Dataset Information

The day-to-day reliability of peak fat oxidation and FATMAX.

ABSTRACT: PURPOSE:Prior studies exploring the reliability of peak fat oxidation (PFO) and the intensity that elicits PFO (FATMAX) are often limited by small samples. This study characterised the reliability of PFO and FATMAX in a large cohort of healthy men and women. METHODS:Ninety-nine adults [49 women; age: 35 (11) years; [Formula: see text]O2peak: 42.2 (10.3) mL·kg BM-1·min-1; mean (SD)] completed two identical exercise tests (7-28 days apart) to determine PFO (g·min-1) and FATMAX (%[Formula: see text]O2peak) by indirect calorimetry. Systematic bias and the absolute and relative reliability of PFO and FATMAX were explored in the whole sample and sub-categories of: cardiorespiratory fitness, biological sex, objectively measured physical activity levels, fat mass index (derived by dual-energy X-ray absorptiometry) and menstrual cycle status. RESULTS:No systematic bias in PFO or FATMAX was found between exercise tests in the entire sample (- 0.01 g·min-1 and 0%[Formula: see text]O2peak, respectively; p?>?0.05). Absolute reliability was poor [within-subject coefficient of variation: 21% and 26%; typical errors:?±?0.06 g·min-1 and?×?/?÷?1.26%[Formula: see text]O2peak; 95% limits of agreement:?±?0.17 g·min-1 and?×?/?÷?1.90%[Formula: see text]O2peak, respectively), despite high (r?=?0.75) and moderate (r?=?0.45) relative reliability for PFO and FATMAX, respectively. These findings were consistent across all sub-groups. CONCLUSION:Repeated assessments are required to more accurately determine PFO and FATMAX.

SUBMITTER: Chrzanowski-Smith OJ

PROVIDER: S-EPMC7340634 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The day-to-day reliability of peak fat oxidation and FAT<sub>MAX</sub>.

Chrzanowski-Smith Oliver J OJ Edinburgh Robert M RM Thomas Mark P MP Haralabidis Nicos N Williams Sean S Betts James A JA Gonzalez Javier T JT

European journal of applied physiology 20200601 8

<h4>Purpose</h4>Prior studies exploring the reliability of peak fat oxidation (PFO) and the intensity that elicits PFO (FAT<sub>MAX</sub>) are often limited by small samples. This study characterised the reliability of PFO and FAT<sub>MAX</sub> in a large cohort of healthy men and women.<h4>Methods</h4>Ninety-nine adults [49 women; age: 35 (11) years; [Formula: see text]O<sub>2</sub>peak: 42.2 (10.3) mL·kg BM<sup>-1</sup>·min<sup>-1</sup>; mean (SD)] completed two identical exercise tests (7-28 ...[more]

PMID: 32488584

Similar Datasets

Project description:PURPOSE:To provide empirically-supported thresholds for step-based intensity (i.e., peak 30-min cadence; average of the top 30 steps/min in a day) and steps/day in relation to cardiometabolic health outcomes. METHODS:Receiver operating characteristic curve analysis was applied to the National Health and Nutrition Examination Survey (NHANES) 2005-2006 accelerometer-derived step data to determine steps/day and peak 30-min cadence as risk screening values (i.e., thresholds) for fasting glucose, body mass index, waist circumference, high blood pressure, triglycerides, and HDL cholesterol. Thresholds for peak 30-min cadence and steps/day were derived that, when exceeded, classify the absence of each cardiometabolic risk factor. Additionally, logistic regression models that included the influence of age and smoking were developed using the sample weights, primary sampling units (PSUs), and stratification variables provided by the NHANES survey. Finally, a decision tree analysis was performed to delineate criteria for at-risk versus healthy populations using cadence bands. RESULTS:Peak 30-min cadence thresholds across cardiometabolic outcomes ranged from 66-72 steps/min. Steps/day thresholds ranged from 4325-6192 steps/day. Higher thresholds were observed in men compared to women. In men, higher steps/day thresholds were observed in age ranges of 30-39, while in women, higher thresholds were observed in the age-range 50-59 years. Decision trees for classifying being at low risk for metabolic syndrome contained one risk-free leaf at higher cadence bands, specifically for any time accumulated at ≥120 steps/min. CONCLUSIONS:Minimum thresholds representing absence of cardiometabolic risk range from 4325-6192 steps/day and 66-72 steps/min for peak 30-min cadence. Any time accumulated at ≥120 steps/min was associated with an absence of cardiometabolic risk. Although based on cross-sectional data, these thresholds represent potentially important and clinically interpretable daily physical activity goals.

Project description:Biomarker development is currently a high priority in neurodevelopmental disorder research. For many types of biomarkers (particularly biomarkers of diagnosis), reliability over short periods is critically important. In the field of autism spectrum disorder (ASD), resting electroencephalography (EEG) power spectral densities (PSD) are well-studied for their potential as biomarkers. Classically, such data have been decomposed into pre-specified frequency bands (e.g., delta, theta, alpha, beta, and gamma). Recent technical advances, such as the Fitting Oscillations and One-Over-F (FOOOF) algorithm, allow for targeted characterization of the features that naturally emerge within an EEG PSD, permitting a more detailed characterization of the frequency band-agnostic shape of each individual's EEG PSD. Here, using two resting EEGs collected a median of 6 days apart from 22 children with ASD and 25 typically developing (TD) controls during the Feasibility Visit of the Autism Biomarkers Consortium for Clinical Trials, we estimate test-retest reliability based on the characterization of the PSD shape in two ways: (1) Using the FOOOF algorithm we estimate six parameters (offset, slope, number of peaks, and amplitude, center frequency and bandwidth of the largest alpha peak) that characterize the shape of the EEG PSD; and (2) using nonparametric functional data analyses, we decompose the shape of the EEG PSD into a reduced set of basis functions that characterize individual power spectrum shapes. We show that individuals exhibit idiosyncratic PSD signatures that are stable over recording sessions using both characterizations. Our data show that EEG activity from a brief 2-min recording provides an efficient window into characterizing brain activity at the single-subject level with desirable psychometric characteristics that persist across different analytical decomposition methods. This is a necessary step towards analytical validation of biomarkers based on the EEG PSD and provides insights into parameters of the PSD that offer short-term reliability (and thus promise as potential biomarkers of trait or diagnosis) vs. those that are more variable over the short term (and thus may index state or other rapidly dynamic measures of brain function). Future research should address the longer-term stability of the PSD, for purposes such as monitoring development or response to treatment.

Dataset Information

The day-to-day reliability of peak fat oxidation and FATMAX.

Publications

The day-to-day reliability of peak fat oxidation and FAT<sub>MAX</sub>.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets