Reliability and Validity of a Portable Metabolic Measurement System

1996 ◽  
Vol 21 (2) ◽  
pp. 109-119 ◽  
Author(s):  
Edward L. Melanson ◽  
Patty S. Freedson ◽  
Devra Hendelman ◽  
Edward Debold
Keyword(s):  
Oxygen Consumption ◽  
Respiratory Exchange Ratio ◽  
Maximal Exercise ◽  
Reliability And Validity ◽  
Submaximal Exercise ◽  
Metabolic System ◽  
Key Words Oxygen Consumption ◽  
Computer Based ◽  
Metabolic Measurement ◽  
Key Words Oxygen

The purpose of this study was to assess the reliability and validity of a portable metabolic system (TEEM 100) during submaximal and maximal [Formula: see text] exercise using a computer-based metabolic system as the reference system (REF). Between repeated trials of submaximal exercise at three constant loads, differences in ventilation [Formula: see text] and oxygen consumption [Formula: see text] were 0.2 ± 4.9 L∙min−1 and 0.03 ± 0.10 L∙min−1 for REF, and 1.9 ± 0.7 L∙min−1 and 0.00 ± 0.17 L∙min−1 for TEEM 100. Pooled intraclass reliability coefficients for [Formula: see text] and [Formula: see text] calculated from the repeated submaximal trials were r =.89 and r =.94 for REF, and r =.86 and r =.94 for the TEEM 100. Respiratory exchange ratio (RER) measured by the TEEM 100 was significantly higher (p =.01) at only the lowest workload. At [Formula: see text], the TEEM 100 recorded significantly higher values for FeO2 (p =.01) and RER (p <.001). These results suggest that the TEEM 100 provides reliable and valid measurements of [Formula: see text] during submaximal and maximal exercise. Key words: oxygen consumption, indirect calorimetry, portable analysis, exercise, metabolism

The effect of feed deprivation on gastrointestinal respiration and Na+, K+-ATPase in chicks

1998 ◽  
Vol 78 (3) ◽  
pp. 315-326
Author(s):  
H. Park ◽  
B. W. McBride ◽  
L. P. Milligan ◽  
L. M. Trouten-Radford
Keyword(s):  
Small Intestine ◽  
Oxygen Consumption ◽  
Binding Sites ◽  
Dry Matter ◽  
Nutrient Deprivation ◽  
White Leghorn ◽  
Feed Deprivation ◽  
Pump Activity ◽  
Key Words Oxygen Consumption ◽  
Key Words Oxygen

In order to investigate the effect of nutrient availability on energy metabolism of the gastrointestinal tract (GIT) of chicks, two experiments were conducted. In exp. 1, jejunal slices from male White Leghorn chicks at 14 d were incubated in salt-based balanced medium (SBM) or complex medium (CM) for 30 min. The total O2 (TO2) and ouabain-sensitive O2 (OSO2) consumption in jejunal slices were significantly decreased in SBM. The results from exp. 1 imply that when the GIT mucosa is subjected to nutrient deprivation, the utilization of oxygen consumption is altered primarily by shifting active Na+ pump activity. Changes in the TO2, OSO2 and amiloride-sensitive O2 (ASO2) uptake in response to feed deprivation in the small intestine of male White Leghorn chicks were investigated in exp. 2. There was little change in TO2, OSO2 and ASO2 per unit of dry matter of the small intestine from birds subjected to fasting, except for a TO2 decrease in the jejunum of 48 h fasted chicks. However, there were significant reductions in TO2, OSO2 and ASO2 in the jejunum when data were expressed per unit DNA. Na+, K+-ATPase-dependent respiration represented 31–37% of TO2 in the avian jejunoileum. Amiloride-sensitive respiration accounted for 10–18% of TO2 in the jejunoileum. The maximal amount of 3Houabain binding sites of jejunal enterocytes was significantly decreased in chicks fasted for 48 h (P < 0.05). Key words: Oxygen consumption, fasting, Na+, K+-ATPase, ouabain, jejunum, ileum, chicks

Reproducibility of cardiac power output and other cardiopulmonary exercise indices in patients with chronic heart failure

2011 ◽  
Vol 122 (4) ◽  
pp. 175-181 ◽  
Author(s):  
Djordje G. Jakovljevic ◽  
Petar M. Seferovic ◽  
David Nunan ◽  
Gay Donovan ◽  
Michael I. Trenell ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Chronic Heart Failure ◽  
Power Output ◽  
Respiratory Exchange Ratio ◽  
Maximal Exercise ◽  
Peak Oxygen Consumption ◽  
Cardiopulmonary Exercise ◽  
Cardiac Power

Cardiac power output is a direct measure of overall cardiac function that integrates both flow- and pressure-generating capacities of the heart. The present study assessed the reproducibility of cardiac power output and other more commonly reported cardiopulmonary exercise variables in patients with chronic heart failure. Metabolic, ventilatory and non-invasive (inert gas re-breathing) central haemodynamic measurements were undertaken at rest and near-maximal exercise of the modified Bruce protocol in 19 patients with stable chronic heart failure. The same procedure was repeated 7 days later to assess reproducibility. Cardiac power output was calculated as the product of cardiac output and mean arterial pressure. Resting central haemodynamic variables demonstrate low CV (coefficient of variation) (ranging from 3.4% for cardiac output and 5.6% for heart rate). The CV for resting metabolic and ventilatory measurements ranged from 8.2% for respiratory exchange ratio and 14.2% for absolute values of oxygen consumption. The CV of anaerobic threshold, peak oxygen consumption, carbon dioxide production and respiratory exchange ratio ranged from 3.8% (for anaerobic threshold) to 6.4% (for relative peak oxygen consumption), with minute ventilation having a CV of 11.1%. Near-maximal exercise cardiac power output and cardiac output had CVs of 4.1 and 2.2%, respectively. Cardiac power output demonstrates good reproducibility suggesting that there is no need for performing more than one cardiopulmonary exercise test. As a direct measure of cardiac function (dysfunction) and an excellent prognostic marker, it is strongly advised in the assessment of patients with chronic heart failure undergoing cardiopulmonary exercise testing.

Validity of the Step Test for Exercise Prescription: No Extension to a Larger Age Range

2013 ◽  
Vol 21 (4) ◽  
pp. 444-454 ◽  
Author(s):  
Eric D. Vidoni ◽  
Anna Mattlage ◽  
Jonathan Mahnken ◽  
Jeffrey M. Burns ◽  
Joe McDonough ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Exercise Testing ◽  
Maximal Exercise ◽  
Exercise Prescription ◽  
Submaximal Exercise ◽  
Step Test ◽  
Peak Oxygen Consumption ◽  
Submaximal Exercise Test ◽  
Test Exercise ◽  
Age Range

The purpose of this study was to determine the validity of a submaximal exercise test, the Step Test Exercise Prescription (STEP), in a broad age range and in individuals in the earliest stages of Alzheimer’s disease (AD). Individuals (n = 102) underwent treadmill-based maximal exercise testing and a STEP. The STEP failed to predict peak oxygen consumption (VO2peak), and was a biased estimate of VO2peak (p < .0001). Only 43% of subjects’ STEP results were within 3.5 ml · kg–1 · min–1 of VO2peak. When categorized into fitness levels these 2 measures demonstrated moderate agreement (kappa = .59). The validity of the STEP was not supported in our participants, including those with AD. The STEP may not be appropriate in the clinic as a basis for exercise recommendations in these groups, although it may continue to have utility in classifying fitness in research or community health screenings.

Nonlinear increases in diffusing capacity during exercise by seated and supine subjects

1981 ◽  
Vol 51 (4) ◽  
pp. 858-863 ◽  
Author(s):  
D. L. Stokes ◽  
N. R. MacIntyre ◽  
J. A. Nadel
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Consumption ◽  
Healthy Subjects ◽  
Vital Capacity ◽  
Maximal Exercise ◽  
Sitting Position ◽  
Diffusing Capacity ◽  
Heavy Exercise ◽  
Lung Volumes ◽  
Rate Of Increase

To study the effects of exercise on pulmonary diffusing capacity, we measured the lungs' diffusing capacity for carbon monoxide (DLCO) during exhalation from 30 to 45% exhaled vital capacity in eight healthy subjects at rest and during exercise while both sitting and supine. We found that DLCO at these lung volumes in resting subjects was 26.3 +/- 3.2% (mean +/- SE) higher in the supine than in the sitting position (P less than 0.001). We also found that, in both positions, DLCO at these lung volumes increased significantly (P less than 0.001) with increasing exercise and approached similar values at maximal exercise. The pattern of increase in DLCO with an increase in oxygen consumption in both positions was curvilinear in that the rate of increase in DLCO during mild exercise was greater than the rate of increase in DLCO during heavy exercise (P = 0.02). Furthermore, in the supine position during exercise, it appeared that DLCO reached a physiological maximum.

Effects of moderate hyperoxia on oxygen consumption during submaximal and maximal exercise

2002 ◽  
Vol 88 (3) ◽  
pp. 235-242 ◽  
Author(s):  
Prieur F. ◽  
Benoit H. ◽  
Busso T. ◽  
Castells J. ◽  
Geyssant A. ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Maximal Exercise

scholarly journals Reliability and Validity of Composite Scores from the NIH Toolbox Cognition Battery in Adults

2014 ◽  
Vol 20 (6) ◽  
pp. 588-598 ◽  
Author(s):  
Robert K. Heaton ◽  
Natacha Akshoomoff ◽  
David Tulsky ◽  
Dan Mungas ◽  
Sandra Weintraub ◽  
...  
Keyword(s):  
Cognitive Abilities ◽  
Gold Standard ◽  
Reliability And Validity ◽  
Epidemiologic Studies ◽  
Memory Processing ◽  
Significant Relationships ◽  
Gender Education ◽  
Computer Based ◽  
Composite Scores ◽  
Test Retest Reliability

AbstractThis study describes psychometric properties of the NIH Toolbox Cognition Battery (NIHTB-CB) Composite Scores in an adult sample. The NIHTB-CB was designed for use in epidemiologic studies and clinical trials for ages 3 to 85. A total of 268 self-described healthy adults were recruited at four university-based sites, using stratified sampling guidelines to target demographic variability for age (20–85 years), gender, education, and ethnicity. The NIHTB-CB contains seven computer-based instruments assessing five cognitive sub-domains: Language, Executive Function, Episodic Memory, Processing Speed, and Working Memory. Participants completed the NIHTB-CB, corresponding gold standard validation measures selected to tap the same cognitive abilities, and sociodemographic questionnaires. Three Composite Scores were derived for both the NIHTB-CB and gold standard batteries: “Crystallized Cognition Composite,” “Fluid Cognition Composite,” and “Total Cognition Composite” scores. NIHTB Composite Scores showed acceptable internal consistency (Cronbach’s alphas=0.84 Crystallized, 0.83 Fluid, 0.77 Total), excellent test–retest reliability (r: 0.86–0.92), strong convergent (r: 0.78–0.90) and discriminant (r: 0.19–0.39) validities versus gold standard composites, and expected age effects (r=0.18 crystallized, r=−0.68 fluid, r=−0.26 total). Significant relationships with self-reported prior school difficulties and current health status, employment, and presence of a disability provided evidence of external validity. The NIH Toolbox Cognition Battery Composite Scores have excellent reliability and validity, suggesting they can be used effectively in epidemiologic and clinical studies. (JINS, 2014, 20, 1–11)

Measurements of metabolic rate in rats: a comparison of techniques

1988 ◽  
Vol 65 (2) ◽  
pp. 964-970 ◽  
Author(s):  
T. I. Musch ◽  
A. Bruno ◽  
G. E. Bradford ◽  
A. Vayonis ◽  
R. L. Moore
Keyword(s):  
Metabolic Rate ◽  
Maximal Exercise ◽  
Ambient Air ◽  
Open Circuit ◽  
Submaximal Exercise ◽  
Co2 Production ◽  
Arterial Blood ◽  
In Series ◽  
Series Of Experiments ◽  
Four Levels

Two different open-circuit techniques of measuring metabolic rate were examined in rats at rest and during exercise. With one technique ambient air was drawn through a tightly fitting mask that was secured to the rat's head, whereas with the other technique the rat was placed into and ambient air was drawn through a Plexiglas box. Two series of experiments were performed. In series I, two groups were studied that consisted of rats that had received myocardial infarctions produced by coronary arterial ligations and rats that had received sham operations. In this series of experiments O2 uptake (VO2) and CO2 production (VCO2) were measured at rest, during four levels of submaximal exercise, and during maximal treadmill exercise in the same group of rats by use of both techniques in random order. VO2, VCO2, and the calculated respiratory exchange ratio (R) were similar at rest, during the highest level of submaximal exercise (20% grade, 37 m/min), and during maximal exercise; however, VO2 and VCO2 were significantly lower with the metabolic box technique compared with the mask technique during the three lowest work loads (5% grade, 19 m/min; 10% grade, 24 m/min; and 15% grade, 31 m/min). These differences appeared to be associated with a change in gait produced when the mask was worn. In series II, the arterial blood gas and acid-base responses to both submaximal and maximal exercise were measured using both techniques in a group of instrumented rats that had a catheter placed into the right carotid artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Endurance training in older men and women II. Blood lactate response to submaximal exercise

1984 ◽  
Vol 57 (4) ◽  
pp. 1030-1033 ◽  
Author(s):  
D. R. Seals ◽  
B. F. Hurley ◽  
J. Schultz ◽  
J. M. Hagberg
Keyword(s):  
Endurance Training ◽  
Blood Lactate ◽  
Respiratory Exchange Ratio ◽  
Submaximal Exercise ◽  
Older Individuals ◽  
O2 Uptake ◽  
Men And Women ◽  
Low Intensity ◽  
Older Men And Women ◽  
Intensity Training

Seven men and four women (age 63 +/- 2 yr, mean +/- SD, range 61–67 yr) participated in a 12-mo endurance training program to determine the effects of low-intensity (LI) and high-intensity (HI) training on the blood lactate response to submaximal exercise in older individuals. Maximal oxygen uptake (VO2max), blood lactate, O2 uptake (VO2), heart rate (HR), ventilation (VE), and respiratory exchange ratio (R) during three submaximal exercise bouts (65–90% VO2max) were determined before training, after 6 mo of LI training, and after an additional 6 mo of HI training. VO2max (ml X kg-1 X min-1) was increased 12% after LI training (P less than 0.05), while HI training induced a further increase of 18% (P less than 0.01). Lactate, HR, VE, and R were significantly lower (P less than 0.05) at the same absolute work rates after LI training, while HI training induced further but smaller reductions in these parameters (P greater than 0.05). In general, at the same relative work rates (ie., % of VO2max) after training, lactate was lower or unchanged, HR and R were unchanged, and VO2 and VE were higher. These findings indicate that LI training in older individuals results in adaptations in the response to submaximal exercise that are similar to those observed in younger populations and that additional higher intensity training results in further but less-marked changes.

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