Caltrac Validity for Estimating Caloric Expenditure with Children

1992 ◽  
Vol 4 (2) ◽  
pp. 166-179 ◽  
Author(s):  
Molly S. Bray ◽  
James R. Morrow ◽  
James M. Pivarnik ◽  
John T. Bricker
Keyword(s):  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Respiratory Exchange Ratio ◽  
Treadmill Walking ◽  
Caloric Expenditure ◽  
Measured Energy ◽  
Exercise Energy Expenditure

This study investigated the validity of the Caltrac accelerometer for estimating resting and exercise energy expenditure for children. Seventeen children 9 to 12 years of age participated in the study. Criterion values of energy expenditure were determined from measures of oxygen consumption (VO2) and respiratory exchange ratio (RER), and Caltrac estimates of energy expenditure were obtained concurrently for each experimental condition. Correlations were significant between Caltrac estimates and measured energy expenditure at rest (r = .53, p<.03) and at slow (r = .89, p<.001) and brisk (r = .85, p<.001) treadmill walking. The Caltrac overestimated caloric expenditure for rest (M = 7%; range = −8 to 36%) and also for both slow (M = 17%; range = −3 to 30%) and brisk (M = 25%; range = 5 to 46%) walking. However, because of the high validity coefficients during activity, and because of its practicality in field settings, the Caltrac may be useful in estimating daily resting and walking energy expenditure for groups of children.

Metabolic Effects of Low-Dose Dopamine Infusion in Normal Volunteers

1990 ◽  
Vol 79 (6) ◽  
pp. 605-611 ◽  
Author(s):  
Cathy J. Regan ◽  
R. Duckworth ◽  
Judith A. Fairhurst ◽  
Paula F. Maycock ◽  
K. N. Frayn ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Fatty Acid ◽  
Blood Glucose ◽  
Free Fatty Acid ◽  
Energy Expenditure ◽  
Glucose Concentration ◽  
Respiratory Exchange Ratio ◽  
Blood Glucose Concentration ◽  
Metabolic Effects ◽  
Dopamine Infusion

1. Dopamine in 5% (w/v) d-glucose was infused into five healthy male volunteers at doses of 2, 5 and 10 μg min−1 kg−1 over three sequential periods of 45 min each. 2. Oxygen consumption, respiratory exchange ratio, blood glucose concentration and plasma levels of free fatty acids, glycerol, lactate, dopamine, adrenaline and noradrenaline were measured. The results were compared with values obtained during infusion over the same time period of the corresponding volumes of 5% (w/v) d-glucose alone. 3. Energy expenditure calculated from the oxygen consumption and the respiratory exchange ratio was higher than control values during infusion of dopamine (P < 0.001, analysis of variance) specifically at a rate of 10 μg min−1 kg−1 (P < 0.05) when it was 14% higher, but not at a rate 2 of or 5 μg min−1 kg−1. The plasma noradrenaline concentration was 74 and 230% and the blood glucose concentration was 21 and 36% higher than control values at 5 and 10 μg of dopamine min−1 kg−1, respectively (P < 0.01). At 10 μg of dopamine min−1 kg−1 the plasma free fatty acid concentration was 70% and the plasma glycerol concentration was 80% higher than during the control infusion (P < 0.01). The respiratory exchange ratio and the plasma lactate concentration were the same in the two groups and did not alter during the dopamine infusion. The plasma adrenaline concentration rose significantly (P < 0.01), but only transiently, during dopamine infusion at a rate of 2 μg min−1 kg−1. 4. Dopamine at low doses has metabolic effects. It increases the blood glucose concentration and the circulating noradrenaline level at an infusion rate of 5 μg min−1 kg−1. It increases energy expenditure and circulating free fatty acid and glycerol levels at an infusion rate of 10 μg min−1 kg−1, presumably due to stimulation of lipolysis.

Physiological comparison of three types of ergometry

1960 ◽  
Vol 15 (6) ◽  
pp. 1007-1014 ◽  
Author(s):  
A. C. Bobbert
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Work Load ◽  
Treadmill Walking ◽  
Energy Expenditures

A physiological comparison of cycling, cranking and walking has been made, using in all experiments the same subjects and methods. In cycling and cranking energy expenditure increases with work load in a rectilinear way, the energy expenditures being always higher in cranking. In treadmill walking energy expenditure per kilogram of body weight rises curvilinearly both with increasing speed and grade. In cycling, cranking and walking there are nearly the same relations between heart rate and metabolism. Ventilation in cranking always exceeds that in walking and cycling at the same level of oxygen consumption. The curve of ventilation versus oxygen consumption shows a steeper rise in cranking. In level and grade walking ventilation increases curvilinearly with oxygen consumption. Submitted on September 17, 1959

Failure to Find Increased TEM at Rest and during Exercise in Aerobically Trained and Resistance Trained Subjects

1993 ◽  
Vol 3 (1) ◽  
pp. 55-66 ◽  
Author(s):  
Jennie A. Gilbert ◽  
James E. Misner
Keyword(s):  
Oxygen Consumption ◽  
Food Intake ◽  
Energy Expenditure ◽  
Indirect Calorimetry ◽  
Respiratory Exchange Ratio ◽  
Metabolic Response ◽  
Maximal Oxygen Consumption ◽  
Mixed Meal ◽  
Trained Subjects ◽  
Aerobically Trained

This study examined the metabolic response to a 763-kcal mixed meal at rest and during 30 min of exercise at 50% maximal oxygen consumption () in 8 aerobically trained (AT), 8 resistance trained (RT), and 8 untrained (UT) subjects. Oxygen consumption (VO,) was measured minute by minute during 30 min of exercise by indirect calorimetry on 2 nonconsecutive days (postabsorptive exercise, PA; and postprandial exercise, PP). Total VO, consumed and total caloric expenditure during the PA and PP conditions were similar for the three groups, indicating that prior food intake did not affect energy expenditure during exercise. Consequently, TEM during exercise did not differ significantly among the groups. Respiratory exchange ratio (R) differed significantly only during the PA condition, with the AT group exhibiting significantly lower R values compared to the RT group, and significantly lower R values compared to the UT group. These data suggest that the consumption of a meal 30 min prior to exercise does not increase TEM during exercise in AT, RT, and UT subjects.

The Influence of Sport-Field Properties on Muscle-Recruitment Patterns and Metabolic Response

2019 ◽  
Vol 14 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Michael E. Hales ◽  
John D. Johnson
Keyword(s):  
Mechanical Properties ◽  
Heart Rate ◽  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Muscle Activity ◽  
Respiratory Exchange Ratio ◽  
Metabolic Response ◽  
Maximal Oxygen Consumption ◽  
Muscle Recruitment ◽  
Metabolic Equivalent

Purpose: To investigate different sport-field properties’ influence on muscle-recruitment patterns and metabolic response during a series of running and agility drills. Methods: Eleven male athletes were fitted with a standard multipurpose training shoe. The test protocol consisting of 4 high-intensity trials with 60-s rests between trials performed on 2 fields with different properties. Time-dependent field properties were measured using the American Standards for Testing and Materials protocol (F-1936). A 30-m pretest and posttest sprint determined fatigue and player performance. Electromyography (EMG) recorded muscle activity for vastus medialis, biceps femoris, gastrocnemius medial head, and tibialis anterior, and metabolic activity analyzed maximal oxygen consumption, heart rate, respiratory exchange ratio, metabolic equivalent, and energy expenditure. Results: A difference was calculated for muscle activity across trials (P = .01) for both surfaces. Muscle activity was <13% on the field with less energy return (P = .01). Metabolic components (maximal oxygen consumption, heart rate, respiratory exchange ratio, metabolic equivalent, and energy expenditure) were significantly different across trials (P = .01) but not significantly different between fields. The participants completed the agility course (5.2%) faster on the field with greater energy return, while caloric expenditure was similar between fields. Conclusions: The findings indicate that field mechanical properties influence muscle-activation patterns. The field demonstrating the greatest magnitude of energy return produces the lowest sprint and agility course times; however, performing on a field exhibiting unfamiliar mechanical properties could cause the athlete to produce atypical movement patterns that might contribute to overuse of the neuromuscular system.

scholarly journals Heat Stress Reduces Metabolic Rate While Increasing Respiratory Exchange Ratio in Growing Pigs

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 215
Author(s):  
Dane W. Fausnacht ◽  
Kellie A. Kroscher ◽  
Ryan P. McMillan ◽  
Luciane S. Martello ◽  
Lance H. Baumgard ◽  
...  
Keyword(s):  
Heat Stress ◽  
Energy Expenditure ◽  
Metabolic Rate ◽  
Respiratory Exchange Ratio ◽  
Muscle Growth ◽  
Growing Pigs ◽  
Metabolic Phenotype ◽  
Substrate Regulation ◽  
Enclosed Chamber ◽  
Muscle Biopsies

Heat stress (HS) diminishes animal production, reducing muscle growth and increasing adiposity, especially in swine. Excess heat creates a metabolic phenotype with limited lipid oxidation that relies on aerobic and anaerobic glycolysis as a predominant means of energy production, potentially reducing metabolic rate. To evaluate the effects of HS on substrate utilization and energy expenditure, crossbred barrows (15.2 ± 2.4 kg) were acclimatized for 5 days (22 °C), then treated with 5 days of TN (thermal neutral, 22 °C, n = 8) or HS (35 °C, n = 8). Pigs were fed ad libitum and monitored for respiratory rate (RR) and rectal temperature. Daily energy expenditure (DEE) and respiratory exchange ratio (RER, CO2:O2) were evaluated fasted in an enclosed chamber through indirect calorimetry. Muscle biopsies were obtained from the longissimus dorsi pre/post. HS increased temperature (39.2 ± 0.1 vs. 39.6 ± 0.1 °C, p < 0.01) and RER (0.91 ± 0.02 vs. 1.02 ± 0.02 VCO2:VO2, p < 0.01), but decreased DEE/BW (68.8 ± 1.7 vs. 49.7 ± 4.8 kcal/day/kg, p < 0.01) relative to TN. Weight gain (p = 0.80) and feed intake (p = 0.84) did not differ between HS and TN groups. HS decreased muscle metabolic flexibility (~33%, p = 0.01), but increased leucine oxidation (~35%, p = 0.02) compared to baseline values. These data demonstrate that HS disrupts substrate regulation and energy expenditure in growing pigs.

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