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Mirko Brandes, Berit Steenbock and Norman Wirsik

.6 METs). 13 Although Mackintosh et al 13 included children aged 11.4 (0.3) years, an older population compared with our study population, their results do indicate that the energy cost of fast walking is underestimated in the compendium. This could then be even more pronounced in preschool children, as

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Kate Ridley and Tim Olds

Time spent playing video games has been linked to increases in childhood obesity and sedentary behavior. However, “new generation” video games require total body movement and greater physical exertion. The aim of this study was to describe children’s behavior and energy expenditure while visiting video game centers. Observations were undertaken on 134 children’s activity patterns while playing at a video game center. The energy cost of 10 children (5 male and 5 female) aged 12.5 ± 0.5 yr, playing 4 popular video games was then measured. Gross energy cost ranged from 7.6 to 26.5 ml · kg−1 · min−1. Based on our observations, we estimate that the gross energy expenditure during a child’s typical session in a video game center will range from 2.3–2.6 METS.

Open access

Maurice R. Puyau, Anne L. Adolph, Yan Liu, Theresa A. Wilson, Issa F. Zakeri and Nancy F. Butte

Background:

The absolute energy cost of activities in children increases with age due to greater muscle mass and physical capability associated with growth and developmental maturation; however, there is a paucity of data in preschool-aged children. Study aims were 1) to describe absolute and relative energy cost of common activities of preschool-aged children in terms of VO2, energy expenditure (kilocalories per minute) and child-specific metabolic equivalents (METs) measured by room calorimetry for use in the Youth Compendium of Physical Activity, and 2) to predict METs from age, sex and heart rate (HR).

Methods:

Energy expenditure (EE), oxygen consumption (VO2), HR, and child-METs of 13 structured activities were measured by room respiration calorimetry in 119 healthy children, ages 3 to 5 years.

Results:

EE, VO2, HR, and child-METs are presented for 13 structured activities ranging from sleeping, sedentary, low-, moderate- to high-active. A significant curvilinear relationship was observed between child-METs and HR (r 2 = .85; P = .001).

Conclusion:

Age-specific child METs for 13 structured activities in preschool-aged children will be useful to extend the Youth Compendium of Physical Activity for research purposes and practical applications. HR may serve as an objective measure of MET intensity in preschool-aged children.

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Kate Lyden, Sarah Kozey Keadle, John Staudenmayer, Patty Freedson and Sofiya Alhassan

Background:

The Compendium of Energy Expenditures for Youth assigns MET values to a wide range of activities. However, only 35% of activity MET values were derived from energy cost data measured in youth; the remaining activities were estimated from adult values.

Purpose:

To determine the energy cost of common activities performed by children and adolescents and compare these data to similar activities reported in the compendium.

Methods:

Thirty-two children (8−11 years old) and 28 adolescents (12−16 years) completed 4 locomotion activities on a treadmill (TRD) and 5 age-specific activities of daily living (ADL). Oxygen consumption was measured using a portable metabolic analyzer.

Results:

In children, measured METs were significantly lower than compendium METs for 3 activities [basketball, bike riding, and Wii tennis (1.1−3.5 METs lower)]. In adolescents, measured METs were significantly lower than compendium METs for 4 ADLs [basketball, bike riding, board games, and Wii tennis (0.3−2.5 METs lower)] and 3 TRDs [2.24 m·s-1, 1.56 m·s-1, and 1.34 m·s-1 (0.4−0.8 METs lower)].

Conclusion:

The Compendium of Energy Expenditures for Youth is an invaluable resource to applied researchers. Inclusion of empirically derived data would improve the validity of the Compendium of Energy Expenditures for Youth.

Open access

Kimberly A. Clevenger, Aubrey J. Aubrey, Rebecca W. Moore, Karissa L. Peyer, Darijan Suton, Stewart G. Trost and Karin A. Pfeiffer

Background:

Limited data are available on energy cost of common children’s games using measured oxygen consumption.

Methods:

Children (10.6 ± 2.9 years; N = 37; 26 male, 9 female) performed a selection of structured (bowling, juggling, obstacle course, relays, active kickball) and unstructured (basketball, catch, tennis, clothespin tag, soccer) activities for 5 to 30 minutes. Resting metabolic rate (RMR) was calculated using Schofield’s age- and sex-specific equation. Children wore a portable metabolic unit, which measured expired gases to obtain oxygen consumption (VO2), youth METs (relative VO2/child’s calculated RMR), and activity energy expenditure (kcal/kg/min). Descriptive statistics were used to summarize data.

Results:

Relative VO2 ranged from 16.8 ± 4.6 ml/kg/min (bowling) to 32.2 ± 6.8 ml/kg/min (obstacle course). Obstacle course, relays, active kickball, soccer, and clothespin tag elicited vigorous intensity (>6 METs), the remainder elicited moderate intensity (3–6 METs).

Conclusions:

This article contributes energy expenditure data for the update and expansion of the youth compendium.

Open access

Stewart G. Trost, Christopher C. Drovandi and Karin Pfeiffer

Background:

Published energy cost data for children and adolescents are lacking. The purpose of this study was to measure and describe developmental trends in the energy cost of 12 physical activities commonly performed by youth.

Methods:

A mixed age cohort of 209 participants completed 12 standardized activity trials on 4 occasions over a 3-year period (baseline, 12-months, 24-months, and 36-months) while wearing a portable indirect calorimeter. Bayesian hierarchical regression was used to link growth curves from each age cohort into a single curve describing developmental trends in energy cost from age 6 to 18 years.

Results:

For sedentary and light-intensity household chores, YOUTH METs (METy) remained stable or declined with age. In contrast, METy values associated with brisk walking, running, basketball, and dance increased with age.

Conclusions:

The reported energy costs for specific activities will contribute to efforts to update and expand the youth compendium.

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Edward C. Frederick

Elite biathletes now ski using skating techniques in place of the more traditional diagonal stride. Because of the more extreme flexion and extension of the trunk with these new techniques, it has become necessary to reevaluate the method of rifle carriage. This paper describes a model which evaluates the incremental mechanical power required to move the additional weight of the rifle through defined angular flexions and extensions of the trunk. By combining this model with actual observations of typical kinematics of trunk flexion, we can generate realistic estimates of the energy cost of rifle carriage. This approach is also used to evaluate the energy consequences of reduced rifle mass and of different rifle carriage strategies while moving with ski skating techniques. These results show that rotational kinetic energy changes are a minor part of the overall energy cost of rifle carriage, and that changes in the horizontal velocity of the rifle are the greatest source of increased cost of transport. The largest reductions in this cost, however, would come from reducing rifle mass because both potential and kinetic energies are affected. Additional but secondary reductions can be obtained by placing the rifle center of mass opposite the lumbosacral joint, thereby reducing horizontal and vertical excursions of the rifle.

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Anja Groβek, Christiana van Loo, Gregory E. Peoples, Markus Hagenbuchner, Rachel Jones and Dylan P. Cliff

Background:

This study reports energy expenditure (EE) data for lifestyle and ambulatory activities in young children.

Methods:

Eleven children aged 3 to 6 years (mean age = 4.8 ± 0.9; 55% boys) completed 12 semistructured activities including sedentary behaviors (SB), light (LPA), and moderate-to-vigorous physical activities (MVPA) over 2 laboratory visits while wearing a portable metabolic system to measure EE.

Results:

Mean EE values for SB (TV, reading, tablet and toy play) were between 0.9 to 1.1 kcal/min. Standing art had an energy cost that was 1.5 times that of SB (mean = 1.4 kcal/min), whereas bike riding (mean = 2.5 kcal/min) was similar to LPA (cleaning-up, treasure hunt and walking) (mean = 2.3 to 2.5 kcal/min), which had EE that were 2.5 times SB. EE for MVPA (running, active games and obstacle course) was 4.2 times SB (mean = 3.8 to 3.9 kcal/min).

Conclusion:

EE values reported in this study can contribute to the limited available data on the energy cost of lifestyle and ambulatory activities in young children.

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Gordon J. Bell, Vicki Harber, Terra Murray, Kerry S. Courneya and Wendy Rodgers

Background:

Fitness and health variables were measured in 128 sedentary men and women randomly assigned to 6 months of fitness training (F), a walking program (W), or a control (C) group.

Methods:

The F program gradually increased volume and intensity until 4 d/wk of training, at 70% of peak VO2 for 43 min/session was prescribed while the W group performed daily walking monitored with pedometers and increased until 10,000 steps×d−1 were prescribed. Total weekly energy expenditure was matched between the activity groups. The control group was asked to maintain their usual activity.

Results:

Body mass, waist circumference, waist/hip ratio, resting HR were reduced in all groups after 6 months (P < .05). Fasting glucose, glucose tolerance, and total cholesterol were similarly improved in all groups (P < .05). Blood pressure and HR decreased during submaximal exercise in all groups (P < .05) but rating of perceived exertion (RPE) was decreased only in the F group (P < .05). Only the F participants showed a significant increase in ventilatory threshold (VT; ~15%) and peak VO2 (~9%) after 6 months.

Conclusions:

Supervised fitness training in previously sedentary adults produced greater improvements in submaximal RPE, BPsys, VT, and peak VO2 but not other fitness and health-related variables compared with a pedometer-based walking program matched for total energy cost.

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Stefano Lazzer, Desy Salvadego, Paolo Taboga, Enrico Rejc, Nicola Giovanelli and Pietro E. di Prampero

Purpose:

To investigate the effects of an extreme uphill marathon on the mechanical parameters that are likely to affect the energy cost of running (Cr).

Methods:

Eleven runners (27–59 y) participated in the Etna SuperMarathon (43 km, 0–3063 m above sea level). Anthropometric characteristics, maximal explosive power of the lower limb (P max), and maximal oxygen uptake were determined before the competition. In addition, before and immediately after the race, Cr, contact (t c) and aerial (t a) times, step frequency (f), and running velocity were measured at constant self-selected speed. Then, peak vertical ground-reaction force (F max), vertical downward displacement of the center of mass (Δz), leg-length change (ΔL), and vertical (k vert) and leg (k leg) stiffness were calculated.

Results:

A direct relationship between Cr, measured before the race, and race time was shown (r = .61, P < .001). Cr increased significantly at the end of the race by 8.7%. Immediately after the race, the subjects showed significantly lower t a (–58.6%), f (–11.3%), F max (–17.6%), k vert (–45.6%), and k leg (–42.3%) and higher t c (+28.6%), Δz (+52.9%), and ΔL (+44.5%) than before the race. The increase of Cr was associated with a decrement in F max (r = –.45), k vert (r = –.44), and k leg (r = –.51). Finally, an inverse relationship between P max measured before the race and ΔCr during race was found (r = –.52).

Conclusions:

Lower Cr was related with better performance, and athletes characterized by the greater P max showed lower increases in Cr during the race. This suggests that specific power training of the lower limbs may lead to better performance in ultraendurance running competition.