AI Article Synopsis
Article Abstract
We hypothesized that the performance of prior heavy exercise would speed pulmonary oxygen uptake (V̇o) kinetics (i.e., as described by the time constant, [Formula: see text]) and reduce the amplitude of muscle deoxygenation (deoxy[heme]) kinetics in the supine (S) but not upright (U) body position. Seventeen healthy men completed heavy-intensity constant-work rate exercise tests in S and U consisting of two bouts of 6-min cycling separated by 6-min cycling at 20 W. Pulmonary V̇o was measured breath by breath; total and deoxy[heme] were determined via time-resolved near-infrared spectroscopy (NIRS) at three muscle sites. Priming exercise reduced [Formula: see text] in S (: 36 ± 10 vs. : 28 ± 10 s, < 0.05) but not U (: 27 ± 8 s vs. : 25 ± 7 s, > 0.05). Deoxy[heme] amplitude was increased after priming in S (: 25-28 μM vs. : 30-35 μM, < 0.05) and U (: 13-18 μM vs. : 17-25 μM, > 0.05), whereas baseline total[heme] was enhanced in S (: 110-179 μM vs. : 121-193 μM, < 0.05) and U (: 123-186 μM vs. : 137-197 μM, < 0.05). Priming exercise increased total[heme] in both S and U, likely indicating enhanced diffusive O delivery. However, the observation that after priming the amplitude of the deoxy[heme] response was increased in S suggests that the reduction in [Formula: see text] subsequent to priming was related to a combination of both enhanced intracellular O utilization and increased O delivery. Here we show that oxygen uptake (V̇o) kinetics are slower in the supine compared with upright body position, an effect that is associated with an increased amplitude of skeletal muscle deoxygenation in the supine position. After priming in the supine position, the amplitude of muscle deoxygenation remained markedly elevated above that observed during upright exercise. Hence, the priming effect cannot be solely attributed to enhanced O delivery, and enhancements to intracellular O utilization must also be contributory.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1152/japplphysiol.00478.2020 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
IMPACT OF NOCTURNAL OXYGEN ENRICHMENT ON HIGH-ALTITUDE ACCLIMATIZATION.
Am J Physiol Regul Integr Comp Physiol
December 2024
School of Integrative Physiology and Athletic Training, Montana Center for Work Physiology and Exercise Metabolism, University of Montana, Missoula, MT, USA.
Nocturnal oxygen enrichment improves sleep at high-altitude but may impair acclimatization. Determine if nocturnal oxygen enrichment impacts acclimatization. A 7-day acclimatization protocol occurred at a field-based research site between 0-4200m.
View Article and Find Full Text PDFBoys vs men differences in muscular fatigue, muscle and cerebral oxygenation during maximal effort isometric contractions: the effect of muscle blood flow restriction.
Eur J Appl Physiol
November 2024
Laboratory of Exercise Physiology and Biochemistry, Department of Physical Education and Sports Science at Serres, Aristotle University of Thessaloniki, Ag. Ioannis, 62100, Serres, Greece.
Purpose: To examine whether the children's superiority, over adults, to resist fatigue during repeated maximal-efforts depends on their often-cited oxidative advantage, attributed to greater muscle blood flow and O-delivery. We also investigated the mechanisms underlying child-adult differences in muscle-oxygenation (due to O-supply or O-utilization) and examined if there are age-differences in cerebral-oxygenation response (a brain-activation index).
Methods: Eleven men (23.
Is Kinesio taping acutely effective for peripheral tissue perfusion in women with mild to moderate chronic venous insufficiency? A randomized controlled trial.
J Bodyw Mov Ther
October 2024
Graduate Program in Rehabilitation Sciences, Department of Physical Therapy - Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil. Electronic address:
Article Synopsis
- *Methods: The trial involved 59 women, split into a KT group and a control group, who had their muscle blood perfusion measured using near-infrared spectroscopy before and after applying the tape, with statistical analysis to compare results.
- *Results: While there were no significant differences in blood oxygen levels or deoxygenated hemoglobin between the KT and control groups, the KT group showed a notably larger decrease in certain measurements, suggesting potential clinical relevance despite the lack of statistical significance.
Oxygenation Kinetics of Three Quadriceps Muscles During Squatting Exercise in Trained Men.
Sports (Basel)
October 2024
Laboratory of Evaluation of Human Biological Performance, School of Physical Education and Sport Science at Thessaloniki, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
This study aimed to monitor the oxygenation and blood supply in three quadriceps muscles [the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF)] during squatting exercise to exhaustion. Eighteen young resistance-trained males performed five sets of 15 back squats in a Smith machine, with two warm-up sets [at 14% and 45% of the 15-repetition maximum (15RM)] and three main sets at 100% of the 15RM. Three near-infrared spectroscopy devices were attached to the VL, VM, and RF to record the muscle oxygen saturation (SmO) and total hemoglobin (tHb, an index of muscle blood supply).
View Article and Find Full Text PDFCombined effect of sprint interval training and post-exercise blood flow restriction on muscle deoxygenation responses during ramp incremental cycling.
Eur J Appl Physiol
October 2024
School of Sport, Exercise and Health Sciences, Loughborough University, Epinal Way, Loughborough, LE11 3TU, UK.
Article Synopsis
- This study examined how combining sprint-interval training (SIT) with post-exercise blood flow restriction (BFR) affects breathing and blood oxygen levels during exercise in untrained males.
- Results showed that both training methods improved peak oxygen uptake by 7%, but SIT + BFR specifically enhanced muscle oxygen extraction and reduced oxygen saturation at exhaustion.
- The findings suggest that post-exercise BFR alters how training affects oxygen use in muscles, potentially benefiting those new to exercise.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!