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Ortiz de Zevallos J, Hogwood AC, Kruse K, De Guzman J, Buckley M, Weltman AL, Allen JD. Sex differences in the effects of inorganic nitrate supplementation on exercise economy and endurance capacity in healthy young adults. J Appl Physiol (1985) 2023; 135:1157-1166. [PMID: 37823208 DOI: 10.1152/japplphysiol.00220.2023] [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: 04/06/2023] [Revised: 10/10/2023] [Accepted: 10/10/2023] [Indexed: 10/13/2023] Open
Abstract
Dietary nitrate (NO3-) is a widely used supplement purported to provide beneficial effects during exercise. Most studies to date include predominantly males. Therefore, the present study aimed to investigate if there is a sex-dependent effect of NO3- supplementation on exercise outcomes. We hypothesized that both sexes would exhibit improvements in exercise economy and exercise capacity following NO3- supplementation, but males would benefit to a greater extent. In a double-blind, randomized, crossover study, twelve females (24 ± 4 yr) and fourteen males (23 ± 4 yr) completed two 4-min moderate-intensity (MOD) exercise bouts followed by a time-to-exhaustion (TTE) task after following 3 days of NO3- supplementation (beetroot juice or BRJ) or NO3--depleted placebo (PL). Females were tested during the early follicular phase of the menstrual cycle. During MOD exercise, BRJ reduced the steady-state V̇o2 by ∼5% in males (M: Δ -87 ± 115 mL·min-1; P < 0.05) but not in females (F: Δ 6 ± 195 mL·min-1). Similarly, BRJ extended TTE by ∼15% in males (P < 0.05) but not in females. Dietary NO3- supplementation improved exercise economy during moderate-intensity exercise and exercise capacity during severe-intensity TTE in males but not in females. These differences could be related to estrogen levels, antioxidant capacity, nitrate-reducing bacteria, or a variety of known physiologic differences such as skeletal muscle calcium handling, and/or fiber type. Overall, our data suggests the ergogenic benefits of oral NO3- supplementation found in studies predominantly on male subjects may not be applicable to females.NEW & NOTEWORTHY While inorganic nitrate (NO3-) supplementation has increased in popularity as an ergogenic aid to improve exercise performance, the role of sex in NO3- supplementation on exercise outcomes is lacking despite known physiological differences during exercise between sex. This study revealed that males, but not females, improved exercise economy during submaximal exercise and exercise capacity during exercise within the severe-intensity domain following NO3- supplementation.
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Affiliation(s)
- Joaquin Ortiz de Zevallos
- Department of Kinesiology, School of Education and Human Development, University of Virginia, Charlottesville, Virginia, United States
| | - Austin C Hogwood
- Department of Kinesiology, School of Education and Human Development, University of Virginia, Charlottesville, Virginia, United States
| | - Ka'eo Kruse
- Department of Kinesiology, School of Education and Human Development, University of Virginia, Charlottesville, Virginia, United States
| | - Jeison De Guzman
- Department of Kinesiology, School of Education and Human Development, University of Virginia, Charlottesville, Virginia, United States
| | - Meredith Buckley
- Department of Kinesiology, School of Education and Human Development, University of Virginia, Charlottesville, Virginia, United States
| | - Arthur L Weltman
- Department of Kinesiology, School of Education and Human Development, University of Virginia, Charlottesville, Virginia, United States
- Division of Cardiovascular Medicine, School of Medicine, University of Virginia, Charlottesville, Virginia, United States
| | - Jason D Allen
- Department of Kinesiology, School of Education and Human Development, University of Virginia, Charlottesville, Virginia, United States
- Division of Cardiovascular Medicine, School of Medicine, University of Virginia, Charlottesville, Virginia, United States
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Skeletal muscle as a reservoir for nitrate and nitrite: The role of xanthine oxidase reductase (XOR). Nitric Oxide 2022; 129:102-109. [DOI: 10.1016/j.niox.2022.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 09/16/2022] [Accepted: 10/20/2022] [Indexed: 11/06/2022]
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Ruan Y, Xiang KF, Zhang HM, Qin Z, Sun Y, Wan JJ, Gu W, Liu X. Orosomucoid: a promising biomarker for the assessment of exercise-induced fatigue triggered by basic combat training. BMC Sports Sci Med Rehabil 2022; 14:100. [PMID: 35658935 PMCID: PMC9166395 DOI: 10.1186/s13102-022-00490-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 05/19/2022] [Indexed: 11/22/2022]
Abstract
Background Orosomucoid (ORM) is a positive acute phase protein verified to be upregulated in various forms of exercise-induced fatigued (EIF) rodents. However, its association with EIF among human beings remained unknown. This study aimed to explore the association between serum ORM and EIF triggered by military basic combat training (BCT). Methods The degree of EIF were measured by Borg’s Rating of Perceived Exertion Scale (Borg-RPE-Scale®) as RPE score after BCT. Fifty-three male recruits were classified into three groups according to the RPE score: (1) group 1 (slight fatigue group): RPE score after BCT < 13; (2) group 2 (moderate fatigue group): RPE score after BCT = 13 or 14; (3) group 3 (severe fatigue group): RPE score after BCT > 14. The levels of blood ORM, lactate (LAC), cortisol and C-reactive protein (CRP) were determined before and after BCT. The diagnostic value of ORM was evaluated by receiver operating characteristic (ROC) curve analysis and logistic regression. Results After BCT, the level of LAC, CRP, and cortisol increased among all groups, but the changes had no significant between-group difference (all p > 0.05). The level of ORM had a specific significant increase in group 3 (p = 0.039), and the changes of ORM (ΔORM) had significant difference among groups (p = 0.033). ROC curve analysis showed that the estimated area under ROC curve for ΔORM was 0.724 (p = 0.009) with the recommended optimal cut-off value as 0.2565 mg/mL. Logistic analysis showed that recruits with ΔORM ≥ 0.2565 mg/mL had higher odds for suffering from severe EIF, 5.625 times (95% CI 1.542–20.523, p = 0.009) as large as those with ΔORM < 0.2565 mg/mL. Conclusion ORM might be a promising biomarker of severe EIF triggered by BCT among male recruits. Its potential optimal cut-off value regarding ΔORM was recommended to be 0.2565 mg/mL. Supplementary Information The online version contains supplementary material available at 10.1186/s13102-022-00490-6.
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Affiliation(s)
- Yi Ruan
- Department of Pharmacology, School of Pharmacy, Naval Medical University (Second Military Medical University), Shanghai, 200433, China.,School of Traditional Chinese Medicine, Naval Medical University (Second Military Medical University), Shanghai, 200433, China
| | - Ke-Fa Xiang
- Department of Pharmacology, School of Pharmacy, Naval Medical University (Second Military Medical University), Shanghai, 200433, China
| | - Hui-Min Zhang
- Department of Pharmacology, School of Pharmacy, Naval Medical University (Second Military Medical University), Shanghai, 200433, China
| | - Zhen Qin
- Department of Pharmacology, School of Pharmacy, Naval Medical University (Second Military Medical University), Shanghai, 200433, China
| | - Yang Sun
- Department of Pharmacology, School of Pharmacy, Naval Medical University (Second Military Medical University), Shanghai, 200433, China
| | - Jing-Jing Wan
- Department of Pharmacology, School of Pharmacy, Naval Medical University (Second Military Medical University), Shanghai, 200433, China
| | - Wei Gu
- School of Traditional Chinese Medicine, Naval Medical University (Second Military Medical University), Shanghai, 200433, China.
| | - Xia Liu
- Department of Pharmacology, School of Pharmacy, Naval Medical University (Second Military Medical University), Shanghai, 200433, China.
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Ferretti G, Fagoni N, Taboni A, Vinetti G, di Prampero PE. A century of exercise physiology: key concepts on coupling respiratory oxygen flow to muscle energy demand during exercise. Eur J Appl Physiol 2022; 122:1317-1365. [PMID: 35217911 PMCID: PMC9132876 DOI: 10.1007/s00421-022-04901-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 01/25/2022] [Indexed: 12/26/2022]
Abstract
After a short historical account, and a discussion of Hill and Meyerhof's theory of the energetics of muscular exercise, we analyse steady-state rest and exercise as the condition wherein coupling of respiration to metabolism is most perfect. The quantitative relationships show that the homeostatic equilibrium, centred around arterial pH of 7.4 and arterial carbon dioxide partial pressure of 40 mmHg, is attained when the ratio of alveolar ventilation to carbon dioxide flow ([Formula: see text]) is - 21.6. Several combinations, exploited during exercise, of pertinent respiratory variables are compatible with this equilibrium, allowing adjustment of oxygen flow to oxygen demand without its alteration. During exercise transients, the balance is broken, but the coupling of respiration to metabolism is preserved when, as during moderate exercise, the respiratory system responds faster than the metabolic pathways. At higher exercise intensities, early blood lactate accumulation suggests that the coupling of respiration to metabolism is transiently broken, to be re-established when, at steady state, blood lactate stabilizes at higher levels than resting. In the severe exercise domain, coupling cannot be re-established, so that anaerobic lactic metabolism also contributes to sustain energy demand, lactate concentration goes up and arterial pH falls continuously. The [Formula: see text] decreases below - 21.6, because of ensuing hyperventilation, while lactate keeps being accumulated, so that exercise is rapidly interrupted. The most extreme rupture of the homeostatic equilibrium occurs during breath-holding, because oxygen flow from ambient air to mitochondria is interrupted. No coupling at all is possible between respiration and metabolism in this case.
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Affiliation(s)
- Guido Ferretti
- Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Brescia, Italy.
- Département d'Anesthésiologie, Pharmacologie et Soins Intensifs, Université de Genève, Genève, Switzerland.
| | - Nazzareno Fagoni
- Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Brescia, Italy
| | - Anna Taboni
- Département d'Anesthésiologie, Pharmacologie et Soins Intensifs, Université de Genève, Genève, Switzerland
| | - Giovanni Vinetti
- Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Brescia, Italy
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No differences in splenic emptying during on-transient supine cycling between aerobically trained and untrained participants. Eur J Appl Physiol 2022; 122:903-917. [PMID: 35013810 PMCID: PMC8747858 DOI: 10.1007/s00421-021-04843-w] [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: 07/09/2021] [Accepted: 11/09/2021] [Indexed: 11/17/2022]
Abstract
Purpose The role of splenic emptying in O2 transport during aerobic exercise still remains a matter of debate. Our study compared the differences in spleen volume changes between aerobically trained and untrained individuals during step-transition supine cycling exercise at moderate-intensity. We also examined the relationship between spleen volume changes, erythrocyte release, and O2 uptake parameters. Methods Fourteen healthy men completed all study procedures, including a detailed medical examination, supine maximal O2 uptake (\documentclass[12pt]{minimal}
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\begin{document}$${\dot{\text{V}}\text{O}}_{2}$$\end{document}V˙O2 max.) test, and three step-transitions from 20 W to a moderate-intensity power output, equivalent to \documentclass[12pt]{minimal}
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\begin{document}$${\dot{\text{V}}\text{O}}_{2}$$\end{document}V˙O2 uptake at 90% gas exchange threshold. During these step-transitions pulmonary \documentclass[12pt]{minimal}
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\begin{document}$${\dot{\text{V}}\text{O}}_{{2{\text{p}}}}$$\end{document}V˙O2p, near-infrared spectroscopy of the vastus lateralis, and cardiovascular responses were continuously measured. In parallel, minute-by-minute ultrasonic measurements of the spleen were performed. Blood samples were taken before and immediately after step-transition cycling. Results On average, \documentclass[12pt]{minimal}
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\begin{document}$${\dot{\text{V}}\text{O}}_{2}$$\end{document}V˙O2 max. was 10 mL kg min−1 (p = 0.001) higher in trained compared to their aerobically untrained peers. In response to supine step-transition cycling, the splenic volume was significantly reduced, and the largest reduction (~ 106 to 115 mL, ~ 38%, p = 0.001) was similar in both aerobically trained and untrained individuals. Erythrocyte concentration and platelet count transiently increased after exercise cessation, with no differences observed between groups. However, the vastus lateralis deoxygenation amplitude was 30% (p = 0.001) greater in trained compared to untrained individuals. No associations existed between: (i) spleen volumes at rest (ii) spleen volume changes (%), (iii) resting hematocrit and oxygen uptake parameters. Conclusion Greater splenic emptying and subsequent erythrocyte release do not lead to a slower \documentclass[12pt]{minimal}
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\begin{document}$$\tau {\dot{\text{V}}\text{O}}_{{2{\text{p}}}}$$\end{document}τV˙O2p, regardless of individual \documentclass[12pt]{minimal}
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\begin{document}$${\dot{\text{V}}\text{O}}_{2}$$\end{document}V˙O2 max. readings.
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Lewis MT, Levitsky Y, Bazil JN, Wiseman RW. Measuring Mitochondrial Function: From Organelle to Organism. Methods Mol Biol 2022; 2497:141-172. [PMID: 35771441 DOI: 10.1007/978-1-0716-2309-1_10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Mitochondrial energy production is crucial for normal daily activities and maintenance of life. Herein, the logic and execution of two main classes of measurements are outlined to delineate mitochondrial function: ATP production and oxygen consumption. Aerobic ATP production is quantified by phosphorus magnetic resonance spectroscopy (31PMRS) in vivo in both human subjects and animal models using the same protocols and maintaining the same primary assumptions. Mitochondrial oxygen consumption is quantified by oxygen polarography and applied in isolated mitochondria, cultured cells, and permeabilized fibers derived from human or animal tissue biopsies. Traditionally, mitochondrial functional measures focus on maximal oxidative capacity-a flux rate that is rarely, if ever, observed outside of experimental conditions. Perhaps more physiologically relevant, both measurement classes herein focus on one principal design paradigm; submaximal mitochondrial fluxes generated by graded levels of ADP to map the function for ADP sensitivity. We propose this function defines the bioenergetic role that mitochondria fill within the myoplasm to sense and match ATP demands. Any deficit in this vital role for ATP homeostasis leads to symptoms often seen in cardiovascular and cardiopulmonary diseases, diabetes, and metabolic syndrome.
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Affiliation(s)
- Matthew T Lewis
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA.,Geriatric Research, Education, and Clinical Center, VA Medical Center, Salt Lake City, UT, USA
| | - Yan Levitsky
- Department of Physiology, Michigan State University, East Lansing, MI, USA
| | - Jason N Bazil
- Department of Physiology, Michigan State University, East Lansing, MI, USA
| | - Robert W Wiseman
- Department of Physiology, Michigan State University, East Lansing, MI, USA. .,Department of Radiology, Michigan State University, East Lansing, MI, USA.
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7
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Grassi B, Quaresima V. Mathematical modeling versus experimental data: how to interpret conflicting evidence? J Appl Physiol (1985) 2022; 132:220-221. [PMID: 35030042 DOI: 10.1152/japplphysiol.00796.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Bruno Grassi
- Department of Medicine, University of Udine, Udine, Italy
| | - Valentina Quaresima
- Department of Life, Health and Environmental Science, University of L'Aquila, L'Aquila, Italy
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8
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Lewis MT, Blain GM, Hart CR, Layec G, Rossman MJ, Park SY, Trinity JD, Gifford JR, Sidhu SK, Weavil JC, Hureau TJ, Jessop JE, Bledsoe AD, Amann M, Richardson RS. Acute high-intensity exercise and skeletal muscle mitochondrial respiratory function: role of metabolic perturbation. Am J Physiol Regul Integr Comp Physiol 2021; 321:R687-R698. [PMID: 34549627 DOI: 10.1152/ajpregu.00158.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Recently it was documented that fatiguing, high-intensity exercise resulted in a significant attenuation in maximal skeletal muscle mitochondrial respiratory capacity, potentially due to the intramuscular metabolic perturbation elicited by such intense exercise. With the utilization of intrathecal fentanyl to attenuate afferent feedback from group III/IV muscle afferents, permitting increased muscle activation and greater intramuscular metabolic disturbance, this study aimed to better elucidate the role of metabolic perturbation on mitochondrial respiratory function. Eight young, healthy males performed high-intensity cycle exercise in control (CTRL) and fentanyl-treated (FENT) conditions. Liquid chromatography-mass spectrometry and high-resolution respirometry were used to assess metabolites and mitochondrial respiratory function, respectively, pre- and postexercise in muscle biopsies from the vastus lateralis. Compared with CTRL, FENT yielded a significantly greater exercise-induced metabolic perturbation (PCr: -67% vs. -82%, Pi: 353% vs. 534%, pH: -0.22 vs. -0.31, lactate: 820% vs. 1,160%). Somewhat surprisingly, despite this greater metabolic perturbation in FENT compared with CTRL, with the only exception of respiratory control ratio (RCR) (-3% and -36%) for which the impact of FENT was significantly greater, the degree of attenuated mitochondrial respiratory capacity postexercise was not different between CTRL and FENT, respectively, as assessed by maximal respiratory flux through complex I (-15% and -33%), complex II (-36% and -23%), complex I + II (-31% and -20%), and state 3CI+CII control ratio (-24% and -39%). Although a basement effect cannot be ruled out, this failure of an augmented metabolic perturbation to extensively further attenuate mitochondrial function questions the direct role of high-intensity exercise-induced metabolite accumulation in this postexercise response.
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Affiliation(s)
- Matthew T Lewis
- Division of Geriatrics, Department of Medicine, University of Utah, Salt Lake City, Utah.,Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Gregory M Blain
- LAMHESS, University Nice Sophia Antipolis, Nice, France.,LAMHESS, University of Toulon, La Garde, France
| | - Corey R Hart
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah
| | - Gwenael Layec
- Division of Geriatrics, Department of Medicine, University of Utah, Salt Lake City, Utah.,Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Matthew J Rossman
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah
| | - Song-Young Park
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah.,School of Health and Kinesiology, University of Nebraska, Omaha, Nebraska
| | - Joel D Trinity
- Division of Geriatrics, Department of Medicine, University of Utah, Salt Lake City, Utah.,Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Jayson R Gifford
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah
| | - Simranjit K Sidhu
- Division of Geriatrics, Department of Medicine, University of Utah, Salt Lake City, Utah.,Discipline of Physiology, School of Medicine, University of Adelaide, Adelaide, South Australia, Australia
| | - Joshua C Weavil
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah
| | - Thomas J Hureau
- Division of Geriatrics, Department of Medicine, University of Utah, Salt Lake City, Utah.,LAMHESS, University Nice Sophia Antipolis, Nice, France.,LAMHESS, University of Toulon, La Garde, France
| | - Jacob E Jessop
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| | - Amber D Bledsoe
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| | - Markus Amann
- Division of Geriatrics, Department of Medicine, University of Utah, Salt Lake City, Utah.,Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah.,Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| | - Russell S Richardson
- Division of Geriatrics, Department of Medicine, University of Utah, Salt Lake City, Utah.,Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
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9
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Goulding RP, Okushima D, Marwood S, Poole DC, Barstow TJ, Lei TH, Kondo N, Koga S. Impact of supine exercise on muscle deoxygenation kinetics heterogeneity: mechanistic insights into slow pulmonary oxygen uptake dynamics. J Appl Physiol (1985) 2020; 129:535-546. [PMID: 32702271 DOI: 10.1152/japplphysiol.00213.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Oxygen uptake (V̇o2) kinetics are slowed in the supine (S) position purportedly due to impaired muscle O2 delivery ([Formula: see text]); however, these conclusions are predicated on single-site measurements in superficial muscle using continuous-wave near-infrared spectroscopy (NIRS). This study aimed to determine the impact of body position [i.e., upright (U) versus S] on deep and superficial muscle deoxygenation (deoxy[heme]) using time-resolved (TR-) NIRS, and how these relate to slowed pulmonary V̇o2 kinetics. Seventeen healthy men completed constant power tests during 1) S heavy-intensity exercise and 2) U exercise at the same absolute work rate, with a subset of 10 completing additional tests at the same relative work rate as S. Pulmonary V̇o2 was measured breath-by-breath and, deoxy- and total[heme] were resolved via TR-NIRS in the superficial and deep vastus lateralis and superficial rectus femoris. The fundamental phase V̇o2 time constant was increased during S compared with U (S: 36 ± 10 vs. U: 27 ± 8 s; P < 0.001). The deoxy[heme] amplitude (S: 25-28 vs. U: 13-18 µM; P < 0.05) and total[heme] amplitude (S: 17-20 vs. U: 9-16 µM; P < 0.05) were greater in S compared with U and were consistent for the same absolute (above data) and relative work rates (n = 10, all P < 0.05). The greater deoxy- and total[heme] amplitudes in S vs. U supports that reduced perfusive [Formula: see text] in S, even within deep muscle, necessitated a greater reliance on fractional O2 extraction and diffusive [Formula: see text]. The slower V̇o2 kinetics in S versus U demonstrates that, ultimately, these adjustments were insufficient to prevent impairments in whole body oxidative metabolism.NEW & NOTEWORTHY We show that supine exercise causes a greater degree of muscle deoxygenation in both deep and superficial muscle and increases the spatial heterogeneity of muscle deoxygenation. Therefore, this study suggests that any O2 delivery gradient toward deep versus superficial muscle is insufficient to mitigate impairments in oxidative function in response to reduced whole muscle O2 delivery. More heterogeneous muscle deoxygenation is associated with slower V̇o2 kinetics.
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Affiliation(s)
- Richie P Goulding
- Applied Physiology Laboratory, Kobe Design University, Kobe, Japan.,International Research Fellow of Japan Society for Promotion of Sciences, Tokyo, Japan
| | - Dai Okushima
- Osaka International University, Moriguchi, Japan
| | - Simon Marwood
- School of Health Sciences, Liverpool Hope University, Liverpool, Merseyside, United Kingdom
| | - David C Poole
- Departments of Anatomy and Physiology, and Kinesiology, Kansas State University, Manhattan, Kansas
| | - Thomas J Barstow
- Departments of Anatomy and Physiology, and Kinesiology, Kansas State University, Manhattan, Kansas
| | - Tze-Huan Lei
- International Research Fellow of Japan Society for Promotion of Sciences, Tokyo, Japan.,Applied Physiology Laboratory, Kobe University, Kobe, Japan
| | - Narihiko Kondo
- Applied Physiology Laboratory, Kobe University, Kobe, Japan
| | - Shunsaku Koga
- Applied Physiology Laboratory, Kobe Design University, Kobe, Japan
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10
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Colburn TD, Hirai DM, Craig JC, Ferguson SK, Weber RE, Schulze KM, Behnke BJ, Musch TI, Poole DC. Transcapillary PO 2 gradients in contracting muscles across the fibre type and oxidative continuum. J Physiol 2020; 598:3187-3202. [PMID: 32445225 DOI: 10.1113/jp279608] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 05/14/2020] [Indexed: 12/11/2022] Open
Abstract
KEY POINTS Within skeletal muscle the greatest resistance to oxygen transport is thought to reside across the short distance at the red blood cell-myocyte interface. These structures generate a significant transmural oxygen pressure (PO2 ) gradient in mixed fibre-type muscle. Increasing O2 flux across the capillary wall during exercise depends on: (i) the transmural O2 pressure gradient, which is maintained in mixed-fibre muscle, and/or (ii) elevating diffusing properties between microvascular and interstitial compartments resulting, in part, from microvascular haemodynamics and red blood cell distribution. We evaluated the PO2 within the microvascular and interstitial spaces of muscles spanning the slow- to fast-twitch fibre and high- to low-oxidative capacity spectrums, at rest and during contractions, to assess the magnitude of transcapillary PO2 gradients in rats. Our findings demonstrate that, across the metabolic rest-contraction transition, the transcapillary pressure gradient for O2 flux is: (i) maintained in all muscle types, and (ii) the lowest in contracting highly oxidative fast-twitch muscle. ABSTRACT In mixed fibre-type skeletal muscle transcapillary PO2 gradients (PO2 mv-PO2 is; microvascular and interstitial, respectively) drive O2 flux across the blood-myocyte interface where the greatest resistance to that O2 flux resides. We assessed a broad spectrum of fibre-type and oxidative-capacity rat muscles across the rest-to-contraction (1 Hz, 120 s) transient to test the novel hypotheses that: (i) slow-twitch PO2 is would be greater than fast-twitch, (ii) muscles with greater oxidative capacity have greater PO2 is than glycolytic counterparts, and (iii) whether PO2 mv-PO2 is at rest is maintained during contractions across all muscle types. PO2 mv and PO2 is were determined via phosphorescence quenching in soleus (SOL; 91% type I+IIa fibres and CSa: ∼21 μmol min-1 g-1 ), peroneal (PER; 33% and ∼20 μmol min-1 g-1 ), mixed (MG; 9% and ∼26 μmol min-1 g-1 ) and white gastrocnemius (WG; 0% and ∼8 μmol min-1 g-1 ) across the rest-contraction transient. PO2 mv was higher than PO2 is in each muscle (∼6-13 mmHg; P < 0.05). SOL PO2 isarea was greater than in the fast-twitch muscles during contractions (P < 0.05). Oxidative muscles had greater PO2 isnadir (9.4 ± 0.8, 7.4 ± 0.9 and 6.4 ± 0.4; SOL, PER and MG, respectively) than WG (3.0 ± 0.3 mmHg, P < 0.05). The magnitude of PO2 mv-PO2 is at rest decreased during contractions in MG only (∼11 to 7 mmHg; time × (PO2 mv-PO2 is) interaction, P < 0.05). These data support the hypothesis that, since transcapillary PO2 gradients during contractions are maintained in all muscle types, increased O2 flux must occur via enhanced intracapillary diffusing conductance, which is most extreme in highly oxidative fast-twitch muscle.
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Affiliation(s)
| | - Daniel M Hirai
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN
| | - Jesse C Craig
- Department of Internal Medicine, University of Utah, Salt Lake City, UT
| | - Scott K Ferguson
- Department of Kinesiology and Exercise Sciences, University of Hawaii, Hilo, HI
| | - Ramona E Weber
- Department of Kinesiology, Kansas State University Manhattan, KS
| | - Kiana M Schulze
- Department of Kinesiology, Kansas State University Manhattan, KS
| | - Brad J Behnke
- Department of Kinesiology, Kansas State University Manhattan, KS
| | - Timothy I Musch
- Department of Kinesiology, Kansas State University Manhattan, KS.,Department of Anatomy and Physiology, Kansas State University Manhattan, KS
| | - David C Poole
- Department of Kinesiology, Kansas State University Manhattan, KS.,Department of Anatomy and Physiology, Kansas State University Manhattan, KS
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11
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Corvino RB, Oliveira MFM, Denadai BS, Rossiter HB, Caputo F. Speeding of oxygen uptake kinetics is not different following low-intensity blood-flow-restricted and high-intensity interval training. Exp Physiol 2019; 104:1858-1867. [PMID: 31613029 DOI: 10.1113/ep087727] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 10/10/2019] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Can interval blood-flow-restricted (BFR) cycling training, undertaken at a low intensity, promote a similar adaptation to oxygen uptake ( V ̇ O 2 ) kinetics to high-intensity interval training? What is the main finding and its importance? Speeding of pulmonary V ̇ O 2 on-kinetics in healthy young subjects was not different between low-intensity interval BFR training and traditional high-intensity interval training. Given that very low workloads are well tolerated during BFR cycle training and speed V ̇ O 2 on-kinetics, this training method could be used when high mechanical loads are contraindicated. ABSTRACT Low-intensity blood-flow-restricted (BFR) endurance training is effective to increase aerobic capacity. Whether it speeds pulmonary oxygen uptake ( V ̇ O 2 p ), CO2 output ( V ̇ C O 2 p ) and ventilatory ( V ̇ Ep ) kinetics has not been examined. We hypothesized that low-intensity BFR training would reduce the phase 2 time constant (τp ) of V ̇ O 2 p , V ̇ C O 2 p and V ̇ Ep by a similar magnitude to traditional high-intensity interval training (HIT). Low-intensity interval training with BFR served as a control. Twenty-four participants (25 ± 6 years old; maximal V ̇ O 2 46 ± 6 ml kg-1 min-1 ) were assigned to one of the following: low-intensity BFR interval training (BFR; n = 8); low-intensity interval training without BFR (LOW; n = 7); or high-intensity interval training without BFR (HIT; n = 9). Training was 12 sessions of two sets of five to eight × 2 min cycling and 1 min resting intervals. LOW and BFR were conducted at 30% of peak incremental power (Ppeak ), and HIT was at ∼103% Ppeak . For BFR, cuffs were inflated on both thighs (140-200 mmHg) during exercise and deflated during rest intervals. Six moderate-intensity step transitions (30% Ppeak ) were averaged for analysis of pulmonary on-kinetics. Both BFR (pre- versus post-training τp = 18.3 ± 3.2 versus 14.5 ± 3.4 s; effect size = 1.14) and HIT (τp = 20.3 ± 4.0 versus 13.1 ± 2.9 s; effect size = 1.75) reduced the V ̇ O 2 p τp (P < 0.05). As expected, there was no change in LOW ( V ̇ O 2 p τp = 17.9 ± 6.2 versus 17.7 ± 4.3 s; P = 0.9). The kinetics of V ̇ C O 2 p and V ̇ Ep were speeded only after HIT (38.5 ± 10.6%, P < 0.001 and 31.2 ± 24.7%, P = 0.004, respectively). Both HIT and low-intensity BFR training were effective in speeding moderate-intensity V ̇ O 2 p kinetics. These data support the findings of others that low-intensity cycling training with BFR increases muscle oxidative capacity.
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Affiliation(s)
- Rogério B Corvino
- Human Performance Research Group, Center for Health and Exercise Science, Santa Catarina State University, Florianopolis, Brazil
| | - Mariana F M Oliveira
- Human Performance Research Group, Center for Health and Exercise Science, Santa Catarina State University, Florianopolis, Brazil.,Physical Effort Laboratory, Sports Center, Federal University of the State of Santa Catarina, Florianopolis, Brazil
| | - Benedito S Denadai
- Physical Effort Laboratory, Sports Center, Federal University of the State of Santa Catarina, Florianopolis, Brazil.,Human Performance Laboratory, São Paulo State University, Rio Claro, Brazil
| | - Harry B Rossiter
- Division of Pulmonary and Critical Care Physiology and Medicine, Rehabilitation Clinical Trials Center, Los Angeles Biomedical Research Center at Harbor-UCLA Medical Center, Torrance, CA, USA.,School of Biomedical Sciences, University of Leeds, Leeds, UK
| | - Fabrizio Caputo
- Human Performance Research Group, Center for Health and Exercise Science, Santa Catarina State University, Florianopolis, Brazil
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12
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Chung S, Nelson MD, Hamaoka T, Jacobs RA, Pearson J, Subudhi AW, Jenkins NT, Bartlett MF, Fitzgerald LF, Miehm JD, Kent JA, Lucero AA, Rowlands DS, Stoner L, McCully KK, Call J, Rodriguez-Miguelez P, Harris RA, Porcelli S, Rasica L, Marzorati M, Quaresima V, Ryan TE, Vernillo G, Millet GP, Malatesta D, Millet GY, Zuo L, Chuang CC. Commentaries on Viewpoint: Principles, insights, and potential pitfalls of the noninvasive determination of muscle oxidative capacity by near-infrared spectroscopy. J Appl Physiol (1985) 2019; 124:249-255. [PMID: 29364790 DOI: 10.1152/japplphysiol.00857.2017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | - Lee Stoner
- Massey University,University of North Carolina at Chapel Hill
| | | | | | | | | | | | - Letizia Rasica
- National Research Council, Italy,University of Milan, Italy
| | | | | | | | | | | | | | | | - Li Zuo
- The Ohio State University College of Medicine
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13
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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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14
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Craig JC, Colburn TD, Caldwell JT, Hirai DM, Tabuchi A, Baumfalk DR, Behnke BJ, Ade CJ, Musch TI, Poole DC. Central and peripheral factors mechanistically linked to exercise intolerance in heart failure with reduced ejection fraction. Am J Physiol Heart Circ Physiol 2019; 317:H434-H444. [PMID: 31225988 DOI: 10.1152/ajpheart.00164.2019] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Exercise intolerance is a primary symptom of heart failure (HF); however, the specific contribution of central and peripheral factors to this intolerance is not well described. The hyperbolic relationship between exercise intensity and time to exhaustion (speed-duration relationship) defines exercise tolerance but is underused in HF. We tested the hypotheses that critical speed (CS) would be reduced in HF, resting central functional measurements would correlate with CS, and the greatest HF-induced peripheral dysfunction would occur in more oxidative muscle. Multiple treadmill-constant speed runs to exhaustion were used to quantify CS and D' (distance coverable above CS) in healthy control (Con) and HF rats. Central function was determined via left ventricular (LV) Doppler echocardiography [fractional shortening (FS)] and a micromanometer-tipped catheter [LV end-diastolic pressure (LVEDP)]. Peripheral O2 delivery-to-utilization matching was determined via phosphorescence quenching (interstitial Po2, Po2 is) in the soleus and white gastrocnemius during electrically induced twitch contractions (1 Hz, 8V). CS was lower in HF compared with Con (37 ± 1 vs. 44 ± 1 m/min, P < 0.001), but D' was not different (77 ± 8 vs. 69 ± 13 m, P = 0.6). HF reduced FS (23 ± 2 vs. 47 ± 2%, P < 0.001) and increased LVEDP (15 ± 1 vs. 7 ± 1 mmHg, P < 0.001). CS was related to FS (r = 0.72, P = 0.045) and LVEDP (r = -0.75, P = 0.02) only in HF. HF reduced soleus Po2 is at rest and during contractions (both P < 0.01) but had no effect on white gastrocnemius Po2 is (P > 0.05). We show in HF rats that decrements in central cardiac function relate directly with impaired exercise tolerance (i.e., CS) and that this compromised exercise tolerance is likely due to reduced perfusive and diffusive O2 delivery to oxidative muscles.NEW & NOTEWORTHY We show that critical speed (CS), which defines the upper boundary of sustainable activity, can be resolved in heart failure (HF) animals and is diminished compared with controls. Central cardiac function is strongly related with CS in the HF animals, but not controls. Skeletal muscle O2 delivery-to-utilization dysfunction is evident in the more oxidative, but not glycolytic, muscles of HF rats and is explained, in part, by reduced nitric oxide bioavailability.
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Affiliation(s)
- Jesse C Craig
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - Trenton D Colburn
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - Jacob T Caldwell
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - Daniel M Hirai
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - Ayaka Tabuchi
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - Dryden R Baumfalk
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - Bradley J Behnke
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - Carl J Ade
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - 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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GRASSI BRUNO, PORCELLI SIMONE, MARZORATI MAURO. Translational Medicine: Exercise Physiology Applied to Metabolic Myopathies. Med Sci Sports Exerc 2019; 51:2183-2192. [DOI: 10.1249/mss.0000000000002056] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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16
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Poole DC. Edward F. Adolph Distinguished Lecture. Contemporary model of muscle microcirculation: gateway to function and dysfunction. J Appl Physiol (1985) 2019; 127:1012-1033. [PMID: 31095460 DOI: 10.1152/japplphysiol.00013.2019] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
This review strikes at the very heart of how the microcirculation functions to facilitate blood-tissue oxygen, substrate, and metabolite fluxes in skeletal muscle. Contemporary evidence, marshalled from animals and humans using the latest techniques, challenges iconic perspectives that have changed little over the past century. Those perspectives include the following: the presence of contractile or collapsible capillaries in muscle, unitary control by precapillary sphincters, capillary recruitment at the onset of contractions, and the notion of capillary-to-mitochondrial diffusion distances as limiting O2 delivery. Today a wealth of physiological, morphological, and intravital microscopy evidence presents a completely different picture of microcirculatory control. Specifically, capillary red blood cell (RBC) and plasma flux is controlled primarily at the arteriolar level with most capillaries, in healthy muscle, supporting at least some flow at rest. In healthy skeletal muscle, this permits substrate access (whether carried in RBCs or plasma) to a prodigious total capillary surface area. Pathologies such as heart failure or diabetes decrease access to that exchange surface by reducing the proportion of flowing capillaries at rest and during exercise. Capillary morphology and function vary disparately among tissues. The contemporary model of capillary function explains how, following the onset of exercise, muscle O2 uptake kinetics can be extremely fast in health but slowed in heart failure and diabetes impairing contractile function and exercise tolerance. It is argued that adoption of this model is fundamental for understanding microvascular function and dysfunction and, as such, to the design and evaluation of effective therapeutic strategies to improve exercise tolerance and decrease morbidity and mortality in disease.
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Affiliation(s)
- David C Poole
- Departments of Kinesiology, Anatomy and Physiology, Kansas State University, Manhattan, Kansas
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17
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Monitoring Exercise-Induced Muscle Fatigue and Adaptations: Making Sense of Popular or Emerging Indices and Biomarkers. Sports (Basel) 2018; 6:sports6040153. [PMID: 30486243 PMCID: PMC6315493 DOI: 10.3390/sports6040153] [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: 10/30/2018] [Revised: 11/17/2018] [Accepted: 11/21/2018] [Indexed: 11/17/2022] Open
Abstract
Regular exercise with the appropriate intensity and duration may improve an athlete’s physical capacities by targeting different performance determinants across the endurance–strength spectrum aiming to delay fatigue. The mechanisms of muscle fatigue depend on exercise intensity and duration and may range from substrate depletion to acidosis and product inhibition of adenosinetriphosphatase (ATPase) and glycolysis. Fatigue mechanisms have been studied in isolated muscles; single muscle fibers (intact or skinned) or at the level of filamentous or isolated motor proteins; with each approach contributing to our understanding of the fatigue phenomenon. In vivo methods for monitoring fatigue include the assessment of various functional indices supported by the use of biochemical markers including blood lactate levels and more recently redox markers. Blood lactate measurements; as an accompaniment of functional assessment; are extensively used for estimating the contribution of the anaerobic metabolism to energy expenditure and to help interpret an athlete’s resistance to fatigue during high intensity exercise. Monitoring of redox indices is gaining popularity in the applied sports performance setting; as oxidative stress is not only a fatigue agent which may play a role in the pathophysiology of overtraining syndrome; but also constitutes an important signaling pathway for training adaptations; thus reflecting training status. Careful planning of sampling and interpretation of blood biomarkers should be applied; especially given that their levels can fluctuate according to an athlete’s lifestyle and training histories.
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18
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Wilson DF, Matschinsky FM. Metabolic homeostasis: oxidative phosphorylation and the metabolic requirements of higher plants and animals. J Appl Physiol (1985) 2018; 125:1183-1192. [DOI: 10.1152/japplphysiol.00352.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
A model of oxidative phosphorylation and its regulation is presented, which is consistent with the experimental data on metabolism in higher plants and animals. The variables that provide real-time control of metabolic status are: intramitochondrial [NAD+]/[NADH], energy state ([ATP]/[ADP][Pi]), and local oxygen concentration ([O2]). ATP consumption and respiratory chain enzyme content are tissue specific (liver vs. heart muscle), and the latter is modulated by chronic alterations in ATP consumption (i.e., endurance training etc.). ATP consumption affects the energy state, which increases or decreases as necessary to match synthesis with consumption. [NAD+]/[NADH], local [O2], and respiratory chain content determine the energy state at which match of synthesis and utilization is achieved. Tissues vary widely in their ranges of ATP consumption. Expressed as the turnover of cytochrome c, the rates may change little (7 to 12/s) (liver) or a lot (1 to >300/s) (flight muscle of birds, bats, and insects). Ancillary metabolic pathways, including creatine or arginine kinase, glycerol phosphate shuttle, fatty acid, and citric acid cycle dehydrogenases, are responsible for meeting tissue-specific differences in maximal rate and range in ATP utilization without displacing metabolic homeostasis. Intramitochondrial [NAD+]/[NADH], [ATP], and [Pi] are adjusted to keep [ADP] and [AMP] similar for all tissues despite large differences in ranges in ATP utilization. This is essential because [ADP] and [AMP], particularly the latter, have major roles in regulating the activity of many enzymes and signaling pathways (AMP deaminase, AMP dependent protein kinases, etc.) common to all higher plants and animals. NEW & NOTEWORTHY Oxidative phosphorylation has an intrinsic program that sets and stabilizes cellular energy state ([ATP]/[ADP][Pi]), and thereby metabolic homeostasis. A computational model consistent with regulation of oxidative phosphorylation in higher plants and animals is presented. Focus is on metabolism ancillary to oxidative phosphorylation by which it was integrated into preexisting metabolic regulation and adapted by evolution to develop cells and tissues with differing rates of ATP utilization: i.e., liver versus brain versus muscle.
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Affiliation(s)
- David F. Wilson
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Franz M. Matschinsky
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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19
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Niemeijer VM, Snijders T, Verdijk LB, van Kranenburg J, Groen BBL, Holwerda AM, Spee RF, Wijn PFF, van Loon LJC, Kemps HMC. Skeletal muscle fiber characteristics in patients with chronic heart failure: impact of disease severity and relation with muscle oxygenation during exercise. J Appl Physiol (1985) 2018; 125:1266-1276. [PMID: 30091667 DOI: 10.1152/japplphysiol.00057.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
INTRODUCTION Skeletal muscle function in patients with heart failure and reduced ejection fraction (HFrEF) greatly determines exercise capacity. However, reports on skeletal muscle fiber dimensions, fiber capillarization, and their physiological importance are inconsistent. METHODS Twenty-five moderately-impaired patients with HFrEF and 25 healthy control (HC) subjects underwent muscle biopsy sampling. Type I and type II muscle fiber characteristics were determined by immunohistochemistry. In patients with HFrEF, enzymatic oxidative capacity was assessed, and pulmonary oxygen uptake (VO2) and skeletal muscle oxygenation during maximal and moderate-intensity exercise were measured using near-infrared spectroscopy. RESULTS While muscle fiber cross-sectional area (CSA) was not different between patients with HFrEF and HC, percentage of type I fibers was higher in HC (46±15% versus 37±12%, respectively, P=0.041). Fiber type distribution and CSA were not different between patients in New York Heart Association (NYHA) class II and III. Type I muscle fiber capillarization was higher in HFrEF compared with controls (capillary-to-fiber perimeter exchange (CFPE) index: 5.70±0.92 versus 5.05±0.82, respectively, P=0.027). Patients in NYHA class III had slower VO2 and muscle deoxygenation kinetics during onset of exercise, and lower muscle oxidative capacity than those in class II (P<0.05). Also, fiber capillarization was lower, but not compared with HC. Higher CFPE index was related to faster deoxygenation (rspearman=-0.682, P=0.001), however, not to muscle oxidative capacity (r=-0.282, P=0.216). CONCLUSIONS Type I muscle fiber capillarization is higher in HFrEF compared with HC, but not in patients with greater exercise impairment. Greater capillarization may positively affect VO2 kinetics by enhancing muscle oxygen diffusion.
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Affiliation(s)
- Victor M Niemeijer
- Department of Cardiology, Máxima Medical Centre, Veldhoven, the Netherlands, Netherlands
| | - Tim Snijders
- Human Movement Sciences, Maastricht University Medical Centre+, Netherlands
| | - Lex B Verdijk
- Human Movement Sciences, Maastricht University Medical Centre, Netherlands
| | - Janneau van Kranenburg
- Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre+ (MUMC+)
| | - Bart B L Groen
- Department of Human Movement Sciences, Maastricht University Medical Centre, Netherlands
| | | | - Ruud F Spee
- Department of Cardiology, Maxima Medical Center, Netherlands
| | - Pieter F F Wijn
- Department of Applied Physics, Eindhoven University of Technology
| | - Luc J C van Loon
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Netherlands
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20
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Korzeniewski B, Rossiter HB, Zoladz JA. Mechanisms underlying extremely fast muscle V˙O 2 on-kinetics in humans. Physiol Rep 2018; 6:e13808. [PMID: 30156055 PMCID: PMC6113137 DOI: 10.14814/phy2.13808] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 07/02/2018] [Indexed: 01/31/2023] Open
Abstract
The time constant of the primary phase of pulmonary V˙O2 on-kinetics (τp ), which reflects muscle V˙O2 kinetics during moderate-intensity exercise, is about 30 s in young healthy untrained individuals, while it can be as low as 8 s in endurance-trained athletes. We aimed to determine the intramuscular factors that enable very low values of t0.63 to be achieved (analogous to τp , t0.63 is the time to reach 63% of the V˙O2 amplitude). A computer model of oxidative phosphorylation (OXPHOS) in skeletal muscle was used. Muscle t0.63 was near-linearly proportional to the difference in phosphocreatine (PCr) concentration between rest and work (ΔPCr). Of the two main factors that determine t0.63 , a huge increase in either OXPHOS activity (six- to eightfold) or each-step activation (ESA) of OXPHOS intensity (>3-fold) was needed to reduce muscle t0.63 from the reference value of 29 s (selected to represent young untrained subjects) to below 10 s (observed in athletes) when altered separately. On the other hand, the effect of a simultaneous increase of both OXPHOS activity and ESA intensity required only a twofold elevation of each to decrease t0.63 below 10 s. Of note, the dependence of t0.63 on OXPHOS activity and ESA intensity is hyperbolic, meaning that in trained individuals a large increase in OXPHOS activity and ESA intensity are required to elicit a small reduction in τp . In summary, we postulate that the synergistic action of elevated OXPHOS activity and ESA intensity is responsible for extremely low τp (t0.63 ) observed in highly endurance-trained athletes.
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Affiliation(s)
| | - Harry B. Rossiter
- Rehabilitation Clinical Trials CenterDivision of Pulmonary Critical Care Physiology and MedicineLos Angeles Biomedical Research Institute at Harbor‐UCLA Medical CenterTorranceCalifornia
- Faculty of Biological SciencesUniversity of LeedsLeedsUnited Kingdom
| | - Jerzy A. Zoladz
- Department of Muscle PhysiologyChair of Physiology and BiochemistryFaculty of RehabilitationUniversity School of Physical EducationKrakówPoland
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21
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Koschate J, Thieschäfer L, Drescher U, Hoffmann U. Impact of 60 days of 6° head down tilt bed rest on muscular oxygen uptake and heart rate kinetics: efficacy of a reactive sledge jump countermeasure. Eur J Appl Physiol 2018; 118:1885-1901. [PMID: 29946969 DOI: 10.1007/s00421-018-3915-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 06/08/2018] [Indexed: 01/06/2023]
Abstract
PURPOSE The effects of 60 days of head down tilt bed rest (HDBR) with and without the application of a reactive jump countermeasure were investigated, using a method which enables to discriminate between pulmonary ([Formula: see text]O2pulm) and muscular ([Formula: see text]O2musc) oxygen uptake kinetics to control for hemodynamic influences. METHODS 22 subjects were randomly allocated to either a group performing a reactive jumps countermeasure (JUMP; n = 11, male, 29 ± 7 years, 23.9 ± 1.3 kg m- 2) or a control group (CTRL; n = 11, male, 29 ± 6 years, 23.3 ± 2.0 kg m- 2). Heart rate (HR) and [Formula: see text]O2pulm were measured in response to repeated changes in work rate between 30 and 80 W before (BDC-9) and two times after HDBR (R+ 2, R+ 13). Kinetic responses of HR, [Formula: see text]O2pulm, and [Formula: see text]O2musc were assessed applying time series analysis. Higher maxima in cross-correlation functions (CCFmax(x)) between work rate and the respective parameter indicate faster kinetics responses. Statistical analysis was performed applying multifactorial analysis of variance. RESULTS CCFmax([Formula: see text]O2musc) and CCFmax([Formula: see text]O2pulm) were not significantly different before and after HDBR (P > 0.05). CCFmax(HR) decreased following bed rest (JUMP: BDC-9: 0.30 ± 0.09 vs. R+ 2: 0.28 ± 0.06 vs. R+13: 0.28 ± 0.07; CTRL: 0.35 ± 0.09 vs. 0.27 ± 0.06 vs. 0.33 ± 0.07 P = 0.025). No significant differences between the groups were observed (P > 0.05). Significant alterations were found for CCFmax of mean arterial blood pressure (mBP) after HDBR (JUMP: BDC-9: 0.21 ± 0.07 vs. R+ 2: 0.30 ± 0.13 vs. R+ 13: 0.28 ± 0.08; CTRL: 0.25 ± 0.07 vs. 0.38 ± 0.13 vs. 0.28 ± 0.08; P = 0.008). CONCLUSIONS Despite hemodynamic changes, [Formula: see text]O2 kinetics seem to be preserved for a longer period of HDBR, even without the application of a countermeasure.
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Affiliation(s)
- J Koschate
- Institute of Physiology and Anatomy, German Sport University Cologne, Am Sportpark Muengersdorf 6, 50933, Cologne, Germany.
| | - L Thieschäfer
- Institute of Physiology and Anatomy, German Sport University Cologne, Am Sportpark Muengersdorf 6, 50933, Cologne, Germany
| | - U Drescher
- Institute of Physiology and Anatomy, German Sport University Cologne, Am Sportpark Muengersdorf 6, 50933, Cologne, Germany
| | - U Hoffmann
- Institute of Physiology and Anatomy, German Sport University Cologne, Am Sportpark Muengersdorf 6, 50933, Cologne, Germany
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22
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Gandra PG, Shiah AA, Nogueira L, Hogan MC. A mitochondrial-targeted antioxidant improves myofilament Ca 2+ sensitivity during prolonged low frequency force depression at low PO2. J Physiol 2018; 596:1079-1089. [PMID: 29334129 DOI: 10.1113/jp275470] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 01/08/2018] [Indexed: 12/22/2022] Open
Abstract
KEY POINTS Skeletal muscle contractile activity is associated with an enhanced reactive oxygen species (ROS) generation. At very low PO2, ROS generation by mitochondria can be elevated in intact cells. An elevated intracellular oxidant activity may affect muscle force development and recovery from fatigue. We treated intact single muscle fibres with a mitochondrial antioxidant and stimulated the fibres to contract at a low extracellular PO2 that is similar to the intracellular PO2 that is observed during moderate to intense exercise in vivo. The mitochondrial antioxidant prevented a sustained decrease in the myofibrillar Ca2+ sensitivity and improved muscle submaximal force development after fatigue at low extracellular PO2. ABSTRACT Skeletal muscle can develop a prolonged low frequency-stimulation force depression (PLFFD) following fatigue-inducing contractions. Increased levels of reactive oxygen species (ROS) have been implicated in the development of PLFFD. During exercise the skeletal muscle intracellular PO2 decreases to relatively low levels, and can be further decreased when there is an impairment in O2 diffusion or availability, such as in certain chronic diseases and during exercise at high altitude. Since ROS generation by mitochondria is elevated at very low PO2 in cells, we tested the hypothesis that treatment of muscle fibres with a mitochondrial-targeted antioxidant at a very low, near hypoxic, PO2 can attenuate PLFFD. We treated intact single fibres from mice with the mitochondrial-specific antioxidant SS31, and measured force development and intracellular [Ca2+ ] 30 min after fatigue at an extracellular PO2 of ∼5 Torr. After 30 min following the end of the fatiguing contractions, fibres treated with SS31 showed significantly less impairment in force development compared to untreated fibres at submaximal frequencies of stimulation. The cytosolic peak [Ca2+ ] transients (peak [Ca2+ ]c ) were equally decreased in both groups compared to pre-fatigue values. The combined force and peak [Ca2+ ]c data demonstrated that myofibrillar Ca2+ sensitivity was diminished in the untreated fibres 30 min after fatigue compared to pre-fatigue values, but Ca2+ sensitivity was unaltered in the SS31 treated fibres. These results demonstrate that at a very low PO2, treatment of skeletal muscle fibres with a mitochondrial antioxidant prevents a decrease in the myofibrillar Ca2+ sensitivity, which alleviates the fatigue induced PLFFD.
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Affiliation(s)
- Paulo G Gandra
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (Unicamp), Campinas, Brazil.,Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Amy A Shiah
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Leonardo Nogueira
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Michael C Hogan
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
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23
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Davies MJ, Benson AP, Cannon DT, Marwood S, Kemp GJ, Rossiter HB, Ferguson C. Dissociating external power from intramuscular exercise intensity during intermittent bilateral knee-extension in humans. J Physiol 2017; 595:6673-6686. [PMID: 28776675 PMCID: PMC5663836 DOI: 10.1113/jp274589] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 07/28/2017] [Indexed: 12/25/2022] Open
Abstract
Key points Continuous high‐intensity constant‐power exercise is unsustainable, with maximal oxygen uptake (V˙O2 max ) and the limit of tolerance attained after only a few minutes. Performing the same power intermittently reduces the O2 cost of exercise and increases tolerance. The extent to which this dissociation is reflected in the intramuscular bioenergetics is unknown. We used pulmonary gas exchange and 31P magnetic resonance spectroscopy to measure whole‐body V˙O2, quadriceps phosphate metabolism and pH during continuous and intermittent exercise of different work:recovery durations. Shortening the work:recovery durations (16:32 s vs. 32:64 s vs. 64:128 s vs. continuous) at a work rate estimated to require 110% peak aerobic power reduced V˙O2, muscle phosphocreatine breakdown and muscle acidification, eliminated the glycolytic‐associated contribution to ATP synthesis, and increased exercise tolerance. Exercise intensity (i.e. magnitude of intramuscular metabolic perturbations) can be dissociated from the external power using intermittent exercise with short work:recovery durations.
Abstract Compared with work‐matched high‐intensity continuous exercise, intermittent exercise dissociates pulmonary oxygen uptake (V˙O2) from the accumulated work. The extent to which this reflects differences in O2 storage fluctuations and/or contributions from oxidative and substrate‐level bioenergetics is unknown. Using pulmonary gas‐exchange and intramuscular 31P magnetic resonance spectroscopy, we tested the hypotheses that, at the same power: ATP synthesis rates are similar, whereas peak V˙O2 amplitude is lower in intermittent vs. continuous exercise. Thus, we expected that: intermittent exercise relies less upon anaerobic glycolysis for ATP provision than continuous exercise; shorter intervals would require relatively greater fluctuations in intramuscular bioenergetics than in V˙O2 compared to longer intervals. Six men performed bilateral knee‐extensor exercise (estimated to require 110% peak aerobic power) continuously and with three different intermittent work:recovery durations (16:32, 32:64 and 64:128 s). Target work duration (576 s) was achieved in all intermittent protocols; greater than continuous (252 ± 174 s; P < 0.05). Mean ATP turnover rate was not different between protocols (∼43 mm min−1 on average). However, the intramuscular phosphocreatine (PCr) component of ATP generation was greatest (∼30 mm min−1), and oxidative (∼10 mm min−1) and anaerobic glycolytic (∼1 mm min−1) components were lowest for 16:32 and 32:64 s intermittent protocols, compared to 64:128 s (18 ± 6, 21 ± 10 and 10 ± 4 mm min−1, respectively) and continuous protocols (8 ± 6, 20 ± 9 and 16 ± 14 mm min−1, respectively). As intermittent work duration increased towards continuous exercise, ATP production relied proportionally more upon anaerobic glycolysis and oxidative phosphorylation, and less upon PCr breakdown. However, performing the same high‐intensity power intermittently vs. continuously reduced the amplitude of fluctuations in V˙O2 and intramuscular metabolism, dissociating exercise intensity from the power output and work done. Continuous high‐intensity constant‐power exercise is unsustainable, with maximal oxygen uptake (V˙O2 max ) and the limit of tolerance attained after only a few minutes. Performing the same power intermittently reduces the O2 cost of exercise and increases tolerance. The extent to which this dissociation is reflected in the intramuscular bioenergetics is unknown. We used pulmonary gas exchange and 31P magnetic resonance spectroscopy to measure whole‐body V˙O2, quadriceps phosphate metabolism and pH during continuous and intermittent exercise of different work:recovery durations. Shortening the work:recovery durations (16:32 s vs. 32:64 s vs. 64:128 s vs. continuous) at a work rate estimated to require 110% peak aerobic power reduced V˙O2, muscle phosphocreatine breakdown and muscle acidification, eliminated the glycolytic‐associated contribution to ATP synthesis, and increased exercise tolerance. Exercise intensity (i.e. magnitude of intramuscular metabolic perturbations) can be dissociated from the external power using intermittent exercise with short work:recovery durations.
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Affiliation(s)
- Matthew J Davies
- School of Biomedical Sciences, Faculty of Biological Sciences & Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, UK
| | - Alan P Benson
- School of Biomedical Sciences, Faculty of Biological Sciences & Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, UK
| | - Daniel T Cannon
- School of Exercise & Nutritional Sciences, San Diego State University, San Diego, CA, USA
| | - Simon Marwood
- School of Health Sciences, Liverpool Hope University, Liverpool, UK
| | - Graham J Kemp
- Magnetic Resonance & Image Analysis Research Centre, University of Liverpool, Liverpool, UK.,Department of Musculoskeletal Biology, University of Liverpool, Liverpool, UK
| | - Harry B Rossiter
- School of Biomedical Sciences, Faculty of Biological Sciences & Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, UK.,Rehabilitation Clinical Trials Center, Division of Respiratory & Critical Care Physiology & Medicine, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Carrie Ferguson
- School of Biomedical Sciences, Faculty of Biological Sciences & Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, UK
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24
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Moll K, Gussew A, Hein C, Stutzig N, Reichenbach JR. Combined spiroergometry and 31 P-MRS of human calf muscle during high-intensity exercise. NMR IN BIOMEDICINE 2017; 30:e3723. [PMID: 28340292 DOI: 10.1002/nbm.3723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 02/07/2017] [Accepted: 02/08/2017] [Indexed: 06/06/2023]
Abstract
Simultaneous measurements of pulmonary oxygen consumption (VO2 ), carbon dioxide exhalation (VCO2 ) and phosphorus magnetic resonance spectroscopy (31 P-MRS) are valuable in physiological studies to evaluate muscle metabolism during specific loads. Therefore, the aim of this study was to adapt a commercially available spirometric device to enable measurements of VO2 and VCO2 whilst simultaneously performing 31 P-MRS at 3 T. Volunteers performed intense plantar flexion of their right calf muscle inside the MR scanner against a pneumatic MR-compatible pedal ergometer. The use of a non-magnetic pneumotachograph and extension of the sampling line from 3 m to 5 m to place the spirometric device outside the MR scanner room did not affect adversely the measurements of VO2 and VCO2 . Response and delay times increased, on average, by at most 0.05 s and 0.79 s, respectively. Overall, we were able to demonstrate a feasible ventilation response (VO2 = 1.05 ± 0.31 L/min; VCO2 = 1.11 ± 0.33 L/min) during the exercise of a single calf muscle, as well as a good correlation between local energy metabolism and muscular acidification (τPCr fast and pH; R2 = 0.73, p < 0.005) and global respiration (τPCr fast and VO2 ; R2 = 0.55, p = 0.01). This provides improved insights into aerobic and anaerobic energy supply during strong muscular performances.
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Affiliation(s)
- K Moll
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - A Gussew
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - C Hein
- Ganshorn Medizin Electronic GmbH, Niederlauer, Germany
| | - N Stutzig
- Exercise Science, Institute of Sport and Movement Science, University of Stuttgart, Stuttgart, Germany
| | - J R Reichenbach
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
- Michael Stifel Center for Data-Driven and Simulation Science Jena, Friedrich Schiller University Jena, Jena, Germany
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25
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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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26
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Muller MD, Li Z, Sica CT, Luck JC, Gao Z, Blaha CA, Cauffman AE, Ross AJ, Winkler NJR, Herr MD, Brandt K, Wang J, Gallagher DC, Karunanayaka P, Vesek J, Leuenberger UA, Yang QX, Sinoway LI. Muscle oxygenation during dynamic plantar flexion exercise: combining BOLD MRI with traditional physiological measurements. Physiol Rep 2016; 4:4/20/e13004. [PMID: 27798357 PMCID: PMC5099966 DOI: 10.14814/phy2.13004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 09/26/2016] [Indexed: 11/24/2022] Open
Abstract
Blood-oxygen-level-dependent magnetic resonance imaging (BOLD MRI) has the potential to quantify skeletal muscle oxygenation with high temporal and high spatial resolution. The purpose of this study was to characterize skeletal muscle BOLD responses during steady-state plantar flexion exercise (i.e., during the brief rest periods between muscle contraction). We used three different imaging modalities (ultrasound of the popliteal artery, BOLD MRI, and near-infrared spectroscopy [NIRS]) and two different exercise intensities (2 and 6 kg). Six healthy men underwent three separate protocols of dynamic plantar flexion exercise on separate days and acute physiological responses were measured. Ultrasound studies showed the percent change in popliteal velocity from baseline to the end of exercise was 151 ± 24% during 2 kg and 589 ± 145% during 6 kg. MRI studies showed an abrupt decrease in BOLD signal intensity at the onset of 2 kg exercise, indicating deoxygenation. The BOLD signal was further reduced during 6 kg exercise (compared to 2 kg) at 1 min (-4.3 ± 0.7 vs. -1.2 ± 0.4%, P < 0.001). Similarly, the change in the NIRS muscle oxygen saturation in the medial gastrocnemius was -11 ± 4% at 2 kg and -38 ± 11% with 6 kg (P = 0.041). In conclusion, we demonstrate that BOLD signal intensity decreases during plantar flexion and this effect is augmented at higher exercise workloads.
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Affiliation(s)
- Matthew D Muller
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Zhijun Li
- Department of Radiology, Center for NMR Research, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Christopher T Sica
- Department of Radiology, Center for NMR Research, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - J Carter Luck
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Zhaohui Gao
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Cheryl A Blaha
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Aimee E Cauffman
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Amanda J Ross
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Nathan J R Winkler
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Michael D Herr
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Kristen Brandt
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Jianli Wang
- Department of Radiology, Center for NMR Research, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - David C Gallagher
- Department of Radiology, Center for NMR Research, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Prasanna Karunanayaka
- Department of Radiology, Center for NMR Research, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Jeffrey Vesek
- Department of Radiology, Center for NMR Research, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Urs A Leuenberger
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Qing X Yang
- Department of Radiology, Center for NMR Research, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Lawrence I Sinoway
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
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27
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Roman MA, Rossiter HB, Casaburi R. Exercise, ageing and the lung. Eur Respir J 2016; 48:1471-1486. [PMID: 27799391 DOI: 10.1183/13993003.00347-2016] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 06/27/2016] [Indexed: 02/07/2023]
Abstract
This review provides a pulmonary-focused description of the age-associated changes in the integrative physiology of exercise, including how declining lung function plays a role in promoting multimorbidity in the elderly through limitation of physical function. We outline the ageing of physiological systems supporting endurance activity: 1) coupling of muscle metabolism to mechanical power output; 2) gas transport between muscle capillary and mitochondria; 3) matching of muscle blood flow to its requirement; 4) oxygen and carbon dioxide carrying capacity of the blood; 5) cardiac output; 6) pulmonary vascular function; 7) pulmonary oxygen transport; 8) control of ventilation; and 9) pulmonary mechanics and respiratory muscle function. Deterioration in function occurs in many of these systems in healthy ageing. Between the ages of 25 and 80 years pulmonary function and aerobic capacity each decline by ∼40%. While the predominant factor limiting exercise in the elderly likely resides within the function of the muscles of ambulation, muscle function is (at least partially) rescued by exercise training. The age-associated decline in pulmonary function, however, is not recovered by training. Thus, loss in pulmonary function may lead to ventilatory limitation in exercise in the active elderly, limiting the ability to accrue the health benefits of physical activity into senescence.
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Affiliation(s)
- Michael A Roman
- Division of Respiratory Medicine, Rockyview Hospital, University of Calgary, Calgary, AB, Canada
| | - Harry B Rossiter
- Rehabilitation Clinical Trials Center, Division of Respiratory and Critical Care Physiology and Medicine, Los Angeles Biomedical Research Institute, Torrance, CA, USA.,Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Richard Casaburi
- Rehabilitation Clinical Trials Center, Division of Respiratory and Critical Care Physiology and Medicine, Los Angeles Biomedical Research Institute, Torrance, CA, USA
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28
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Richardson RS, Wary C, Wray DW, Hoff J, Rossiter HB, Layec G, Carlier PG. Response. Med Sci Sports Exerc 2016; 47:2481-2. [PMID: 26473761 DOI: 10.1249/mss.0000000000000739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Russell S Richardson
- Division of Geriatrics Department of Medicine University of Utah Salt Lake City, UT Department of Exercise and Sport Science University of Utah Salt Lake City, UT Geriatric Research Education, and Clinical Center Salt Lake City VA Medical Center Salt Lake City, UT Institut of Myology Paris, FRANCE CEA, I2BM, MIRcen IdM NMR Laboratory Paris, FRANCE Division of Geriatrics Department of Medicine University of Utah Salt Lake City, UT Department of Exercise and Sport Science University of Utah Salt Lake City, UT Geriatric Research Education, and Clinical Center Salt Lake City VA Medical Center Salt Lake City, UT Faculty of Medicine Norwegian University of Science and Technology Trondheim, NORWAY Division of Respiratory and Critical Care Physiology, and Medicine Department of Medicine Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center Torrance, CA Division of Geriatrics Department of Medicine University of Utah Salt Lake City, UT Geriatric Research Education, and Clinical Center Salt Lake City VA Medical Center Salt Lake City, UT Institut of Myology Paris, FRANCE CEA, I2BM, MIRcen IdM NMR Laboratory Paris, FRANCE
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29
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Affiliation(s)
- Juan M Murias
- Faculty of Kinesiology University of Calgary Calgary, AB CANADA Canadian Centre for Activity and Aging University of Western Ontario London, ON CANADA School of Kinesiology University of Western Ontario London, ON CANADA
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