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Hogwood AC, Decker KP, Darling AM, Weggen JB, Chiu A, Richardson J, Garten RS. Exaggerated pressor responses, but unaltered blood flow regulation and functional sympatholysis during lower limb exercise in young, non-Hispanic black males. Microvasc Res 2023; 145:104445. [PMID: 36209773 DOI: 10.1016/j.mvr.2022.104445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 10/03/2022] [Accepted: 10/03/2022] [Indexed: 11/05/2022]
Abstract
PURPOSE Young non-Hispanic black (BL) males have displayed lower blood flow (BF) and vascular conductance (VC), but intact functional sympatholysis, during upper limb exercise when compared to non-Hispanic white (WH) males. This study sought to explore if similar differences were also present in the lower limbs. METHODS Thirteen young BL males and thirteen WH males completed one visit comprised of rhythmic lower limb (plantar flexion) exercise as well as upper limb (handgrip) exercise for a limb-specific comparison. Limb BF, mean arterial pressure (MAP), and VC were evaluated at three submaximal workloads (8, 16, and 24 kg). To determine potential limb differences in functional sympatholysis, the impact of sympathetic nervous system activation (via cold-pressor test (CPT)) was evaluated at rest and during steady state exercise (30 % of maximal voluntary contraction) on a subsequent visit. RESULTS MAP responses to lower and upper limb exercise were elevated in young BL males (vs WH males), resulting in significantly lower VC responses in the upper limb, but not the lower limb. Further, BL males, when compared to WH males, revealed no differences in functional sympatholysis, evident by similar responses in both the exercising leg and arm VC during CPT. CONCLUSION The findings of the current study indicate that although elevated MAP responses were observed during both lower and upper limb exercise in young BL males, vascular conductance was only hindered in the upper limbs. This may potentially highlight enhanced compensatory mechanisms in the lower limb (vs upper limb) to maintain perfusion in young BL males.
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Affiliation(s)
- Austin C Hogwood
- Department of Kinesiology, University of Virginia, Charlottesville, VA, USA
| | - Kevin P Decker
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA
| | - Ashley M Darling
- Department of Kinesiology, University of Texas at Arlington, Arlington, TX, USA
| | - Jennifer B Weggen
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Alex Chiu
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Jacob Richardson
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Ryan S Garten
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA.
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2
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Usaj A, Kapus J, Štrumbelj B, Debevec T, Vodičar J. Effects of Moderate Altitude Training Combined with Moderate or High-altitude Residence. Int J Sports Med 2022; 43:1129-1136. [PMID: 35926513 DOI: 10.1055/a-1885-4053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
We aimed to identify potential physiological and performance differences of trained cross-country skiers (V˙o2max=60±4 ml ∙ kg-1 ∙ min-1) following two, 3-week long altitude modalities: 1) training at moderate altitudes (600-1700 m) and living at 1500 m (LMTM;N=8); and 2) training at moderate altitudes (600-1700 m) and living at 1500 m with additional nocturnal normobaric hypoxic exposures (FiO2 =0.17;LHTM; N=8). All participants conducted the same training throughout the altitude training phase and underwent maximal roller ski trials and submaximal cyclo-ergometery before, during and one week after the training camps. No exercise performance or hematological differences were observed between the two modalities. The average roller ski velocities were increased one week after the training camps following both LMTM (p=0.03) and LHTM (p=0.04) with no difference between the two (p=0.68). During the submaximal test, LMTM increased the Tissue Oxygenation Index (11.5±6.5 to 1.0±8.5%; p=0.04), decreased the total hemoglobin concentration (15.1±6.5 to 1.7±12.9 a.u.;p=0.02), and increased blood pH (7.36±0.03 to 7.39±0.03;p=0.03). On the other hand, LHTM augmented minute ventilation (76±14 to 88±10 l·min-1;p=0.04) and systemic blood oxygen saturation by 2±1%; (p=0.02) with no such differences observed following the LMTM. Collectively, despite minor physiological differences observed between the two tested altitude training modalities both induced comparable exercise performance modulation.
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Affiliation(s)
- Anton Usaj
- Laboratory of Biodynamics, Faculty of Sport, University of Ljubljana, Slovenia
| | - Jernej Kapus
- Laboratory of Biodynamics, Faculty of Sport, University of Ljubljana, Slovenia
| | - Boro Štrumbelj
- Laboratory of Biodynamics, Faculty of Sport, University of Ljubljana, Slovenia
| | - Tadej Debevec
- Laboratory of Biodynamics, Faculty of Sport, University of Ljubljana, Slovenia.,Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Janez Vodičar
- Institute of Sport, Faculty of Sport, University of Ljubljana, Slovenia
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3
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Vezer M, Demeter Á, Szekeres M, Jósvai A, Bányai B, Oláh A, Balogh F, Horváth EM, Radovits T, Merkely B, Ács N, Nádasy GL, Török M, Várbiró S. Sex differences in rat renal arterial responses following exercise training. Am J Physiol Heart Circ Physiol 2022; 322:H310-H318. [PMID: 34995166 DOI: 10.1152/ajpheart.00398.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During aerobic exercise, hemodynamic alterations occure; while blood flow in skeletal muscle arteries increases, it decreases in visceral vessels due to mesenterial vasoconstriction. However, maintaining renal blood flow during intensive sport is also a priority. Our aim was to investigate the changes of vascular reactivity and histology of isolated renal artery of male and female rats in response to swim-training. Wistar rats were distributed into four groups: male sedentary (MSed), male trained (MTr), female sedentary (FSed), and female trained (FTr). Trained animals underwent a 12-week-long intensive swimming program. Vascular function of isolated renal artery segments was examined by wire myography. Phenylephrine-induced contraction was lower in FSed compared to MSed animals, and it was decreased by training in male but not in female animals. Inhibition of cyclooxygenases by indomethacin reduced contraction in both sedentary groups, and in MTr but not in FTr animals. Inhibition of nitric oxide production increased contraction in both trained groups. Acetylcholine induced relaxation was similar in all experimental groups showing predominant NO-dependency. Elastin and smooth muscle cell actin density was reduced in female rats after aerobic training. This study shows that, as a result of 12-weeks-long training, there are sex differences in renal arterial responses following exercise training. Swimming moderates renal artery vasoconstriction in male animals, while it depresses elastic fiber and smooth muscle actin density in females.
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Affiliation(s)
- Marton Vezer
- Department of Obstetrics and Gynaecology, Semmelweis University, Budapest, Hungary.,Department of Physiology, Semmelweis University, Budapest, Hungary
| | - Ágota Demeter
- Department of Physiology, Semmelweis University, Budapest, Hungary
| | - Maria Szekeres
- Department of Physiology, Semmelweis University, Budapest, Hungary.,Department of Morphology and Physiology, Faculty of Health Sciences, Semmelweis University, Hungary
| | - Attila Jósvai
- Department of Neurosurgery, Military Hospital, Budapest, Hungary
| | - Bálint Bányai
- Department of Physiology, Semmelweis University, Budapest, Hungary
| | - Attila Oláh
- Heart and Vascular Centre, Semmelweis University, Budapest, Hungary
| | - Fruzsina Balogh
- Faculty of Electrical Engineering and Informatics, Technical University Budapest, Budapest, Hungary
| | - Eszter M Horváth
- Department of Physiology, Semmelweis University, Budapest, Hungary
| | - Tamás Radovits
- Heart and Vascular Centre, Semmelweis University, Budapest, Hungary
| | - Béla Merkely
- Heart and Vascular Centre, Semmelweis University, Budapest, Hungary
| | - Nándor Ács
- Department of Obstetrics and Gynaecology, Semmelweis University, Budapest, Hungary
| | - György L Nádasy
- Department of Physiology, Semmelweis University, Budapest, Hungary
| | - Marianna Török
- Department of Obstetrics and Gynaecology, Semmelweis University, Budapest, Hungary.,Workgroup for Science Management, Doctoral School, Semmelweis University, Budapest, Hungary
| | - Szabolcs Várbiró
- Department of Obstetrics and Gynaecology, Semmelweis University, Budapest, Hungary.,Workgroup for Science Management, Doctoral School, Semmelweis University, Budapest, Hungary
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4
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Gliemann L, Rytter N, Yujia L, Tamariz-Ellemann A, Carter H, Hellsten Y. A High Activity Level Is Required for Augmented Muscle Capillarization in Older Women. Med Sci Sports Exerc 2021; 53:894-903. [PMID: 33844669 DOI: 10.1249/mss.0000000000002566] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This study aimed to evaluate the influence of lifelong regular physical activity on skeletal muscle capillarization in women. METHODS Postmenopausal women, 61±4 yr old, were divided according to self-reported physical activity level over the past 20 yrs: sedentary (SED; n = 14), moderately active (MOD; n = 12), and very active (VERY; n = 15). Leg blood flow (LBF) was determined by ultrasound Doppler, and blood samples were drawn from the femoral artery and vein for calculation of leg oxygen uptake (LVO2) at rest and during one-legged knee extensor exercise. A skeletal muscle biopsy was obtained from the vastus lateralis and analyzed for capillarization and vascular endothelial growth factor (VEGF) and mitochondrial OXPHOS proteins. Platelets were isolated from venous blood and analyzed for VEGF content and effect on endothelial cell proliferation. RESULTS The exercise-induced rise in LBF and LVO2 was faster (P = 0.008) in VERY compared with SED and MOD. Steady-state LBF and LVO2 were lower (P < 0.04) in MOD and VERY compared with SED. Capillary-fiber ratio and capillary density were greater (P < 0.03) in VERY (1.65 ± 0.48 and 409.3 ± 57.5) compared with MOD (1.30 ± 0.19 and 365.0 ± 40.2) and SED (1.30 ± 0.30 and 356.2 ± 66.3). Skeletal muscle VEGF and OXPHOS complexes I, II, and V were ~1.6-fold and ~1.25-fold (P < 0.01) higher, respectively, in VERY compared with SED. Platelets from all groups induced an approximately nine-fold (P < 0.001) increase in endothelial cell proliferation. CONCLUSION A very active lifestyle is associated with superior skeletal muscle exercise hemodynamics and greater potential for oxygen extraction concurrent with a higher skeletal muscle capillarization and mitochondrial capacity.
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Affiliation(s)
- Lasse Gliemann
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, DENMARK
| | - Nicolai Rytter
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, DENMARK
| | | | | | - Howard Carter
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, DENMARK
| | - Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, DENMARK
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5
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Zarębska EA, Kusy K, Słomińska EM, Kruszyna Ł, Zieliński J. Alterations in Exercise-Induced Plasma Adenosine Triphosphate Concentration in Highly Trained Athletes in a One-Year Training Cycle. Metabolites 2019; 9:metabo9100230. [PMID: 31623086 PMCID: PMC6836270 DOI: 10.3390/metabo9100230] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 10/13/2019] [Accepted: 10/14/2019] [Indexed: 12/18/2022] Open
Abstract
This study aimed to assess the effect of training loads on plasma adenosine triphosphate responsiveness in highly trained athletes in a 1 y cycle. Highly trained futsal players (11 men, age range 20–31 y), endurance athletes (11 men, age range 18–31 y), sprinters (11 men, age range 21–30 y), and control group (11 men, age range 22–34 y) were examined across four characteristic training phases in response to an incremental treadmill test until exhaustion. A considerably higher exercise and post-exercise plasma adenosine triphosphate concentrations were observed in consecutive training phases in highly trained athletes, with the highest values reached after the competitive period. No differences in plasma adenosine triphosphate concentrations were found in the control group during the 1 y cycle. Sprinters showed a higher absolute and net increase in plasma adenosine triphosphate concentration by 60–114% during exercise in consecutive training phases than futsal players (63–101%) and endurance athletes (64–95%). In this study, we demonstrated that exercise-induced adenosine triphosphate concentration significantly changes in highly trained athletes over an annual training cycle. The obtained results showed that high-intensity but not low- to moderate-intensity training leads to an increased adenosine triphosphate response to exercise, suggesting an important role of ATP for vascular plasticity.
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Affiliation(s)
- Ewa Anna Zarębska
- Department of Athletics, Strength and Conditioning, Poznan University of Physical Education, Królowej Jadwigi 27/39, 61-871 Poznan, Poland.
| | - Krzysztof Kusy
- Department of Athletics, Strength and Conditioning, Poznan University of Physical Education, Królowej Jadwigi 27/39, 61-871 Poznan, Poland.
| | - Ewa Maria Słomińska
- Department of Biochemistry, Medical University of Gdansk, Dębinki 1, 80-211 Gdansk, Poland.
| | - Łukasz Kruszyna
- Department of General and Vascular Surgery, Poznan University of Medical Sciences, Długa 1/2, 61-848 Poznan, Poland.
| | - Jacek Zieliński
- Department of Athletics, Strength and Conditioning, Poznan University of Physical Education, Królowej Jadwigi 27/39, 61-871 Poznan, Poland.
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6
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Elia A, Barlow MJ, Deighton K, Wilson OJ, O'Hara JP. Erythropoietic responses to a series of repeated maximal dynamic and static apnoeas in elite and non-breath-hold divers. Eur J Appl Physiol 2019; 119:2557-2565. [PMID: 31563983 PMCID: PMC6858396 DOI: 10.1007/s00421-019-04235-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 09/23/2019] [Indexed: 02/06/2023]
Abstract
Purpose Serum erythropoietin (EPO) concentration is increased following static apnoea-induced hypoxia. However, the acute erythropoietic responses to a series of dynamic apnoeas in non-divers (ND) or elite breath-hold divers (EBHD) are unknown. Methods Participants were stratified into EBHD (n = 8), ND (n = 10) and control (n = 8) groups. On two separate occasions, EBHD and ND performed a series of five maximal dynamic apnoeas (DYN) or two sets of five maximal static apnoeas (STA). Control performed a static eupnoeic (STE) protocol to control against any effects of water immersion and diurnal variation on EPO. Peripheral oxygen saturation (SpO2) levels were monitored up to 30 s post each maximal effort. Blood samples were collected at 30, 90, and 180 min after each protocol for EPO, haemoglobin and haematocrit concentrations. Results No between group differences were observed at baseline (p > 0.05). For EBHD and ND, mean end-apnoea SpO2 was lower in DYN (EBHD, 62 ± 10%, p = 0.024; ND, 85 ± 6%; p = 0.020) than STA (EBHD, 76 ± 7%; ND, 96 ± 1%) and control (98 ± 1%) protocols. EBHD attained lower end-apnoeic SpO2 during DYN and STA than ND (p < 0.001). Serum EPO increased from baseline following the DYN protocol in EBHD only (EBHD, p < 0.001; ND, p = 0.622). EBHD EPO increased from baseline (6.85 ± 0.9mlU/mL) by 60% at 30 min (10.82 ± 2.5mlU/mL, p = 0.017) and 63% at 180 min (10.87 ± 2.1mlU/mL, p = 0.024). Serum EPO did not change after the STA (EBHD, p = 0.534; ND, p = 0.850) and STE (p = 0.056) protocols. There was a significant negative correlation (r = − 0.49, p = 0.003) between end-apnoeic SpO2 and peak post-apnoeic serum EPO concentrations. Conclusions The novel findings demonstrate that circulating EPO is only increased after DYN in EBHD. This may relate to the greater hypoxemia achieved by EBHD during the DYN.
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Affiliation(s)
- Antonis Elia
- Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK. .,Division of Environmental Physiology, School of Chemistry, Bioengineering and Health, KTH Royal Institute of Technology, Stockholm, Sweden.
| | - Matthew J Barlow
- Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK
| | - Kevin Deighton
- Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK
| | - Oliver J Wilson
- Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK
| | - John P O'Hara
- Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK
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7
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Hureau TJ, Weavil JC, Thurston TS, Wan HY, Gifford JR, Jessop JE, Buys MJ, Richardson RS, Amann M. Pharmacological attenuation of group III/IV muscle afferents improves endurance performance when oxygen delivery to locomotor muscles is preserved. J Appl Physiol (1985) 2019; 127:1257-1266. [PMID: 31513446 DOI: 10.1152/japplphysiol.00490.2019] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We sought to investigate the role of group III/IV muscle afferents in limiting endurance exercise performance, independently of their role in optimizing locomotor muscle O2 delivery. While breathing 100% O2 to ensure a similar arterial O2 content ([Formula: see text]) in both trials, eight male cyclists performed 5-km time trials under control conditions (HCTRL) and with lumbar intrathecal fentanyl (HFENT) impairing neural feedback from the lower limbs. After each time trial, common femoral artery blood flow (FBF) was quantified (Doppler ultrasound) during constant-load cycling performed at the average power of the preceding time trial. The assessment of end-tidal gases, hemoglobin content and saturation, and FBF facilitated the calculation of leg O2 delivery. Locomotor muscle activation during cycling was estimated from vastus lateralis EMG. With electrical femoral nerve stimulation, peripheral and central fatigue were quantified by pre- to postexercise decreases in quadriceps twitch torque (ΔQtw) and voluntary activation (ΔVA), respectively. FBF (~16 mL·min-1·W-1; P = 0.6), [Formula: see text] (~24 mL O2/dL; P = 0.9), and leg O2 delivery (~0.38 mL O2·min-1·W-1; P = 0.9) were not different during HCTRL and HFENT. Mean power output and time to completion were significantly improved by 9% (~310 W vs. ~288 W) and 3% (~479 s vs. ~463 s), respectively, during HFENT compared with HCTRL. Quadriceps muscle activation was 9 ± 7% higher during HFENT compared with HCTRL (P < 0.05). ΔQtw was significantly greater in HFENT compared with HCTRL (54 ± 8% vs. 39 ± 9%), whereas ΔVA was not different (~5%; P = 0.3) in both trials. These findings reveal that group III/IV muscle afferent feedback limits whole body endurance exercise performance and peripheral fatigue by restricting neural activation of locomotor muscle.NEW & NOTEWORTHY Group III/IV muscle afferent feedback facilitates endurance performance by optimizing locomotor muscle O2 delivery but also limits performance by restricting neural drive to locomotor muscle. To isolate the performance-limiting effect of these sensory neurons, we pharmacologically attenuated their central projection during a cycling time trial while controlling for locomotor muscle O2 delivery. With no difference in leg O2 delivery, afferent blockade attenuated the centrally mediated restriction in motoneuronal output and improved cycling performance.
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Affiliation(s)
- Thomas J Hureau
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Department of Medicine and EA 3072: Mitochondria, Oxidative Stress and Muscular Protection Laboratory, University of Strasbourg, Strasbourg, France
| | - Joshua C Weavil
- Geriatric Research, Education, and Clinical Center, Salt Lake City Department of Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Taylor S Thurston
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Hsuan-Yu Wan
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| | - Jayson R Gifford
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Jacob E Jessop
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| | - Michael J Buys
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| | - Russell S Richardson
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Geriatric Research, Education, and Clinical Center, Salt Lake City Department of Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Markus Amann
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Geriatric Research, Education, and Clinical Center, Salt Lake City Department of Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah.,Department of Anesthesiology, University of Utah, Salt Lake City, Utah
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8
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Proctor DN, Luck JC, Maman SR, Leuenberger UA, Muller MD. Esmolol acutely alters oxygen supply-demand balance in exercising muscles of healthy humans. Physiol Rep 2019; 6:e13673. [PMID: 29665297 PMCID: PMC5903697 DOI: 10.14814/phy2.13673] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 03/09/2018] [Indexed: 01/13/2023] Open
Abstract
Beta‐adrenoreceptor antagonists (β blockers) reduce systemic O2 delivery and blood pressure (BP) during exercise, but the subsequent effects on O2 extraction within the active limb muscles are unknown. In this study, we examined the effects of the fast‐acting, β1 selective blocker esmolol on systemic hemodynamics and leg muscle O2 saturation (near infrared spectroscopy, NIRS) during submaximal leg ergometry. Our main hypothesis was that esmolol would augment exercise‐induced reductions in leg muscle O2 saturation. Eight healthy adults (6 men, 2 women; 23–67 year) performed light and moderate intensity bouts of recumbent leg cycling before (PRE), during (β1‐blocked), and 45 min following (POST) intravenous infusion of esmolol. Oxygen uptake, heart rate (HR), BP, and O2 saturation (SmO2) of the vastus lateralis (VL) and medial gastrocnemius (MG) muscles were measured continuously. Esmolol attenuated the increases in HR and systolic BP during light (−12 ± 9 bpm and −26 ± 12 mmHg vs. PRE) and moderate intensity (−20 ± 10 bpm and −40 ± 18 mmHg vs. PRE) cycling (all P < 0.01). Exercise‐induced reductions in SmO2 occurred to a greater extent during the β1‐blockade trial in both the VL (P = 0.001 vs. PRE) and MG muscles (P = 0.022 vs. PRE). HR, SBP and SmO2 were restored during POST (all P < 0.01 vs. β1‐blocked). In conclusion, esmolol rapidly and reversibly increases O2 extraction within exercising muscles of healthy humans.
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Affiliation(s)
- David N Proctor
- Noll Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania.,Penn State Heart and Vascular Institute, Penn State University College of Medicine, Hershey, Pennsylvania
| | - J Carter Luck
- Penn State Heart and Vascular Institute, Penn State University College of Medicine, Hershey, Pennsylvania
| | - Stephan R Maman
- Penn State Heart and Vascular Institute, Penn State University College of Medicine, Hershey, Pennsylvania
| | - Urs A Leuenberger
- Penn State Heart and Vascular Institute, Penn State University College of Medicine, Hershey, Pennsylvania
| | - Matthew D Muller
- Penn State Heart and Vascular Institute, Penn State University College of Medicine, Hershey, Pennsylvania.,Master of Science in Anesthesia Program, Case Western Reserve University School of Medicine, Cleveland, Ohio
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9
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Garten RS, Hogwood AC, Weggen J, Decker K, Darling A, Maniyar R, Michael A. Examining Arm Vascular Function and Blood Flow Regulation in Row-trained Males. Med Sci Sports Exerc 2019; 51:2058-2066. [PMID: 31009422 DOI: 10.1249/mss.0000000000002014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Vascular function and blood flow responses to upper limb exercise are differentially altered in response to different exercise training modalities. Rowing is a unique exercise modality that incorporates the upper limbs and can significantly augment upper limb endurance, strength, and power capacity. PURPOSE This study sought to determine whether vascular function and blood flow regulation during handgrip exercise are altered in row-trained males. METHODS Nine young row-trained males (ROW, 20 ± 1 yr; V˙O2peak = 51 ± 2 mL·kg·min) and 14 recreationally active male controls (C: 22 ± 1 yr; V˙O2peak = 37 ± 2 mL·kg·min) were recruited for this study. Subjects performed multiple bouts of progressive rhythmic handgrip exercise. Brachial artery (BA) diameter, blood flow, shear rate, and mean arterial pressure were measured at rest and during the last minute of each exercise workload. RESULTS Resting values for BA diameter, blood flow, shear rate, and mean arterial pressure were not different between groups. During handgrip exercise, the ROW group reported significantly lower BA blood flow (ROW vs C: 4 kg [146 ± 21 vs 243 ± 13 mL·min], 8 kg [248 ± 29 vs 375 ± 17 mL·min], 12 kg [352 ± 43 vs 490 ± 22 mL·min]) across all workloads when compared with controls. The examination of BA dilation, when controlled for the shear rate stimulus and evaluated across all workloads, was revealed to be significantly greater in ROW group versus controls. CONCLUSION This study revealed that vascular function and blood flow regulation were significantly different in row-trained males when compared with untrained controls evidenced by greater shear-induced BA dilation and lower arm blood flow during progressive handgrip exercise.
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Affiliation(s)
- Ryan S Garten
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA
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10
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Exercise-induced sympathetic dilatation in arterioles of the guinea pig tibial periosteum. Auton Neurosci 2019; 217:7-17. [DOI: 10.1016/j.autneu.2018.12.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 12/06/2018] [Accepted: 12/21/2018] [Indexed: 11/23/2022]
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11
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Okushima D, Poole DC, Barstow TJ, Rossiter HB, Kondo N, Bowen TS, Amano T, Koga S. Greater V˙O2peak is correlated with greater skeletal muscle deoxygenation amplitude and hemoglobin concentration within individual muscles during ramp-incremental cycle exercise. Physiol Rep 2018; 4:4/23/e13065. [PMID: 27986837 PMCID: PMC5260088 DOI: 10.14814/phy2.13065] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 11/03/2016] [Indexed: 11/24/2022] Open
Abstract
It is axiomatic that greater aerobic fitness (V˙O2peak) derives from enhanced perfusive and diffusive O2 conductances across active muscles. However, it remains unknown how these conductances might be reflected by regional differences in fractional O2 extraction (i.e., deoxy [Hb+Mb] and tissue O2 saturation [StO2]) and diffusive O2 potential (i.e., total[Hb+Mb]) among muscles spatially heterogeneous in blood flow, fiber type, and recruitment (vastus lateralis, VL; rectus femoris, RF). Using quantitative time‐resolved near‐infrared spectroscopy during ramp cycling in 24 young participants (V˙O2peak range: ~37.4–66.4 mL kg−1 min−1), we tested the hypotheses that (1) deoxy[Hb+Mb] and total[Hb+Mb] at V˙O2peak would be positively correlated with V˙O2peak in both VL and RF muscles; (2) the pattern of deoxygenation (the deoxy[Hb+Mb] slopes) during submaximal exercise would not differ among subjects differing in V˙O2peak. Peak deoxy [Hb+Mb] and StO2 correlated with V˙O2peak for both VL (r = 0.44 and −0.51) and RF (r = 0.49 and −0.49), whereas for total[Hb+Mb] this was true only for RF (r = 0.45). Baseline deoxy[Hb+Mb] and StO2 correlated with V˙O2peak only for RF (r = −0.50 and 0.54). In addition, the deoxy[Hb+Mb] slopes were not affected by aerobic fitness. In conclusion, while the pattern of deoxygenation (the deoxy[Hb+Mb] slopes) did not differ between fitness groups the capacity to deoxygenate [Hb+Mb] (index of maximal fractional O2 extraction) correlated significantly with V˙O2peak in both RF and VL muscles. However, only in the RF did total[Hb+Mb] (index of diffusive O2 potential) relate to fitness.
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Affiliation(s)
- Dai Okushima
- Applied Physiology Laboratory, Kobe Design University, Kobe, Japan
| | - David C Poole
- Departments of Kinesiology and Anatomy and Physiology, Kansas State University, Manhattan, Kansas
| | - Thomas J Barstow
- Departments of Kinesiology and Anatomy and Physiology, Kansas State University, Manhattan, Kansas
| | - Harry B Rossiter
- Rehabilitation Clinical Trials Center, Division of Respiratory & Critical Care Physiology & Medicine Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California
| | - Narihiko Kondo
- Laboratory for Applied Human Physiology, Graduate School of Human Development and Environment Kobe University, Kobe, Japan
| | - T Scott Bowen
- Department of Internal Medicine & Cardiology, Heart Center, Leipzig University, Leipzig, Germany
| | - Tatsuro Amano
- Faculty of Education Niigata University, Niigata, Japan
| | - Shunsaku Koga
- Applied Physiology Laboratory, Kobe Design University, Kobe, Japan
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12
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Piil P, Smith Jørgensen T, Egelund J, Damsgaard R, Gliemann L, Hellsten Y, Nyberg M. Exercise training improves blood flow to contracting skeletal muscle of older men via enhanced cGMP signaling. J Appl Physiol (1985) 2017; 124:109-117. [PMID: 28982945 DOI: 10.1152/japplphysiol.00634.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Physical activity has the potential to offset age-related impairments in the regulation of blood flow and O2 delivery to the exercising muscles; however, the mechanisms underlying this effect of physical activity remain poorly understood. The present study examined the role of cGMP in training-induced adaptations in the regulation of skeletal muscle blood flow and oxidative metabolism during exercise in aging humans. We measured leg hemodynamics and oxidative metabolism during exercise engaging the knee extensor muscles in young [ n = 15, 25 ± 1 (SE) yr] and older ( n = 15, 72 ± 1 yr) subjects before and after a period of aerobic high-intensity exercise training. To determine the role of cGMP signaling, pharmacological inhibition of phosphodiesterase 5 (PDE5) was performed. Before training, inhibition of PDE5 increased ( P < 0.05) skeletal muscle blood flow and O2 uptake during moderate-intensity exercise in the older group; however, these effects of PDE5 inhibition were not detected after training. These findings suggest a role for enhanced cGMP signaling in the training-induced improvement of regulation of blood flow in contracting skeletal muscle of older men. NEW & NOTEWORTHY The present study provides evidence for enhanced cyclic GMP signaling playing an essential role in the improved regulation of blood flow in contracting skeletal muscle of older men with aerobic exercise training.
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Affiliation(s)
- Peter Piil
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Tue Smith Jørgensen
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark.,Department of Orthopedics, Herlev and Gentofte Hospital, Copenhagen, Denmark
| | - Jon Egelund
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Rasmus Damsgaard
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Lasse Gliemann
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Michael Nyberg
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
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13
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Kruse NT, Hughes WE, Hanada S, Ueda K, Bock JM, Iwamoto E, Casey DP. Evidence of a greater functional sympatholysis in habitually aerobic trained postmenopausal women. J Appl Physiol (1985) 2017; 124:583-591. [PMID: 28970201 DOI: 10.1152/japplphysiol.00411.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Habitual aerobic exercise attenuates elevated vasoconstriction during acute exercise (functional sympatholysis) in older men; however, this effect remains unknown in postmenopausal women (PMW). This study tested the hypothesis that PMW who participate in habitual aerobic exercise demonstrate a greater functional sympatholysis compared with their untrained counterparts. Nineteen PMW (untrained n = 9 vs. trained n = 10) performed 5 min of steady-state (SS) forearm exercise at relative [10% and 20% of maximum voluntary contraction (MVC)] and absolute (5 kg) contraction intensities. Lower-body negative pressure (LBNP) was used to increase sympathetic vasoconstriction during rest and forearm exercise. Brachial artery diameter and blood velocities (via Doppler ultrasound) determined forearm blood flow (FBF; ml/min). Forearm muscle oxygen consumption ([Formula: see text]; ml/min) and arteriovenous oxygen difference (a-vO2diff) were estimated during SS-exercise and SS-exercise with LBNP. Forearm vascular conductance (FVC; ml·min-1·100 mmHg-1) was calculated from FBF and mean arterial pressure (MAP; mmHg). Vasoconstrictor responsiveness was determined as the %change in FVC during LBNP. The reduction in FVC (% change FVC) during LBNP was lower in trained compared with untrained PMW at 10% MVC (-7.3 ± 1.2% vs. -13.0 ± 1.1%; P < 0.05), 20% MVC (-4.4 ± 0.8% vs. -8.6 ± 1.4%; P < 0.05), and 5 kg (-5.3 ± 0.8% vs. -8.9 ± 1.4%; P < 0.05) conditions, whereas there were no differences at rest (-32.7 ± 4.4% vs. -33.7 ± 4.0%). Peripheral (FVC, FBF, and [Formula: see text]) and the magnitude change in systemic hemodynamics (heart rate and MAP) did not differ between groups during exercise. Collectively, the findings present the first evidence suggesting that PMW who participate in aerobic exercise demonstrate a greater functional sympatholysis compared with untrained PMW during mild to moderate forearm exercise. NEW & NOTEWORTHY Habitual aerobic exercise attenuates the elevated sympathetic nervous system-induced vasoconstriction during an acute bout of exercise (improved functional sympatholysis) in aging men; however, this effect remains unknown in postmenopausal women (PMW). The novel findings of this study suggest that habitual aerobic exercise results in an enhanced functional sympatholysis in PMW. Conversely, habitual aerobic exercise does not alter blood flow and oxygen utilization during acute forearm exercise compared with PMW who do not habitually exercise.
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Affiliation(s)
- Nicholas T Kruse
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa , Iowa City, Iowa.,Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa , Iowa City, Iowa
| | - William E Hughes
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa , Iowa City, Iowa
| | - Satoshi Hanada
- Department of Anesthesia, Carver College of Medicine, University of Iowa , Iowa City, Iowa
| | - Kenichi Ueda
- Department of Anesthesia, Carver College of Medicine, University of Iowa , Iowa City, Iowa
| | - Joshua M Bock
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa , Iowa City, Iowa
| | - Erika Iwamoto
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa , Iowa City, Iowa
| | - Darren P Casey
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa , Iowa City, Iowa.,Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa , Iowa City, Iowa.,Fraternal Order of Eagles Diabetes Research, Carver College of Medicine, University of Iowa , Iowa City, Iowa
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14
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Nyberg M, Egelund J, Mandrup CM, Andersen CB, Hansen KMBE, Hergel IMF, Valbak-Andersen N, Frikke-Schmidt R, Stallknecht B, Bangsbo J, Hellsten Y. Leg vascular and skeletal muscle mitochondrial adaptations to aerobic high-intensity exercise training are enhanced in the early postmenopausal phase. J Physiol 2017; 595:2969-2983. [PMID: 28231611 DOI: 10.1113/jp273871] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 02/08/2017] [Indexed: 12/15/2022] Open
Abstract
KEY POINTS Exercise training effectively improves vascular and skeletal muscle function; however, these effects of training may be blunted in postmenopausal women as a result of the loss of oestrogens. Accordingly, the capacity to deliver oxygen to the active muscles may also be impaired in postmenopausal women. In both premenopausal and recent postmenopausal women, exercise training was shown to improve leg vascular and skeletal muscle mitochondrial function. Interestingly, these effects were more pronounced in postmenopausal women. Skeletal muscle oxygen supply and utilization were similar in the two groups of women. These findings suggest that the early postmenopausal phase is associated with an enhanced capacity of the leg vasculature and skeletal muscle mitochondria to adapt to exercise training and that the ability to deliver oxygen to match the demand of the active muscles is preserved in the early phase following the menopausal transition. ABSTRACT Exercise training leads to favourable adaptations within skeletal muscle; however, this effect of exercise training may be blunted in postmenopausal women as a result of the loss of oestrogens. Furthermore, postmenopausal women may have an impaired vascular response to acute exercise. We examined the haemodynamic response to acute exercise in matched pre- and postmenopausal women before and after 12 weeks of aerobic high intensity exercise training. Twenty premenopausal and 16 early postmenopausal (mean ± SEM: 3.1 ± 0.5 years after final menstrual period) women only separated by 4 years of age (mean ± SEM: 50 ± 0 years vs. 54 ± 1 years) were included. Before training, leg blood flow, O2 delivery, O2 uptake and lactate release during knee-extensor exercise were similar in pre- and postmenopausal women. Exercise training reduced (P < 0.05) leg blood flow, O2 delivery, O2 uptake, lactate release, blood pressure and heart rate during the same absolute workloads in postmenopausal women. These effects were not detected in premenopausal women. Quadriceps muscle protein contents of mitochondrial complex II, III and IV; endothelial nitric oxide synthase (eNOS); cyclooxygenase (COX)-1; COX-2; and oestrogen-related receptor α (ERRα) were increased (P < 0.05) with training in postmenopausal women, whereas only the levels of mitochondrial complex V, eNOS and COX-2 were increased (P < 0.05) in premenopausal women. These findings demonstrate that vascular and skeletal muscle mitochondrial adaptations to aerobic high intensity exercise training are more pronounced in recent post- compared to premenopausal women, possibly as an effect of enhanced ERRα signalling. Also, the hyperaemic response to acute exercise appears to be preserved in the early postmenopausal phase.
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Affiliation(s)
- Michael Nyberg
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Jon Egelund
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Camilla M Mandrup
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Caroline B Andersen
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.,Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Karen M B E Hansen
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Ida-Marie F Hergel
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | | | - Ruth Frikke-Schmidt
- Department of Clinical Biochemistry, Rigshospitalet, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Bente Stallknecht
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bangsbo
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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15
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Abstract
Aerobic exercise training leads to cardiovascular changes that markedly increase aerobic power and lead to improved endurance performance. The functionally most important adaptation is the improvement in maximal cardiac output which is the result of an enlargement in cardiac dimension, improved contractility, and an increase in blood volume, allowing for greater filling of the ventricles and a consequent larger stroke volume. In parallel with the greater maximal cardiac output, the perfusion capacity of the muscle is increased, permitting for greater oxygen delivery. To accommodate the higher aerobic demands and perfusion levels, arteries, arterioles, and capillaries adapt in structure and number. The diameters of the larger conduit and resistance arteries are increased minimizing resistance to flow as the cardiac output is distributed in the body and the wall thickness of the conduit and resistance arteries is reduced, a factor contributing to increased arterial compliance. Endurance training may also induce alterations in the vasodilator capacity, although such adaptations are more pronounced in individuals with reduced vascular function. The microvascular net increases in size within the muscle allowing for an improved capacity for oxygen extraction by the muscle through a greater area for diffusion, a shorter diffusion distance, and a longer mean transit time for the erythrocyte to pass through the smallest blood vessels. The present article addresses the effect of endurance training on systemic and peripheral cardiovascular adaptations with a focus on humans, but also covers animal data.
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Affiliation(s)
- Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Michael Nyberg
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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16
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Nyberg M, Gliemann L, Hellsten Y. Vascular function in health, hypertension, and diabetes: effect of physical activity on skeletal muscle microcirculation. Scand J Med Sci Sports 2015; 25 Suppl 4:60-73. [DOI: 10.1111/sms.12591] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2015] [Indexed: 12/31/2022]
Affiliation(s)
- M. Nyberg
- Department of Nutrition, Exercise and Sports; University of Copenhagen; Copenhagen Denmark
| | - L. Gliemann
- Department of Nutrition, Exercise and Sports; University of Copenhagen; Copenhagen Denmark
| | - Y. Hellsten
- Department of Nutrition, Exercise and Sports; University of Copenhagen; Copenhagen Denmark
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17
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18
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Nyberg M, Hellsten Y. Reduced blood flow to contracting skeletal muscle in ageing humans: is it all an effect of sand through the hourglass? J Physiol 2015; 594:2297-305. [PMID: 26095873 DOI: 10.1113/jp270594] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 06/05/2015] [Indexed: 01/27/2023] Open
Abstract
The ability to sustain a given absolute submaximal workload declines with advancing age, likely to be due to a lower level of blood flow and O2 delivery to the exercising muscles. Given that physical inactivity mimics many of the physiological changes associated with ageing, separating the physiological consequences of ageing and physical inactivity can be challenging; yet, observations from cross-sectional and longitudinal studies on the effects of physical activity have provided some insight. Physical activity has the potential to offset the age-related decline in blood flow to contracting skeletal muscle during exercise where systemic blood flow is not limited by cardiac output, thereby improving O2 delivery and allowing for an enhanced energy production from oxidative metabolism. The mechanisms underlying the increase in blood flow with regular physical activity include improved endothelial function and the ability for functional sympatholysis - an attenuation of the vasoconstrictor effect of sympathetic nervous activity. These vascular adaptations with physical activity are likely to be an effect of improved nitric oxide and ATP signalling. Collectively, precise matching of blood flow and O2 delivery to meet the O2 demand of the active skeletal muscle of aged individuals during conditions where systemic blood flow is not limited by cardiac output seems to a large extent to be related to the level of physical activity.
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Affiliation(s)
- Michael Nyberg
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
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19
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Montero D. Arterial dilator function in athletes: present and future perspectives. Front Physiol 2015; 6:163. [PMID: 26042052 PMCID: PMC4436563 DOI: 10.3389/fphys.2015.00163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 05/06/2015] [Indexed: 01/23/2023] Open
Affiliation(s)
- David Montero
- Zurich Center for Integrative Human Physiology, Institute of Physiology, University of Zurich Zurich, Switzerland
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20
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Laughlin MH, Davis MJ, Secher NH, van Lieshout JJ, Arce-Esquivel AA, Simmons GH, Bender SB, Padilla J, Bache RJ, Merkus D, Duncker DJ. Peripheral circulation. Compr Physiol 2013; 2:321-447. [PMID: 23728977 DOI: 10.1002/cphy.c100048] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Blood flow (BF) increases with increasing exercise intensity in skeletal, respiratory, and cardiac muscle. In humans during maximal exercise intensities, 85% to 90% of total cardiac output is distributed to skeletal and cardiac muscle. During exercise BF increases modestly and heterogeneously to brain and decreases in gastrointestinal, reproductive, and renal tissues and shows little to no change in skin. If the duration of exercise is sufficient to increase body/core temperature, skin BF is also increased in humans. Because blood pressure changes little during exercise, changes in distribution of BF with incremental exercise result from changes in vascular conductance. These changes in distribution of BF throughout the body contribute to decreases in mixed venous oxygen content, serve to supply adequate oxygen to the active skeletal muscles, and support metabolism of other tissues while maintaining homeostasis. This review discusses the response of the peripheral circulation of humans to acute and chronic dynamic exercise and mechanisms responsible for these responses. This is accomplished in the context of leading the reader on a tour through the peripheral circulation during dynamic exercise. During this tour, we consider what is known about how each vascular bed controls BF during exercise and how these control mechanisms are modified by chronic physical activity/exercise training. The tour ends by comparing responses of the systemic circulation to those of the pulmonary circulation relative to the effects of exercise on the regional distribution of BF and mechanisms responsible for control of resistance/conductance in the systemic and pulmonary circulations.
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Affiliation(s)
- M Harold Laughlin
- Department of Medical Pharmacology and Physiology, and the Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA.
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21
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Gliemann L, Nyberg M, Hellsten Y. Nitric oxide and reactive oxygen species in limb vascular function: what is the effect of physical activity? Free Radic Res 2013; 48:71-83. [PMID: 23962038 DOI: 10.3109/10715762.2013.835045] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Nitric oxide (NO) is known to be one of the most important regulatory compounds within the cardiovascular system where it is central for functions such as regulation of blood pressure, blood flow, and vascular growth. The bioavailability of NO is determined by a balance between, on one hand, the extent of enzymatic and non-enzymatic formation of NO and on the other hand, removal of NO, which in part is dependent on the reaction of NO with reactive oxygen species (ROS). The presence of ROS is dependent on the extent of ROS formation via mitochondria and/or enzymes such as NAD(P)H oxidase (NOX) and xanthine oxidase (XO) and the degree of ROS removal through the antioxidant defense system or other reactions. The development of cardiovascular disease has been proposed to be closely related to a reduced bioavailability of NO in parallel with an increased presence of ROS. Excessive levels of ROS not only lower the bioavailability of NO but may also cause cellular damage in the cardiovascular system. Physical activity has been shown to greatly improve cardiovascular function, in part through improved bioavailability of NO, enhanced endogenous antioxidant defense and a lowering of the expression of ROS-forming enzymes. Regular physical activity is therefore likely to be a highly useful tool in the treatment of cardiovascular disease. Future studies should focus on which form of exercise may be most optimal for enhancing NO bioavailability and improving cardiovascular health.
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Affiliation(s)
- L Gliemann
- Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, Cardiovascular Physiology, University of Copenhagen , Copenhagen , Denmark
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22
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Bacon AP, Carter RE, Ogle EA, Joyner MJ. VO2max trainability and high intensity interval training in humans: a meta-analysis. PLoS One 2013; 8:e73182. [PMID: 24066036 PMCID: PMC3774727 DOI: 10.1371/journal.pone.0073182] [Citation(s) in RCA: 191] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 07/18/2013] [Indexed: 01/15/2023] Open
Abstract
Endurance exercise training studies frequently show modest changes in VO2max with training and very limited responses in some subjects. By contrast, studies using interval training (IT) or combined IT and continuous training (CT) have reported mean increases in VO2max of up to ∼1.0 L · min−1. This raises questions about the role of exercise intensity and the trainability of VO2max. To address this topic we analyzed IT and IT/CT studies published in English from 1965–2012. Inclusion criteria were: 1)≥3 healthy sedentary/recreationally active humans <45 yrs old, 2) training duration 6–13 weeks, 3) ≥3 days/week, 4) ≥10 minutes of high intensity work, 5) ≥1∶1 work/rest ratio, and 6) results reported as mean ± SD or SE, ranges of change, or individual data. Due to heterogeneity (I2 value of 70), statistical synthesis of the data used a random effects model. The summary statistic of interest was the change in VO2max. A total of 334 subjects (120 women) from 37 studies were identified. Participants were grouped into 40 distinct training groups, so the unit of analysis was 40 rather than 37. An increase in VO2max of 0.51 L ·min−1 (95% CI: 0.43 to 0.60 L · min−1) was observed. A subset of 9 studies, with 72 subjects, that featured longer intervals showed even larger (∼0.8–0.9 L · min−1) changes in VO2max with evidence of a marked response in all subjects. These results suggest that ideas about trainability and VO2max should be further evaluated with standardized IT or IT/CT training programs.
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Affiliation(s)
- Andrew P. Bacon
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Rickey E. Carter
- Department of Health Sciences Research, Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Eric A. Ogle
- Creighton University Medical School, Omaha, Nebraska, United States of America
| | - Michael J. Joyner
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota, United States of America
- * E-mail:
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23
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Jendzjowsky NG, Delorey DS. Short-term exercise training enhances functional sympatholysis through a nitric oxide-dependent mechanism. J Physiol 2013; 591:1535-49. [PMID: 23297301 DOI: 10.1113/jphysiol.2012.238998] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
We tested the hypothesis that short-term mild- (M) and heavy-intensity (H) exercise training would enhance sympatholysis through a nitric oxide (NO)-dependent mechanism. Sprague-Dawley rats (n = 36) were randomly assigned to sedentary (S) or to M (20 m min(-1) 5% gradient) or H exercise training groups (40 m min(-1) 5% gradient). Rats assigned to M and H groups trained on 5 days week(-1) for 4 weeks, with the volume of training being matched between groups. Rats were anaesthetized and instrumented for stimulation of the lumbar sympathetic chain and the measurement of arterial blood pressure and femoral artery blood flow. The triceps surae muscle group was stimulated to contract rhythmically at 30 and 60% of maximal contractile force (MCF). The percentage change of femoral vascular conductance (%FVC) in response to sympathetic stimulation delivered at 2 and 5 Hz was determined at rest and during contraction at 30 and 60% MCF. The vascular response to sympathetic stimulation was reduced as a function of MCF in all rats (P < 0.05). At 30% MCF, the magnitude of sympatholysis (%FVC rest - contraction; %FVC) was greater in H compared with M and S groups (%FVC at 2 Hz, S, 9 ± 5; M, 11 ± 8; and H, 18 ± 7; and %FVC at 5 Hz, S, 6 ± 6; M, 12 ± 9; and H, 18 ± 7; P < 0.05) and was greater in H and M compared with S at 60% MCF (%FVC at 2 Hz, S, 15 ± 5; M, 25 ± 3; and H, 36 ± 6; and %FVC at 5 Hz, S, 22 ± 6; M, 33 ± 9; and H, 39 ± 9; P < 0.05). Blockade of NO synthase did not alter the magnitude of sympatholysis in S during contraction at 30 or 60% MCF. In contrast, NO synthase inhibition diminished sympatholysis in H at 30% MCF and in M and H at 60% MCF (P < 0.05). The present findings indicate that short-term exercise training augments sympatholysis in a training-intensity-dependent manner and through an NO-dependent mechanism.
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Affiliation(s)
- Nicholas G Jendzjowsky
- Faculty of Physical Education and Recreation, University of Alberta, E-435 Van Vliet Centre, Edmonton, Alberta, Canada T6G 2H9.
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24
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Calbet JAL, Lundby C. Skeletal muscle vasodilatation during maximal exercise in health and disease. J Physiol 2012; 590:6285-96. [PMID: 23027820 DOI: 10.1113/jphysiol.2012.241190] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Maximal exercise vasodilatation results from the balance between vasoconstricting and vasodilating signals combined with the vascular reactivity to these signals. During maximal exercise with a small muscle mass the skeletal muscle vascular bed is fully vasodilated. During maximal whole body exercise, however, vasodilatation is restrained by the sympathetic system. This is necessary to avoid hypotension since the maximal vascular conductance of the musculature exceeds the maximal pumping capacity of the heart. Endurance training and high-intensity intermittent knee extension training increase the capacity for maximal exercise vasodilatation by 20-30%, mainly due to an enhanced vasodilatory capacity, as maximal exercise perfusion pressure changes little with training. The increase in maximal exercise vascular conductance is to a large extent explained by skeletal muscle hypertrophy and vascular remodelling. The vasodilatory capacity during maximal exercise is reduced or blunted with ageing, as well as in chronic heart failure patients and chronically hypoxic humans; reduced vasodilatory responsiveness and increased sympathetic activity (and probably, altered sympatholysis) are potential mechanisms accounting for this effect. Pharmacological counteraction of the sympathetic restraint may result in lower perfusion pressure and reduced oxygen extraction by the exercising muscles. However, at the same time fast inhibition of the chemoreflex in maximally exercising humans may result in increased vasodilatation, further confirming a restraining role of the sympathetic nervous system on exercise-induced vasodilatation. This is likely to be critical for the maintenance of blood pressure in exercising patients with a limited heart pump capacity.
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Affiliation(s)
- Jose A L Calbet
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira, Las Palmas de Gran Canaria, 35017, Spain.
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25
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Effect of high-intensity interval training on the profile of muscle deoxygenation heterogeneity during incremental exercise. Eur J Appl Physiol 2012; 113:249-57. [DOI: 10.1007/s00421-012-2430-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 05/19/2012] [Indexed: 10/27/2022]
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Mortensen SP, Mørkeberg J, Thaning P, Hellsten Y, Saltin B. Two weeks of muscle immobilization impairs functional sympatholysis but increases exercise hyperemia and the vasodilatory responsiveness to infused ATP. Am J Physiol Heart Circ Physiol 2012; 302:H2074-82. [PMID: 22408019 DOI: 10.1152/ajpheart.01204.2011] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During exercise, contracting muscles can override sympathetic vasoconstrictor activity (functional sympatholysis). ATP and adenosine have been proposed to play a role in skeletal muscle blood flow regulation. However, little is known about the role of muscle training status on functional sympatholysis and ATP- and adenosine-induced vasodilation. Eight male subjects (22 ± 2 yr, Vo(2max): 49 ± 2 ml O(2)·min(-1)·kg(-1)) were studied before and after 5 wk of one-legged knee-extensor training (3-4 times/wk) and 2 wk of immobilization of the other leg. Leg hemodynamics were measured at rest, during exercise (24 ± 4 watts), and during arterial ATP (0.94 ± 0.03 μmol/min) and adenosine (5.61 ± 0.03 μmol/min) infusion with and without coinfusion of tyramine (11.11 μmol/min). During exercise, leg blood flow (LBF) was lower in the trained leg (2.5 ± 0.1 l/min) compared with the control leg (2.6 ± 0.2 l/min; P < 0.05), and it was higher in the immobilized leg (2.9 ± 0.2 l/min; P < 0.05). Tyramine infusion lowers LBF similarly at rest, but, when tyramine was infused during exercise, LBF was blunted in the immobilized leg (2.5 ± 0.2 l/min; P < 0.05), whereas it was unchanged in the control and trained leg. Mean arterial pressure was lower during exercise with the trained leg compared with the immobilized leg (P < 0.05), and leg vascular conductance was similar. During ATP infusion, the LBF response was higher after immobilization (3.9 ± 0.3 and 4.5 ± 0.6 l/min in the control and immobilized leg, respectively; P < 0.05), whereas it did not change after training. When tyramine was coinfused with ATP, LBF was reduced in the immobilized leg (P < 0.05) but remained similar in the control and trained leg. Training increased skeletal muscle P2Y2 receptor content (P < 0.05), whereas it did not change with immobilization. These results suggest that muscle inactivity impairs functional sympatholysis and that the magnitude of hyperemia and blood pressure response to exercise is dependent on the training status of the muscle. Immobilization also increases the vasodilatory response to infused ATP.
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Affiliation(s)
- S P Mortensen
- The Copenhagen Muscle Research Centre, Rigshospitalet, Denmark.
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Nyberg M, Jensen LG, Thaning P, Hellsten Y, Mortensen SP. Role of nitric oxide and prostanoids in the regulation of leg blood flow and blood pressure in humans with essential hypertension: effect of high-intensity aerobic training. J Physiol 2012; 590:1481-94. [PMID: 22271868 DOI: 10.1113/jphysiol.2011.225136] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
We examined the role of nitric oxide (NO) and prostanoids in the regulation of leg blood flow and systemic blood pressure before and after 8 weeks of aerobic high-intensity training in individuals with essential hypertension (n = 10) and matched healthy control subjects (n = 11). Hypertensive subjects were found to have a lower (P < 0.05) blood flow to the exercising leg than normotensive subjects (30 W: 2.92 ± 0.16 vs. 3.39 ± 0.37 l min(−1)). Despite the lower exercise hyperaemia, pharmacological inhibition of the NO and prostanoid systems reduced leg blood flow to a similar extent during exercise in the two groups and vascular relaxation to the NO-dependent vasodilator acetylcholine was also similar between groups. High-intensity aerobic training lowered (P < 0.05) resting systolic (∼9 mmHg) and diastolic (∼12 mmHg) blood pressure in subjects with essential hypertension, but this effect of training was abolished when the NO and prostanoid systems were inhibited. Skeletal muscle vascular endothelial NO synthase uncoupling, expression and phosphorylation status were similar in the two groups before and after training. These data demonstrate that a reduction in exercise hyperaemia in hypertensive subjects is not associated with a reduced capacity of the NO and prostanoid systems to induce vasodilatation or with altered acetylcholine-induced response. However, our data suggest that the observed reduction in blood pressure is related to a training-induced change in the tonic effect of NO and/or prostanoids on vascular tone.
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Affiliation(s)
- Michael Nyberg
- Department of Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark.
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Padilla J, Simmons GH, Bender SB, Arce-Esquivel AA, Whyte JJ, Laughlin MH. Vascular effects of exercise: endothelial adaptations beyond active muscle beds. Physiology (Bethesda) 2011; 26:132-45. [PMID: 21670160 PMCID: PMC3286126 DOI: 10.1152/physiol.00052.2010] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Endothelial adaptations to exercise training are not exclusively conferred within the active muscle beds. Herein, we summarize key studies that have evaluated the impact of chronic exercise on the endothelium of vasculatures perfusing nonworking skeletal muscle, brain, viscera, and skin, concluding with discussion of potential mechanisms driving these endothelial adaptations.
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Affiliation(s)
- Jaume Padilla
- Biomedical Sciences, University of Missouri, Columbia, Missouri, USA.
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Parker B, Capizzi J, Augeri A, Grimaldi A, Proctor D, Thompson P. Sex-specific effect of aging on submaximal leg exercise hemodynamics in middle-aged and older adults. Eur J Appl Physiol 2010; 111:1369-79. [PMID: 21153657 DOI: 10.1007/s00421-010-1766-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/27/2010] [Indexed: 10/18/2022]
Abstract
The purpose of the study was to examine predictors of the leg hemodynamic response to exercise in middle- and older-aged men and women. Femoral artery blood flow (FBF), mean arterial pressure (MAP), and femoral vascular conductance (FVC, calculated as the quotient of FBF and MAP) were measured at rest and during 5 min of single knee-extensor exercise at ~10 W workload in healthy men (n = 31) and women (n = 32) (age 40-72 years). Age, menopausal status, maximal quadriceps strength, blood lipids, vitamin D levels, maximal oxygen uptake (VO(2max)), physical activity, blood pressure, estimated quadriceps muscle mass, and body mass index (BMI) were also assessed. The effect of age on FBF and FVC was negative and significant in men (r = -0.44 and -0.42 and p = 0.01 and 0.02, respectively) but was abolished by normalization to estimated quadriceps muscle (p = 0.18 and 0.73, respectively). There was no effect of age on leg hemodynamic responses to exercise in women (alone or normalized to quadriceps muscle), but menopausal status was a significant predictor of FVC and normalized FVC (p = 0.04 and 0.02, respectively). The multivariate model for exercising FVC in men (in order of strongest to weakest predictors) included quadriceps strength, BMI, resting FVC, age, and high-density lipoprotein cholesterol. The multivariate model for exercising FVC in women included quadriceps mass, systolic blood pressure, vitamin D, age, VO(2max), waist circumference, and physical activity score. These findings suggest that factors besides chronological age mediate exercising leg hemodynamics in middle-aged to older adults and that these factors are sex-specific.
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Affiliation(s)
- Beth Parker
- Henry Low Heart Center, Department of Cardiology, Hartford Hospital, Hartford, CT 06102, USA.
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30
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Identifying a long standing error in single-bolus determination of the hepatic extraction ratio for indocyanine green. Eur J Appl Physiol 2010; 111:641-6. [DOI: 10.1007/s00421-010-1678-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2010] [Indexed: 11/28/2022]
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31
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Parker BA, Kalasky MJ, Proctor DN. Evidence for sex differences in cardiovascular aging and adaptive responses to physical activity. Eur J Appl Physiol 2010; 110:235-46. [PMID: 20480371 DOI: 10.1007/s00421-010-1506-7] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/03/2010] [Indexed: 11/25/2022]
Abstract
There are considerable data addressing sex-related differences in cardiovascular system aging and disease risk/progression. Sex differences in cardiovascular aging are evident during resting conditions, exercise, and other acute physiological challenges (e.g., orthostasis). In conjunction with these sex-related differences-or perhaps even as an underlying cause-the impact of cardiorespiratory fitness and/or physical activity on the aging cardiovascular system also appears to be sex-specific. Potential mechanisms contributing to sex-related differences in cardiovascular aging and adaptability include changes in sex hormones with age as well as sex differences in baseline fitness and the dose of activity needed to elicit cardiovascular adaptations. The purpose of the present paper is thus to review the primary research regarding sex-specific plasticity of the cardiovascular system to fitness and physical activity in older adults. Specifically, the paper will (1) briefly review known sex differences in cardiovascular aging, (2) detail emerging evidence regarding observed cardiovascular outcomes in investigations of exercise and physical activity in older men versus women, (3) explore mechanisms underlying the differing adaptations to exercise and habitual activity in men versus women, and (4) discuss implications of these findings with respect to chronic disease risk and exercise prescription.
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Affiliation(s)
- Beth A Parker
- Department of Preventive Cardiology, Hartford Hospital, Hartford, CT, USA
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Olivier N, Weissland T, Rogez J, Legrand R, Berthoin S, Thevenon A, Prieur F. Effets d’un entraînement en endurance à partir d’un pédalage unilatéral sur l’oxygénation et le volume sanguin musculaire après chirurgie du genou. Sci Sports 2009. [DOI: 10.1016/j.scispo.2009.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Boone J, Koppo K, Barstow TJ, Bouckaert J. Pattern of deoxy[Hb + Mb] during ramp cycle exercise: influence of aerobic fitness status. Eur J Appl Physiol 2009; 105:851-9. [DOI: 10.1007/s00421-008-0969-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2008] [Indexed: 11/29/2022]
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The oxygen delivery response to acute hypoxia during incremental knee extension exercise differs in active and trained males. DYNAMIC MEDICINE : DM 2008; 7:11. [PMID: 18700024 PMCID: PMC2526084 DOI: 10.1186/1476-5918-7-11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2008] [Accepted: 08/12/2008] [Indexed: 11/10/2022]
Abstract
Background It is well known that hypoxic exercise in healthy individuals increases limb blood flow, leg oxygen extraction and limb vascular conductance during knee extension exercise. However, the effect of hypoxia on cardiac output, and total vascular conductance is less clear. Furthermore, the oxygen delivery response to hypoxic exercise in well trained individuals is not well known. Therefore our aim was to determine the cardiac output (Doppler echocardiography), vascular conductance, limb blood flow (Doppler echocardiography) and muscle oxygenation response during hypoxic knee extension in normally active and endurance-trained males. Methods Ten normally active and nine endurance-trained males (VO2max = 46.1 and 65.5 mL/kg/min, respectively) performed 2 leg knee extension at 25, 50, 75 and 100% of their maximum intensity in both normoxic and hypoxic conditions (FIO2 = 15%; randomized order). Results were analyzed with a 2-way mixed model ANOVA (group × intensity). Results The main finding was that in normally active individuals hypoxic sub-maximal exercise (25 – 75% of maximum intensity) brought about a 3 fold increase in limb blood flow but decreased stroke volume compared to normoxia. In the trained group there were no significant changes in stroke volume, cardiac output and limb blood flow at sub-maximal intensities (compared to normoxia). During maximal intensity hypoxic exercise limb blood flow increased approximately 300 mL/min compared to maximal intensity normoxic exercise. Conclusion Cardiorespiratory fitness likely influences the oxygen delivery response to hypoxic exercise both at a systemic and limb level. The increase in limb blood flow during maximal exercise in hypoxia (both active and trained individuals) suggests a hypoxic stimulus that is not present in normoxic conditions.
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Ferreira LF, McDonough P, Behnke BJ, Musch TI, Poole DC. Blood flow and O2 extraction as a function of O2 uptake in muscles composed of different fiber types. Respir Physiol Neurobiol 2006; 153:237-49. [PMID: 16376620 DOI: 10.1016/j.resp.2005.11.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Revised: 11/08/2005] [Accepted: 11/08/2005] [Indexed: 10/25/2022]
Abstract
We examined how the greater vasodilatory capacity of slow--(ST) versus fast-twitch (FT) muscles impacts the relationship between blood flow (Q ) and O2 uptake (VO2) and, consequently, the O2 extraction (a-vO2 diff.)-to-VO2 relationship. Q was measured with radiolabelled microspheres, while VO2 was calculated by the Fick principle using measurements of microvascular O2 pressure (phosphorescence quenching) at rest, low--(2.5 V) and high-intensity contractions (4.5 V) for soleus (Sol; ST, n=5), mixed-gastrocnemius (MG; FT, n=7) and white-gastrocnemius (WG; FT, n=7). The slope of the Q-to-VO2 relationship (delta Q/delta VO2] ) was not different among muscles (Sol = 5.5 +/- 0.2, MG = 6.0 +/- 0.11 and WG = 5.8 +/- 0.06; P > 0.05). In contrast, the intercept was greater (P < 0.05) for Sol (16.3 +/- 2.7 ml min(-1) 100 g(-1)) versus MG and WG (in ml min(-1) 100 g(-1): 1.39 +/- 0.26 and 1.45 +/- 0.23, respectively; MG and WG, P > 0.05). In addition, the a-vO2 diff.-to-VO2] relationship for Sol was shifted rightward compared to MG and WG. These data suggest that the increase in Q for a given change in VO2 is similar for slow- and fast-twitch muscles, at least for the range of metabolic rates and muscles studied herein and that a-vO2 diff. differences result from the lower resting Q in FT muscles.
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Affiliation(s)
- Leonardo F Ferreira
- Clarenburg Research Laboratory, Department of Anatomy & Physiology, Kansas State University, Manhattan, KS 66506-5802, USA
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36
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Koch DW, Newcomer SC, Proctor DN. Blood Flow to Exercising Limbs Varies With Age, Gender, and Training Status. ACTA ACUST UNITED AC 2005; 30:554-75. [PMID: 16293904 DOI: 10.1139/h05-141] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Understanding the effects of physiological aging on blood flow to active skeletal muscle and its regulation during exercise has important functional, hemodynamic, and metabolic implications for our rapidly expanding elderly population. During peak exercise involving a large muscle mass, blood flow to the legs is lower in healthy older compared to younger persons; this results from central (reduced cardiac output) and peripheral (reduced leg vascular conductance) limitations. There is considerable variability in the literature concerning age-related changes in leg blood flow during submaximal exercise, with reports of similar or reduced leg blood flaw and vascular conductance in older vs. younger subjects depending on the exercise intensity and the gender and training status of the subjects. However, all the studies involving non-endurance-trained subjects are consistent in that older subjects achieve the requisite leg blood flow at higher arterial perfusion pressures than young subjects, suggesting altered local vasoregulatory mechanisms with aging. Although the nature of these age- related alterations is poorly understood, we have preliminary evidence for augmented sympathetic vasoconstrictor responsiveness in the legs of older men during exercise, and blunted leg vasodilator responsiveness in older women. Systematic research will be needed in order to define the central and local mechanisms underlying these age- and gender-specific differences in muscle vascular responsiveness. Such information will be important for designing future interventions aimed at improving muscle blood supply and functional capacity in older persons. Key words: exercise, vascular responsiveness, human
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Affiliation(s)
- Dennis W Koch
- Dept. of Kinesiology, The Pennsylvania State University, University Park, PA 16802, USA
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37
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Lawrenson L, Hoff J, Richardson RS. Aging attenuates vascular and metabolic plasticity but does not limit improvement in muscle VO(2) max. Am J Physiol Heart Circ Physiol 2003; 286:H1565-72. [PMID: 14684375 DOI: 10.1152/ajpheart.01070.2003] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The interactions between exercise, vascular and metabolic plasticity, and aging have provided insight into the prevention and restoration of declining whole body and small muscle mass exercise performance known to occur with age. Metabolic and vascular adaptations to normoxic knee-extensor exercise training (1 h 3 times a week for 8 wk) were compared between six sedentary young (20 +/- 1 yr) and six sedentary old (67 +/- 2 yr) subjects. Arterial and venous blood samples, in conjunction with a thermodilution technique facilitated the measurement of quadriceps muscle blood flow and hematologic variables during incremental knee-extensor exercise. Pretraining, young and old subjects attained a similar maximal work rate (WR(max)) (young = 27 +/- 3, old = 24 +/- 4 W) and similar maximal quadriceps O(2) consumption (muscle Vo(2 max)) (young = 0.52 +/- 0.03, old = 0.42 +/- 0.05 l/min), which increased equally in both groups posttraining (WR(max), young = 38 +/- 1, old = 36 +/- 4 W, Muscle Vo(2 max), young = 0.71 +/- 0.1, old = 0.63 +/- 0.1 l/min). Before training, muscle blood flow was approximately 500 ml lower in the old compared with the young throughout incremental knee-extensor exercise. After 8 wk of knee-extensor exercise training, the young reduced muscle blood flow approximately 700 ml/min, elevated arteriovenous O(2) difference approximately 1.3 ml/dl, and increased leg vascular resistance approximately 17 mmHg x ml(-1) x min(-1), whereas the old subjects revealed no training-induced changes in these variables. Together, these findings indicate that after 8 wk of small muscle mass exercise training, young and old subjects of equal initial metabolic capacity have a similar ability to increase quadriceps muscle WR(max) and muscle Vo(2 max), despite an attenuated vascular and/or metabolic adaptation to submaximal exercise in the old.
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Affiliation(s)
- L Lawrenson
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0623, USA
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Proctor DN, Koch DW, Newcomer SC, Le KU, Leuenberger UA. Impaired leg vasodilation during dynamic exercise in healthy older women. J Appl Physiol (1985) 2003; 95:1963-70. [PMID: 12882993 DOI: 10.1152/japplphysiol.00472.2003] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of the present study was to test the hypothesis that leg blood flow responses during leg cycle ergometry are reduced with age in healthy non-estrogen-replaced women. Thirteen younger (20-27 yr) and thirteen older (61-71 yr) normotensive, non-endurance-trained women performed both graded and constant-load bouts of leg cycling at the same absolute exercise intensities. Leg blood flow (femoral vein thermodilution), mean arterial pressure (MAP; radial artery), mean femoral venous pressure, cardiac output (acetylene rebreathing), and blood O2 contents were measured. Leg blood flow responses at light workloads (20-40 W) were similar in younger and older women. However, at moderate workloads (50-60 W), leg blood flow responses were significantly attenuated in older women. MAP was 20-25 mmHg higher (P < 0.01) in the older women across all work intensities, and calculated leg vascular conductance (leg blood flow/estimated leg perfusion pressure) was lower (P < 0.05). Exercise-induced increases in leg arteriovenous O2 difference and O2 extraction were identical between groups (P > 0.6). Leg O2 uptake was tightly correlated with leg blood flow across all workloads in both subject groups (r2 = 0.80). These results suggest the ability of healthy older women to undergo limb vasodilation in response to submaximal exercise is impaired and that the legs are a potentially important contributor to the augmented systemic vascular resistance seen during dynamic exercise in older women.
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Affiliation(s)
- David N Proctor
- Noll Physiological Research Center, The Pennsylvania State University, University Park 16802-6900, USA.
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Proctor DN, Newcomer SC, Koch DW, Le KU, MacLean DA, Leuenberger UA. Leg blood flow during submaximal cycle ergometry is not reduced in healthy older normally active men. J Appl Physiol (1985) 2003; 94:1859-69. [PMID: 12547841 DOI: 10.1152/japplphysiol.00898.2002] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The purpose of the present study was to test the hypothesis that leg blood flow responses during submaximal cycle ergometry are reduced with age in healthy normally active men. Eleven younger (20-25 yr) and eight older (62-73 yr) normotensive, nonendurance-trained men performed both graded and constant-load bouts of leg cycling at the same absolute and relative [% of peak O(2) consumption (Vo(2 peak))] exercise intensities while leg blood flow (femoral vein thermodilution), mean arterial pressure (MAP; radial artery), cardiac output (acetylene rebreathing), blood O(2) content, and plasma catecholamines were measured. Leg blood flow responses at the same absolute submaximal power outputs (20-100 W) and at a fixed systemic O(2) demand (1.1 l/min) did not differ between groups (P = 0.14-0.19), despite lower absolute levels of cardiac output in the older men (P < 0.05). MAP at the same absolute power outputs was 8-12 mmHg higher (P < 0.05) in the older men, but calculated leg vascular conductance responses (leg blood flow/MAP) were identical in the two groups (P > 0.9). At the same relative intensity (60% Vo(2 peak)), leg norepinephrine spillover rates were approximately twofold higher in the older men (P = 0.38). Exercise-induced increases in leg arterial-venous O(2) difference were identical between groups (P > 0.9) because both arterial and venous O(2) contents were lower in the older vs. younger men. These results suggest that the ability to augment active limb blood flow and O(2) extraction during submaximal large muscle mass exercise is not impaired but is well preserved with age in healthy men who are normally active.
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Affiliation(s)
- David N Proctor
- Noll Physiological Research Center, Department of Kinesiology, The Pennsylvania State University, University Park, 16802-6900, USA.
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