obese preschool and school-aged children. PA enhancement programmes for overweight/obese children cannot rely solely on the active participation of children in organized leisure-time PA; they also need to take other family-based PA, especially at weekends, into account.

Weekday-weekend variations in mother-/father-child physical activity and screen time relationship: A cross-sectional study in a random sample of Czech families with 5- to 12-year-old children

This study assessed the associations between these factors in a random sample of Czech families with preschool and school-aged children. A nationally representative sample comprised 185 families with preschool children and 649 families with school-aged children (dyads; both parents and child n = 365, mother and child n = 730, and father and child n = 469). The participants wore Yamax Digiwalker SW-200 pedometers at least four weekdays and both weekend days and completed family logbooks (anthropometric parameters, daily step counts (SC), and screen time (ST)). When a parent (fathers at weekends and mothers both on weekdays and at weekends) achieved 10,000 SC per day, their children were also significantly (OR = 2.93-6.06, 95% CI = 2.02-9.26) more likely to meet the daily SC recommendation. On the contrary, the involvement of fathers in organized leisure-time PA reduced their children's odds of meeting the SC recommendation on weekdays (OR = 0.53, 95% CI = 0.31-0.89) and at weekends (OR = 0.41, 95% CI = 0.24-0.72). The excessive ST of parents at weekends reduced the odds of their children meeting the SC recommendation (mother-child dyads: OR = 0.44, 95% CI = 0.26-0.72; father-child dyads: OR = 0.63, 95% CI = 0.37-1.06). High levels of parents' PA contribute to the achievement of the recommended daily PA in children on weekdays and at weekends. Excessive weekend ST of parents reduces their odds of their children achieving the recommended daily PA; however, the influence of parents' PA on their children's achieving the recommended daily PA is stronger than the inhibitory effect of ST.

Variables influencing wearable sensor outcome estimates in individuals with stroke and incomplete spinal cord injury: a pilot investigation validating two research grade sensors

Background

Monitoring physical activity and leveraging wearable sensor technologies to facilitate active living in individuals with neurological impairment has been shown to yield benefits in terms of health and quality of living. In this context, accurate measurement of physical activity estimates from these sensors are vital. However, wearable sensor manufacturers generally only provide standard proprietary algorithms based off of healthy individuals to estimate physical activity metrics which may lead to inaccurate estimates in population with neurological impairment like stroke and incomplete spinal cord injury (iSCI). The main objective of this cross-sectional investigation was to evaluate the validity of physical activity estimates provided by standard proprietary algorithms for individuals with stroke and iSCI. Two research grade wearable sensors used in clinical settings were chosen and the outcome metrics estimated using standard proprietary algorithms were validated against designated golden standard measures (Cosmed K4B2 for energy expenditure and metabolic equivalent and manual tallying for step counts). The influence of sensor location, sensor type and activity characteristics were also studied.

Methods

28 participants (Healthy (n = 10); incomplete SCI (n = 8); stroke (n = 10)) performed a spectrum of activities in a laboratory setting using two wearable sensors (ActiGraph and Metria-IH1) at different body locations. Manufacturer provided standard proprietary algorithms estimated the step count, energy expenditure (EE) and metabolic equivalent (MET). These estimates were compared with the estimates from gold standard measures. For verifying validity, a series of Kruskal Wallis ANOVA tests (Games-Howell multiple comparison for post-hoc analyses) were conducted to compare the mean rank and absolute agreement of outcome metrics estimated by each of the devices in comparison with the designated gold standard measurements.

Results

The sensor type, sensor location, activity characteristics and the population specific condition influences the validity of estimation of physical activity metrics using standard proprietary algorithms.

Conclusions

Implementing population specific customized algorithms accounting for the influences of sensor location, type and activity characteristics for estimating physical activity metrics in individuals with stroke and iSCI could be beneficial.

Electronic supplementary material

The online version of this article (10.1186/s12984-018-0358-y) contains supplementary material, which is available to authorized users.

Higher step count is associated with greater bone mass and strength in women but not in men

In this cross-sectional study, peripheral bone traits were examined relative to total daily steps measured with pedometer. Higher number of steps was associated with greater bone values at the calcaneus and tibia in women, but not in men. In women, dose-dependent associations at the radius were congruent with the weight-bearing bones.

INTRODUCTION

Habitual physical activity measured as daily steps may contribute to bone density and strength at the calcaneus and other weight-bearing bones.

METHODS

Subgroups of 705-837 women and 480-615 men aged 31-46 years from the Cardiovascular Risk in Young Finns Study participated in the present study. Participants were instructed to use pedometer for 1 week, and the total daily steps, divided into tertiles, were evaluated relative to quantitative ultrasound-measured bone traits at the calcaneus and peripheral quantitative computed tomography-measured bone traits at the tibia and radius. Analysis of covariance was used to examine the between-group differences.

RESULTS

In women, significant dose-dependent between-group differences were found in the weight-bearing bones and in non-weight-bearing radius. The differences in broadband ultrasound attenuation and speed of sound at the calcaneus were 3.8 and 0.5% greater in women within the highest tertile of daily steps compared to the lowest tertile (p values for trend ≤ 0.04). In tibia, women in the highest tertile (> 8765 steps/day) had on average 1-5.4% greater bone cross-sectional area, bone mineral content (BMC), trabecular density, and bone strength index at the distal site and 1.6-2.7% greater bone areas, BMC and strength strain index (SSI) at the shaft compared to women with less daily steps (p values for trend ≤ 0.02). Similarly, in radius, BMC and BSI at the distal site, and bone cross-sectional areas, BMC and SSI at the shaft were 1.7-3.4% greater in women within the highest tertile of daily steps compared to their peers (p values for trend ≤ 0.04). In men, the differences in calcaneal, tibial, and radial bone traits were mainly non-significant between the tertiles of daily steps.

CONCLUSION

Observed significant positive associations between daily steps and various bone traits at the calcaneus, tibia, and radius in women suggest that habitual physical activity may benefit skeletal health in adulthood.

Cross-Sectional and longitudinal associations of objectively-measured physical activity on blood pressure: evaluation in 37 countries

Background: We examined the cross-sectional and longitudinal associations of objectively-measured physical activity (step counts) and blood pressure (BP) among adults spanning 37 countries.

Methods: Across 37 countries, we used data from a pool of 9238 adult owners of Withings’ Pulse activity trackers, which measures steps taken each day, and Wireless Blood Pressure Monitor, which measures BP. Analyses were adjusted on age, sex, number of days where the tracker was worn, and number of BP measurements. Data was collected from 2009 to 2013.

Results: Subjects had a mean ± standard deviation (SD) age of 51.6 ± 11.3 years and a body mass index (BMI) of 28.7±5.5 kg/m². A 1-month increase of more than 3000 steps per day was associated with a decrease of systolic BP (SBP) and diastolic BP (DBP) among the obese (1.57mm Hg and 1.29 mm Hg respectively, both P<0.001) and the overweight population (0.79 mm Hg and 0.84 mm Hg respectively, both P≤0.001), but not in the normal weight population (P=0.60 and P=0.36 respectively).

Conclusion: One-month increases in daily step counts was associated with a decrease of SBP and DBP in a large obese and overweight free living population.

Accuracy of step count measured by physical activity monitors: The effect of gait speed and anatomical placement site

INTRODUCTION

Consumer-based physical activity monitors (PAMs) are becoming increasingly popular, with multiple global organisations recommending physical activity levels that equate to 10,000 steps per day for optimal health. We therefore aimed to compare the step count of five PAMs to a visual step count to identify the most accurate monitors at varying gait speeds, along with the optimal anatomical placement site.

METHODS

Participants completed 3min on a treadmill for five speeds (5.0km/h, 6.5km/h, 8.0km/h, 10km/h, 12km/h). An Actigraph wGT3XBT-BT was placed on the waist and wrist, a FitBit One on the waist, and a Fitbit Flex, Fitbit Charge HR and Jawbone UP24 on both wrists. A video of participant's lower limbs was recorded for visual count. Analyses of variance (ANOVAs) were conducted to examine the effects of gait speed and device placement site on step count accuracy.

RESULTS

Thirty-one participants (mean age 24.3±5.2yrs) took part. Step count error ranged from 41.3±13.8% for the wrist-worn Actigraph to only 0.04±4.3% and -0.3±4.0% for the waist-worn Fitbit One and Actigraph, respectively. Across all gait speeds, waist-worn devices achieved better accuracy than those on the wrist (p<0.001). The Jawbone was the most accurate wrist-worn consumer-based device at slower speeds (p=0.026), with the Fitbit Flex, and Fitbit Charge HR increasing in accuracy to match the Jawbone at higher speeds.

CONCLUSION

The accuracy and reliability of consumer-based PAMs and the Actigraph is affected by anatomical placement site and walking speed. The Fitbit One and Actigraph on the waist were the strongest performers across all speeds.

Effect and process evaluation of a kindergarten-based, family-involved cluster randomised controlled trial in six European countries on four- to six-year-old children's steps per day: the ToyBox-study

BACKGROUND

The ToyBox-intervention is a theory- and evidence-based intervention delivered in kindergartens to improve four- to six-year-old children's energy balance-related behaviours and prevent obesity. The current study aimed to (1) examine the effect of the ToyBox-intervention on increasing European four- to six-year-old children' steps per day, and (2) examine if a higher process evaluation score from teachers and parents was related to a more favourable effect on steps per day.

METHODS

A sample of 2438 four- to six-year-old children (51.9% boys, mean age 4.75 ± 0.43 years) from 6 European countries (Belgium, Bulgaria, Germany, Greece, Poland and Spain) wore a motion sensor (pedometer or accelerometer) for a minimum of two weekdays and one weekend day both at baseline and follow-up to objectively measure their steps per day. Kindergarten teachers implemented the physical activity component of the ToyBox-intervention for 6 weeks in total, with a focus on (1) environmental changes in the classroom, (2) the child performing the actual behaviour and (3) classroom activities. Children's parents received newsletters, tip cards and posters. To assess intervention effects, multilevel repeated measures analyses were conducted for the total sample and the six intervention countries separately. In addition, process evaluation questionnaires were used to calculate a total process evaluation score (with implementation and satisfaction as a part of the overall score) for teachers and parents which was then linked with the physical activity outcomes.

RESULTS

No significant intervention effects on four- to six-year-old children' steps per weekday, steps per weekend day and steps per average day were found, both in the total sample and in the country-specific samples (all p > 0.05). In general, the intervention effects on steps per day were least favourable in four- to six-year-old children with a low teachers process evaluation score and most favourable in four- to six-year-old children with a high teachers process evaluation score. No differences in intervention effects were found for a low, medium or high parents' process evaluation score.

CONCLUSION

The physical activity component of the ToyBox-intervention had no overall effect on four- to six-year-old children' steps per day. However, the process evaluation scores showed that kindergarten teachers that implemented the physical activity component of the ToyBox-intervention as planned and were satisfied with the physical activity component led to favourable effects on children's steps per day. Strategies to motivate, actively involve and engage the kindergarten teachers and parents/caregivers are needed to induce larger effects.

Association between daily step counts and physical activity level among Korean elementary schoolchildren

[Purpose]

The purpose of the current study was to investigate steps per day (steps/d) and physical activity level (PAL) in Korean elementary school children having normal weight (normal-weight). We also clarified whether a gender difference exited between steps/d and PAL.

[Methods]

Children aged 9 to 12 y were recruited from two elementary schools located in different urban districts in Korea. The present study included 33 Korean children, of which 18 were normal-weight boys and 15 were normal-weight girls. During the same 1 week study period under free-living conditions the total energy expenditure (TEE) and step counts were estimated using the doubly labeled water (DLW) method and an accelerometer, respectively. We calculated PAL as the TEE/ resting metabolic rate.

[Results]

The range of PAL was 1.25 – 1.93 with a mean value of 1.57. None of the variables of energy expenditure was significantly different by sex. However, steps/d were significantly higher in boys than in girls. When adjusting regression analysis by gender, steps/ d were positively associated with PAL among all subjects (r = 0.56, P < 0.01). Furthermore, steps/d were positively associated with PAL in boys (r = 0.68, P < 0.01), but not in girls (r = 0.27, P = 0.34).

[Conclusion]

Our results suggest that locomotive activity may be the main contributor to the individual PAL differences for elementary school boys, while non-locomotive activity may be the main contributor for elementary school girls.

Comparison of physical activity assessed using hip- and wrist-worn accelerometers

OBJECTIVES

It is unclear how physical activity estimates differ when assessed using hip- vs wrist-worn accelerometers. The objective of this study was to compare physical activity assessed by hip- and wrist-worn accelerometers in free-living older women.

DESIGN

A cross-sectional study collecting data in free-living environment.

METHODS

Participants were from the Women's Health Study, in which an ancillary study is objectively measuring physical activity using accelerometers (ActiGraph GT3X+). We analyzed data from 94 women (mean (SD) age=71.9 (6.0) years) who wore a hip-worn and wrist-worn accelerometers simultaneously for 7 days.

RESULTS

Using triaxial data (vector magnitude, VM), total activity volume (counts per day) between the two locations was moderately correlated (Spearman's r=0.73). Hip and wrist monitors wear locations identically classified 71% individuals who were at the highest 40% or lowest 40% of their respective distributions. Similar patterns and slightly stronger agreements were observed when examining steps instead of VM counts.

CONCLUSIONS

Accelerometer-assessed physical activity using hip- vs wrist-worn devices was moderately correlated in older, free-living women. However, further research needs to be conducted to examine comparisons of specific activities or physical activity intensity levels.