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Belbis MD, Yap Z, Hobart SE, Ferguson SK, Hirai DM. Effects of acute phosphodiesterase type 5 inhibition on skeletal muscle interstitial PO 2 during contractions and recovery. Nitric Oxide 2024; 142:16-25. [PMID: 37979932 DOI: 10.1016/j.niox.2023.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 10/26/2023] [Accepted: 11/14/2023] [Indexed: 11/20/2023]
Abstract
The oxygen partial pressure within the interstitial space (PO2is; mmHg) provides the driving force for oxygen diffusion into the myocyte thereby supporting oxidative phosphorylation. We tested the hypothesis that potentiation of the nitric oxide pathway with sildenafil (phosphodiesterase type 5 inhibitor) would enhance PO2is during muscle metabolic transitions, thereby slowing PO2is on- and accelerating PO2is off-kinetics. The rat spinotrapezius muscle (n = 17) was exposed for PO2is measurements via phosphorescence quenching under control (CON), low-dose sildenafil (1 mg/kg i.a., SIL1) and high-dose sildenafil (7 mg/kg i.a., SIL7). Data were collected at rest and during submaximal twitch contractions (1 Hz, 4-6 V, 3 min) and recovery (3 min). Mean arterial blood pressure (MAP; mmHg) was reduced with both SIL1 (pre:132 ± 5; post:99 ± 5) and SIL7 (pre:111 ± 6; post:99 ± 4) (p < 0.05). SIL7 elevated resting PO2is (18.4 ± 1.1) relative to both CON (15.7 ± 0.7) and SIL1 (15.2 ± 0.7) (p < 0.05). In addition, SIL7 increased end-recovery PO2is (17.7 ± 1.6) compared to CON (12.8 ± 0.9) and SIL1 (13.4 ± 0.8) (p < 0.05). The overall PO2is response during recovery (i.e., area under the PO2is curve) was greater in SIL7 (4107 ± 444) compared to CON (3493 ± 222) and SIL1 (3114 ± 205 mmHg s) (p < 0.05). Contrary to our hypothesis, there was no impact of acute SIL (1 or 7 mg/kg) on the speed of the PO2is response during contractions or recovery (p > 0.05). However, sildenafil lowered MAP and improved skeletal muscle interstitial oxygenation in healthy rats. Specifically, SIL7 enhanced PO2is at rest and during recovery from submaximal muscle contractions. Potentiation of the nitric oxide pathway with sildenafil enhances microvascular blood-myocyte O2 transport and is expected to improve repeated bouts of contractile activity.
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Affiliation(s)
- Michael D Belbis
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA; Department of Exercise Science, Aurora University, Aurora, IL, USA
| | - Zhen Yap
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA
| | - Sara E Hobart
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA
| | - Scott K Ferguson
- Department of Human Factors and Behavioral Neurobiology, Embry-Riddle Aeronautical University, Daytona Beach, FL, USA
| | - Daniel M Hirai
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA.
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Love LK, Hodgson MD, Keir DA, Kowalchuk JM. The effect of increasing work rate amplitudes from a common metabolic baseline on the kinetic response of V̇o 2p, blood flow, and muscle deoxygenation. J Appl Physiol (1985) 2023; 135:584-600. [PMID: 37439241 DOI: 10.1152/japplphysiol.00566.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 06/29/2023] [Accepted: 07/06/2023] [Indexed: 07/14/2023] Open
Abstract
A step-transition in external work rate (WR) increases pulmonary O2 uptake (V̇o2p) in a monoexponential fashion. Although the rate of this increase, quantified by the time constant (τ), has frequently been shown to be similar between multiple different WR amplitudes (ΔWR), the adjustment of O2 delivery to the muscle (via blood flow; BF), a potential regulator of V̇o2p kinetics, has not been extensively studied. To investigate the role of BF on V̇o2p kinetics, 10 participants performed step-transitions on a knee-extension ergometer from a common baseline WR (3 W) to: 24, 33, 45, 54, and 66 W. Each transition lasted 8 min and was repeated four to six times. Volume turbinometry and mass spectrometry, Doppler ultrasound, and near-infrared spectroscopy were used to measure V̇o2p, BF, and muscle deoxygenation (deoxy[Hb + Mb]), respectively. Similar transitions were ensemble-averaged, and phase II V̇o2p, BF, and deoxy[Hb + Mb] were fit with a monoexponential nonlinear least squares regression equation. With increasing ΔWR, τV̇o2p became larger at the higher ΔWRs (P < 0.05), while τBF did not change significantly, and the mean response time (MRT) of deoxy[Hb + Mb] became smaller. These findings that V̇o2p kinetics become slower with increasing ΔWR, while BF kinetics are not influenced by ΔWR, suggest that O2 delivery could not limit V̇o2p in this situation. However, the speeding of deoxy[Hb + Mb] kinetics with increasing ΔWR does imply that the O2 delivery-to-O2 utilization of the microvasculature decreases at higher ΔWRs. This suggests that the contribution of O2 delivery and O2 extraction to V̇O2 in the muscle changes with increasing ΔWR.NEW & NOTEWORTHY A step increase in work rate produces a monoexponential increase in V̇o2p and blood flow to a new steady-state. We found that step transitions from a common metabolic baseline to increasing work rate amplitudes produced a slowing of V̇o2p kinetics, no change in blood flow kinetics, and a speeding of muscle deoxygenation kinetics. As work rate amplitude increased, the ratio of blood flow to V̇o2p became smaller, while the amplitude of muscle deoxygenation became greater. The gain in vascular conductance became smaller, while kinetics tended to become slower at higher work rate amplitudes.
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Affiliation(s)
- Lorenzo K Love
- Canadian Centre for Activity and Aging, The University of Western Ontario, London, Ontario, Canada
- School of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, Ontario, Canada
- Department of Kinesiology and Physical Education, Redeemer University, Ancaster, Ontario, Canada
| | - Michael D Hodgson
- Canadian Centre for Activity and Aging, The University of Western Ontario, London, Ontario, Canada
- School of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, Ontario, Canada
| | - Daniel A Keir
- Canadian Centre for Activity and Aging, The University of Western Ontario, London, Ontario, Canada
- School of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, Ontario, Canada
- Toronto General Research Institute, Toronto General Hospital, Toronto, Ontario, Canada
| | - John M Kowalchuk
- Canadian Centre for Activity and Aging, The University of Western Ontario, London, Ontario, Canada
- School of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, Ontario, Canada
- Department of Kinesiology and Physical Education, Redeemer University, Ancaster, Ontario, Canada
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Lampe D, Deml B. Increasing physical activity in the vehicle with an interactive seating system in a male sample. ERGONOMICS 2023; 66:536-553. [PMID: 35876479 DOI: 10.1080/00140139.2022.2098384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 06/29/2022] [Indexed: 06/15/2023]
Abstract
An interactive seating system (IASS) was compared to a state-of-the-art massage seating system (MS) regarding the potential of reducing health risks from prolonged sitting in the vehicle. The study investigated if the systems (1) increase heart rate, which is associated with reduced metabolic and cardiovascular risks; (2) activate muscles with the potential to reduce musculoskeletal pain; (3) influence seating comfort and discomfort. The systems were compared in a passenger scenario in a laboratory study (30 male subjects). Only the use of the IASS significantly elevated the heart rate. Muscle activity showed tendencies to increase in the lower back only while using the MS. In comparison, the IASS activated all six captured muscles. Significantly less discomfort was found for the IASS compared to the MS. In comparison to the MS, the IASS showed a substantially higher potential for reducing health risks from static sitting in the vehicle.Practitioner summary: This laboratory study compared the effects of a novel automotive interactive seating system with those of a state-of-the-art massage seating system. Muscle activity, heart rate and discomfort indicated that the IASS has a significantly higher potential to reduce health risks associated with static seating in a vehicle.Abbreviations: AB: air bladder; AC: active condition; ADSS: active dynamic seating system; CLBP: chronic lumbar back pain; ECG: electrocardiography; EMG: electromyography; IASS: interactive seating system; MS: massage seating system; PC: passive condition; PDSS: passive dynamic seating system; RMS: rootmean-square; TI: time interval.
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Affiliation(s)
- Dario Lampe
- Mercedes-Benz AG, Boeblingen, Germany
- Institute of Human and Industrial Engineering (IFAB), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Barbara Deml
- Institute of Human and Industrial Engineering (IFAB), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
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Desanlis J, Gordon D, Calveyrac C, Cottin F, Gernigon M. Intra- and Inter-Day Reliability of the NIRS Portamon Device after Three Induced Muscle Ischemias. SENSORS (BASEL, SWITZERLAND) 2022; 22:5165. [PMID: 35890846 PMCID: PMC9317239 DOI: 10.3390/s22145165] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 07/06/2022] [Accepted: 07/07/2022] [Indexed: 06/15/2023]
Abstract
(1) Background: Near-infrared spectroscopy (NIRS) is an innovative and non-invasive technology used to investigate muscular oxygenation. The aim of this study is to assess the within- and between-session reliability of the NIRS Portamon (Artinis, Elst, Netherlands) device following three sets of induced muscle ischemia. (2) Methods: Depending on the experimental group (G1, G2 or G3), a cuff was inflated three times on the left upper arm to 50 mmHg (G1), systolic blood pressure (SBP) + 50 mmHg (G2) or 250 mmHg (G3). Maximum, minimum and reoxygenation rate values were assessed after each occlusion phase, using a Portamon device placed on the left brachioradialis. Reliability was assessed with intraclass correlation coefficient (ICC) value and ICC 95% confidence interval (CI-95%), coefficient of variation (CV) and standard error of measurement (SEM) (3) Results: Our results showed a good to excellent reliability for maximums and minimums within-session. However, the reoxygenation rate within sessions as well as measurements between sessions cannot predominantly show good reliability. (4) Conclusions: Multiple measurements of maximums and minimums within a single session appeared to be reliable which shows that only one measurement is necessary to assess these parameters. However, it is necessary to be cautious with a comparison of maximum, minimum and reoxygenation rate values between sessions.
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Affiliation(s)
- Julien Desanlis
- CIAMS, Université Paris-Saclay, CEDEX, 91405 Orsay, France; (C.C.); (F.C.); (M.G.)
- CIAMS, Université d’Orléans, 45067 Orléans, France
- Anglia Ruskin University, Cambridge CB1 1PT, UK;
| | - Dan Gordon
- Anglia Ruskin University, Cambridge CB1 1PT, UK;
| | - Camille Calveyrac
- CIAMS, Université Paris-Saclay, CEDEX, 91405 Orsay, France; (C.C.); (F.C.); (M.G.)
- CIAMS, Université d’Orléans, 45067 Orléans, France
| | - François Cottin
- CIAMS, Université Paris-Saclay, CEDEX, 91405 Orsay, France; (C.C.); (F.C.); (M.G.)
- CIAMS, Université d’Orléans, 45067 Orléans, France
| | - Marie Gernigon
- CIAMS, Université Paris-Saclay, CEDEX, 91405 Orsay, France; (C.C.); (F.C.); (M.G.)
- CIAMS, Université d’Orléans, 45067 Orléans, France
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Amin SB, Mugele H, Dobler FE, Marume K, Moore JP, Lawley JS. Intra-rater reliability of leg blood flow during dynamic exercise using Doppler ultrasound. Physiol Rep 2021; 9:e15051. [PMID: 34617675 PMCID: PMC8496156 DOI: 10.14814/phy2.15051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/30/2021] [Accepted: 08/31/2021] [Indexed: 11/24/2022] Open
Abstract
Developing an exercise model that resembles a traditional form of aerobic exercise and facilitates a complete simultaneous assessment of multiple parameters within the oxygen cascade is critically for understanding exercise intolerances in diseased populations. Measurement of muscle blood flow is a crucial component of such a model and previous studies have used invasive procedures to determine blood flow kinetics; however, this may not be appropriate in certain populations. Furthermore, current models utilizing Doppler ultrasound use isolated limb exercise and while these studies have provided useful data, the exercise model does not mimic the whole-body physiological response to continuous dynamic exercise. Therefore, we aimed to measure common femoral artery blood flow using Doppler ultrasound during continuous dynamic stepping exercise performed at three independent workloads to assess the within day and between-day reliability for such an exercise modality. We report a within-session coefficient of variation of 5.8% from three combined workloads and a between-day coefficient of variation of 12.7%. These values demonstrate acceptable measurement accuracy and support our intention of utilizing this noninvasive exercise model for an integrative assessment of the whole-body physiological response to exercise in a range of populations.
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Affiliation(s)
- Sachin B. Amin
- Department Sport ScienceDivision of Performance Physiology and PreventionUniversity InnsbruckInnsbruckAustria
| | - Hendrik Mugele
- Department Sport ScienceDivision of Performance Physiology and PreventionUniversity InnsbruckInnsbruckAustria
| | - Florian E. Dobler
- Department Sport ScienceDivision of Performance Physiology and PreventionUniversity InnsbruckInnsbruckAustria
| | | | | | - Justin S. Lawley
- Department Sport ScienceDivision of Performance Physiology and PreventionUniversity InnsbruckInnsbruckAustria
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Kojima C, Yamaguchi K, Ito H, Kasai N, Girard O, Goto K. Acute Effect of Repeated Sprint Exercise With Blood Flow Restriction During Rest Periods on Muscle Oxygenation. Front Physiol 2021; 12:665383. [PMID: 34393809 PMCID: PMC8358934 DOI: 10.3389/fphys.2021.665383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 06/21/2021] [Indexed: 11/18/2022] Open
Abstract
Purpose This study aimed to examine the effect of applying BFR during rest periods of repeated cycling sprints on muscle oxygenation. Methods Seven active males performed 5 × 10-s maximal pedaling efforts with 40-s passive rest, with or without BFR application during rest period. BFR was applied for 30 s between sprints (between 5 and 35 s into rest) through a pneumatic pressure cuff inflated at 140 mmHg. Vastus lateralis muscle oxygenation was monitored using near-infrared spectroscopy. In addition, blood lactate concentration and heart rate were also evaluated. Results The BFR trial showed significantly lower oxyhemoglobin (oxy-Hb) and tissue saturation (StO2) levels than the CON trial (P < 0.05). However, power output and blood lactate concentration did not significantly differ between the two trials (P > 0.05). Conclusion Applying BFR during rest periods of repeated cycling sprints decreased muscle oxygenation of active musculature, without interfering with power output during sprints.
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Affiliation(s)
| | - Keiichi Yamaguchi
- Graduate School of Sport and Health Science, Ritsumeikan University, Shiga, Japan
| | - Hiroto Ito
- Graduate School of Sport and Health Science, Ritsumeikan University, Shiga, Japan
| | | | - Olivier Girard
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawly, WA, Australia
| | - Kazushige Goto
- Graduate School of Sport and Health Science, Ritsumeikan University, Shiga, Japan
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Reliability of Low-Cost Near-Infrared Spectroscopy in the Determination of Muscular Oxygen Saturation and Hemoglobin Concentration during Rest, Isometric and Dynamic Strength Activity. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17238824. [PMID: 33261036 PMCID: PMC7730940 DOI: 10.3390/ijerph17238824] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 11/23/2020] [Accepted: 11/25/2020] [Indexed: 02/07/2023]
Abstract
Background: The objective of this study was to establish the reliability of the Humon Hex near-infrared reflectance spectroscopy (NIRS) in determining muscle oxygen saturation (SmO2) and hemoglobin concentration (Hgb) at rest and during isometric and dynamic strength exercises using a functional electromechanical dynamometer (FEMD). Methods: The SmO2 and Hgb values of sixteen healthy adults (mean ± standard deviation (SD): Age = 36.1 ± 6.4 years) were recorded at rest and during isometry (8 s), dynamic strength I (initial load of 40% of the average isometric load, with 2 kg increments until muscle failure) and dynamic strength II (same as I, but with an initial load of 40% of the maximum isometric load) activity. To evaluate the reliability in the determination of SmO2 and Hgb of this device, intraclass correlation coefficient (ICC), standard error of measurement (SEM) and coefficient of variation (CV) were obtained. Results: The main results obtained are SmO2 at rest (CV = 5.76%, SEM = 3.81, ICC = 0.90), isometric strength (CV = 3.03%, SEM = 2.08, ICC = 0.92), dynamic strength I (CV = 10.6, SEM = 7.17, ICC = 0.22) and dynamic strength II (CV = 9.69, SEM = 6.75, ICC = 0.32); Hgb at rest (CV = 1.97%, SEM = 0.24, ICC = 0.65), isometric strength (CV = 0.98%, SEM = 0.12, ICC = 0.96), dynamic strength I (CV = 3.25, SEM = 0.40, ICC = 0.54) and dynamic strength II (CV = 2.74, SEM = 0.34, ICC = 0.65). Conclusions: The study shows that Humon Hex is a reliable device to obtain SmO2 and Hgb data in healthy adult subjects at rest and during isometric strength, providing precision for measurements made with this device.
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Morris RI, Sobotka PA, Balmforth PK, Stöhr EJ, McDonnell BJ, Spencer D, O'Sullivan GJ, Black SA. Iliocaval Venous Obstruction, Cardiac Preload Reserve and Exercise Limitation. J Cardiovasc Transl Res 2020; 13:531-539. [PMID: 32040765 PMCID: PMC7423854 DOI: 10.1007/s12265-020-09963-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 01/22/2020] [Indexed: 12/16/2022]
Abstract
Cardiac output during exercise increases by as much as fivefold in the untrained man, and by as much as eightfold in the elite athlete. Increasing venous return is a critical but much overlooked component of the physiological response to exercise. Cardiac disorders such as constrictive pericarditis, restrictive cardiomyopathy and pulmonary hypertension are recognised to impair preload and cause exercise limitation; however, the effects of peripheral venous obstruction on cardiac function have not been well described. This manuscript will discuss how obstruction of the iliocaval venous outflow can lead to impairment in exercise tolerance, how such obstructions may be diagnosed, the potential implications of chronic obstructions on sympathetic nervous system activation, and relevance of venous compression syndromes in heart failure with preserved ejection fraction.
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Affiliation(s)
- Rachael I Morris
- School of Cardiovascular Medicine and Sciences, King's College London, London, UK.
| | - Paul A Sobotka
- The Ohio State University, Columbus, OH, USA
- V-Flow Medical Inc., Saint Paul, CA, USA
| | | | - Eric J Stöhr
- Department of Medicine, Division of Cardiology, Columbia University Irving Medical Centre, New York City, USA
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | - Barry J McDonnell
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | | | | | - Stephen A Black
- School of Cardiovascular Medicine and Sciences, King's College London, London, UK
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9
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Junejo RT, Ray CJ, Marshall JM. Prostaglandin contribution to postexercise hyperemia is dependent on tissue oxygenation during rhythmic and isometric contractions. Physiol Rep 2020; 8:e14471. [PMID: 32562377 PMCID: PMC7305242 DOI: 10.14814/phy2.14471] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/27/2020] [Accepted: 05/10/2020] [Indexed: 12/21/2022] Open
Abstract
The role of prostaglandins (PGs) in exercise hyperemia is controversial. We tested their contributions in moderate intensity forearm exercise, whether their release is oxygen (O2)‐dependent or affected by aging. A total of 12 young (21 ± 1 years) and 11 older (66 ± 2 years) recreationally active men performed rhythmic and isometric handgrip contractions at 60% maximum voluntary contraction for 3 min during air breathing after placebo, after cyclooxygenase (COX) inhibition with aspirin, while breathing 40% O2 and during their combination (aspirin + 40% O2). Forearm blood flow (FBF) was recorded with venous occlusion plethysmography (forearm vascular conductance (FVC): FBF/mean arterial pressure). Venous efflux of PGI2 and PGE2 were assessed by immunoassay. Postcontraction increases in FVC were similar for rhythmic and isometric contractions in young and older men, and accompanied by similar increases in efflux of PGI2 and PGE2. Aspirin attenuated the efflux of PGI2 by 75%–85%, PGE2 by 50%–70%, (p < .05 within group; p > .05 young versus. older), and postcontraction increases in FVC by 22%–27% and 17%–21% in young and older men, respectively (p < .05 within group and young versus. older). In both age groups, 40% O2 and aspirin + 40% O2 caused similar inhibition of the increases in FVC and efflux of PGs as aspirin alone (p < .05 within group). These results indicate that PGs make substantial contributions to the postcontraction hyperemia of rhythmic and isometric contractions at moderate intensities in recreationally active young and older men. Given PGI2 is mainly released by endothelium and PGE2 by muscle fibers, we propose PG generation is dependent on the contraction‐induced falls in O2 at these sites.
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Affiliation(s)
- Rehan T Junejo
- School of Sport, Exercise & Rehabilitation Sciences, College of Life & Environmental Sciences, Birmingham, UK
| | - Clare J Ray
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Janice M Marshall
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
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Barnes MJ, Perry BG, Hurst RD, Lomiwes D. Anthocyanin-Rich New Zealand Blackcurrant Extract Supports the Maintenance of Forearm Blood-Flow During Prolonged Sedentary Sitting. Front Nutr 2020; 7:74. [PMID: 32537457 PMCID: PMC7267005 DOI: 10.3389/fnut.2020.00074] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 04/30/2020] [Indexed: 12/22/2022] Open
Abstract
Objectives: We examined the acute effects of anthocyanin-rich New Zealand blackcurrant extract and a placebo on hemodynamics during 120 min of sedentary sitting in healthy males. Additionally, we investigated whether changes in resting hemodynamics altered repeated isometric hand-grip exercise performance and post exercise forearm blood flow (FBF). Methods: Ten healthy males completed two trials during which they ingested either blackcurrant extract (1.87 mg total anthocyanins/kg bodyweight) or placebo powder. Heart rate, blood pressure and forearm blood flow were measured, and venous blood was sampled, prior to and 30, 60, 90 and 120 min-post ingestion. Participants remained seated for the duration of each trial. At 120 min post-ingestion participants completed as many repetitions of isometric hand-grip contractions as possible. Results: Heart rate, blood pressure and mean arterial pressure changed over time (all p < 0.001) but did not differ between treatments. A treatment x time interaction for FBF (p = 0.025) and forearm vascular resistance (FVR) (p = 0.002) was found. No difference in the number of isometric hand-grip contractions was observed between treatments (p = 0.68) nor was there any treatment x time interaction in post-exercise FBF (p = 0.997). Plasma endothelin-1 (p = 0.023) and nitrate (p = 0.047) changed over time but did not differ between treatments (both p > 0.1). Plasma nitrite did not change over time (p = 0.732) or differ between treatments (p = 0.373). Conclusion: This study demonstrated that acute ingestion of a single dose of blackcurrant extract maintained FBF and FVR during an extended period of sitting; however, this did not influence exercise performance during hand-grip exercise.
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Affiliation(s)
- Matthew J Barnes
- School of Sport, Exercise and Nutrition, Massey University, Palmerston North, New Zealand
| | - Blake G Perry
- School of Health Sciences, Massey University, Wellington, New Zealand
| | - Roger D Hurst
- The New Zealand Institute for Plant and Food Research Ltd, Palmerston North, New Zealand
| | - Dominic Lomiwes
- The New Zealand Institute for Plant and Food Research Ltd, Palmerston North, New Zealand
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Sun P, Chen X, Zeng Z, Li S, Wang J, Yu F, Liu S, Li H, Fernhall B. Sex differences in lower-limb arterial stiffness following acute aerobic exercise. Sci Sports 2020. [DOI: 10.1016/j.scispo.2019.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Zamani P, Proto EA, Mazurek JA, Prenner SB, Margulies KB, Townsend RR, Kelly DP, Arany Z, Poole DC, Wagner PD, Chirinos JA. Peripheral Determinants of Oxygen Utilization in Heart Failure With Preserved Ejection Fraction: Central Role of Adiposity. ACTA ACUST UNITED AC 2020; 5:211-225. [PMID: 32215346 PMCID: PMC7091498 DOI: 10.1016/j.jacbts.2020.01.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 12/27/2019] [Accepted: 01/02/2020] [Indexed: 01/04/2023]
Abstract
ΔAVo2 during exercise is a complex metric that incorporates into its calculation skeletal muscle blood flow and DmO2 across the skeletal muscle capillary membrane. Although ΔAVo2 was reduced in patients with HFpEF during both systemic and local (forearm) exercise, there was no difference in forearm DmO2 among subjects with HFpEF, those with hypertension, and healthy control subjects; therefore, abnormalities in forearm DmO2 cannot explain the reduced forearm ΔAVo2 seen in subjects with HFpEF. Local forearm exercise performance predicted about one-third of the variability in systemic aerobic capacity, demonstrating that peripheral factors are important in determining whole-body exercise tolerance. Degree of adiposity strongly correlated with ΔAVo2 during both local and whole-body exercise, suggesting that adipose tissue may play an active role in limiting exercise capacity in subjects with HFpEF.
The aim of this study was to determine the arteriovenous oxygen content difference (ΔAVo2) in adult subjects with and without heart failure with preserved ejection fraction (HFpEF) during systemic and forearm exercise. Subjects with HFpEF had reduced ΔAVo2. Forearm diffusional conductance for oxygen, a lumped conductance parameter that incorporates all impediments to the movement of oxygen from red blood cells in skeletal muscle capillaries into the mitochondria within myocytes, was estimated. Forearm diffusional conductance for oxygen was not different among adults with HFpEF, those with hypertension, and healthy control subjects; therefore, diffusional conductance cannot explain the reduced forearm ΔAVo2. Instead, adiposity was strongly associated with ΔAVo2, suggesting an active role for adipose tissue in reducing exercise capacity in patients with HFpEF.
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Key Words
- CO, cardiac output
- DEXA, dual-energy x-ray absorptiometry
- DmO2, skeletal muscle diffusional conductance for oxygen
- FIo2, fraction of inspired oxygen
- HFpEF
- HFpEF, heart failure with preserved ejection fraction
- MVC, maximal voluntary contraction force
- NT-proBNP, N-terminal pro–brain natriuretic peptide
- Po2, partial pressure of oxygen
- Vo2, oxygen consumption
- adiposity
- aerobic capacity
- exercise
- oxygen transport
- ΔAVo2, arteriovenous oxygen content difference
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Affiliation(s)
- Payman Zamani
- Division of Cardiovascular Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Elizabeth A Proto
- Division of Cardiovascular Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jeremy A Mazurek
- Division of Cardiovascular Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Stuart B Prenner
- Division of Cardiovascular Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Kenneth B Margulies
- Division of Cardiovascular Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Raymond R Townsend
- Division of Nephrology/Hypertension, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Daniel P Kelly
- Division of Cardiovascular Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Zoltan Arany
- Division of Cardiovascular Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | - David C Poole
- Departments of Kinesiology, Anatomy, and Physiology, Kansas State University, Manhattan, Kansas
| | - Peter D Wagner
- Division of Pulmonary Medicine, University of California-San Diego, San Diego, California
| | - Julio A Chirinos
- Division of Cardiovascular Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
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13
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Halley SL, Marshall P, Siegler JC. Effect of ischemic preconditioning and changing inspired O2 fractions on neuromuscular function during intense exercise. J Appl Physiol (1985) 2019; 127:1688-1697. [DOI: 10.1152/japplphysiol.00539.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The aim of the present study was to determine whether ischemic preconditioning (IPC)-mediated effects on neuromuscular function are dependent on tissue oxygenation. Eleven resistance-trained males completed four exercise trials (6 sets of 11 repetitions of maximal effort dynamic single-leg extensions) in either normoxic [fraction of inspired oxygen ([Formula: see text]): 21%) or hypoxic [Formula: see text]: 14%] conditions, preceded by treatments of either IPC (3 × 5 min bilateral leg occlusions at 220 mmHg) or sham (3 × 5 min at 20 mmHg). Femoral nerve stimulation was utilized to assess voluntary activation and potentiated twitch characteristics during maximal voluntary contractions (MVCs). Tissue oxygenation (via near-infrared spectroscopy) and surface electromyography activity were measured throughout the exercise task. MVC and twitch torque declined 62 and 54%, respectively (MVC: 96 ± 24 N·m, Cohen’s d = 2.9, P < 0.001; twitch torque: 37 ± 11 N·m, d = 1.6, P < 0.001), between pretrial measurements and the sixth set without reductions in voluntary activation ( P > 0.21); there were no differences between conditions. Tissue oxygenation was reduced in both hypoxic conditions compared with normoxia ( P < 0.001), with an even further reduction of 3% evident in the hypoxic IPC compared with the sham trial (mean decrease 1.8 ± 0.7%, d = 1.0, P < 0.05). IPC did not affect any measure of neuromuscular function regardless of tissue oxygenation. A reduction in [Formula: see text] did invoke a humoral response and improved muscle O2 extraction during exercise, however, it did not manifest into any performance benefit. NEW & NOTEWORTHY Ischemic preconditioning did not affect any facet of neuromuscular function regardless of the degree of tissue oxygenation. Reducing the fraction of inspired oxygen induced localized tissue deoxygenation, subsequently invoking a humoral response, which improved muscle oxygen extraction during exercise. This physiological response, however, did not manifest into any performance benefits.
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Affiliation(s)
- Samuel L. Halley
- Sport and Exercise Science, School of Health Sciences, Western Sydney University, Sydney, Australia
| | - Paul Marshall
- Sport and Exercise Science, School of Health Sciences, Western Sydney University, Sydney, Australia
| | - Jason C. Siegler
- Sport and Exercise Science, School of Health Sciences, Western Sydney University, Sydney, Australia
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14
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Hirai DM, Craig JC, Colburn TD, Eshima H, Kano Y, Musch TI, Poole DC. Skeletal muscle interstitial Po 2 kinetics during recovery from contractions. J Appl Physiol (1985) 2019; 127:930-939. [PMID: 31369325 DOI: 10.1152/japplphysiol.00297.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The oxygen partial pressure in the interstitial space (Po2 is) drives O2 into the myocyte via diffusion, thus supporting oxidative phosphorylation. Although crucial for metabolic recovery and the capacity to perform repetitive tasks, the time course of skeletal muscle Po2 is during recovery from contractions remains unknown. We tested the hypothesis that Po2 is would recover to resting values and display considerable on-off asymmetry (fast on-, slow off-kinetics), reflective of asymmetric capillary hemodynamics. Microvascular Po2 (Po2 mv) was also evaluated to test the hypothesis that a significant transcapillary gradient (ΔPo2 = Po2 mv - Po2 is) would be sustained during recovery. Po2 mv and Po2 is (expressed in mmHg) were determined via phosphorescence quenching in the exposed rat spinotrapezius muscle during and after submaximal twitch contractions (n = 12). Po2 is rose exponentially (P < 0.05) from end-contraction (11.1 ± 5.1), such that the end-recovery value (17.9 ± 7.9) was not different from resting Po2 is (18.5 ± 8.1; P > 0.05). Po2 is off-kinetics were slower than on-kinetics (mean response time: 53.1 ± 38.3 versus 18.5 ± 7.3 s; P < 0.05). A significant transcapillary ΔPo2 observed at end-contraction (16.6 ± 7.4) was maintained throughout recovery (end-recovery: 18.8 ± 9.6; P > 0.05). Consistent with our hypotheses, muscle Po2 is recovered to resting values with slower off-kinetics compared with the on-transient in line with the on-off asymmetry for capillary hemodynamics. Maintenance of a substantial transcapillary ΔPo2 during recovery supports that the microvascular-interstitium interface provides considerable resistance to O2 transport. As dictated by Fick's law (V̇o2 = Do2 × ΔPo2), modulation of O2 flux (V̇o2) during recovery must be achieved via corresponding changes in effective diffusing capacity (Do2; mainly capillary red blood cell hemodynamics and distribution) in the face of unaltered ΔPo2.NEW & NOTEWORTHY Capillary blood-myocyte O2 flux (V̇o2) is determined by effective diffusing capacity (Do2; mainly erythrocyte hemodynamics and distribution) and microvascular-interstitial Po2 gradients (ΔPo2 = Po2 mv - Po2 is). We show that Po2 is demonstrates on-off asymmetry consistent with Po2 mv and erythrocyte kinetics during metabolic transitions. A substantial transcapillary ΔPo2 was preserved during recovery from contractions, indicative of considerable resistance to O2 diffusion at the microvascular-interstitium interface. This reveals that effective Do2 declines in step with V̇o2 during recovery, as per Fick's law.
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Affiliation(s)
- Daniel M Hirai
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana.,Department of Kinesiology, Kansas State University, Manhattan, Kansas.,Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas
| | - Jesse C Craig
- Department of Kinesiology, Kansas State University, Manhattan, Kansas.,Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas.,Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Trenton D Colburn
- Department of Kinesiology, Kansas State University, Manhattan, Kansas.,Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas
| | - Hiroaki Eshima
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Yutaka Kano
- Department of Engineering Science, University of Electro-Communications, Tokyo, Japan
| | - Timothy I Musch
- Department of Kinesiology, Kansas State University, Manhattan, Kansas.,Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas
| | - David C Poole
- Department of Kinesiology, Kansas State University, Manhattan, Kansas.,Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas
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15
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Zuj KA, Prince CN, Hughson RL, Peterson SD. Superficial femoral artery blood flow with intermittent pneumatic compression of the lower leg applied during walking exercise and recovery. J Appl Physiol (1985) 2019; 127:559-567. [DOI: 10.1152/japplphysiol.00656.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of this study was to determine if muscle blood flow during walking exercise and postexercise recovery can be augmented through the application of intermittent compression of the lower legs applied during the diastolic phase of the cardiac cycle. Results from four conditions were assessed: no compression (NoComp), compression during walking (ExComp), compression during postexercise recovery (RecComp), and compression applied throughout (AllComp). Superficial femoral artery (SFA) blood flow was measured (Doppler ultrasound) during rest and postexercise recovery. Mean arterial blood pressure (MAP, finger photoplethysmography) was used to calculate vascular conductance as VC = SFA flow/MAP. Near infrared spectroscopy measured changes in oxygenated (O2Hb) and deoxygenated hemoglobin concentration throughout the test. Compression during exercise increased SFA blood flow measured over the first 15 s of postexercise recovery (AllComp: 532.2 ± 123.1 mL/min; ExComp: 529.8 ± 99.2 mL/min) compared with NoComp (462.3 ± 87.3 mL/min P < 0.05) and corresponded to increased VC (NoComp: 4.7 ± 0.9 mL·min−1·mmHg−1 versus ExComp: 5.5 ± 1.0 mL·min−1·mmHg−1, P < 0.05). Similarly, compression throughout postexercise recovery also resulted in increased SFA flow (AllComp: 190.5 ± 57.1 mL/min; RecComp: 158.7 ± 49.1 mL/min versus NoComp: 108.8 ± 28.5 mL/min, P < 0.05) and vascular conductance. Muscle contractions during exercise reduced total hemoglobin with O2Hb comprising ~57% of the observed reduction. Compression during exercise augmented this reduction ( P < 0.05) with O2HB again comprising ~55% of the reduction. Total hemoglobin was reduced with compression during postexercise recovery ( P < 0.05) with O2Hb accounting for ~40% of this reduction. Results from this study indicate that intermittent compression applied during walking and during postexercise recovery enhanced vascular conductance during exercise and elevated postexercise SFA blood flow and tissue oxygenation during recovery. NEW & NOTEWORTHY Intermittent compression mimics the mechanical actions of voluntary muscle contraction on venous volume. This study demonstrates that compression applied during the diastolic phase of the cardiac cycle while walking accentuates the actions of the muscle pump resulting in increased immediate postexercise muscle blood flow and vascular conductance. Similarly, compression applied during the recovery period independently increased arterial flow and tissue oxygenation, potentially providing conditions conducive to faster recovery.
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Affiliation(s)
- Kathryn A. Zuj
- University of Waterloo, Department of Kinesiology, Waterloo, ON, Canada
| | - Chekema N. Prince
- University of Waterloo, Department of Mechanical and Mechatronics Engineering, Waterloo, ON, Canada
| | - Richard L. Hughson
- University of Waterloo, Department of Kinesiology, Waterloo, ON, Canada
- Schlegel-University of Waterloo Research Institute for Aging, Waterloo, ON, Canada
| | - Sean D. Peterson
- University of Waterloo, Department of Mechanical and Mechatronics Engineering, Waterloo, ON, Canada
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16
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Jeffries O, Waldron M, Pattison JR, Patterson SD. Enhanced Local Skeletal Muscle Oxidative Capacity and Microvascular Blood Flow Following 7-Day Ischemic Preconditioning in Healthy Humans. Front Physiol 2018; 9:463. [PMID: 29867526 PMCID: PMC5954802 DOI: 10.3389/fphys.2018.00463] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 04/13/2018] [Indexed: 01/05/2023] Open
Abstract
Ischemic preconditioning (IPC), which involves intermittent periods of ischemia followed by reperfusion, is an effective clinical intervention that reduces the risk of myocardial injury and confers ischemic tolerance to skeletal muscle. Repeated bouts of IPC have been shown to stimulate long-term changes vascular function, however, it is unclear what metabolic adaptations may occur locally in the muscle. Therefore, we investigated 7 days of bilateral lower limb IPC (4 × 5 min) above limb occlusion pressure (220 mmHg; n = 10), or sham (20 mmHg; n = 10), on local muscle oxidative capacity and microvascular blood flow. Oxidative capacity was measured using near-infrared spectroscopy (NIRS) during repeated short duration arterial occlusions (300 mmHg). Microvascular blood flow was assessed during the recovery from submaximal isometric plantar flexion exercises at 40 and 60% of maximal voluntary contraction (MVC). Following the intervention period, beyond the late phase of protection (72 h), muscle oxidative recovery kinetics were speeded by 13% (rate constant pre 2.89 ± 0.47 min-1 vs. post 3.32 ± 0.69 min-1; P < 0.05) and resting muscle oxygen consumption (m O2) was reduced by 16.4% (pre 0.39 ± 0.16%.s-1 vs. post 0.33 ± 0.14%.s-1; P < 0.05). During exercise, changes in deoxygenated hemoglobin (HHb) from rest to steady state were reduced at 40 and 60% MVC (16 and 12%, respectively, P < 0.05) despite similar measures of total hemoglobin (tHb). At the cessation of exercise, the time constant for recovery in oxygenated hemoglobin (O2Hb) was accelerated at 40 and 60% MVC (by 33 and 43%, respectively) suggesting enhanced reoxygenation in the muscle. No changes were reported for systemic measures of resting heart rate or blood pressure. In conclusion, repeated bouts of IPC over 7 consecutive days increased skeletal muscle oxidative capacity and microvascular muscle blood flow. These findings are consistent with enhanced mitochondrial and vascular function following repeated IPC and may be of clinical or sporting interest to enhance or offset reductions in muscle oxidative capacity.
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Affiliation(s)
- Owen Jeffries
- School of Sport, Health and Applied Science, St Mary's University, London, United Kingdom.,School of Biomedical Science, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Mark Waldron
- School of Sport, Health and Applied Science, St Mary's University, London, United Kingdom.,School of Science and Technology, University of New England, Armidale, NSW, Australia
| | - John R Pattison
- School of Sport, Health and Applied Science, St Mary's University, London, United Kingdom
| | - Stephen D Patterson
- School of Sport, Health and Applied Science, St Mary's University, London, United Kingdom
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17
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Stöcker F, Von Oldershausen C, Paternoster FK, Schulz T, Oberhoffer R. Does postexercise modelled capillary blood flow accurately reflect cardiovascular effects by different exercise intensities? Clin Physiol Funct Imaging 2018; 38:431-438. [PMID: 28444930 DOI: 10.1111/cpf.12434] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 03/16/2017] [Indexed: 11/28/2022]
Abstract
Blood flow (BF) in exercising muscles is an important factor for exercise capacity. Recently, a non-invasive method to estimate capillary BF (Qcap ) was introduced. Using this method, the Fick principle is re-arranged by using relative differences in deoxygenated haemoglobin (ΔHHb) as a surrogate for arteriovenous O2 difference and pulmonary oxygen uptake (VO2 ) instead of muscular oxygen uptake. The aim of this study was to examine (I) the relationship between Qcap and exercise intensity during and following exercise, and (II) to critically reflect the Qcap approach. Seventeen male subjects completed six bouts of cycling exercise with different exercise intensities (40-90% peak oxygen uptake, VO2peak ) in randomized order. VO2 and ΔHHb were monitored continuously during the trail. Qcap was modelled bi-exponentially, and mean response time (MRT) was calculated during recovery as well as the dissociation of modelled VO2 and Qcap recovery kinetics (MRT/τVO2 ). End-exercise Qcap increased continuously with exercise intensity. This also applied to MRT. Postexercise MRT/τVO2 increased from 40 to 60% VO2peak but remained stable thereafter. The results show that Qcap response to exercise is linearly related to exercise intensity. This is presumably due to vasoactive factors like shear-stress or endothelial-mediated vasodilation. MRT/τVO2 shows that postexercise Qcap is elevated for a longer period than VO2 , which is representative for metabolic demand following exercise ≥70% VO2peak . This is a hint for prolonged local vasodilation. According to previous studies, Qcap could not be modelled properly in some cases, which is a limitation to the method and therefore has to be interpreted with caution.
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Affiliation(s)
- F Stöcker
- Center for Teaching and Learning, Technical University Munich, Munich, Germany
| | - C Von Oldershausen
- Center for Teaching and Learning, Technical University Munich, Munich, Germany
| | - F K Paternoster
- Department for Biomechanics in Sports, Technical University Munich, Munich, Germany
| | - T Schulz
- Department for Preventive Pediatrics, Technical University Munich, Munich, Germany
| | - R Oberhoffer
- Department for Preventive Pediatrics, Technical University Munich, Munich, Germany
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18
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Nyberg SK, Berg OK, Helgerud J, Wang E. Reliability of forearm oxygen uptake during handgrip exercise: assessment by ultrasonography and venous blood gas. Physiol Rep 2018; 6:e13696. [PMID: 29845765 PMCID: PMC5974736 DOI: 10.14814/phy2.13696] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 04/11/2018] [Accepted: 04/12/2018] [Indexed: 01/18/2023] Open
Abstract
Assessment of forearm oxygen uptake (V˙O2 ) during handgrip exercise is a keenly investigated concept for observing small muscle mass metabolism. Although a combination of Doppler ultrasound measurements of brachial artery blood flow (Q˙) and blood gas drawn from a deep forearm vein has been utilized to calculate forearm V˙O2 for more than two decades, the applicability of this experimental design may benefit from a thorough evaluation of its reliability during graded exercise. Therefore, we evaluated the reliability of this technique during incremental handgrip exercise in ten healthy young (24 ± 3(SD) years.) males. V˙O2 and work rate (WR) exhibited a linear relationship (1.0 W: 43.8 ± 10.1 mL·min-1 ; 1.5 W: 53.8 ± 14.1 mL·min-1 ; 2.0 W: 63.4 ± 16.3 mL·min-1 ; 2.5 W: 72.2 ± 17.6 mL·min-1 ; 3.0 W: 79.2 ± 18.6 mL·min-1 ; r = 0.65, P < 0.01). In turn, V˙O2 was strongly associated with Q˙ (1.0 W: 359 ± 86 mL·min-1 ; 1.5 W: 431 ± 112 mL·min-1 ; 2.0 W: 490 ± 123 mL·min-1 ; 2.5 W: 556 ± 112 mL·min-1 ; 3.0 W: 622 ± 131 mL·min-1 ; r = 0.96; P < 0.01), whereas arteriovenous oxygen difference (a-vO2diff ) remained constant following all WRs (123 ± 11-130 ± 10 mL·L-1 ). Average V˙O2 test-retest difference was -0.4 mL·min-1 with ±2SD limits of agreement (LOA) of 8.4 and -9.2 mL·min-1 , respectively, whereas coefficients of variation (CVs) ranged from 4-7%. Accordingly, test-retest Q˙ difference was 11.9 mL·min-1 (LOA: 84.1 mL·min-1 ; -60.4 mL·min-1 ) with CVs between 4 and 7%. Test-retest difference for a-vO2diff was -0.28 mL·dL-1 (LOA: 1.26mL·dL-1 ; -1.82 mL·dL-1 ) with 3-5% CVs. In conclusion, our results revealed that forearm V˙O2 determination by Doppler ultrasound and direct venous sampling is linearly related to WR, and a reliable experimental design across a range of exercise intensities.
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Affiliation(s)
- Stian K. Nyberg
- Department of Circulation and Medical ImagingFaculty of MedicineNorwegian University of Science and TechnologyTrondheimNorway
| | - Ole Kristian Berg
- Faculty of Health and Social SciencesMolde University CollegeMoldeNorway
| | - Jan Helgerud
- Department of Circulation and Medical ImagingFaculty of MedicineNorwegian University of Science and TechnologyTrondheimNorway
| | - Eivind Wang
- Department of Circulation and Medical ImagingFaculty of MedicineNorwegian University of Science and TechnologyTrondheimNorway
- Faculty of Health and Social SciencesMolde University CollegeMoldeNorway
- Department of Internal MedicineUniversity of UtahSalt Lake CityUtah
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19
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Nyberg SK, Berg OK, Helgerud J, Wang E. Blood flow regulation and oxygen uptake during high-intensity forearm exercise. J Appl Physiol (1985) 2017; 122:907-917. [PMID: 28057820 DOI: 10.1152/japplphysiol.00983.2016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 12/20/2016] [Accepted: 01/03/2017] [Indexed: 12/29/2022] Open
Abstract
The vascular strain is very high during heavy handgrip exercise, but the intensity and kinetics to reach peak blood flow, and peak oxygen uptake, are uncertain. We included 9 young (25 ± 2 yr) healthy males to evaluate blood flow and oxygen uptake responses during continuous dynamic handgrip exercise with increasing intensity. Blood flow was measured using Doppler-ultrasound, and venous blood was drawn from a deep forearm vein to determine arteriovenous oxygen difference (a-vO2diff) during 6-min bouts of 60, 80, and 100% of maximal work rate (WRmax), respectively. Blood flow and oxygen uptake increased (P < 0.05) from 60%WRmax [557 ± 177(SD) ml/min; 56.0 ± 21.6 ml/min] to 80%WRmax (679 ± 190 ml/min; 70.6 ± 24.8 ml/min), but no change was seen from 80%WRmax to 100%WRmax Blood velocity (49.5 ± 11.5 to 58.1 ± 11.6 cm/s) and brachial diameter (0.49 ± 0.05 to 0.50 ± 0.06 cm) showed concomitant increases (P < 0.05) with blood flow from 60% to 80%WRmax, whereas no differences were observed in a-vO2diff Shear rate also increased (P < 0.05) from 60% (822 ± 196 s-1) to 80% (951 ± 234 s-1) of WRmax The mean response time (MRT) was slower (P < 0.05) for blood flow (60%WRmax 50 ± 22 s; 80%WRmax 51 ± 20 s; 100%WRmax 51 ± 23 s) than a-vO2diff (60%WRmax 29 ± 9 s; 80%WRmax 29 ± 5 s; 100%WRmax 20 ± 5 s), but not different from oxygen uptake (60%WRmax 44 ± 25 s; 80%WRmax 43 ± 14 s; 100%WRmax 41 ± 32 s). No differences were observed in MRT for blood flow or oxygen uptake with increased exercise intensity. In conclusion, when approaching maximal intensity, oxygen uptake appeared to reach a critical level at ~80% of WRmax and be regulated by blood flow. This implies that high, but not maximal, exercise intensity may be an optimal stimulus for shear stress-induced small muscle mass training adaptations.NEW & NOTEWORTHY This study evaluated blood flow regulation and oxygen uptake during small muscle mass forearm exercise with high to maximal intensity. Despite utilizing only a fraction of cardiac output, blood flow reached a plateau at 80% of maximal work rate and regulated peak oxygen uptake. Furthermore, the results revealed that muscle contractions dictated bulk oxygen delivery and yielded three times higher peak blood flow in the relaxation phase compared with mean values.
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Affiliation(s)
- S K Nyberg
- Department of Circulation and Medical Imaging, Faculty of Medicine, the Norwegian University of Science and Technology, Trondheim, Norway
| | - O K Berg
- Faculty of Health and Social Sciences, Molde University College, Molde, Norway
| | - J Helgerud
- Department of Circulation and Medical Imaging, Faculty of Medicine, the Norwegian University of Science and Technology, Trondheim, Norway.,Hokksund Medical Rehabilitation Centre, Hokksund, Norway.,Department of Sports and Outdoor Life Studies, Telemark University College, Bø, Norway
| | - E Wang
- Department of Circulation and Medical Imaging, Faculty of Medicine, the Norwegian University of Science and Technology, Trondheim, Norway; .,Department of Medicine, University of Utah, Salt Lake City, Utah; and.,Department of Research and Development, St. Olav's University Hospital, Trondheim, Norway
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20
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Niemeijer VM, Spee RF, Schoots T, Wijn PFF, Kemps HMC. Limitations of skeletal muscle oxygen delivery and utilization during moderate-intensity exercise in moderately impaired patients with chronic heart failure. Am J Physiol Heart Circ Physiol 2016; 311:H1530-H1539. [DOI: 10.1152/ajpheart.00474.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/28/2016] [Indexed: 11/22/2022]
Abstract
The extent and speed of transient skeletal muscle deoxygenation during exercise onset in patients with chronic heart failure (CHF) are related to impairments of local O2 delivery and utilization. This study examined the physiological background of submaximal exercise performance in 19 moderately impaired patients with CHF (Weber class A, B, and C) compared with 19 matched healthy control (HC) subjects by measuring skeletal muscle oxygenation (SmO2) changes during cycling exercise. All subjects performed two subsequent moderate-intensity 6-min exercise tests (bouts 1 and 2) with measurements of pulmonary oxygen uptake kinetics and SmO2 using near-infrared spatially resolved spectroscopy at the vastus lateralis for determination of absolute oxygenation values, amplitudes, kinetics (mean response time for onset), and deoxygenation overshoot characteristics. In CHF, deoxygenation kinetics were slower compared with HC (21.3 ± 5.3 s vs. 16.7 ± 4.4 s, P < 0.05, respectively). After priming exercise (i.e., during bout 2), deoxygenation kinetics were accelerated in CHF to values no longer different from HC (16.9 ± 4.6 s vs. 15.4 ± 4.2 s, P = 0.35). However, priming did not speed deoxygenation kinetics in CHF subjects with a deoxygenation overshoot, whereas it did reduce the incidence of the overshoot in this specific group ( P < 0.05). These results provide evidence for heterogeneity with respect to limitations of O2 delivery and utilization during moderate-intensity exercise in patients with CHF, with slowed deoxygenation kinetics indicating a predominant O2 utilization impairment and the presence of a deoxygenation overshoot, with a reduction after priming in a subgroup, indicating an initial O2 delivery to utilization mismatch.
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Affiliation(s)
- Victor M. Niemeijer
- Department of Cardiology, Máxima Medical Centre, Veldhoven, the Netherlands
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven, the Netherlands; and
| | - Ruud F. Spee
- Department of Cardiology, Máxima Medical Centre, Veldhoven, the Netherlands
| | - Thijs Schoots
- Department of Cardiology, Máxima Medical Centre, Veldhoven, the Netherlands
| | - Pieter F. F. Wijn
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven, the Netherlands; and
- Department of Medical Physics, Máxima Medical Centre, Veldhoven, the Netherlands
| | - Hareld M. C. Kemps
- Department of Cardiology, Máxima Medical Centre, Veldhoven, the Netherlands
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21
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Olver TD, Reid SM, Smith AR, Zamir M, Lemon PWR, Laughlin MH, Shoemaker JK. Effects of acute and chronic interval sprint exercise performed on a manually propelled treadmill on upper limb vascular mechanics in healthy young men. Physiol Rep 2016; 4:4/13/e12861. [PMID: 27405970 PMCID: PMC4945842 DOI: 10.14814/phy2.12861] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 06/20/2016] [Indexed: 11/24/2022] Open
Abstract
Interval sprint exercise performed on a manually propelled treadmill, where the hands grip the handle bars, engages lower and upper limb skeletal muscle, but little is known regarding the effects of this exercise modality on the upper limb vasculature. We tested the hypotheses that an acute bout of sprint exercise and 6 weeks of training induces brachial artery (BA) and forearm vascular remodeling, favoring a more compliant system. Before and following a single bout of exercise as well as 6 weeks of training three types of vascular properties/methodologies were examined in healthy men: (1) stiffness of the entire upper limb vascular system (pulse wave velocity (PWV); (2) local stiffness of the BA; and (3) properties of the entire forearm vascular bed (determined by a modified lumped parameter Windkessel model). Following sprint exercise, PWV declined (P < 0.01), indices of BA stiffness did not change (P ≥ 0.10), and forearm vascular bed compliance increased and inertance and viscoelasticity decreased (P ≤ 0.03). Following manually propelled treadmill training, PWV remained unchanged (P = 0.31), indices of BA stiffness increased (P ≤ 0.05) and forearm vascular bed viscoelasticity declined (P = 0.02), but resistance, compliance, and inertance remained unchanged (P ≥ 0.10) compared with pretraining values. Sprint exercise induced a more compliant forearm vascular bed, without altering indices of BA stiffness. These effects were transient, as following training the forearm vascular bed was not more compliant and indices of BA stiffness increased. On the basis of these data, we conclude that adaptations to acute and chronic sprint exercise on a manually propelled treadmill are not uniform along the arterial tree in upper limb.
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Affiliation(s)
- T Dylan Olver
- Neurovascular Research Laboratory, School of Kinesiology, The University of Western Ontario, London, Ontario, Canada Department of Biomedical Sciences, University of Missouri-Columbia, Columbia, Missouri
| | - Steph M Reid
- Exercise Nutrition Laboratory, School of Kinesiology, The University of Western Ontario, London, Ontario, Canada
| | - Alan R Smith
- Exercise Nutrition Laboratory, School of Kinesiology, The University of Western Ontario, London, Ontario, Canada
| | - Mair Zamir
- Neurovascular Research Laboratory, School of Kinesiology, The University of Western Ontario, London, Ontario, Canada Departments of Applied Mathematics and of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada
| | - Peter W R Lemon
- Exercise Nutrition Laboratory, School of Kinesiology, The University of Western Ontario, London, Ontario, Canada
| | - M Harold Laughlin
- Department of Biomedical Sciences, University of Missouri-Columbia, Columbia, Missouri
| | - J Kevin Shoemaker
- Neurovascular Research Laboratory, School of Kinesiology, The University of Western Ontario, London, Ontario, Canada
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22
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Patil P, Hazarey V, Chaudhari R, Nimbalkar-Patil S. Clinical Efficacy of a Mouth-Exercising Device Adjunct to Local Ointment, Intra-Lesional Injections and Surgical Treatment for Oral Submucous Fibrosis: a Randomized Controlled Trial. Asian Pac J Cancer Prev 2016; 17:1255-9. [DOI: 10.7314/apjcp.2016.17.3.1255] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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23
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Campbell MD, Marcinek DJ. Evaluation of in vivo mitochondrial bioenergetics in skeletal muscle using NMR and optical methods. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1862:716-724. [PMID: 26708941 PMCID: PMC4788529 DOI: 10.1016/j.bbadis.2015.12.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 11/20/2015] [Accepted: 12/16/2015] [Indexed: 12/13/2022]
Abstract
It is now clear that mitochondria are involved as either a cause or consequence of many chronic diseases. This central role of the mitochondria is due to their position in the cell as important integrators of cellular energetics and signaling. Mitochondrial function affects many aspects of the cellular environment such as redox homeostasis and calcium signaling, which then also exert control over mitochondrial function. This complex dynamic between mitochondrial function and the cellular environment highlights the value of examining mitochondria in vivo in the intact physiological environment. This review discusses NMR and optical approaches used to measure mitochondria ATP and oxygen fluxes that provide in vivo measures of mitochondrial capacity and quality in animal and human models. Combining these in vivo measurements with more traditional ex vivo analyses can lead to new insights into the importance of the cellular environment in controlling mitochondrial function under pathological conditions. Interpretation and underlying assumptions for each technique are discussed with the goal of providing an overview of some of the most common approaches used to measure in vivo mitochondrial function encountered in the literature.
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Affiliation(s)
- Matthew D Campbell
- University of Washington, Seattle, 850 Republican St., Brotman D142, Seattle, WA 98109, USA.
| | - David J Marcinek
- University of Washington, Seattle, 850 Republican St., Brotman D142, Seattle, WA 98109, USA.
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Shadgan B, Med S, Pakravan AH, Hoens A, Reid WD. Subcutaneous and Intramuscular Hemodynamics and Oxygenation After Cold-Spray Application as Monitored by Near-Infrared Spectroscopy. J Athl Train 2015; 50:800-5. [PMID: 26098273 DOI: 10.4085/1062-6050-50.6.02] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Vapocoolant spray, commonly known as cold spray (CS), is a cryotherapy modality used in sports medicine, athletic training, and rehabilitation settings. Proposed physiologic effects of cryotherapy modalities include reductions in tissue blood flow, oxygenation, and cell metabolism in addition to attenuation of pain perception attributed to reduced superficial nerve conduction velocity. OBJECTIVE To examine the effects of CS on subcutaneous and intramuscular blood flow and oxygenation on the thigh muscle using near-infrared spectroscopy, an optical method to monitor changes in tissue oxygenated (O2Hb), deoxygenated (HHb), and total (tHb) hemoglobin. DESIGN Cross-sectional study. SETTING Muscle Biophysics Laboratory. PATIENTS OR OTHER PARTICIPANTS Participants were 13 healthy adults (8 men, 5 women; age = 37.4 ± 6 years, body mass index = 27.4 ± 2.6, adipose tissue thickness = 7.2 ± 1.8 mm). INTERVENTION(S) Conventional CS was applied to the vastus medialis muscles. MAIN OUTCOME MEASURE(S) Changes in chromophore concentrations of O2Hb, HHb, and tHb at superficial and deep layers were monitored for 5 minutes using a 2-channel near-infrared spectroscopy. RESULTS Thirty seconds after CS application, we observed a decrease from baseline in O2Hb and tHb only in the superficial layer that was maintained for 3 minutes. CONCLUSIONS Application of CS induced a transient change in blood flow and oxygenation of the superficial tissues with no change in deeper tissues over the healthy vastus medialis muscle. The limited physiologic effect of CS on the superficial hemodynamics and oxygenation of limb muscles may limit the therapeutic benefit of this cryotherapy modality to a temporary analgesic effect, a hypothesis that warrants a clinical trial on traumatized muscles.
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Affiliation(s)
| | - Sports Med
- Centre of International Collaborations on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Amir H Pakravan
- Cambridge University Hospital, United Kingdom. Dr Reid is now at Department of Physical Therapy, University of Toronto, ON, Canada
| | - Alison Hoens
- Department of Physical Therapy, University of British Columbia, Vancouver, Canada
| | - W Darlene Reid
- Department of Physical Therapy, University of British Columbia, Vancouver, Canada
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Barbosa TC, Machado AC, Braz ID, Fernandes IA, Vianna LC, Nobrega ACL, Silva BM. Remote ischemic preconditioning delays fatigue development during handgrip exercise. Scand J Med Sci Sports 2014; 25:356-64. [DOI: 10.1111/sms.12229] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2014] [Indexed: 12/16/2022]
Affiliation(s)
- T. C. Barbosa
- Laboratory of Exercise Sciences; Department of Physiology and Pharmacology; Fluminense Federal University; Niterói Rio de Janeiro Brazil
| | - A. C. Machado
- Laboratory of Exercise Sciences; Department of Physiology and Pharmacology; Fluminense Federal University; Niterói Rio de Janeiro Brazil
| | - I. D. Braz
- Laboratory of Exercise Sciences; Department of Physiology and Pharmacology; Fluminense Federal University; Niterói Rio de Janeiro Brazil
| | - I. A. Fernandes
- Laboratory of Exercise Sciences; Department of Physiology and Pharmacology; Fluminense Federal University; Niterói Rio de Janeiro Brazil
| | - L. C. Vianna
- Laboratory of Exercise Sciences; Department of Physiology and Pharmacology; Fluminense Federal University; Niterói Rio de Janeiro Brazil
| | - A. C. L. Nobrega
- Laboratory of Exercise Sciences; Department of Physiology and Pharmacology; Fluminense Federal University; Niterói Rio de Janeiro Brazil
| | - B. M. Silva
- Laboratory of Exercise Sciences; Department of Physiology and Pharmacology; Fluminense Federal University; Niterói Rio de Janeiro Brazil
- Department of Physiology; Section of Exercise Physiology; Federal University of São Paulo; São Paulo Brazil
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26
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Gregson W, Allan R, Holden S, Phibbs P, Doran D, Campbell I, Waldron S, Joo CH, Morton JP. Postexercise cold-water immersion does not attenuate muscle glycogen resynthesis. Med Sci Sports Exerc 2014; 45:1174-81. [PMID: 23274601 DOI: 10.1249/mss.0b013e3182814462] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE The aim of this study was to test the hypothesis that postexercise cold-water immersion (CWI, via its associated reductions in skeletal muscle blood flow) attenuates muscle glycogen resynthesis during short-term recovery from exhaustive exercise. METHODS In a repeated-measures design, nine recreationally active men performed an exhaustive glycogen depleting cycling protocol (consisting of intermittent exercise the night before and steady-state exercise on the subsequent morning of the main trial) followed by 10 min of lower-limb CWI (8°C) or remained seated in normal ambient conditions (CONT). Subjects were fed carbohydrate (CHO) at an ingestion rate of 0.6 g·kg body mass at 30 min postexercise and at 1, 2, and 3 h postexercise. RESULTS Reductions in thigh skin temperature and muscle temperature during postexercise recovery were greater in CWI compared with CONT (P < 0.01). In addition, norepinephrine and blood glucose concentrations were increased and decreased, respectively, during recovery in CWI compared with CONT (P < 0.01). Postexercise muscle glycogen (CONT and CWI postexercise = 76 ± 43 and 77 ± 26 mmol·kg dry weight [dw], respectively; mean ± SD) progressively increased (P < 0.01) during recovery, although rates of resynthesis did not differ (P = 0.719) between conditions (CONT and CWI 4 h postexercise = 160 ± 34 and 157 ± 59 mmol·kg dw, respectively). Total glycogen synthesis during recovery was comparable (CONT and CWI = 83 ± 43 and 79 ± 58 mmol·kg dw, respectively). CONCLUSIONS Postexercise CWI does not attenuate muscle glycogen resynthesis rates during short-term recovery even when CHO availability is considered suboptimal. Athletes who regularly incorporate CWI as a recovery strategy to alleviate symptoms of exercise-induced muscle damage should therefore not be concerned with potential negative effects of the associated reductions in muscle blood flow on the restoration of muscle glycogen stores.
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Affiliation(s)
- Warren Gregson
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom.
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27
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In vivo (31)P NMR spectroscopy assessment of skeletal muscle bioenergetics after spinal cord contusion in rats. Eur J Appl Physiol 2014; 114:847-58. [PMID: 24399112 DOI: 10.1007/s00421-013-2810-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 11/29/2013] [Indexed: 10/25/2022]
Abstract
PURPOSE Muscle paralysis after spinal cord injury leads to muscle atrophy, enhanced muscle fatigue, and increased energy demands for functional activities. Phosphorus magnetic resonance spectroscopy ((31)P-MRS) offers a unique non-invasive alternative of measuring energy metabolism in skeletal muscle and is especially suitable for longitudinal investigations. We determined the impact of spinal cord contusion on in vivo muscle bioenergetics of the rat hind limb muscle using (31)P-MRS. METHODS A moderate spinal cord contusion injury (cSCI) was induced at the T8-T10 thoracic spinal segments. (31)P-MRS measurements were performed weekly in the rat hind limb muscles for 3 weeks. Spectra were acquired in a Bruker 11 T/470 MHz spectrometer using a 31P surface coil. The sciatic nerve was electrically stimulated by subcutaneous needle electrodes. Spectra were acquired at rest (5 min), during stimulation (6 min), and recovery (20 min). Phosphocreatine (PCr) depletion rates and the pseudo first-order rate constant for PCr recovery (k PCr) were determined. The maximal rate of PCr resynthesis, the in vivo maximum oxidative capacity (V max) and oxidative adenosine triphosphate (ATP) synthesis rate (Q max) were subsequently calculated. RESULTS One week after cSCI, there was a decline in the resting total creatine of the paralyzed muscle. There was a significant reduction (~24 %) in k PCr measures of the paralyzed muscle, maximum in vivo mitochondrial capacity (V max) and the maximum oxidative ATP synthesis rate (Q max) at 1 week post-cSCI. During exercise, the PCr depletion rates in the paralyzed muscle one week after injury were rapid and to a greater extent than in a healthy muscle. CONCLUSIONS Using in vivo MRS assessments, we reveal an acute oxidative metabolic defect in the paralyzed hind limb muscle. These altered muscle bioenergetics might contribute to the host of motor dysfunctions seen after cSCI.
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Influence of duty cycle on the power-duration relationship: observations and potential mechanisms. Respir Physiol Neurobiol 2013; 192:102-11. [PMID: 24361503 DOI: 10.1016/j.resp.2013.11.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 11/27/2013] [Accepted: 11/28/2013] [Indexed: 11/22/2022]
Abstract
The highest sustainable rate of aerobic metabolism [critical power (CP)] and the finite amount of work that can be performed above CP (W' [curvature constant]) were determined under two muscle contraction duty cycles. Eight men completed at least three constant-power handgrip tests to exhaustion to determine CP and W' for 50% and 20% duty cycles, while brachial artery blood flow (Q̇BA) and deoxygenated-[hemoglobin + myoglobin] (deoxy-[Hb+Mb]) were measured. CP was lower for the 50% duty cycle (3.9 ± 0.9 W) than the 20% duty cycle (5.1 ± 0.8 W; p < 0.001), while W' was not significantly different (50% duty cycle: 452 ± 141 J vs. 20% duty cycle: 432 ± 130 J; p > 0.05). At the same power output, Q̇BA and deoxy-[Hb + Mb] achieved higher end-exercise values for the 20% duty cycle (9.87 ± 1.73 ml·s(-1); 51.7 ± 4.7 μM) than the 50% duty cycle (7.37 ± 1.76 ml·s(-1), p < 0.001; 44.3 ± 2.4 μM, p < 0.03). These findings indicate that blood flow influences CP, but not W'.
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29
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Erickson ML, Ryan TE, Young HJ, McCully KK. Near-infrared assessments of skeletal muscle oxidative capacity in persons with spinal cord injury. Eur J Appl Physiol 2013; 113:2275-83. [PMID: 23703066 PMCID: PMC3754783 DOI: 10.1007/s00421-013-2657-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 04/30/2013] [Indexed: 01/25/2023]
Abstract
After spinal cord injury (SCI) skeletal muscle decreases in size, increases in intramuscular fat, and has potential declines in mitochondrial function. Reduced mitochondrial function has been linked to the development of metabolic disease. The aim of this study was to measure mitochondrial function in persons with SCI using near-infrared spectroscopy (NIRS). Oxygen consumption of the vastus lateralis muscle was measured with NIRS during repeated short-duration arterial occlusions in nine able-bodied (AB) and nine persons with motor complete SCI. Skeletal muscle oxidative capacity (V max) was evaluated with two approaches: (1) rate constant of the recovery of oxygen consumption after exercise and (2) extrapolated maximum oxygen consumption from a progressive work test. V max as indicated by the rate constant (k) from the recovery kinetics test was lower in SCI compared with AB participants (k: SCI 0.7 ± 0.3 vs. AB 1.9 ± 0.4 min(-1); p < 0.001). Time constants were SCI 91.9 ± 37.8 vs. AB 33.6 ± 8.3 s. V max from the progressive work test approached a significant difference between groups (SCI 5.1 ± 2.9 vs. AB 9.8 ± 5.5 % Hb-Mb/s; p = 0.06). NIRS measurements of V max suggest a deficit of 50-60 % in participants with SCI compared with AB controls, consistent with previous studies using (31)P-MRS and muscle biopsies. NIRS measurements can assess mitochondrial capacity in people with SCI and potentially other injured/diseased populations.
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30
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Layec G, Haseler LJ, Trinity JD, Hart CR, Liu X, Le Fur Y, Jeong EK, Richardson RS. Mitochondrial function and increased convective O2 transport: implications for the assessment of mitochondrial respiration in vivo. J Appl Physiol (1985) 2013; 115:803-11. [PMID: 23813526 DOI: 10.1152/japplphysiol.00257.2013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Although phosphorus magnetic resonance spectroscopy (31P-MRS)-based evidence suggests that in vivo peak mitochondrial respiration rate in young untrained adults is limited by the intrinsic mitochondrial capacity of ATP synthesis, it remains unknown whether a large, locally targeted increase in convective O2 delivery would alter this interpretation. Consequently, we examined the effect of superimposing reactive hyperemia (RH), induced by a period of brief ischemia during the last minute of exercise, on oxygen delivery and mitochondrial function in the calf muscle of nine young adults compared with free-flow conditions (FF). To this aim, we used an integrative experimental approach combining 31P-MRS, Doppler ultrasound imaging, and near-infrared spectroscopy. Limb blood flow [area under the curve (AUC), 1.4 ± 0.8 liters in FF and 2.5 ± 0.3 liters in RH, P < 0.01] and convective O2 delivery (AUC, 0.30 ± 0.16 liters in FF and 0.54 ± 0.05 liters in RH, P < 0.01), were significantly increased in RH compared with FF. RH was also associated with significantly higher capillary blood flow (P < 0.05) and faster tissue reoxygenation mean response times (70 ± 15 s in FF and 24 ± 15 s in RH, P < 0.05). This resulted in a 43% increase in estimated peak mitochondrial ATP synthesis rate (29 ± 13 mM/min in FF and 41 ± 14 mM/min in RH, P < 0.05) whereas the phosphocreatine (PCr) recovery time constant in RH was not significantly different (P = 0.22). This comprehensive assessment of local skeletal muscle O2 availability and utilization in untrained subjects reveals that mitochondrial function, assessed in vivo by 31P-MRS, is limited by convective O2 delivery rather than an intrinsic mitochondrial limitation.
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Affiliation(s)
- Gwenael Layec
- Department of Medicine, Division of Geriatrics, University of Utah, Salt Lake City, Utah
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31
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Jones AM, Krustrup P, Wilkerson DP, Berger NJ, Calbet JA, Bangsbo J. Influence of exercise intensity on skeletal muscle blood flow, O2 extraction and O2 uptake on-kinetics. J Physiol 2012; 590:4363-76. [PMID: 22711961 PMCID: PMC3473291 DOI: 10.1113/jphysiol.2012.233064] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Accepted: 06/15/2012] [Indexed: 11/08/2022] Open
Abstract
Following the start of low-intensity exercise in healthy humans, it has been established that the kinetics of skeletal muscle O(2) delivery is faster than, and does not limit, the kinetics of muscle O(2) uptake (V(O(2)(m))). Direct data are lacking, however, on the question of whether O(2) delivery might limit (V(O(2)(m))) kinetics during high-intensity exercise. Using multiple exercise transitions to enhance confidence in parameter estimation, we therefore investigated the kinetics of, and inter-relationships between, muscle blood flow (Q(m)), a-(V(O(2))) difference and (V(O(2)(m))) following the onset of low-intensity (LI) and high-intensity (HI) exercise. Seven healthy males completed four 6 min bouts of LI and four 6 min bouts of HI single-legged knee-extension exercise. Blood was frequently drawn from the femoral artery and vein during exercise and Q(m), a-(V(O(2))) difference and (V(O(2)(m))) were calculated and subsequently modelled using non-linear regression techniques. For LI, the fundamental component mean response time (MRT(p)) for Q(m) kinetics was significantly shorter than (V(O(2)(m))) kinetics (mean ± SEM, 18 ± 4 vs. 30 ± 4 s; P < 0.05), whereas for HI, the MRT(p) for Q(m) and (V(O(2)(m))) was not significantly different (27 ± 5 vs. 29 ± 4 s, respectively). There was no difference in the MRT(p) for either Q(m) or (V(O(2)(m))) between the two exercise intensities; however, the MRT(p)for a-(V(O(2)) difference was significantly shorter for HI compared with LI (17 ± 3 vs. 28 ± 4 s; P < 0.05). Excess O(2), i.e. oxygen not taken up (Q(m) x (V(O(2))), was significantly elevated within the first 5 s of exercise and remained unaltered thereafter, with no differences between LI and HI. These results indicate that bulk O(2) delivery does not limit (V(O(2)(m))) kinetics following the onset of LI or HI knee-extension exercise.
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Affiliation(s)
- Andrew M Jones
- Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Heavitree Road, Exeter, UK.
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32
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Abstract
Oral submucous fibrosis (OSMF) is a chronic inflammatory disease resulting in progressive juxtaepithelial fibrosis of the oral soft tissues and can cause increasing difficulty in mastication, swallowing, speaking, and mouth opening. The treatment of severe trismus requires a combination of surgical release and physiotherapy. Often physiotherapy alone can modify tissue remodeling in OSMF to increase oral opening. This article describes the fabrication and use of a new mouth-exercising device that helps the patient to squeeze/stretch the cheek mucosa to increase elasticity. The device can be used as a sole treatment modality or can be used in association with pharmacological and surgical treatment modalities for OSMF. Improvement in mouth opening was observed in four OSMF patients treated with a mouth-exercising device for 6 months as a sole treatment modality.
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Affiliation(s)
- Pravinkumar G Patil
- Department of Prosthodontics, Government Dental College and Hospital, Nagpur, India
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33
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Gurley K, Shang Y, Yu G. Noninvasive optical quantification of absolute blood flow, blood oxygenation, and oxygen consumption rate in exercising skeletal muscle. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:075010. [PMID: 22894482 PMCID: PMC3395077 DOI: 10.1117/1.jbo.17.7.075010] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 06/11/2012] [Accepted: 06/13/2012] [Indexed: 05/19/2023]
Abstract
This study investigates a method using novel hybrid diffuse optical spectroscopies [near-infrared spectroscopy (NIRS) and diffuse correlation spectroscopy (DCS)] to obtain continuous, noninvasive measurement of absolute blood flow (BF), blood oxygenation, and oxygen consumption rate (V̇O(2)) in exercising skeletal muscle. Healthy subjects (n=9) performed a handgrip exercise to increase BF and V̇O(2) in forearm flexor muscles, while a hybrid optical probe on the skin surface directly monitored oxy-, deoxy-, and total hemoglobin concentrations ([HbO(2)], [Hb], and THC), tissue oxygen saturation (S(t)O(2)), relative BF (rBF), and relative oxygen consumption rate (rV̇O(2)). The rBF and rV̇O(2) signals were calibrated with absolute baseline BF and V̇O(2) obtained through venous and arterial occlusions, respectively. Known problems with muscle-fiber motion artifacts in optical measurements during exercise were mitigated using a novel gating algorithm that determined muscle contraction status based on control signals from a dynamometer. Results were consistent with previous findings in the literature. This study supports the application of NIRS/DCS technology to quantitatively evaluate hemodynamic and metabolic parameters in exercising skeletal muscle and holds promise for improving diagnosis and treatment evaluation for patients suffering from diseases affecting skeletal muscle and advancing fundamental understanding of muscle and exercise physiology.
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Affiliation(s)
- Katelyn Gurley
- University of Kentucky, Center for Biomedical Engineering, Lexington, Kentucky 40506
| | - Yu Shang
- University of Kentucky, Center for Biomedical Engineering, Lexington, Kentucky 40506
| | - Guoqiang Yu
- University of Kentucky, Center for Biomedical Engineering, Lexington, Kentucky 40506
- Address all correspondence to: Guoqiang Yu, University of Kentucky, Center for Biomedical Engineering, 204 Wenner-Gren Research Lab, 600 Rose Street, Lexington, Kentucky 40506-0070. Tel: +859 257 9110; Fax: 859 257 1856; E-mail:
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Emhoff CAW, Barrett-O’Keefe Z, Padgett RC, Hawn JA, Halliwill JR. Histamine-receptor blockade reduces blood flow but not muscle glucose uptake during postexercise recovery in humans. Exp Physiol 2011; 96:664-73. [DOI: 10.1113/expphysiol.2010.056150] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Faisal A, Dyson KS, Hughson RL. Prolonged ischaemia impairs muscle blood flow and oxygen uptake dynamics during subsequent heavy exercise. J Physiol 2011; 588:3785-97. [PMID: 20679356 DOI: 10.1113/jphysiol.2010.188698] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Muscle oxygen uptake ( ˙VO₂,mus) dynamics at the onset of exercise can be affected by prior heavy exercise.We tested the hypothesis that elevated forearm blood flow (FBF) following prior circulatory occlusion would also be associated with accelerated ˙VO₂,mus dynamics during subsequent heavy hand-grip exercise. Ten trained young men performed 5 min of heavy hand-grip exercise at 30% MVC as a control (CON), and four additional heavy bouts after brief recovery from: (1) prior heavy exercise (Heavy A), (2) heavy exercise followed by 2 min occlusion (Heavy B), (3) 15 min occlusion (Heavy C), and (4) 5 min occlusion with 1 min of moderate exercise during occlusion (Heavy D). FBF was measured by ultrasound and arterial venous oxygen content difference was calculated from venous blood samples to estimate ˙VO₂,mus. FBF and ˙VO₂,mus dynamics were quantified from the rise time. All priming conditions elevated FBF immediately before the start of subsequent heavy bout (Heavy A: 207.4 ±92.8, B: 207.8±75.8, C: 135.8±59.2, D: 199.5±59.0 vs. CON: 57.4±16.6mlmin−1, P <0.01). Unexpectedly, prior occlusion reduced FBF and O2 extraction at the onset of subsequent heavy exercise and consequently slowed ˙VO₂,mus dynamics (Heavy C: rise time=95.9±28.9 vs. CON: 58.6±14.3 s, P <0.01). FBF and ˙VO₂,mus dynamics were faster in Heavy A, B and D compared to CON (P <0.05). Overall, there was a positive correlation between the rise times for ˙VO₂,mus and FBF (r² =0.75) indicating that ˙VO₂,mus dynamics during heavy forearm exercise are linked to O₂ delivery in trained young men. To investigate a possible mechanism for slower adaptation of ˙VO₂,mus following ischaemia, the prior occlusion condition was repeated after ingesting a high dose of ibuprofen. This resulted in restoration of the FBF and ˙VO₂,mus to control levels suggesting that a prostaglandin-mediated mechanism after occlusion retarded the adaptation of blood flow and oxygen consumption at the onset of subsequent heavy exercise.
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Affiliation(s)
- Azmy Faisal
- Faculty of Applied Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
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36
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Wiltshire EV, Poitras V, Pak M, Hong T, Rayner J, Tschakovsky ME. Massage impairs postexercise muscle blood flow and "lactic acid" removal. Med Sci Sports Exerc 2010; 42:1062-71. [PMID: 19997015 DOI: 10.1249/mss.0b013e3181c9214f] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This study tested the hypothesis that one of the ways sports massage aids muscle recovery from exercise is by increasing muscle blood flow to improve "lactic acid" removal. METHODS Twelve subjects performed 2 min of strenuous isometric handgrip (IHG) exercise at 40% maximum voluntary contraction to elevate forearm muscle lactic acid. Forearm blood flow (FBF; Doppler and Echo ultrasound of the brachial artery) and deep venous forearm blood lactate and H+ concentration ([La-], [H+]) were measured every minute for 10 min post-IHG under three conditions: passive (passive rest), active (rhythmic exercise at 10% maximum voluntary contraction), and massage (effleurage and pétrissage). Arterialized [La-] and [H+] from a superficial heated hand vein was measured at baseline. RESULTS Data are presented as mean +/- SE. Venoarterial [La-] difference ([La-]v-a) at 30 s of post-IHG was the same across conditions (passive = 6.1 +/- 0.6 mmol x L(-1), active = 5.7 +/- 0.6 mmol x L(-1), massage = 5.5 +/- 0.6 mmol x L(-1), NS), whereas FBF was greater in passive (766 +/- 101 mL x min(-1)) versus active (614 +/- 62 mL x min(-1), P = 0.003) versus massage (540 +/- 60 mL x min(-1), P < 0.0001). Total FBF area under the curve (AUC) for 10 min after handgrip was significantly higher in passive versus massage (4203 +/- 531 vs 3178 +/- 304 mL, P = 0.024) but not versus active (3584 +/- 284 mL, P = 0.217). La(-)- efflux (FBF x [La-]v-a) AUC mirrored FBF AUC (passive = 20.5 +/- 2.8 mmol vs massage = 14.7 +/- 1.6 mmol, P = 0.03, vs active = 15.4 +/- 1.9 mmol, P = 0.064). H+ efflux (FBF x [H+]v-a) was greater in passive versus massage at 30 s (2.2 +/- 0.4e(-5) vs 1.3 +/- 0.2e(-5) mmol, P < 0.001) and 1.5 min (1.0 +/- 0.2e(-5) vs 0.6 +/- 0.09e(-5) mmol, P = 0.003) after IHG. CONCLUSIONS Massage impairs La(-) and H+ removal from muscle after strenuous exercise by mechanically impeding blood flow.
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Affiliation(s)
- E Victoria Wiltshire
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
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The effect of recovery time on strength performance following a high-intensity bench press workout in males and females. Int J Sports Physiol Perform 2010; 5:184-96. [PMID: 20625191 DOI: 10.1123/ijspp.5.2.184] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
PURPOSE To determine the effects of training sessions, involving high-resistance, low-repetition bench press exercise, on strength recovery patterns, as a function of gender and training background. METHODS The subjects were 12 athletes (6 males and 6 females) and age-matched college students of both genders (4 males and 4 females). The subjects completed a 3-wk resistance training program involving a bench press exercise, 3 d/wk, to become familiar with the testing procedure. After the completion of the resistance training program, the subjects, on three consecutive weeks, participated in two testing sessions per week, baseline session and recovery session. During the testing sessions, subjects performed five sets of the bench press exercise at 50% to 100% of perceived five repetition maximum (5-RM). Following the weekly baseline sessions, subjects rested during a 4-, 24-, or 48-h recovery period. Strength measurements were estimates of one repetition maximum (1-RM), using equivalent percentages for the number of repetitions completed by the subject at the perceived 5-RM effort of the bench press exercise. RESULTS The full-factorial ANOVA model revealed a Gender by Recovery Period by Testing Session interaction effect, F(2, 32) = 10.65; P < .05. Among male subjects, decreases in estimated 1-RM were detected at the 4- and 24-h recovery times. There were no differences in muscle strength among the female subjects, regardless of recovery time. CONCLUSIONS For bench press exercises, using different recovery times of 48 h for males and 4 h for females may optimize strength development as a function of gender.
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Sarelius I, Pohl U. Control of muscle blood flow during exercise: local factors and integrative mechanisms. Acta Physiol (Oxf) 2010; 199:349-65. [PMID: 20353492 DOI: 10.1111/j.1748-1716.2010.02129.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Understanding the control mechanisms of blood flow within the vasculature of skeletal muscle is clearly fascinating from a theoretical point of view due to the extremely tight coupling of tissue oxygen demands and blood flow. It also has practical implications as impairment of muscle blood flow and its prevention/reversal by exercise training has a major impact on widespread diseases such as hypertension and diabetes. Here we analyse the role of mediators generated by skeletal muscle activity on smooth muscle relaxation in resistance vessels in vitro and in vivo. We summarize their cellular mechanisms of action and their relative roles in exercise hyperaemia with regard to early and late responses. We also discuss the consequences of interactions among mediators with regard to identifying their functional significance. We focus on (potential) mechanisms integrating the action of the mediators and their effects among the cells of the intact arteriolar wall. This integration occurs both locally, partly due to myoendothelial communication, and axially along the vascular tree, thus enabling the local responses to be manifest along an entire functional vessel path. Though the concept of signal integration is intriguing, its specific role on the control of exercise hyperaemia and the consequences of its modulation under physiological and pathophysiological conditions still await additional analysis.
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Affiliation(s)
- I Sarelius
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, USA
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Plasma ATP concentration and venous oxygen content in the forearm during dynamic handgrip exercise. BMC PHYSIOLOGY 2009; 9:24. [PMID: 20003530 PMCID: PMC2801472 DOI: 10.1186/1472-6793-9-24] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Accepted: 12/15/2009] [Indexed: 11/30/2022]
Abstract
Background It has been proposed that adenosine triphosphate (ATP) released from red blood cells (RBCs) may contribute to the tight coupling between blood flow and oxygen demand in contracting skeletal muscle. To determine whether ATP may contribute to the vasodilatory response to exercise in the forearm, we measured arterialised and venous plasma ATP concentration and venous oxygen content in 10 healthy young males at rest, and at 30 and 180 seconds during dynamic handgrip exercise at 45% of maximum voluntary contraction (MVC). Results Venous plasma ATP concentration was elevated above rest after 30 seconds of exercise (P < 0.05), and remained at this higher level 180 seconds into exercise (P < 0.05 versus rest). The increase in ATP was mirrored by a decrease in venous oxygen content. While there was no significant relationship between ATP concentration and venous oxygen content at 30 seconds of exercise, they were moderately and inversely correlated at 180 seconds of exercise (r = -0.651, P = 0.021). Arterial ATP concentration remained unchanged throughout exercise, resulting in an increase in the venous-arterial ATP difference. Conclusions Collectively these results indicate that ATP in the plasma originated from the muscle microcirculation, and are consistent with the notion that deoxygenation of the blood perfusing the muscle acts as a stimulus for ATP release. That ATP concentration was elevated just 30 seconds after the onset of exercise also suggests that ATP may be a contributing factor to the blood flow response in the transition from rest to steady state exercise.
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Aging impacts microvascular oxygen pressures during recovery from contractions in rat skeletal muscle. Respir Physiol Neurobiol 2009; 169:315-22. [PMID: 19833236 DOI: 10.1016/j.resp.2009.10.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Revised: 09/28/2009] [Accepted: 10/06/2009] [Indexed: 11/20/2022]
Abstract
Aging-induced alterations in peripheral circulatory control during contractions reduce the microvascular partial pressure of O(2) (P(O)(2)mv; which reflects the dynamic balance in the O(2) delivery-to-O(2) uptake ratio), resulting in exaggerated intramuscular metabolic disturbances and premature fatigue. However, the extent to which this altered P(O)(2)mv during contractions is associated with prolongated muscle metabolic recovery is not known. We tested the hypothesis that the aging-induced speeding of the P(O)(2)mv on-kinetics would presage slowed P(O)(2)mv off-kinetics. The spinotrapezius muscle was exposed in six young (6-8 months) and seven old (26-28 months) male Fischer 344xBrown Norway F1-hybrid rats. The P(O)(2)mv kinetic profile was measured via phosphorescence quenching at rest, during electrically stimulated contractions (1Hz, 7-9V, 2ms pulse duration, 180s), and throughout recovery (180s). Aged rats which evidenced faster P(O)(2)mv on-kinetics (reduced mean response time (MRTon), young: 27.3+/-3.6s, old: 19.2+/-1.6s; P<0.05) exhibited markedly slowed P(O)(2)mv off-kinetics (increased MRToff, young: 46.5+/-5.9s, old: 84.8+/-7.9s; P<0.05). Accordingly, a greater degree of P(O)(2)mv on-off asymmetry (MRToff-MRTon) in the aged muscle was observed (young: 19.1+/-4.5s, old: 65.6+/-8.6s; P<0.01). We conclude that aging-induced speeding of the P(O)(2)mv on-kinetics does indeed presage a slowed P(O)(2)mv off-kinetics, which likely compromises muscle metabolic recovery and may reduce subsequent contractile performance. Moreover, the greater degree of P(O)(2)mv on-off asymmetry in the aged muscle suggests a mechanistic link between impaired microvascular oxygenation and altered muscle metabolic responses during exercise transitions.
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Padilla J, Harris RA, Rink LD, Wallace JP. Characterization of the brachial artery shear stress following walking exercise. Vasc Med 2008; 13:105-11. [PMID: 18593799 DOI: 10.1177/1358863x07086671] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Habitual exercise provides repeated episodes of elevated vascular shear stress (SS), which may be a mechanism for repair of endothelial dysfunction in disease. Our aim was to determine the brachial artery SS during the 3-hour period following single bouts of low, moderate, and high-intensity walking exercise. In a randomized crossover design, 14 men walked for 45 minutes on a treadmill at 25%, 50% and 75% of VO2peak separated by 2-7 days. Using Doppler ultrasonography, brachial artery SS was assessed immediately after exercise and then hourly for 3 hours. High-intensity walking elicited greater (p<0.05) post-exercise SS compared with low and moderate intensity. In addition, a 3x4 (intensity x time) ANOVA indicated an absence of interaction (p=0.369) and a decline in post-exercise SS over time (p<0.0001) which was abolished after 2 hours. Thus, we found that brachial artery SS is greatest following high-intensity walking and that the rate of decline in SS is similar across all walking intensities.
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Affiliation(s)
- Jaume Padilla
- Clinical Exercise Physiology Laboratory, Department of Kinesiology, Indiana University, Bloomington, IN 47405, USA.
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Hazell TJ, Thomas GWR, DeGuire JR, Lemon PWR. Vertical whole-body vibration does not increase cardiovascular stress to static semi-squat exercise. Eur J Appl Physiol 2008; 104:903-8. [DOI: 10.1007/s00421-008-0847-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/25/2008] [Indexed: 11/24/2022]
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Kubo K, Ikebukuro T, Tsunoda N, Kanehisa H. Changes in oxygen consumption of human muscle and tendon following repeat muscle contractions. Eur J Appl Physiol 2008; 104:859-66. [DOI: 10.1007/s00421-008-0841-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/25/2008] [Indexed: 10/21/2022]
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Harper AJ, Ferreira LF, Lutjemeier BJ, Townsend DK, Barstow TJ. Matching of blood flow to metabolic rate during recovery from moderate exercise in humans. Exp Physiol 2008; 93:1118-25. [PMID: 18515470 DOI: 10.1113/expphysiol.2008.042895] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
It is unclear whether measurement of limb or conduit artery blood flow during recovery from exercise provides an accurate representation of flow to the muscle capillaries where gas exchange occurs. To investigate this, we: (a) examined the kinetic responses of femoral artery blood flow (QFA), estimated muscle capillary blood flow (Qcap) and estimated muscle oxygen uptake (VO2m) following cessation of exercise; and (b) compared these responses to verify the adequacy of O2 delivery during recovery. Pulmonary VO2 (VO2p) was measured breath by breath, QFA was measured using Doppler ultrasonography, and deoxy-haemoglobin/myoglobin (deoxy-[Hb/Mb]) was estimated by near-infrared spectroscopy over the rectus femoris in nine healthy subjects during a series of transitions from moderate knee-extension exercise to rest. The time course of Qcap was estimated by rearranging the Fick equation [i.e. Qcap(t) alpha VO2m(t)/deoxy-[Hb/Mb](t)], using the primary component of Vo2p to represent VO2m and deoxy-[Hb/Mb] as a surrogate for arteriovenous O2 difference. There were no significant differences among the overall kinetics of VO2m (tau, 31.4+/-8.2 s), QFA [mean response time (MRT), 34.5+/-20.4 s] and Qcap (MRT, 31.7+/-14.7 s). The VO2m kinetics were also significantly correlated (P<0.05) with those of both QFA and Qcap. Both QFA and Qcap appear to be coupled with VO2m during recovery from moderate knee-extension exercise, such that extraction falls (thus cellular energetic state is not further compromised) throughout recovery.
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Affiliation(s)
- Allison J Harper
- Department of Kinesiology, 1A Natatorium, Kansas State University, Manhattan, KA 66506-0302, USA
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Ooue A, Ichinose TK, Inoue Y, Nishiyasu T, Koga S, Kondo N. Changes in blood flow in conduit artery and veins of the upper arm during leg exercise in humans. Eur J Appl Physiol 2008; 103:367-73. [DOI: 10.1007/s00421-008-0706-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2008] [Indexed: 10/22/2022]
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Silvestre R, Kraemer WJ, Quann EE, Seip RL, Maresh CM, Vingren JL, Hatfield DL, Volek JS. Effects of exercise at different times on postprandial lipemia and endothelial function. Med Sci Sports Exerc 2008; 40:264-74. [PMID: 18202576 DOI: 10.1249/mss.0b013e31815c485a] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE The purpose of this study was to examine the effects of previous exercise on metabolic, hormonal, and endothelial responses to an oral fat-tolerance test (OFTT). METHODS Twelve healthy, recreationally trained men (age = 22.3 +/- 2.5 yr, weight = 80.7 +/- 12.4 kg, BMI = 25.1 +/- 3.1 kg.m(-2)) volunteered for this study. In a crossover fashion, subjects completed three OFTT trials that involved no exercise (NoEx) or exercise performed 16 h (EX-16) or 4 h (EX-4) before the ingestion of a meal (13 kcal.kg(-1) and 1.4 g of fat per kilogram of body weight). Blood was collected before and after the meal and hourly for 6 h. Brachial artery reactivity was measured using ultrasound before and at 2, 4, and 6 h after the meal. Dietary intake and exercise were standardized 4 d before the OFTT. The exercise session consisted of six resistance exercises and 30 min of running on a treadmill. The washout period between trials was, on average, 5 d. RESULTS Compared with NoEx, there were significant (P < 0.05) decreases in triglyceride area under the curve (AUC) during EX-16 (-26%) and EX-4 (-15%). Compared with NoEx, there were decreases in insulin AUC during EX-16 (-7%, P < 0.05) and EX-4 (-5%, NS). EX-4 resulted in a significantly larger fasting arterial diameter than EX-16 and NoEx, but there were no other significant effects on endothelial function. Lipemic variables did not show correlations with endothelium function for any of the trials. CONCLUSION An acute exercise session, regardless of the time point chosen (i.e., EX-16 or EX-4), reduced to a similar extent the total and incremental lipemic responses compared with the NoEx condition.
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Affiliation(s)
- Ricardo Silvestre
- Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
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Dupont G, Moalla W, Matran R, Berthoin S. Effect of short recovery intensities on the performance during two Wingate tests. Med Sci Sports Exerc 2007; 39:1170-6. [PMID: 17596786 DOI: 10.1249/mss.0b013e31804c9976] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE To assess the effects of the intensity of short recoveries on performance by a Wingate test and on the deoxyhemoglobin variations. METHODS Twelve male subjects performed a graded test and three sessions of repeated all-out tests with different recovery natures. The repeated all-out tests included two sprints: a 15-s Wingate test followed by a 30-s Wingate test. The recovery between the two was 15 s in duration and was either passive, active at 20% of maximal aerobic power, or active at 40% of maximal aerobic power. Changes in deoxyhemoglobin were measured using by the near-infrared spectroscopy technique. RESULTS Mean power (517 +/- 26 W) and peak power (1085 +/- 153 W) of the 30-s Wingate test performed after passive recovery were significantly higher (P < 0.05) than mean power and peak power performed after active recovery at 20% (484 +/- 30 and 973 +/- 112 W, respectively) and 40% of maximal aerobic power (492 +/- 35 and 928 +/- 116 W, respectively). Deoxyhemoglobin variations were significantly higher (P < 0.05) during the passive recovery (12.8 +/- 5.3 microM) than during the active recovery conditions at 20% (4.3 +/- 2.6 microM) and 40% of maximal aerobic power (3.9 +/- 2.6 microM). CONCLUSION These results demonstrate that when two Wingate tests are performed almost successively but with a short recovery between the two, passive recovery is more appropriate than active recovery to restore the performance level.
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Affiliation(s)
- Gregory Dupont
- Laboratory of Human Movement Studies, EA 3608, Lille 2 University, France.
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Burnley M, Doust JH, Jones AM. Time required for the restoration of normal heavy exercise VO2 kinetics following prior heavy exercise. J Appl Physiol (1985) 2006; 101:1320-7. [PMID: 16857864 DOI: 10.1152/japplphysiol.00475.2006] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Prior heavy exercise markedly alters the O2 uptake (VO2) response to subsequent heavy exercise. However, the time required for VO2 to return to its normal profile following prior heavy exercise is not known. Therefore, we examined the VO2 responses to repeated bouts of heavy exercise separated by five different recovery durations. On separate occasions, nine male subjects completed two 6-min bouts of heavy cycle exercise separated by 10, 20, 30, 45, or 60 min of passive recovery. The second-by-second VO2 responses were modeled using nonlinear regression. Prior heavy exercise had no effect on the primary VO2 time constant (from 25.9 +/- 4.7 s to 23.9 +/- 8.8 s after 10 min of recovery; P = 0.338), but it increased the primary VO2 amplitude (from 2.42 +/- 0.39 to 2.53 +/- 0.41 l/min after 10 min of recovery; P = 0.001) and reduced the VO2 slow component (from 0.44 +/- 0.13 to 0.21 +/- 0.12 l/min after 10 min of recovery; P < 0.001). The increased primary amplitude was also evident after 20-45 min, but not after 60 min, of recovery. The increase in the primary VO2 amplitude was accompanied by an increased baseline blood lactate concentration (to 5.1 +/- 1.0 mM after 10 min of recovery; P < 0.001). Baseline blood lactate concentration was still elevated after 20-60 min of recovery. The priming effect of prior heavy exercise on the VO2 response persists for at least 45 min, although the mechanism underpinning the effect remains obscure.
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Affiliation(s)
- Mark Burnley
- Department of Sport and Exercise Science, University of Wales, Aberystwyth, Aberystwyth, Ceredigion SY23 3FD, UK.
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Walther G, Nottin S, Dauzat M, Obert P. Femoral and Axillary Ultrasound Blood Flow during Exercise. Med Sci Sports Exerc 2006; 38:1353-61. [PMID: 16826035 DOI: 10.1249/01.mss.0000227323.69588.f4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE To use Doppler ultrasound 1) to assess the relationship between exercise intensity and changes in femoral and axillary artery diameter, 2) to determine whether volume blood flow (BF) measured during early recovery accurately reflects exercise BF, and 3) to assess the influence of artery caliber and/or site as well as exercise intensity on BF measurement reproducibility. METHODS Thirteen healthy subjects (mean age 25.9+/-7.7 yr) performed progressive and maximal leg-extension (LE) and elbow-flexion (EF) exercises in the supine position. The duration of each stage was 150 s, followed by a 30-s recovery period. Arterial diameter and blood flow velocity were recorded simultaneously and continuously during the last 30 s of exercise as well as 30 s into recovery. RESULTS Arterial dilation was 3.5 and 6.5% at maximal effort in femoral and axillary arteries, respectively. A significant increase was observed for both arteries from workload 2 to peak exercise when arterial cross-sectional area was calculated. Blood flow velocity during the recovery period was significantly different from end-exercise values, depending on time and workload. The coefficients of variation of BF measurement during exercise were 7.1-12.1% and 6.4-9.5% in LE and EF, respectively. CONCLUSION This study showed that BF measurement with Doppler ultrasound during exercise is reproducible but requires measurement of arterial diameter at each workload. Measurements performed immediately after exercise cannot be used as a surrogate for blood flow velocity during exercise.
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Affiliation(s)
- Guillaume Walther
- Laboratory of Cardiovascular Adaptations to Exercise, Faculty of Sciences, Avignon, France
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Nioka S, Kime R, Sunar U, Im J, Izzetoglu M, Zhang J, Alacam B, Chance B. A novel method to measure regional muscle blood flow continuously using NIRS kinetics information. DYNAMIC MEDICINE : DM 2006; 5:5. [PMID: 16704736 PMCID: PMC1540409 DOI: 10.1186/1476-5918-5-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2005] [Accepted: 05/16/2006] [Indexed: 11/25/2022]
Abstract
BACKGROUND This article introduces a novel method to continuously monitor regional muscle blood flow by using Near Infrared Spectroscopy (NIRS). We demonstrate the feasibility of the new method in two ways: (1) by applying this new method of determining blood flow to experimental NIRS data during exercise and ischemia; and, (2) by simulating muscle oxygenation and blood flow values using these newly developed equations during recovery from exercise and ischemia. METHODS Deoxy (Hb) and oxyhemoglobin (HbO2), located in the blood of the skeletal muscle, carry two internal relationships between blood flow and oxygen consumption. One is a mass transfer principle and the other describes a relationship between oxygen consumption and Hb kinetics in a two-compartment model. To monitor blood flow continuously, we transfer these two relationships into two equations and calculate the blood flow with the differential information of HbO2 and Hb. In addition, these equations are used to simulate the relationship between blood flow and reoxygenation kinetics after cuff ischemia and a light exercise. Nine healthy subjects volunteered for the cuff ischemia, light arm exercise and arm exercise with cuff ischemia for the experimental study. RESULTS Analysis of experimental data of both cuff ischemia and light exercise using the new equations show greater blood flow (four to six times more than resting values) during recovery, agreeing with previous findings. Further, the simulation and experimental studies of cuff ischemia and light exercise agree with each other. CONCLUSION We demonstrate the accuracy of this new method by showing that the blood flow obtained from the method agrees with previous data as well as with simulated data. We conclude that this novel continuous blood flow monitoring method can provide blood flow information non-invasively with NIRS.
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Affiliation(s)
- Shoko Nioka
- Department of Biochemistry and Biophysics, Medical School of University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ryotaro Kime
- Department of Biochemistry and Biophysics, Medical School of University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ulas Sunar
- Department of Biochemistry and Biophysics, Medical School of University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joohee Im
- Department of Biochemistry and Biophysics, Medical School of University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Meltem Izzetoglu
- Department of Biochemistry and Biophysics, Medical School of University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jun Zhang
- Department of Biochemistry and Biophysics, Medical School of University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Burak Alacam
- Department of Biochemistry and Biophysics, Medical School of University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Britton Chance
- Department of Biochemistry and Biophysics, Medical School of University of Pennsylvania, Philadelphia, PA 19104, USA
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