Parameters of walking and jogging in healthy young adults

The purposes of this study were to a) investigate the average heart rate (HR), speed, stride length, and stride rate during moderate intensity walking and jogging in healthy young adults, b) cross validate the walking stride length calculation based on 42% of height and c) provide reliability information for measurement of walking and jogging steps, speed, stride length, and stride rate. Participants (N=130) wore two Yamax SW-200 pedometers and a Polar A-1 HR monitor while performing walking and jogging trials. The correlation between estimated (0.71 ± 0.04 m·stride-1) and actual stride length (0.78 ± 0.05 m·stride-1) was moderate (r = .46). However, a significant difference was observed between the two measurements (t(115) = -14.24, p < .001). The reliability results for speed, stride length, and stride rate showed that two or fewer trials were enough to achieve reliable estimates. In conclusion, when instructed to walk at a moderate pace, healthy young adults tend to walk at an average pace that is greater than that recommended for meeting current public health recommendations (80 m·min-1). Similarly, when instructed to jog at a comfortable pace, healthy young adults tend to jog at a speed greater than that corresponding to vigorous intensity physical activity (134 m·min-1). The results of the reliability analysis indicate that in healthy young adults, to measure typical walking and jogging patterns using a pedometer, only two trials for walking and one trial for jogging are necessary to achieve reliable estimates. Stride rate calculations requires the combination of two trials and one pedometer for both walking and jogging

The Validity Of 7-Site Skinfold Measurements Taken By Exercise Science Students

International Journal of Exercise Science 6(1) : 20-28, 2013. Skinfold (SKF) measurement is arguably the most ubiquitous method of estimating percent body fat (%BF) because of cost, ease, and feasibility. However, it is unknown how accurately novice exercise science students measure SKF thickness. Thus, the purpose of this study was to determine the validity with which exercise science students in an Exercise Physiology course measured skinfold thickness and estimated percent body fat (%BF) when compared to a skilled technician. Twenty-three novice undergraduate students were afforded both verbal measurement instruction and visual measurement demonstration and, subsequently, assessed SKF thicknesses of a male and female testee. %BF was calculated using measurements obtained by the skilled technician and students. Comparisons were made between measurements taken by the skilled technician and students using error, absolute error, and one sample t-tests. For the female testee, average error ranged from -0.5 mm to -4.8 mm for the 7-sites, 1.7±15.4 mm for the sum of 7-sites, and -3.7±2.6% for %BF. The average absolute error ranged from 1.2 mm to 4.9 mm for the 7-sites, 23.3±12.7 mm for the sum of 7-sites, and 3.9±2.2% for %BF. For the male testee, average error ranged from 0.0 mm to 0.9 mm for the 7-sites, 2.9±8.5 mm for the sum of 7-sites, and 0.5±1.4% for %BF. The average absolute error ranged from 0.6 mm to 1.1 mm for the 7-sites, 4.8±7.5 mm for the sum of 7-sites, and 0.8±1.2% for BF%. The one sample t-tests revealed no significant differences in the sum of 7-sites and %BF for the male model (p\u3e0.05), but significant differences were found for the female model (p\u3c0.05). From a practical perspective, when novice exercise science students were provided both verbal and visual instructions of SKF measurement technique, students were able to accurately assess %BF of a male testee as compared to the skilled technician. With respect to the female testee, however, students underestimated the sum of the 7 SKF sites by ~ 20 mm when compared to the skilled technician. Additional tutelage and practice may be necessary when teaching SKF measurement of females and/or individuals with higher %BF to novice undergraduate exercise science students

Validation of the Actiheart Monitor for the Measurement of Physical Activity

The Actiheart monitor uniquely allows simultaneous measurement of heart rate and movement counts. The purpose of this study was to establish validity evidence for the Actiheart monitor under laboratory and free-living conditions. A total of 34 college students (17 males and 17 females, age = 21.8 ± 3.6 years) participated in the study. In the laboratory environment, the participants completed three, 5 min bouts of treadmill walking and/or running at speeds of 3.2, 6.4, and 9.6 km/h. Outside the laboratory, participants were asked to perform free-living physical activity for 30 min. For validation, energy expenditure, movement counts, and heart rate measurements from the Actiheart monitor were compared with an AEI Moxus Metabolic Cart, Actigraph accelerometer, Polar heart rate monitor (HRM), and electrocardiogram (ECG), respectively. The Actiheart underestimated energy expenditure only at the highest workload in the laboratory environment compared with the metabolic cart (p = .009). Actiheart heart rate (HR) was similar to the HR measured by ECG at all workloads. Under free-living conditions, the Actiheart energy expenditure was highly correlated (r = .81) with the Actigraph energy expenditure with no significant differences (t(33) =.26; p = .80). Actiheart heart rate was also highly correlated with HR from the Polar HRM (r = .93), however, there was an overestimation of HR by the Actiheart monitor (t(33) = 3.00; p = .005) under free-living conditions. The Actiheart monitor appears to accurately measure physical activity under free-living conditions and at low and moderate intensities in the laboratory environment

The descriptive epidemiology of sitting among US adults, NHANES 2009/2010

Objectives: Using NHANES 2009/2010, to describe the amount of time a representative sample of the U.S. population spends sitting by age, sex, ethnicity, education, and body mass index. Design: Cross-sectional analysis. Methods: Participants (n= 5911, ≥20 years) self-reported demographic variables and the amount of time they spend sitting on a typical day. Body mass index was calculated from measured height and weight. Results: Mean self-reported sitting time was 285. min/day for males and 281. min/day for females. Mexican-Americans reported sitting less than both non-Hispanic Whites and non-Hispanic Blacks (all p <0.0001). Non-Hispanic White males reported sitting more than non-Hispanic Black males, while Non-Hispanic White females reported sitting more than Other Hispanic females (both p <0.0001). No significant differences were found between sexes in any age group. There was a trend for increased sitting time with increasing age for females (p for trend = 0.0045), for all Mexican-American and Hispanic participants and non-Hispanic Black males (all p ≤ 0.006) and with increasing education (p for trend <0.0001). At the College Graduate level, females reported sitting less than males (p < 0.0001). Obese females reported sitting more than normal weight and overweight females (p = 0.0008). There were no significant differences in sitting time by body mass index for males. Conclusions: Self-reported sitting time differed by ethnicity, age group, education and body mass index but there was no overall difference by sex. These results represent the most up to date prevalence of self-reported sitting for the US adult population. Certain groups should be targeted to reduce sitting time, for example those with higher educational attainment and obese females

Older Adult Compendium of Physical Activities: Energy Costs of Human Activities in Adults Aged 60 and Older

Purpose: To describe the development of a Compendium for estimating the energy costs of activities in adults ≥60 years (OA Compendium). Methods: Physical activities (PAs) and their metabolic equivalent of task (MET) values were obtained from a systematic search of studies published in 4 sport and exercise databases (PubMed, Embase, SPORTDiscus (EBSCOhost), and Scopus) and a review of articles included in the 2011 Adult Compendium that measured PA in older adults. MET values were computed as the oxygen cost (VO2, mL/kg/min) during PA divided by 2.7 mL/kg/min (MET60+) to account for the lower resting metabolic rate in older adults. Results: We identified 68 articles and extracted energy expenditure data on 427 PAs. From these, we derived 99 unique Specific Activity codes with corresponding MET60+ values for older adults. We developed a website to present the OA Compendium MET60+ values: https://pacompendium.com. Conclusion: The OA Compendium uses data collected from adults ≥60 years for more accurate estimation of the energy cost of PAs in older adults. It is an accessible resource that will allow researchers, educators, and practitioners to find MET60+ values for older adults for use in PA research and practice

How fast is fast enough? Walking cadence (steps/min) as a practical estimate of intensity in adults: A narrative review

Background: Cadence (steps/min) may be a reasonable proxy-indicator of ambulatory intensity. A summary of current evidence is needed for cadence-based metrics supporting benchmark (standard or point of reference) and threshold (minimums associated with desired outcomes) values that are informed by a systematic process.Objective: To review how fast, in terms of cadence, is enough, with reference to crafting public health recommendations in adults.Methods: A comprehensive search strategy was conducted to identify relevant studies focused on walking cadence and intensity for adults. Identified studies (n=38) included controlled (n=11), free-living observational (n=18) and intervention (n=9) designs.Results: There was a strong relationship between cadence (as measured by direct observation and objective assessments) and intensity (indirect calorimetry). Despite acknowledged interindividual variability, =100 steps/min is a consistent heuristic (e.g., evidence-based, rounded) value associated with absolutely defined moderate intensity (3 metabolic equivalents (METs)). Epidemiological studies report notably low mean daily cadences (ie, 7.7 steps/min), shaped primarily by the very large proportion of time (13.5 hours/day) spent between zero and purposeful cadences (100 and >70 steps/min, respectively. Peak cadence indicators are negatively associated with increased age and body mass index. Identified intervention studies used cadence to either prescribe and/or quantify ambulatory intensity but the evidence is best described as preliminary.Conclusions: A cadence value of =100 steps/min in adults appears to be a consistent and reasonable heuristic answer to 'How fast is fast enough?' during sustained and rhythmic ambulatory behaviour.Peer reviewedCommunity Health Sciences, Counseling and Counseling Psycholog

Validation of an integrated pedal desk and electronic behavior tracking platform

Background This study tested the validity of revolutions per minute (RPM) measurements from the Pennington Pedal Desk™. Forty-four participants (73 % female; 39 ± 11.4 years-old; BMI 25.8 ± 5.5 kg/m2 [mean ± SD]) completed a standardized trial consisting of guided computer tasks while using a pedal desk for approximately 20 min. Measures of RPM were concurrently collected by the pedal desk and the Garmin Vector power meter. After establishing the validity of RPM measurements with the Garmin Vector, we performed equivalence tests, quantified mean absolute percent error (MAPE), and constructed Bland–Altman plots to assess agreement between RPM measures from the pedal desk and the Garmin Vector (criterion) at the minute-by-minute and trial level (i.e., over the approximate 20 min trial period). Results The average (mean ± SD) duration of the pedal desk trial was 20.5 ± 2.5 min. Measures of RPM (mean ± SE) at the minute-by-minute (Garmin Vector: 54.8 ± 0.4 RPM; pedal desk: 55.8 ± 0.4 RPM) and trial level (Garmin Vector: 55.0 ± 1.7 RPM; pedal desk: 56.0 ± 1.7 RPM) were deemed equivalent. MAPE values for RPM measured by the pedal desk were small (minute-by-minute: 2.1 ± 0.1 %; trial: 1.8 ± 0.1 %) and no systematic relationships in error variance were evident by Bland–Altman plots. Conclusion The Pennington Pedal Desk™ provides a valid count of RPM, providing an accurate metric to promote usage

Improving wear time compliance with a 24-hour waist-worn accelerometer protocol in the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE)

Background: We compared 24-hour waist-worn accelerometer wear time characteristics of 9-11 year old children in the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) to similarly aged U.S. children providing waking-hours waist-worn accelerometer data in the 2003-2006 National Health and Nutrition Examination Survey (NHANES). Methods: Valid cases were defined as having >= 4 days with >= 10 hours of waking wear time in a 24-hour period, including one weekend day. Previously published algorithms for extracting total sleep episode time from 24-hour accelerometer data and for identifying wear time (in both the 24-hour and waking-hours protocols) were applied. The number of valid days obtained and a ratio (percent) of valid cases to the number of participants originally wearing an accelerometer were computed for both ISCOLE and NHANES. Given the two surveys' discrepant sampling designs, wear time (minutes/day, hours/day) from U.S. ISCOLE was compared to NHANES using a meta-analytic approach. Wear time for the 11 additional countries participating in ISCOLE were graphically compared with NHANES. Results: 491 U.S. ISCOLE children (9.92 +/- 0.03 years of age [M +/- SE]) and 586 NHANES children (10.43 +/- 0.04 years of age) were deemed valid cases. The ratio of valid cases to the number of participants originally wearing an accelerometer was 76.7% in U.S. ISCOLE and 62.6% in NHANES. Wear time averaged 1357.0 +/- 4.2 minutes per 24-hour day in ISCOLE. Waking wear time was 884.4 +/- 2.2 minutes/day for U.S. ISCOLE children and 822.6 +/- 4.3 minutes/day in NHANES children (difference = 61.8 minutes/day, p <0.001). Wear time characteristics were consistently higher in all ISCOLE study sites compared to the NHANES protocol. Conclusions: A 24-hour waist-worn accelerometry protocol implemented in U.S. children produced 22.6 out of 24 hours of possible wear time, and 61.8 more minutes/day of waking wear time than a similarly implemented and processed waking wear time waist-worn accelerometry protocol. Consistent results were obtained internationally. The 24-hour protocol may produce an important increase in wear time compliance that also provides an opportunity to study the total sleep episode time separate and distinct from physical activity and sedentary time detected during waking-hours.Peer reviewe

Are Children Like Werewolves? : Full Moon and Its Association with Sleep and Activity Behaviors in an International Sample of Children

In order to verify if the full moon is associated with sleep and activity behaviors, we used a 12-country study providing 33,710 24-h accelerometer recordings of sleep and activity. The present observational, cross-sectional study included 5812 children ages 9-11 years from study sites that represented all inhabited continents and wide ranges of human development (Australia, Brazil, Canada, China, Colombia, Finland, India, Kenya, Portugal, South Africa, United Kingdom, and United States). Three moon phases were used in this analysis: full moon (4 days; reference), half moon (5-9 days), and new moon (+10-14 days) from nearest full moon. Nocturnal sleep duration, moderate -to vigorous physical activity (MVPA), light-intensity physical activity (LPA), and total sedentary time (SED) were monitored over seven consecutive days using a waist -worn accelerometer worn 24 h a day. Only sleep duration was found to significantly differ between moon phases (-5 min/night shorter during full moon compared to new moon). Differences in MVPA, LPA, and SED between moon phases were negligible and non-significant (Peer reviewe

A model for presenting accelerometer paradata in large studies : ISCOLE

Background: We present a model for reporting accelerometer paradata (process-related data produced from survey administration) collected in the International Study of Childhood Obesity Lifestyle and the Environment (ISCOLE), a multi-national investigation of >7000 children (averaging 10.5 years of age) sampled from 12 different developed and developing countries and five continents. Methods: ISCOLE employed a 24-hr waist worn 7-day protocol using the ActiGraph GT3X+. Checklists, flow charts, and systematic data queries documented accelerometer paradata from enrollment to data collection and treatment. Paradata included counts of consented and eligible participants, accelerometers distributed for initial and additional monitoring (site specific decisions in the face of initial monitoring failure), inadequate data (e.g., lost/malfunction, insufficient wear time), and averages for waking wear time, valid days of data, participants with valid data (>= 4 valid days of data, including 1 weekend day), and minutes with implausibly high values (>= 20,000 activity counts/min). Results: Of 7806 consented participants, 7372 were deemed eligible to participate, 7314 accelerometers were distributed for initial monitoring and another 106 for additional monitoring. 414 accelerometer data files were inadequate (primarily due to insufficient wear time). Only 29 accelerometers were lost during the implementation of ISCOLE worldwide. The final locked data file consisted of 6553 participant files (90.0% relative to number of participants who completed monitoring) with valid waking wear time, averaging 6.5 valid days and 888.4 minutes/day (14.8 hours). We documented 4762 minutes with implausibly high activity count values from 695 unique participants (9.4% of eligible participants and Conclusions: Detailed accelerometer paradata is useful for standardizing communication, facilitating study management, improving the representative qualities of surveys, tracking study endpoint attainment, comparing studies, and ultimately anticipating and controlling costs.Peer reviewe