A range of physical activities. Methods: Participants (N = 277) completed 11 activities for 7 min each from a menu of 23 physical activities. Oxygen consumption (V˙O2) was measured using a portable metabolic system, and an accelerometer was worn. MET values were defined as measured METs (V˙O2/measured resting metabolic rate) and standard METs (V˙O2/3.5 mL·kg−1·min−1). For the total sample and by subgroup (age [young < 40 yr], sex, and body mass index [normal weight < 25 kg·m−2]), measured METs and standard METs were compared with the compendium, using 95% confidence intervals to determine statistical significance (α = 0.05). Average counts per minute for each activity and the linear association between counts per minute and METs are presented. Results: Compendium METs were different than measured METs for 17/21 activities (81%). The number of activities different than the compendium was similar between subgroups or when standard METs were used. The average counts for the activities ranged from 11 counts per minute (dishes) to 7490 counts per minute (treadmill: 2.23 m·s−1, 3%). The r2 between counts and METs was 0.65. Conclusions: This study provides valuable information about data collection, metabolic responses, and accelerometer output for common physical activities in a diverse participant sample. The compendium should be updated with additional empirical data, and linear regression models are inappropriate for accurately predicting METs from accelerometer output....

Thods: Two hundred and twelve subjects (aged 20-60 yr) completed TM speeds of 1.34, 1.56, and 2.23 m·s−1 at 0% and 3% grades, stair ascent/descent, moving a box, and two randomly assigned ADL. Subjects wore a portable indirect calorimeter to measure EE to calculate AEE by subtracting resting metabolic rate. Acceleration counts in the vertical (V), medial-lateral, and anterior-posterior planes were collected in a single RT3 secured to the hip. Predicted AEE (RT3AEE) was estimated from vector magnitude (VM) counts using a proprietary algorithm. A paired t-test compared RT3AEE versus AEE. The relationship among V and VM counts and AEE was examined using linear regression analyses. Results: RT3 overestimated AEE for all activities combined, overestimated for TM (9.0%), and underestimated for ADL (34.3%; P < 0.001). The R2 values between RT3AEE and AEE for TM and ADL were R2 = 0.78 and R2 = 0.15, respectively. The RT3 underestimated activity with greater upper body movements by 24.4%-64.5% (P < 0.001). V and VM counts were similarly related to AEE (R2 = 0.35) and RT3AEE (R2 = 0.83-0.89). Conclusions: Although the RT3 did not accurately predict AEE from accelerometer counts, stronger relationships existed between predicted and measured AEE for TM compared with ADL. Compared with V counts, using VM counts to predict AEE did not significantly improve the relationship between counts and AEE. Analytic techniques beyond linear regression with VM as a covariate or with counts from each axis entering the model separately may improve estimates of AEE from triaxial accelerometers....

Objective. To determine if a 10-month after-school physical activity (PA) intervention could prevent deleterious changes in body composition and cardiovascular (CV) fitness in young black boys.Methods. Following baseline measures, 106 boys (8–12 yrs) were randomized to either a control group or an intervention group, further divided into attenders (ATT) and nonattenders (NATT), participating in ≥60% or <60% of the intervention, respectively. The daily intervention consisted of skills development (25 min), vigorous PA (VPA, 35 min), and strengthening/stretching (20 min) components. Body composition was measured by dual-energy X-ray absorptiometry.Results. Following the intervention, the ATT exhibited an increase in moderate-to-vigorous PA and a significant reduction in BMI, fat mass, and %BF compared to the control group. A significant association among the intervention energy expenditure and changes in body composition and CV fitness was observed only in the ATT group.Conclusion. An after-school PA program of sufficient length and intensity can promote healthy changes in body composition and fitness levels in black boys who attend at least 3 days/week.

Objective: New active videogames (AVGs) may provide youth an alternative to traditional play. The purpose of this study was to compare the physical activity energy expenditure (PAEE), intensity, and enjoyment of AVGs with those of seated videogames (SVGs). Materials and Methods: Youth (8–17 years old) volunteered to play a random selection of six (two SVGs, four AVGs) videogames for 6–10 minutes each. Prior to participation, height, weight, and resting metabolic rate (RMR) were measured. A portable metabolic analyzer was worn during the games to measure total energy expenditure, and PAEE was calculated as (total energy expenditure – measured RMR). An accelerometer was worn on the right hip to measure intensity in counts/minute and steps/minute. Youth were classified as child (8–12 years old) versus teen (13–17 years old), healthy weight (body mass index [BMI] <85th percentile) versus overweight (BMI ≥85th percentile), and male versus female. A three-way mixed-model analysis of variance was used to compare differences in PAEE (metabolic equivalents [METs] and kcal/minute) with sex, weight status, and age group as main effects, including Bonferroni's adjustment. Results: Most AVGs were moderate to vigorous intensity (4.6±0.1 METs; range, 2.8–6.6 METs), where steps/minute (lower-body movement) was positively related to PAEE (R²=0.68). All SVGs were classified as light intensity (1.7±0.0 METs). PAEE (kcal/minute) was significantly higher during AVGs and for teens, males, and overweight youth. There was no significant difference in enjoyment between AVGs and SVGs. Conclusions: AVGs elicited sufficient energy cost to be a suitable alternative for traditional play and may contribute to the recommended dose of physical activity, particularly in teens, males, and overweight youth.

Background. North Americans report insufficient moderate-to-vigorous physical activity (MVPA) and ample sedentary behaviors (SBs), suggesting possible barriers to an active lifestyle. This study compared self-reported MVPA and SB before and during COVID-19 “Stay-at-Home” restrictions as a potential barrier across North America. Methods: Questionnaires were distributed from 21 April to 9 May 2020. ANOVAs compared data overall and by group (age, sex, race, income, education, employment status). Results: During restrictions, 51.4% (n = 687) of the 1336 responses (991 female, 1187 Caucasian, 634 18–29 years) shifted to work from home and 12.1% (n = 162) lost their job. Overall, during restrictions, 8.3% (n = 110) fewer reported work-related MVPA (−178.6 ± 20.9 min/week). Similarly, 28.0% (n = 374) fewer reported travel-related MVPA, especially females and younger age groups. While the 7.3% (n = 98) fewer reporting recreational MVPA was not statistically significant (−30.4 ± 11.5 min/week), there was an increase in SB (+94.9 ± 4.1 min/week) in all groups, except the oldest age group (70+ years). Locomotive activities and fitness class remained the predominant MVPA mode. Of those reportedly using facilities (68%; n = 709) before COVID, 31.3% (n = 418) would not return due to it “being unsafe”. Conclusion: While barriers related to pandemic restrictions had a negative short-term impact on MVPA and SB in North America, the long-term impact is unknown.