Purpose: The present study compared the level of agreement of anaerobic threshold (AT) between ventilatory and near-infrared spectroscopy (NIRS) techniques in patients with chronic heart failure (CHF) and healthy subjects.
Methods: Patients with CHF (n = 9) and a control group (CG; n = 14) underwent cardiopulmonary exercise testing on a cycle ergometer until physical exhaustion. Determination of AT was performed visually by (1) ventilatory-expired gas analysis curves and (2) oxyhemoglobin (O2Hb) and deoxyhemoglobin (HHb) curves assessed by NIRS.
Results: The CHF group presented significantly lower oxygen consumption (O2), heart rate, and workload at AT when compared with the CG measured by NIRS (P < .05). However, the effect size, measured by the Cohen d, revealed large magnitude (>0.80) in both techniques when compared between CHF patients and the CG. In addition, ventilatory and NIRS techniques demonstrated significant and very strong/strong correlations for relative O2 (r = 0.91) and heart rate (r = 0.85) in the detection of AT in the CHF group.
Conclusion: Both ventilatory and NIRS assessments are correlated and there are no differences in the responses between CHF patients and healthy subjects in the determination of AT. These findings indicate both approaches may have utility in the assessment of submaximal exercise performance in patients with CHF.
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http://dx.doi.org/10.1097/HCR.0000000000000462 | DOI Listing |
Brain Cogn
December 2024
US Army Combat Capabilities Development Command Soldier Center (DEVCOM SC), Natick, MA, USA; Center for Applied Brain and Cognitive Sciences (CABCS), Tufts University, Medford, MA, USA. Electronic address:
Regular physical activity is deemed beneficial to physical, cognitive, and emotional health. Walking may be an accessible means of meeting physical activity recommendations and improving cognition. However, exercise effects on cognition are often explored at shorter durations (30 min or less), with fewer studies exploring how cognition is impacted during longer bouts of exercise.
View Article and Find Full Text PDFLife (Basel)
August 2024
Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore.
We assessed the feasibility of concurrent monitoring of cerebral hemodynamics in adult, comatose out-of-hospital cardiac arrest (OHCA) patients admitted to the National University Heart Centre Singapore from October 2021 to August 2023. Patients underwent continuous near-infrared spectroscopy (NIRS) monitoring in the first 72 h after return of spontaneous circulation (ROSC) and 30-min transcranial Doppler ultrasound (TCD) monitoring at least once. With constant mechanical ventilatory settings and continuous electrocardiographic, pulse oximeter and end-tidal carbon dioxide monitoring, blood pressure was manipulated via vasopressors and cerebral autoregulation assessed by measuring changes in regional cerebral oxygenation (NIRS) and cerebral blood flow velocities (TCD) in response to changes in mean arterial pressure.
View Article and Find Full Text PDFInt J Sport Nutr Exerc Metab
November 2024
Physical Effort Laboratory, Sports Center, Federal University of Santa Catarina, SC, Florianópolis, Brazil.
This study aimed to investigate the effects of caffeine ingestion by chewing gum (GUMCAF) combined with priming exercise on pulmonary oxygen uptake (V˙O2) and near-infrared spectroscopy-derived muscle oxygen extraction (HHb + Mb) kinetics during cycling performed in a severe-intensity domain. Fifteen trained cyclists completed four visits: two under a placebo gum (GUMPLA) and two under GUMCAF ingestion. Each visit consisted of two square-wave cycling bouts at Δ70 intensity (70% of difference between the V˙O2 at first ventilatory threshold and V˙O2max) with duration of 6 min each and 5 min of passive rest between the bouts.
View Article and Find Full Text PDFThis study evaluated the effects of exercise training (ET) and inspiratory muscle-loaded exercise training (IMLET) on ventilatory response and intercostal muscle deoxygenation levels during incremental cycling exercise. Twenty-one male participants were randomly divided into IMLET ( = 10) or ET ( = 11) groups. All participants underwent a 4-week cycling exercise training at 60% peak oxygen uptake.
View Article and Find Full Text PDFJ Appl Physiol (1985)
August 2024
Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada.
Prior studies of muscle blood flow and muscle-specific oxygen consumption have required invasive injection of dye and magnetic resonance imaging, respectively. Such measures have limited utility for continuous monitoring of the respiratory muscles. Frequency-domain near-infrared spectroscopy and diffuse correlation spectroscopy (FD-NIRS & DCS) can provide continuous surrogate measures of blood flow index (BF) and metabolic rate of oxygen consumption (MRO).
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