Muscle oxygenation and pulmonary gas exchange kinetics during cycling exercise on-transitions in humans

2003 ◽  
Vol 95 (1) ◽  
pp. 149-158 ◽  
Author(s):  
Bruno Grassi ◽  
Silvia Pogliaghi ◽  
Susanna Rampichini ◽  
Valentina Quaresima ◽  
Marco Ferrari ◽  
...  
Keyword(s):  
Near Infrared ◽  
Ventilatory Threshold ◽  
Slow Component ◽  
Vastus Lateralis ◽  
Oxygenation Index ◽  
Constant Load ◽  
Cycle Ergometer ◽  
Primary Component ◽  
Muscle Oxygenation ◽  
Tight Coupling

Near-infrared spectroscopy (NIRS) was utilized to gain insights into the kinetics of oxidative metabolism during exercise transitions. Ten untrained young men were tested on a cycle ergometer during transitions from unloaded pedaling to 5 min of constant-load exercise below (<VT) or above (>VT) the ventilatory threshold. Vastus lateralis oxygenation was determined by NIRS, and pulmonary O2 uptake ( V̇o2) was determined breath-by-breath. Changes in deoxygenated hemoglobin + myoglobin concentration {Δ[deoxy(Hb + Mb)]} were taken as a muscle oxygenation index. At the transition, Δ[deoxy(Hb + Mb)] was unmodified [time delay (TD)] for 8.9 ± 0.5 s at <VT or 6.4 ± 0.9 s at >VT (both significantly different from 0) and then increased, following a monoexponential function [time constant (τ) = 8.5 ± 0.9 s for <VT and 7.2 ± 0.7 s for >VT]. For >VT a slow component of Δ[deoxy(Hb + Mb)] on-kinetics was observed in 9 of 10 subjects after 75.0 ± 14.0 s of exercise. A significant correlation was described between the mean response time (MRT = TD + τ) of the primary component of Δ[deoxy(Hb + Mb)] on-kinetics and the τ of the primary component of the pulmonary V̇o2 on-kinetics. The constant muscle oxygenation during the initial phase of the on-transition indicates a tight coupling between increases in O2 delivery and O2 utilization. The lack of a drop in muscle oxygenation at the transition suggests adequacy of O2 availability in relation to needs.

scholarly journals Effect of PEMF on Muscle Oxygenation during Cycling: A Single-Blind Controlled Pilot Study

2021 ◽  
Vol 11 (8) ◽  
pp. 3624
Author(s):  
Aurelio Trofè ◽  
Milena Raffi ◽  
David Muehsam ◽  
Andrea Meoni ◽  
Francesco Campa ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Slow Component ◽  
Local Level ◽  
Lactate Concentration ◽  
Oxygenation Index ◽  
State Level ◽  
Acute Effect ◽  
Primary Component ◽  
Muscle Oxygenation ◽  
Oxygen Kinetics

Pulsed electromagnetic fields (PEMFs) are used as non-invasive tools to enhance microcirculation and tissue oxygenation, with a modulatory influence on the microvasculature. This study aimed to measure the acute effect of PEMF on muscle oxygenation and its influence on pulmonary oxygen kinetics during exercise. Eighteen male cyclists performed, on different days, a constant-load exercise in both active (ON) and inactive (OFF) PEMF stimulations while deoxyhemoglobin and pulmonary oxygen kinetics, total oxygenation index, and blood lactate were collected. PEMF enhanced muscle oxygenation, with higher values of deoxyhemoglobin both at the primary component and at the steady-state level. Moreover, PEMF accelerated deoxyhemoglobin on-transition kinetic, with a shorter time delay, time constant, and mean response time than the OFF condition. Lactate concentration was higher during stimulation. No differences were found for total oxygenation index and pulmonary oxygen kinetics. Local application of a precise PEMF stimulation can increase the rate of the muscle O2 extraction and utilization. These changes were not accompanied by faster oxygen kinetics, reduced oxygen slow component, or reduced blood lactate level. It seems that oxygen consumption is more influenced by exercise involving large muscle mass like cycling, whereas PEMF might only act at the local level.

Effects of Ultratrail Running on Skeletal-Muscle Oxygenation Dynamics

2017 ◽  
Vol 12 (4) ◽  
pp. 496-504 ◽  
Author(s):  
Gianluca Vernillo ◽  
Alfredo Brighenti ◽  
Eloisa Limonta ◽  
Pietro Trabucchi ◽  
Davide Malatesta ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Vastus Lateralis ◽  
Oxygenation Index ◽  
Constant Load ◽  
Negative Influence ◽  
Muscle Oxygenation ◽  
Vastus Lateralis Muscle ◽  
Skeletal Muscle Oxygenation ◽  
Power Outputs ◽  
And Function

Purpose:To quantify changes in skeletal-muscle oxygenation and pulmonary O2 uptake (V̇O2) after an extreme ultratrail running bout.Methods:Before (PRE) and after (POST) the race (330-km, 24000 D±), profiles of vastus lateralis muscle oxygenation (ie, oxyhemoglobin [O2Hb], deoxyhemoglobin [HHb], and tissue oxygenation index [TOI]) and V̇O2 were determined in 14 athletes (EXP) and 12 control adults (CON) during two 4-min constant-load cycling bouts at power outputs of 1 (p1) and 1.5 (p1.5) W/kg performed in randomized order.Results:At POST, normalized [HHb] values increased (p1, +38.0%; p1.5, +27.9%; P < .05), while normalized [O2Hb] (p1, –20.4%; p1.5, –14.4%; P < .05) and TOI (p1, –17.0%; p1.5, –17.7%; P < .05) decreased in EXP. V̇O2 values were similar (P > 0.05). An “overshoot“ in normalized [HHb]:V̇O2 was observed, although the increase was significant only during p1.5 (+58.7%, P = .003). No difference in the aforementioned variables was noted in CON (P > .05).Conclusions:The concentric and, particularly, the eccentric loads characterizing this extreme ultratrail-running bout may have led to variations in muscle structure and function, increasing the local muscle deoxygenation profile and the imbalance between O2 delivery to working muscles and muscle O2 consumption. This highlights the importance of incorporating graded training, particularly downhill bouts, to reduce the negative influence of concentric and severe eccentric loads to the microcirculatory function and to enhance the ability of runners to sustain such loading.

Effects of respiratory muscle unloading on leg muscle oxygenation and blood volume during high-intensity exercise in chronic heart failure

2008 ◽  
Vol 294 (6) ◽  
pp. H2465-H2472 ◽  
Author(s):  
Audrey Borghi-Silva ◽  
Cláudia Carrascosa ◽  
Cristino Carneiro Oliveira ◽  
Adriano C. Barroco ◽  
Danilo C. Berton ◽  
...  
Keyword(s):  
Heart Failure ◽  
Blood Flow ◽  
Chronic Heart Failure ◽  
Blood Volume ◽  
Near Infrared ◽  
Vastus Lateralis ◽  
Oxygenation Index ◽  
Assisted Ventilation ◽  
Muscle Oxygenation ◽  
Leg Muscle

Blood flow requirements of the respiratory muscles (RM) increase markedly during exercise in chronic heart failure (CHF). We reasoned that if the RM could subtract a fraction of the limited cardiac output (QT) from the peripheral muscles, RM unloading would improve locomotor muscle perfusion. Nine patients with CHF (left ventricle ejection fraction = 26 ± 7%) undertook constant-work rate tests (70-80% peak) receiving proportional assisted ventilation (PAV) or sham ventilation. Relative changes (Δ%) in deoxy-hemoglobyn, oxi-Hb ([O2Hb]), tissue oxygenation index, and total Hb ([HbTOT], an index of local blood volume) in the vastus lateralis were measured by near infrared spectroscopy. In addition, QT was monitored by impedance cardiography and arterial O2 saturation by pulse oximetry (SpO2). There were significant improvements in exercise tolerance (Tlim) with PAV. Blood lactate, leg effort/Tlim and dyspnea/Tlim were lower with PAV compared with sham ventilation ( P < 0.05). There were no significant effects of RM unloading on systemic O2 delivery as QT and SpO2 at submaximal exercise and at Tlim did not differ between PAV and sham ventilation ( P > 0.05). Unloaded breathing, however, was related to enhanced leg muscle oxygenation and local blood volume compared with sham, i.e., higher Δ[O2Hb]% and Δ[HbTOT]%, respectively ( P < 0.05). We conclude that RM unloading had beneficial effects on the oxygenation status and blood volume of the exercising muscles at similar systemic O2 delivery in patients with advanced CHF. These data suggest that blood flow was redistributed from respiratory to locomotor muscles during unloaded breathing.

Muscle Oxygenation Trends During Dynamic Exercise Measured by Near Infrared Spectroscopy

2004 ◽  
Vol 29 (4) ◽  
pp. 504-523 ◽  
Author(s):  
Yagesh N. Bhambhani
Keyword(s):  
Oxygen Uptake ◽  
Blood Volume ◽  
Near Infrared ◽  
Ventilatory Threshold ◽  
Biceps Brachii ◽  
Vastus Lateralis ◽  
Dynamic Exercise ◽  
Muscle Oxygenation ◽  
Muscle Deoxygenation ◽  
Significant Difference

During the last decade, NIRS has been used extensively to evaluate the changes in muscle oxygenation and blood volume during a variety of exercise modes. The important findings from this research are as follows: (a) There is a strong correlation between the lactate (ventilatory) threshold during incremental cycle exercise and the exaggerated reduction in muscle oxygenation measured by NIRS. (b) The delay in steady-state oxygen uptake during constant work rate exercise at intensities above the lactate/ventilatory threshold is closely related to changes in muscle oxygenation measured by NIRS. (c) The degree of muscle deoxygenation at the same absolute oxygen uptake is significantly lower in older persons compared younger persons; however, these changes are negated when muscle oxygenation is expressed relative to maximal oxygen uptake values. (d) There is no significant difference between the rate of biceps brachii and vastus lateralis deoxygenation during arm cranking and leg cycling exercise, respectively, in males and females. (e) Muscle deoxygenation trends recorded during short duration, high-intensity exercise such as the Wingate test indicate that there is a substantial degree of aerobic metabolism during such exercise. Recent studies that have used NIRS at multiple sites, such as brain and muscle tissue, provide useful information pertaining to the regional changes in oxygen availability in these tissues during dynamic exercise. Key words: blood volume, noninvasive measurement

Montmorency cherry supplement does not affect aerobic exercise performance in healthy men

2020 ◽  
Vol 90 (5-6) ◽  
pp. 403-410 ◽  
Author(s):  
Greggory R. Davis ◽  
David Bellar
Keyword(s):  
Exercise Performance ◽  
Near Infrared ◽  
Slow Component ◽  
Vastus Lateralis ◽  
Muscle Oxygenation ◽  
Short Term ◽  
Total Blood ◽  
Post Exercise ◽  
Time Interaction ◽  
The Right

Abstract. Aim: To determine the effects of short-term Montmorency cherry (MC) supplementation upon exercise performance, total blood nitrate levels, muscle oxygenation, and slow-component [Formula: see text]O2 kinetics. Methods: Twelve healthy male participants ingested a MC or placebo (PL) supplement in a randomized cross-over fashion over a six day period then cycled at a power output achieved at 70% of [Formula: see text]O2 peak for a maximum of 30 minutes or until exhaustion. Near-Infrared Spectroscopy sensors were used to determine muscle oxygenation. Blood was collected one hour post-supplement consumption on day one, day six, and one hour post-exercise. Results: All results are presented as mean ± SEM. Blood nitrate (μM/L) levels were not different one hour post-ingestion (MC = 8.30 ± 2.15, PL = 8.18 ± 1.86), following six days of supplementation (MC = 9.14 ± 1.89, PL = 7.24 ± 1.75) or one hour post-exercise (MC = 9.63 ± 1.61, PL = 7.97 ± 1.92) for treatment F = 0.26, p = 0.62; for time F = 0.45, p = 0.64; or treatment by time interaction F = 2.28, p = 0.13. Muscle oxygenation was not different between treatments for the right or left vastus lateralis, F = 0.68, p = 0.81 nor was time to respiratory compensation point (minutes) (MC = 18.40 ± 1.48, PL = 17.16 ± 1.78) F = 0.52, p = 0.60. MC supplement ingestion does not alter blood nitrate levels. Conclusion: Short-term MC ingestion does not increase muscle oxygenation during cycling exercise nor does it change slow-component [Formula: see text]O2 kinetics.

Which common NIRS variable reflects muscle estimated lactate threshold most closely?

2006 ◽  
Vol 31 (5) ◽  
pp. 612-620 ◽  
Author(s):  
Lixin Wang ◽  
Takahiro Yoshikawa ◽  
Taketaka Hara ◽  
Hayato Nakao ◽  
Takashi Suzuki ◽  
...  
Keyword(s):  
Lactate Threshold ◽  
Near Infrared ◽  
Ventilatory Threshold ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Oxygenation Index ◽  
Muscle Lactate ◽  
Tissue Oxygenation Index ◽  
The Mean ◽  
Tissue Hemoglobin

Various near-infrared spectroscopy (NIRS) variables have been used to estimate muscle lactate threshold (LT), but no study has determined which common NIRS variable best reflects muscle estimated LT. Establishing the inflection point of 2 regression lines for deoxyhaemoglobin (ΔHHbi.p.), oxyhaemoglobin (ΔO2Hbi.p.), and tissue oxygenation index (TOIi.p.), as well as for blood lactate concentration, we then investigated the relationships between NIRS variables and ventilatory threshold (VT), LT, or maximal tissue hemoglobin index (nTHImax) during incremental cycling exercise. ΔHHbi.p. and TOIi.p. could be determined for all 15 subjects, but ΔO2Hbi.p. was determined for only 11 subjects. The mean absolute values for the 2 measurable slopes of the 2 continuous linear regression lines exhibited increased changes in 3 NIRS variables. The workload and VO2 at ΔO2Hbi.p. and nTHImax were greater than those at VT, LT, ΔHHbi.p., and TOIi.p.. For workload and VO2, ΔHHbi.p. was correlated with VT and LT, whereas ΔO2Hbi.p. was correlated with nTHImax, and TOIi.p. with VT and nTHImax. These findings indicate that ΔO2Hb strongly corresponds with local perfusion, and TOI corresponds with both local perfusion and deoxygenation, but that ΔHHb can exactly determine deoxygenation changes and reflect O2 metabolic dynamics. The finding of strongest correlations between ΔHHb and VT or LT indicates that ΔHHb is the best variable for muscle LT estimation.

Longitudinal changes in the kinetic response to heavy-intensity exercise in children

2004 ◽  
Vol 97 (2) ◽  
pp. 460-466 ◽  
Author(s):  
Samantha G. Fawkner ◽  
Neil Armstrong
Keyword(s):  
Slow Component ◽  
Phase 1 ◽  
Exponential Model ◽  
Cycle Ergometer ◽  
Primary Component ◽  
Total Change ◽  
Exercise Tests ◽  
Longitudinal Changes ◽  
Dependent Change ◽  
The Difference

The purpose of this study was to investigate longitudinal changes with age in the kinetic response to cycling at heavy-intensity exercise in boys and girls. Twenty-two prepubertal children (13 male, 9 female) carried out a series of exercise tests on two test occasions with a 2-yr interval. On each test occasion, the subject completed multiple transitions from baseline to 40% of the difference between their previously determined V-slope and peak O2 uptake (V̇o2) for 9 min on an electronically braked cycle ergometer. Each subject's breath-by-breath responses were interpolated to 1-s intervals, time aligned, and averaged. The data after phase 1 were fit with 1) a double exponential model and 2) a single exponential model within a fitting window that was previously identified to exclude the slow component. There were no significant differences in the parameters of the primary component between each model. Subsequent analysis was carried out using model 2. The V̇o2 slow component was computed as the difference between the amplitude of the primary component and the end-exercise V̇o2 and was expressed as the percent contribution to the total change in V̇o2. Over the 2-yr period, the primary time constant (boys 16.8 ± 5.3 and 21.7 ± 5.3 s, girls 21.1 ± 8.1 and 26.4 ± 8.4 s, first and second occasion, respectively) and the relative amplitude of the slow component (boys 9.4 ± 4.6 and 13.8 ± 5.3%, girls 10.3 ± 2.4 and 15.5 ± 2.8%, first and second occasion, respectively) significantly increased with no sex differences. The data demonstrate that children do display a slow-component response to exercise and are consistent with an age-dependent change in the muscles' potential for O2 utilization.

scholarly journals Vastus lateralis oxygenation during prolonged cycling in healthy males

2006 ◽  
Vol 31 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Kotaro Kawaguchi ◽  
Yukiko Hayashi ◽  
Kiyokazu Sekikawa ◽  
Mitsuru Tabusadani ◽  
Tsutomu Inamizu ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Oxygen Uptake ◽  
Blood Volume ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Vastus Lateralis ◽  
Muscle Oxygenation ◽  
Cardiovascular Drift ◽  
Systemic Oxygen ◽  
The Relationship

This study examined the relationship between acute cardiorespiratory and muscle oxygenation and blood volume changes during prolonged exercise. Eight healthy male volunteers (mean maximum oxygen uptake ([Formula: see text]O2max) = 41.6 ± 2.4 mL/kg/min) performed 60 min submaximal cycling at 50% [Formula: see text]O2max. Oxygen uptake ([Formula: see text]O2) was measured by indirect spirometry, cardiac output (CO) was estimated using a PortapresTM, and right vastus lateralis oxyhemoglobin/ myoglobin (oxyHb/Mb), deoxyhemoglobin/myoglobin (deoxyHb/Mb), and total hemoglobin/myoglobin (total Hb/Mb) were recorded using near-infrared spectroscopy (NIRS). After 40 min of exercise, there was a significant increase in [Formula: see text]O2 due to a significantly higher arteriovenous oxygen difference ((a - v)O2diff). After 30 min of exercise CO remained unchanged, but there was a significant decrease in stroke volume and a proportionate increase in heart rate, thus indicating the occurrence of cardiovascular drift. During the first few minutes of exercise, there was a decline in oxyHb/Mb and total Hb/Mb, whereas deoxyHb/Mb remained unchanged. Thereafter, oxyHb/Mb and total Hb/Mb increased systematically until the termination of exercise while deoxyHb/Mb declined. After 40 min of exercise, these changes were significantly different from the baseline values. There were no significant correlations between the changes in the NIRS variables and systemic [Formula: see text]O2 or mixed (a - v)O2diff during exercise. These results suggest that factors other than localized changes in muscle oxygenation and blood volume account for the increased [Formula: see text]O2 during prolonged submaximal exercise. Key words: near infrared spectroscopy, cardiovascular drift, systemic oxygen consumption.

Enhanced muscular oxygen extraction in athletes exaggerates hypoxemia during exercise in hypoxia

2016 ◽  
Vol 120 (3) ◽  
pp. 351-361 ◽  
Author(s):  
Ruud Van Thienen ◽  
Peter Hespel
Keyword(s):  
Oxygen Consumption ◽  
Near Infrared ◽  
Vastus Lateralis ◽  
Acute Mountain Sickness ◽  
Maximal Oxygen Consumption ◽  
Arterial Occlusion ◽  
Oxygenation Index ◽  
High Rate ◽  
Oxygen Extraction ◽  
Mountain Sickness

High rate of muscular oxygen utilization facilitates the development of hypoxemia during exercise at altitude. Because endurance training stimulates oxygen extraction capacity, we investigated whether endurance athletes are at higher risk to developing hypoxemia and thereby acute mountain sickness symptoms during exercise at simulated high altitude. Elite athletes (ATL; n = 8) and fit controls (CON; n = 7) cycled for 20 min at 100 W (EX100W), as well as performed an incremental maximal oxygen consumption test (EXMAX) in normobaric hypoxia (0.107 inspired O2 fraction) or normoxia (0.209 inspired O2 fraction). Cardiorespiratory responses, arterial Po2 (PaO2), and oxygenation status in m. vastus lateralis [tissue oxygenation index (TOIM)] and frontal cortex (TOIC) by near-infrared spectroscopy, were measured. Muscle O2 uptake rate was estimated from change in oxyhemoglobin concentration during a 10-min arterial occlusion in m. gastrocnemius. Maximal oxygen consumption in normoxia was 70 ± 2 ml·min−1·kg−1 in ATL vs. 43 ± 2 ml·min−1·kg−1 in CON, and in hypoxia decreased more in ATL (−41%) than in CON (−25%, P < 0.05). Both in normoxia at PaO2 of ∼95 Torr, and in hypoxia at PaO2 of ∼35 Torr, muscle O2 uptake was twofold higher in ATL than in CON (0.12 vs. 0.06 ml·min−1·100 g−1; P < 0.05). During EX100W in hypoxia, PaO2 dropped to lower ( P < 0.05) values in ATL (27.6 ± 0.7 Torr) than in CON (33.5 ± 1.0 Torr). During EXMAX, but not during EX100W, TOIM was ∼15% lower in ATL than in CON ( P < 0.05). TOIC was similar between the groups at any time. This study shows that maintenance of high muscular oxygen extraction rate at very low circulating PaO2 stimulates the development of hypoxemia during submaximal exercise in hypoxia in endurance-trained individuals. This effect may predispose to premature development of acute mountain sickness symptoms during exercise at altitude.

scholarly journals No Influence of Nonivamide-nicoboxil on the Peak Power Output in Competitive Sportsmen

2021 ◽  
Author(s):  
Theresa Schörkmaier ◽  
Yvonne Wahl ◽  
Christian Brinkmann ◽  
Wilhelm Bloch ◽  
Patrick Wahl
Keyword(s):  
Power Output ◽  
Peak Power ◽  
Near Infrared ◽  
Endurance Performance ◽  
Cycle Ergometer ◽  
Muscle Oxygenation ◽  
Peak Power Output ◽  
Exercise Tests ◽  
Hypoxic Conditions ◽  
Placebo Cream

AbstractRecent studies have shown that the oxygenated hemoglobin level can be enhanced during rest through the application of nonivamide-nicoboxil cream. However, the effect of nonivamide-nicoboxil cream on oxygenation and endurance performance under hypoxic conditions is unknown. Therefore, the purpose of this study was to investigate the effects of nonivamide-nicoboxil cream on local muscle oxygenation and endurance performance under normoxic and hypoxic conditions. In a cross-over design, 13 athletes (experienced cyclists or triathletes [age: 25.2±3.5 years; VO2max 62.1±7.3 mL·min−1·kg−1]) performed four incremental exercise tests on the cycle ergometer under normoxic or hypoxic conditions, either with nonivamide-nicoboxil or placebo cream. Muscle oxygenation was recorded with near-infrared spectroscopy. Capillary blood samples were taken after each step, and spirometric data were recorded continuously. The application of nonivamide-nicoboxil cream increased muscle oxygenation at rest and during different submaximal workloads as well as during physical exhaustion, irrespective of normoxic or hypoxic conditions. Overall, there were no significant effects of nonivamide-nicoboxil on peak power output, maximal oxygen uptake or lactate concentrations. Muscle oxygenation is significantly higher with the application of nonivamide-nicoboxil cream. However, its application does not increase endurance performance.

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