Aquatic-Treadmill Walking: Quantifying Drag Force and Energy Expenditure

2012 ◽  
Vol 21 (4) ◽  
Author(s):  
Eadric Bressel ◽  
Gerald Smith ◽  
Andrew Miller ◽  
Dennis Dolny
Keyword(s):  
Energy Expenditure ◽  
Athletic Training ◽  
Drag Force ◽  
Repeated Measures ◽  
Force Transducer ◽  
Water Jet ◽  
Treadmill Walking ◽  
Drag Forces ◽  
Jet Velocities ◽  
Aquatic Treadmill

Context: Quantification of the magnitudes of fluid resistance provided by water jets (currents) and their effect on energy expenditure during aquatic-treadmill walking is lacking in the scientific literature. Objective: To quantify the effect of water-jet intensity on jet velocity, drag force, and oxygen uptake (VO2) during aquatic-treadmill walking. Design: Descriptive and repeated measures. Setting: Athletic training facility. Participants, Interventions, and Measures: Water-jet velocities were measured using an electromagnetic flow meter at 9 different jet intensities (0-80% maximum). Drag forces on 3 healthy subjects with a range of frontal areas (600, 880, and 1250 cm2) were measured at each jet intensity with a force transducer and line attached to the subject, who was suspended in water. Five healthy participants (age 37.2 ± 11.3 y, weight 611 ± 96 N) subsequently walked (~1.03 m/s or 2.3 miles/h) on an aquatic treadmill at the 9 different jet intensities while expired gases were collected to estimate VO2. Results: For the range of jet intensities, water-jet velocities and drag forces were 0-1.2 m/s and 0-47 N, respectively. VO2 increased nonlinearly, with values ranging from 11.4 ± 1.0 to 22.2 ± 3.8 mL × kg-1 × min-1 for 0-80% of jet maximum, respectively. Conclusions: This study presented methodology for quantifying water-jet flow velocities and drag forces in an aquatic-treadmill environment and examined how different jet intensities influenced VO2 during walking. Quantification of these variables provides a fundamental understanding of aquatic-jet use and its effect on VO2. In practice, these results indicate that VO2 may be substantially increased on an aquatic treadmill while maintaining a relatively slow walking speed.

Heart rate responses of two breeds of four-gaited horses to a standardised field gaited test

2012 ◽  
Vol 8 (1) ◽  
pp. 41-46 ◽  
Author(s):  
H.C. Manso Filho ◽  
H.E.C.C.C. Manso ◽  
K.H. McKeever ◽  
S.R.R. Duarte ◽  
J.M.G. Abreu
Keyword(s):  
Heart Rate ◽  
Energy Expenditure ◽  
Negative Correlation ◽  
Repeated Measures ◽  
Recovery Period ◽  
T Test ◽  
Heart Rate Monitor ◽  
Positive Correlation ◽  
Gaited Horses ◽  
Athletic Horse

In order to understand how gaited horses use their energy during exercise, a standardised field gaited test (SFGT) was developed to assess energy expenditure of four beat gaited horses independently of size, sex or breed. This work aimed at developing such an SFGT, using as main measurement parameter the heart rate (HR) of horses during the SFGT performance. Thirty-one four beat gaited horses were evaluated and divided into two groups: FIT (conditioned) and UNFIT (not conditioned). Horses were submitted to the SFGT and their heart rates were measured with a heart rate monitor as follows: right after being mounted, at the beginning of pre-test (HRSADDLE); at 5, 10, 15, 20, 25 and 30 minutes of four beat gait dislocation; and at 15 minutes after the recovery period (T+15). Maximum HR (HRMAX); HR percentage over 150 beats per minute (HR%≯150), HR percentage over 170 beats per minute (HR%≯170), and average HR during the four beat gait stage (HRM@M) of SFGT were calculated. Results were analysed by ANOVA for repeated measures. Where significant differences were observed, ‘T’ test was performed and significance was set at 5%. The FIT group presented HRMAX, HR+15, HRM@M, HR%≯150 and HR%≯170 rates lower (P<0.05) than the UNFIT group. It was noted that there was a negative correlation between fitness and HRMAX (R=−0.67; P<0.001) and a positive correlation between HRMAX and HR+15 (R=0.60; P<0.001) when comparing the FIT to the UNFIT horses. In conclusion, during the SFGT, the FIT group was more efficient in energy expenditure than the UNFIT group, based on the results observed for the significantly lower HRs during the SFGT. It is relevant to note that the SFGT developed and used in this research, which was easily reproduced and accurate, was able to detect and confirm important adaptations related to fitness in the athletic horse.

The Effects of Superficial Heating before 1-MHz Ultrasound on Tissue Temperature

2003 ◽  
Vol 12 (2) ◽  
pp. 95-103 ◽  
Author(s):  
William R. Holcomb ◽  
Chris Blank
Keyword(s):  
Athletic Training ◽  
Repeated Measures ◽  
Outcome Measure ◽  
Tissue Temperature ◽  
Temperature Elevation ◽  
Main Outcome Measure ◽  
Cooling Period ◽  
Dependent Variables ◽  
Within Subjects ◽  
Independent Variable

Context:Ultrasound significantly raises tissue temperature, but the time of temperature elevation is short.Objective:To assess the effectiveness of superficial preheating on temperature elevation and decline when using ultrasound.Design:Within-subjects design to test the independent variable, treatment condition; repeated-measures ANOVAs to analyze the dependent variables, temperature elevation and decline.Setting:Athletic training laboratory.Intervention:Temperature at a depth of 3.75 cm was measured during ultrasound after superficial heating and with ultrasound alone.Subjects:10 healthy men.Main Outcome Measure:Temperature was recorded every 30 s during 15 min of ultrasound and for 15 min afterward.Results:Temperature elevation with ultrasound was significantly greater with preheating (4.0 ± 0.21 °C) than with ultrasound alone (3.0 ± 0.22 °C). Temperature decline was not significantly different between preheating and ultrasound alone.Conclusions:Superficial preheating significantly increases temperature elevation but has no effect on temperature decline during a 15-min cooling period.

Drag Forces on, and Deformation of, Closed Flexible Bags

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Pål Lader ◽  
David W. Fredriksson ◽  
Zsolt Volent ◽  
Jud DeCew ◽  
Trond Rosten ◽  
...  
Keyword(s):  
Drag Force ◽  
Hydrodynamic Forces ◽  
Towing Tank ◽  
Drag Forces ◽  
Uniform Current ◽  
Salmon Production

The use of closed flexible bags is among the suggestions considered as a potential way to expand the salmon production in Norway. Few ocean structures exist with large, heavily compliant submerged components, and there is presently limited existing knowledge about how aquaculture systems with flexible closed cages will respond to external sea loads. The flexibility and deformation of the bag are coupled to the hydrodynamic forces, and the forces and deformation will be dependent on the filling level of the bag. In order to get a better understanding of the drag forces on, and deformation of, such bags, experiments were conducted with a series of closed flexible bags. The bags were towed in a towing tank in order to simulate uniform current. Four different geometries were investigated, cylindrical, cubical, conical, and pyramidal, and the filling levels were varied between 70% and 120%. The main findings from the experiments were that the drag force was highly dependent on the filling level, and that the drag force increases with decreasing filling level. Comparing the drag force on a deflated bag with an inflated one showed an increase of up to 2.5 times.

Effects of subtracting sitting versus adding exercise on glycemic control and variability in sedentary office workers

2014 ◽  
Vol 39 (11) ◽  
pp. 1286-1293 ◽  
Author(s):  
Jennifer M. Blankenship ◽  
Kirsten Granados ◽  
Barry Braun
Keyword(s):  
Energy Expenditure ◽  
Plasma Glucose ◽  
Repeated Measures ◽  
Area Under The Curve ◽  
Glycemic Variability ◽  
Office Workers ◽  
Sitting Time ◽  
Moderate Intensity ◽  
Cardiometabolic Health ◽  
Moderate Intensity Exercise

Recent evidence suggests that, like adding exercise, reducing sitting time may improve cardiometabolic health. There has not been a direct comparison of the 2 strategies with energy expenditure held constant. The purpose of this study was to compare fasting and postmeal glucose and insulin concentrations in response to a day with frequent breaks from sitting but no exercise versus considerable sitting plus moderate exercise. Ten sedentary overweight/obese office workers were tested in 3 conditions: (i) walking per activity guidelines (AGW): sitting for majority of workday with a 30 min pre-lunch walk; (ii) frequent long breaks (FLB): no structured exercise but frequent breaks from sitting during workday with energy expenditure matched to AGW; and (iii) frequent short breaks (FSB): number of breaks matched to FLB, but duration of breaks were shorter. Plasma glucose and insulin areas under the curve were measured in response to a meal tolerance test (MTT) at the end of the workday and interstitial glucose was evaluated throughout the day and overnight using continuous glucose monitoring. Using repeated-measures linear mixed models, area under the curve of plasma glucose or insulin after the MTT was not different between conditions. Glycemic variability was lower in FLB compared with AGW (p < 0.05), and nocturnal duration of elevated glucose (>7.8 mmol/L) was shorter after FLB (2.5 ± 2.5 min) than AGW (32.7 ± 16.4 min) or FSB (45.6 ± 29.6 min, p = 0.05). When energy expenditure was matched, breaks from sitting approximated the effects of moderate-intensity exercise on postmeal glucose and insulin responses and more effectively constrained glycemic variability.

Introduction of adult cats to indirect calorimetry respiration chambers causes increased energy expenditure and respiratory quotient that decrease following acclimation

2022 ◽  
pp. 1-6
Author(s):  
Kylie Hogan ◽  
Nicholas Genova ◽  
James R. Templeman ◽  
Adronie Verbrugghe ◽  
Anna K. Shoveller
Keyword(s):  
Energy Expenditure ◽  
Home Environment ◽  
Indirect Calorimetry ◽  
Repeated Measures ◽  
Respiratory Quotient ◽  
Mixed Model ◽  
Significant Variable ◽  
Level Energy ◽  
Adult Cats ◽  
Space Restriction

Abstract OBJECTIVE To replicate a previously defined behavioral procedure to acclimate adult cats to temporary restriction in indirect calorimetry chambers and measure energy expenditure and respiratory quotient changes during acclimation. ANIMALS 8 healthy adult cats (4 spayed females, and 4 neutered males; mean ± SEM age, 2.5 ± 1.5 years; mean body weight, 4.8 ± 1.8 kg). PROCEDURES Cats underwent a 13-week incremental acclimation procedure whereby cats were acclimated to the chambers in their home environment (weeks 1 to 3), to the study room (weeks 4 to 6), and to increasing lengths of restriction within their home environment (weeks 7 to 8) and the chambers (weeks 9 to 13). Cat stress score, respiratory rate, fearfulness (assessed with a novel object test), energy expenditure, and respiratory quotient were measured. Data were analyzed by use of a repeated-measures mixed model. RESULTS Stress, based on cat stress scores, fearfulness, and respiration, peaked at weeks 4, 9, and 10 but returned to baseline levels by week 11. Energy expenditure and respiratory quotient peaked at weeks 10 and 11, respectively, but were reduced significantly by weeks 11 and 13, respectively. All cats returned to baseline by the end of the study and were deemed fully acclimated. CLINICAL RELEVANCE Changes in perceived stress level, energy expenditure, and respiratory quotient at various stages of the acclimation procedure suggest that stress should be considered a significant variable in energy balance measurements when indirect calorimetry is used in cats. An incremental acclimation procedure should therefore be used to prepare cats for the temporary space restriction necessary for indirect calorimetry studies.

scholarly journals A High-Fidelity Simulation Is Effective in Improving Athletic Training Students' Self-Efficacy with Emergency Cardiovascular Care Skills

2019 ◽  
Vol 14 (2) ◽  
pp. 108-116 ◽  
Author(s):  
Kristin A. Paloncy ◽  
Leah Georges ◽  
Allan J. Liggett
Keyword(s):  
Athletic Training ◽  
Self Efficacy ◽  
Repeated Measures ◽  
National Collegiate Athletic Association ◽  
The United States ◽  
High Fidelity ◽  
High Fidelity Simulation ◽  
Athletic Training Students ◽  
Convenience Sample ◽  
Simulation Center

Context High-fidelity simulation can provide an ideal adjunct to clinical or real-world experience by providing a realistic and safe learning environment for the practice of low-incident encounters. Objective Given that levels of perceived self-efficacy are malleable and high-fidelity simulation can provide many positive outcomes, the purpose of this study was to determine whether participation in a high-fidelity simulated cardiovascular emergency scenario using the Laerdal SimMan in a university simulation center in the United States increased undergraduate athletic training students' self-efficacy scores. Design Cohort design with repeated measures. Patients or Other Participants Convenience sample of undergraduate athletic training students (n = 46) enrolled in a professional program at a National Collegiate Athletic Association Division I university in the Midwest. Intervention(s) Participation in or observation of a high-fidelity cardiopulmonary resuscitation (CPR) simulation. Main Outcome Measure(s) Self-efficacy scores before, immediately after, and 6 months after simulation. Results There was a significant main effect for the 3 repeated measures, with the scores steadily increasing significantly from pretest (mean = 7.60, SD = 1.13) to posttest (mean = 8.04, SD = 1.22, P = .001), then again from immediate posttest to the 6-month posttest (mean = 8.38, SD = 1.04, P = .04). Scores among the participants (mean = 8.21, SD = 1.03) were not significantly higher than scores among the observers (mean = 7.85, SD = 1.40). Scores at the 6-month follow-up posttest (mean = 8.38, SD = 1.04) significantly increased from the posttest immediately after the simulation (P = .04). Conclusions Participating in or observing high-fidelity CPR simulation is an effective method of providing deliberate practice opportunities for athletic training students to increase self-efficacy related to CPR techniques.

ENERGY EXPENDITURE DURING WEIGHT SUPPORTED TREADMILL WALKING.

2005 ◽  
Vol 16 (4) ◽  
pp. 37-38
Author(s):  
James J. Laskin ◽  
Virginia Kudritzki ◽  
Sierra Langstaff ◽  
Travis Obermire ◽  
Molly Sanders
Keyword(s):  
Energy Expenditure ◽  
Treadmill Walking

scholarly journals Simulation of Convection–Diffusion Transport in a Laminar Flow past a Row of Parallel Absorbing Fibers

Fibers ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 90 ◽  
Author(s):  
Vasily A. Kirsch ◽  
Alexandr V. Bildyukevich ◽  
Stepan D. Bazhenov
Keyword(s):  
Laminar Flow ◽  
Drag Force ◽  
Sherwood Number ◽  
Hollow Fiber Membrane ◽  
Reynolds Numbers ◽  
Regular System ◽  
Convection Diffusion ◽  
Drag Forces ◽  
Wide Range ◽  
Diffusion Mass

A numerical simulation of the laminar flow field and convection–diffusion mass transfer in a regular system of parallel fully absorbing fibers for the range of Reynolds numbers up to Re = 300 is performed. An isolated row of equidistant circular fibers arranged normally to the external flow is considered as the simplest model for a hollow-fiber membrane contactor. The drag forces acting on the fibers with dependence on Re and on the ratio of the fiber diameter to the distance between the fiber axes, as well as the fiber Sherwood number versus Re and the Schmidt number, Sc, are calculated. A nonlinear regression formula is proposed for calculating the fiber drag force versus Re in a wide range of the interfiber distances. It is shown that the Natanson formula for the fiber Sherwood number as a function of the fiber drag force, Re, and Sc, which was originally derived in the limit of high Peclet numbers, is applicable for small and intermediate Reynolds numbers; intermediate and large Peclet numbers, where Pe = Re × Sc; and for sparse and moderately dense rows of fibers.

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