Step counting has long been used as a method of measuring distance. Starting in the mid-1900s, researchers became interested in using steps per day to quantify ambulatory physical activity. This line ...of research gained momentum after 1995, with the introduction of reasonably accurate spring-levered pedometers with digital displays. Since 2010, the use of accelerometer-based “activity trackers” by private citizens has skyrocketed. Steps have several advantages as a metric for assessing physical activity: they are intuitive, easy to measure, objective, and they represent a fundamental unit of human ambulatory activity. However, since they measure a human behavior, they have inherent biological variability; this means that measurements must be made over 3–7 days to attain valid and reliable estimates. There are many different kinds of step counters, designed to be worn on various sites on the body; all of these devices have strengths and limitations. In cross-sectional studies, strong associations between steps per day and health variables have been documented. Currently, at least eight prospective, longitudinal studies using accelerometers are being conducted that may help to establish dose–response relationships between steps/day and health outcomes. Longitudinal interventions using step counters have shown that they can help inactive individuals to increase by 2500 steps per day. Step counting is useful for surveillance, and studies have been conducted in a number of countries around the world. Future challenges include the need to establish testing protocols and accuracy standards, and to decide upon the best placement sites. These challenges should be addressed in order to achieve harmonization between studies, and to accurately quantify dose–response relationships.
Conflicting evidence exists on whether physical activity (PA) levels of humans have changed over the last quarter-century. The main objective of this study was to determine if there is evidence of ...time trends in PA, from cross-sectional studies that assessed PA at different time points using wearable devices (e.g., pedometers and accelerometers). A secondary objective was to quantify the rate of change in PA.
A systematic literature review was conducted of English-language studies indexed in PubMed, SPORTDiscus, and Web of Science (1960-2020) using search terms (time OR temporal OR secular) AND trends AND (steps per day OR pedometer OR accelerometer OR MVPA). Subsequently, a meta-analytic approach was used to aggregate data from multiple studies and to examine specific factors (i.e., sex, age-group, sex and age-group, and PA metric).
Based on 16 peer-reviewed scientific studies conducted between 1995 and 2017, levels of ambulatory PA are trending downward in developed countries. Significant declines were seen in both males and females (P < 0.001) as well as in children (P = 0.020), adolescents (P < 0.001), and adults (P = 0.004). The average study duration was 9.4 yr (accelerometer studies, 5.3 yr; pedometer studies, 10.8 yr). For studies that assessed steps, the average change in PA was -1118 steps per day over the course of the study (P < 0.001), and adolescents had the greatest change in PA at -2278 steps per day (P < 0.001). Adolescents also had the steepest rate of change over time, expressed in steps per day per decade.
Evidence from studies conducted in eight developed nations over a 22-yr period indicates that PA levels have declined overall, especially in adolescents. This study emphasizes the need for continued research tracking time trends in PA using wearable devices.
PURPOSEThe purpose of this study was to determine the accuracy of 14-step counting methods under free-living conditions.
METHODSTwelve adults (mean ± SD age, 35 ± 13 yr) wore a chest harness that ...held a GoPro camera pointed down at the feet during all waking hours for 1 d. The GoPro continuously recorded video of all steps taken throughout the day. Simultaneously, participants wore two StepWatch (SW) devices on each ankle (all programmed with different settings), one activPAL on each thigh, four devices at the waist (Fitbit Zip, Yamax Digi-Walker SW-200, New Lifestyles NL-2000, and ActiGraph GT9X (AG)), and two devices on the dominant and nondominant wrists (Fitbit Charge and AG). The GoPro videos were downloaded to a computer and researchers counted steps using a hand tally device, which served as the criterion method.
RESULTSThe SW devices recorded between 95.3% and 102.8% of actual steps taken throughout the day (P > 0.05). Eleven step counting methods estimated less than 100% of actual steps; Fitbit Zip, Yamax Digi-Walker SW-200, and AG with the moving average vector magnitude algorithm on both wrists recorded 71% to 91% of steps (P > 0.05), whereas the activPAL, New Lifestyles NL-2000, and AG (without low-frequency extension (no-LFE), moving average vector magnitude) worn on the hip, and Fitbit Charge recorded 69% to 84% of steps (P < 0.05). Five methods estimated more than 100% of actual steps; AG (no-LFE) on both wrists recorded 109% to 122% of steps (P > 0.05), whereas the AG (LFE) on both wrists and the hip recorded 128% to 220% of steps (P < 0.05).
CONCLUSIONSAcross all waking hours of 1 d, step counts differ between devices. The SW, regardless of settings, was the most accurate method of counting steps.
Background
African-Americans (AAs) have higher rates of inactivity, obesity, and cardiometabolic risk compared to other races/ethnicities. Romantic partners can positively influence health habits, ...yet whether or not couples have to exercise together in order to adopt regular exercise remains unclear. This study examined whether exercising together influences exercise adherence and cardiometabolic risk in AA couples.
Methods
Nine AA romantic couples (age 62.8 ± 7.7 years; body mass index 31.0 ± 4.4 kg/m
2
; 6105 ± 1689 average steps/day) completed a 12-week walking (≥ 30 min, 3 days/week) plus resistance training (RT; 2 days/week) pilot intervention. Couples were randomized to either exercise together (ET) or separately (ES). Waist and hip circumferences, iDXA-measured body composition, blood pressure, and blood biomarkers (glucose, hemoglobin A1c (HbA1c), total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, C-reactive protein, and fibrinogen) were assessed pre- and post-intervention. Independent-sample
t
tests and generalized linear mixed models, controlling for gender, were used to analyze data. Significance was accepted at
P
< 0.05.
Results
There were no significant group × time interactions for any outcome. However, ET trended toward more walking (86.5 ± 57.7 min/week) than ES (66.1 ± 31.7 min/week). There were also significant overall time effects for waist circumference (
P
< 0.001), body fat (
P
= 0.020), fat mass (
P
= 0.007), gynoid fat (
P
= 0.041), HbA1c (
P
= 0.020), and HDL (
P
= 0.047), where all variables decreased.
Conclusions
Trends showed exercising together may promote walking prescription adherence, although more research is needed in a larger sample. This intervention may also improve cardiometabolic risk factors in this population. These pilot data will inform the current investigators’ future exercise intervention research in AA adult dyads.
Previous studies suggest that the magnitude of morbidity/mortality reduction may differ between race-ethnic groups despite equated dose of physical activity (PA). The purpose of this study was to ...compare the potential racial-ethnic differences in cardiometabolic risk factors (CMRF) across quartiles of accelerometer-derived total activity counts/day (TAC/d) among US adults. The final sample (n=4144) included adults who participated in the 2003–2006 National Health and Nutrition Examination Survey (NHANES). CMRF included fasting glucose (FG), fasting insulin (FI), HOMA-IR, resting systolic (SBP) and diastolic blood pressure (DBP), waist circumference (WC), BMI, CRP, HDL-C, LDL-C, and triglycerides. Race-ethnic groups examined included non-Hispanic white (NHW), non-Hispanic black (NHB), and Mexican American (MA). In the highest quartile, NHW had significantly lower values of HOMA-IR, FI, SBP, BMI, WC, and HDL-C when compared to NHB. Compared to MA in the highest quartile, NHW had significantly lower values of HOMA-IR, FI, BMI, and triglycerides. Significant race-ethnic differences were found for several CMRF, especially among those who were in the top quartile of PA (e.g., the most active adults). It is probable that the protective effect of higher volumes of PA on CMRF is moderated by other non-PA factors distinct to NHB and MA.
Highlights • The StepWatch preprogrammed settings provide accurate step counts for walking, but not running, in able-bodied adults. • Modifying the cadence and sensitivity settings can improve ...accuracy in running and tennis. • The default settings enhance accuracy for able-bodied adults who perform light, intermittent lifestyle activities. • The modified settings enhance accuracy for able-bodied adults who perform running or vigorous sports.
Purpose
: To examine the effect of activity monitor placement on daily step counts when monitors are worn at different positions on the wrist/forearm and the hip.
Methods
: Participants (
N
= 18) ...wore eight different models (four wrist and four hip models) across four days. Each day, one hip and one wrist model were selected, and four identical monitors of each model were worn on the right hip and the non-dominant wrist/forearm, respectively, during all waking hours. Step counts of each monitor were compared to the same model worn in the referent position (wrist: proximal to ulnar styloid process; hip: midline of thigh). Percent of referent steps and mean difference between observed and referent positions were computed. Significant differences in steps between positions for each method were determined using one-way repeated measures ANOVAs. For significant main effects, pairwise comparisons with Bonferroni corrections were used to determine which positions were significantly different.
Results
: All wrist methods showed a significant main effect for placement (
p
< .05) and alternate positions were 1–16% lower than the referent position. For hip methods, only the Omron HJ-325 differed across positions (
p
< .05), but differences were among non-referent positions and all were within ±2% of steps recorded by the referent position.
Conclusions
: Researchers should be aware that positions that deviate from the manufacturer’s recommended position at the wrist could influence step counts. Of all hip methods examined, the Omron had a significant placement effect which did not constitute a practical difference.
Response TOTH, LINDSAY P.; PARK, SUSAN; BASSETT, DAVID R.
Medicine and science in sports and exercise,
10/2018, Letnik:
50, Številka:
10
Journal Article
PDF
