Slow Component

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Fabio Borrani - One of the best experts on this subject based on the ideXlab platform.

  • the metabolic profiles of different fiber type populations under the emergence of the Slow Component of oxygen uptake
    Journal of Physiological Sciences, 2020
    Co-Authors: Sonia Conde Alonso, Fabio Borrani, Trishan Gajanand, Joyce S Ramos, Jeanphilippe Antonietti
    Abstract:

    To investigate the influence of different metabolic muscle fiber profiles on the emergence of the Slow Component of oxygen uptake ($${\dot{\text{V}}\text{O}}_{2}$$SC), 12 habitually active males completed four sessions of different combinations of work-to-work transition exercises up to severe intensity. Each transition was modeled to analyze the different kinetic parameters. Using a new approach, combining Henneman’s principle and superposition principle, a reconstructed kinetics was built by temporally aligning the start of each new transition and summing them. The primary phase time constant significantly Slowed and the gain at the end (GainEnd) significantly increased when transitions started from a higher intensity (p < 0.001). Kinetic parameters from the reconstructed curve ($${\dot{\text{V}}\text{O}}_{2} {\text{baseline}}$$, time delay of primary phase, $${\dot{\text{V}}\text{O}}_{2}$$End and GainEnd) were not significantly different from one transition to severe exercise. These results suggest that the appearance of the $${\dot{\text{V}}\text{O}}_{2}$$SC is at least related to, if not the result of, the different metabolic properties of muscle fibers.

  • alterations to neuromuscular properties of skeletal muscle are temporally dissociated from the oxygen uptake Slow Component
    Scientific Reports, 2020
    Co-Authors: Sonia Conde Alonso, Trishan Gajanand, Joyce S Ramos, Jeanphilippe Antonietti, Fabio Borrani
    Abstract:

    To assess if the alteration of neuromuscular properties of knee extensors muscles during heavy exercise co-vary with the SCV ([Formula: see text] Slow Component), eleven healthy male participants completed an incremental ramp test to exhaustion and five constant heavy intensity cycling bouts of 2, 6, 10, 20 and 30 minutes. Neuromuscular testing of the knee extensor muscles were completed before and after exercise. Results showed a significant decline in maximal voluntary contraction (MVC) torque only after 30 minutes of exercise (-17.01% ± 13.09%; p < 0.05) while single twitch (PT), 10 Hz (P10), and 100 Hz (P100) doublet peak torque amplitudes were reduced after 20 and 30 minutes (p < 0.05). Voluntary activation (VA) and M-wave were not affected by exercise, but significant correlation was found between the SCV and PT, MVC, VA, P10, P100, and P10/P100 ratio, respectively (p < 0.015). Therefore, because the development of the SCV occurred mainly between 2-10 minutes, during which neuromuscular properties were relatively stable, and because PT, P10 and P100 were significantly reduced only after 20-30 minutes of exercise while SCV is stable, a temporal relationship between them does not appear to exist. These results suggest that the development of fatigue due to alterations of neuromuscular properties is not an essential requirement to elicit the SCV.

  • effects of two types of fatigue on the vo 2 Slow Component
    International Journal of Sports Medicine, 2006
    Co-Authors: Gaelle Deley, Fabio Borrani, Guillaume Y. Millet, G Lattier, L Brondel
    Abstract:

    The aim of the study was to test the hypothesis of the involvement of type II fibres in the V.O (2) Slow Component phenomenon by using two prior fatiguing protocols on the knee extensor muscles. Nine subjects performed three constant-load cycling exercises at a work rate corresponding to 80 % of their V.O (2) max: (i) preceded by a 20-min fatiguing protocol using electromyostimulation (EMS), (ii) preceded by a 20-min fatiguing protocol using voluntary contractions (VOL), and (iii) without fatiguing protocol (NFP). Voluntary and evoked neuromuscular properties of the knee extensor muscles were tested before (PRE) and after (POST) the two fatiguing protocols. Results show a significant reduction in voluntary force after both fatiguing protocols (-19.9 % and -11.8 %, in EMS and VOL, respectively p<0.01). After EMS, this decrease was greater than after VOL (p<0.05) and was combined with a slackening of muscle contractile properties which was absent after VOL (p<0.05). Regarding the effects on oxygen uptake kinetics, the appearance of the Slow Component was delayed after EMS and its amplitude was lower than those obtained in VOL and NFP conditions (0.48+/-0.07 vs. 0.75+/-0.09 and 0.69+/-0.08 L . min (-1), respectively; p<0.05). It can thus be concluded that exercises dedicated to preferentially fatiguing type II fibres may alter V.O (2) kinetics.

  • Effects of two types of fatigue on the VO(2) Slow Component.
    International Journal of Sports Medicine, 2006
    Co-Authors: Gaelle Deley, Fabio Borrani, Guillaume Y. Millet, G Lattier, L Brondel
    Abstract:

    The aim of the study was to test the hypothesis of the involvement of type II fibres in the V.O (2) Slow Component phenomenon by using two prior fatiguing protocols on the knee extensor muscles. Nine subjects performed three constant-load cycling exercises at a work rate corresponding to 80 % of their V.O (2) max: (i) preceded by a 20-min fatiguing protocol using electromyostimulation (EMS), (ii) preceded by a 20-min fatiguing protocol using voluntary contractions (VOL), and (iii) without fatiguing protocol (NFP). Voluntary and evoked neuromuscular properties of the knee extensor muscles were tested before (PRE) and after (POST) the two fatiguing protocols. Results show a significant reduction in voluntary force after both fatiguing protocols (-19.9 % and -11.8 %, in EMS and VOL, respectively p

  • Addition of inspiratory resistance increases the amplitude of the Slow Component of O2 uptake kinetics
    Journal of Applied Physiology, 2003
    Co-Authors: J. Carra, Fabio Borrani, Robin Candau, Grégoire P. Millet, Alain Varray, S. Keslacy, F. Giolbas, M. Ramonatxo
    Abstract:

    The contribution of respiratory muscle work to the development of the O2consumption (V˙o 2) Slow Component is a point of controversy because it has been shown that the increased ventilation in hypo...

Véronique Billat - One of the best experts on this subject based on the ideXlab platform.

  • Auxiliary Muscles and Slow Component during Rowing
    International Journal of Sports Medicine, 2008
    Co-Authors: S. Demarie, Véronique Billat, Valentina Quaresima, Marco Ferrari, Paola Sbriccoli, Marcello Faina
    Abstract:

    The aim of this study was to investigate the con- tribution of the auxiliary muscles, utilized to sus- tain the subject's position on the ergometer, to the oxygen uptake Slow Component phenome- non. Three tests were performed at the same se- vere relative intensity on a rowing ergometer: a standard rowing exercise test, a rowing exercise performed with the arms and one performed with the legs only. During the three exercise mo- dalities, oxygen uptake, local oxyhemoglobin sat- uration and surface electromyography signals of the trapezius and vastus lateralis muscles were measured. The SlowComponent amplitude, in ab- solute values, resulted statistically lower for row- ing (343.9 mlmin-1) than for arms (795.6ml • min -1 ) and legs (695.8 mlmin -1 ) exercise modes. The same result was found when the Slow com- ponent amplitude was calculated as percentage of VO2peak (7.1% for rowing; 17.2% for arms; 17.3% for legs). The lower SlowComponent ampli- tude measured for the rowing exercise mode with respect to both arms and legs modes, dem- onstrates that the auxiliary muscles involved in the exercise contribute to the increasing ener- getic cost due to the Slow Component. " oxygen uptake kinetics l " muscle oxygenation l " muscle activation

  • The VO2 Slow Component in swimming.
    European Journal of Applied Physiology, 2001
    Co-Authors: S. Demarie, Franco Sardella, Véronique Billat, Walter Magini, Marcello Faina
    Abstract:

    All studies on the oxygen uptake (VO2) Slow Component have been carried out for the sporting disciplines of cycling or running, but never for swimming. Considering that front crawl swimming is a sport discipline that is fundamentally different from both running and cycling, the aim of this study was to verify whether this Slow Component also appears in swimming. Six elite pentathletes were tested in a swimming flume while front crawl swimming to exhaustion. Swimming velocity for the Slow Component test was determined as v50% delta = CV + [vVO2peak - CV)/2], where CV is the critical velocity and vVO2peak the lowest velocity at which peak VO2 occurred. To set the subject's CV, expressed as the slope of a straight line that describes the correlation between swimming distance and time, the record times over three swimming distances were recorded in a 50 m swimming pool. The vVO2peak was measured by means of an incremental test in the swimming flume. Gas exchange was measured by means of a telemetric metabolimeter (K4 RQ, Cosmed, Italy) that was connected to a snorkel. The Slow Component was found in all subjects, with a mean (SD) value of 239 (194) mlO2.min-1. Therefore, although front crawl swimming is fundamentally different from both running and cycling, it appears that it also incurs a VO2 Slow Component. The origin of this phenomenon, however, is even more uncertain than for the other sport disciplines.

  • The VO2 Slow Component in swimming.
    European Journal of Applied Physiology, 2001
    Co-Authors: S. Demarie, Franco Sardella, Véronique Billat, Walter Magini, Marcello Faina
    Abstract:

    All studies on the oxygen uptake (V˙O2) Slow Component have been carried out for the sporting disciplines of cycling or running, but never for swimming. Considering that front crawl swimming is a sport discipline that is fundamentally different from both running and cycling, the aim of this study was to verify whether this Slow Component also appears in swimming. Six elite pentathletes were tested in a swimming flume while front crawl swimming to exhaustion. Swimming velocity for the Slow Component test was determined as v50Δ=CV+[(vV˙O2peak−CV)/2], where CV is the critical velocity and vV˙O2peak the lowest velocity at which peak V˙O2 occurred. To set the subject's CV, expressed as the slope of a straight line that describes the correlation between swimming distance and time, the record times over three swimming distances were recorded in a 50 m swimming pool. The vV˙O2peak was measured by means of an incremental test in the swimming flume. Gas exchange was measured by means of a telemetric metabolimeter (K4 RQ, Cosmed, Italy) that was connected to a snorkel. The Slow Component was found in all subjects, with a mean (SD) value of 239 (194) mlO2 · min−1. Therefore, although front crawl swimming is fundamentally different from both running and cycling, it appears that it also incurs a V˙O2 Slow Component. The origin of this phenomenon, however, is even more uncertain than for the other sport disciplines.

  • VO2 Slow Component and performance in endurance sports.
    British Journal of Sports Medicine, 2000
    Co-Authors: Véronique Billat
    Abstract:

    For almost 80 years, physiological studies have attempted to explain endurance performance and to develop ways of improving it by training. Performance for a runner can be represented by the relation of his/her personal power (velocity) to time to exhaustion (time limit).1 There are particular velocities that delineate intensity domains which are determined by oxygen uptake (Vo2) and blood lactate response versus time.2,3 We are going to use them to define the Slow phase of Vo2 kinetics Vo2 Slow Component) which only appears during intense exercise. A high range of work can be identified at which there is a sustained increase in blood lactate and a decrease in arterial pH with time. These responses decline back towards a baseline value. Oxygen uptake increases in a monoexponential way and stabilises at about 80% in high level marathon runners for at least an hour and a half of continuous exercise. After that time, it is possible for oxygen consumption to increase because of thermoregulatory constraints, and this increase is called the “Vo2 drift”. This intensity of exercise corresponds to the velocity that can be sustained during a marathon and is equal to about 80% of the velocity associated with Vo2max determined in an incremental test—that is, vVo2max.4 During this type of exercise both lipids and carbohydrate are used as fuel. At a higher intensity, the maximal lactate steady state occurs5 when the rate of appearance of blood lactate equals the rate of its disappearance. Vo2 stabilises after three minutes at about 85% Vo2max. This corresponds to the highest velocity that an athlete can sustain for an hour (85% vVo2max for a well trained …

  • The role of cadence on the VO2 Slow Component in cycling and running in triathletes.
    International Journal of Sports Medicine, 1999
    Co-Authors: Véronique Billat, Laurence Mille-hamard, Bernard Petit, J. P. Koralsztein
    Abstract:

    The purpose of this study was to compare the effect of two different types of cyclic severe exercise (running and cycling) on the VO2 Slow Component. Moreover we examined the influence of cadence of exercise (freely chosen [FF] vs. low frequency [LF]) on the hypothesis that: 1) a stride frequency lower than optimal and 2) a pedalling frequency lower than FF one could induce a larger and/or lower VO2 Slow Component. Eight triathletes ran and cycled to exhaustion at a work-rate corresponding to the lactate threshold + 50% of the difference between the work-rate associated with VO2max and the lactate threshold (delta 50) at a freely chosen (FF) and low frequency (LF: - 10 % of FF). The time to exhaustion was not significantly different for both types of exercises and both cadences (13 min 39 s, 15 min 43 s, 13 min 32 s, 15 min 05 s for running at FF and LF and cycling at FF and LF, respectively). The amplitude of the VO2 Slow Component (i.e. difference between VO2 at the last and the 3rd min of the exercise) was significantly smaller during running compared with cycling, but there was no effect of cadence. Consequently, there was no relationship between the magnitude of the VO2 Slow Component and the time to fatigue for a severe exercise (r = 0.20, p = 0.27). However, time to fatigue was inversely correlated with the blood lactate concentration for both modes of exercise and both cadences (r = - 0.42, p = 0.01). In summary, these data demonstrate that: 1) in subjects well trained for both cycling and running, the amplitude of the VO2 Slow Component at fatigue was larger in cycling and that it was not significantly influenced by cadence; 2) the VO2 Slow Component was not correlated with the time to fatigue. If the nature of the linkage between the VO2 Slow Component and the fatigue process remains unclear, the type of contraction regimen depending on exercise biomechanic characteristics seems to be determinant in the VO2 Slow Component phenomenon for a same level of training.

David C. Poole - One of the best experts on this subject based on the ideXlab platform.

  • muscle fiber recruitment and the Slow Component of o2 uptake constant work rate vs all out sprint exercise
    American Journal of Physiology-regulatory Integrative and Comparative Physiology, 2011
    Co-Authors: Anni Vanhatalo, David C. Poole, Fred J Dimenna, Stephen J Bailey, Andrew M. Jones
    Abstract:

    The Slow Component of pulmonary O2 uptake (Vo2) during constant work rate (CWR) high-intensity exercise has been attributed to the progressive recruitment of (type II) muscle fibers. We tested the...

  • Slow Component of VO2 kinetics: mechanistic bases and practical applications.
    Medicine & Science in Sports & Exercise, 2011
    Co-Authors: Andrew M. Jones, Bruno Grassi, Peter M. Christensen, Peter Krustrup, Jens Bangsbo, David C. Poole
    Abstract:

    The V·O₂ Slow Component, a Slowly developing increase in V·O₂ during constant-work-rate exercise performed above the lactate threshold, represents a progressive loss of skeletal muscle contractile efficiency and is associated with the fatigue process. This brief review outlines the current state of knowledge concerning the mechanistic bases of the V·O₂ Slow Component and describes practical interventions that can attenuate the Slow Component and thus enhance exercise tolerance. There is strong evidence that, during constant-work-rate exercise, the development of the V·O₂ Slow Component is associated with the progressive recruitment of additional (type II) muscle fibers that are presumed to have lower efficiency. Recent studies, however, indicate that muscle efficiency is also lowered (resulting in a "mirror-image" V·O₂ Slow Component) during fatiguing, high-intensity exercise in which additional fiber recruitment is unlikely or impossible. Therefore, it seems that muscle fatigue underpins the V·O₂ Slow Component, although the greater fatigue sensitivity of recruited type II fibers might still play a crucial role in the loss of muscle efficiency in both situations. Several interventions can reduce the magnitude of the V·O₂ Slow Component, and these are typically associated with an enhanced exercise tolerance. These include endurance training, inspiratory muscle training, priming exercise, dietary nitrate supplementation, and the inspiration of hyperoxic gas. All of these interventions reduce muscle fatigue development either by improving muscle oxidative capacity and thus metabolic stability or by enhancing bulk muscle O2 delivery or local Q·O₂-to-V·O₂ matching. Future honing of these interventions to maximize their impact on the V·O₂ Slow Component might improve sports performance in athletes and exercise tolerance in the elderly or in patient populations.

  • L-(+)-lactate infusion into working dog gastrocnemius: no evidence lactate per se mediates VO2 Slow Component.
    Journal of Applied Physiology, 1994
    Co-Authors: David C. Poole, L. B. Gladden, S. Sadi Kurdak, Michael C Hogan
    Abstract:

    Constant-load exercise that engenders a sustained lactic acidosis (i.e., above the lactate threshold) is accompanied by a Slow Component of O2 uptake (VO2) kinetics that increases VO2 above rather ...

  • l lactate infusion into working dog gastrocnemius no evidence lactate per se mediates vo2 Slow Component
    Journal of Applied Physiology, 1994
    Co-Authors: David C. Poole, L. B. Gladden, S. Sadi Kurdak, Michael C Hogan
    Abstract:

    Constant-load exercise that engenders a sustained lactic acidosis (i.e., above the lactate threshold) is accompanied by a Slow Component of O2 uptake (VO2) kinetics that increases VO2 above rather ...

  • VO2 Slow Component: physiological and functional significance.
    Medicine & Science in Sports & Exercise, 1994
    Co-Authors: David C. Poole, Thomas J. Barstow, Glenn A. Gaesser, Wayne T. Willis, B. J. Whipp
    Abstract:

    ABSTRACT This paper offers a brief synopsis of the five preceding papers which constitute the proceedings of the symposium “Mechanistic basis of the Slow Component of JOURNAL/mespex/04.02/00005768-199411000-00010/ENTITY_OV0312/v/2017-07-20T222430Z/r/image-pngO2 kinetics during heavy exercise.” The key features have been taken from each paper and a coherent position regarding the site and potential underlying mechanisms for the “excess” JOURNAL/mespex/04.02/00005768-199411000-00010/ENTITY_OV0312/v/2017-07-20T222430Z/r/image-pngO2 is presented. The hypothesis is developed that some aspect of fiber type recruitment patterns might be responsible for this phenomenon. Elucidation of the precise determinants of JOURNAL/mespex/04.02/00005768-199411000-00010/ENTITY_OV0312/v/2017-07-20T222430Z/r/image-pngO2 during heavy exercise is fundamental to our understanding of muscle energetics. Furthermore, certain patient populations, whose exercise tolerance is limited by impaired cardiovascular and/or respiratory capacity, may benefit from interventions designed to constrain the magnitude of the JOURNAL/mespex/04.02/00005768-199411000-00010/ENTITY_OV0312/v/2017-07-20T222430Z/r/image-pngO2 Slow Component.

Guillaume Y. Millet - One of the best experts on this subject based on the ideXlab platform.

  • effects of two types of fatigue on the vo 2 Slow Component
    International Journal of Sports Medicine, 2006
    Co-Authors: Gaelle Deley, Fabio Borrani, Guillaume Y. Millet, G Lattier, L Brondel
    Abstract:

    The aim of the study was to test the hypothesis of the involvement of type II fibres in the V.O (2) Slow Component phenomenon by using two prior fatiguing protocols on the knee extensor muscles. Nine subjects performed three constant-load cycling exercises at a work rate corresponding to 80 % of their V.O (2) max: (i) preceded by a 20-min fatiguing protocol using electromyostimulation (EMS), (ii) preceded by a 20-min fatiguing protocol using voluntary contractions (VOL), and (iii) without fatiguing protocol (NFP). Voluntary and evoked neuromuscular properties of the knee extensor muscles were tested before (PRE) and after (POST) the two fatiguing protocols. Results show a significant reduction in voluntary force after both fatiguing protocols (-19.9 % and -11.8 %, in EMS and VOL, respectively p<0.01). After EMS, this decrease was greater than after VOL (p<0.05) and was combined with a slackening of muscle contractile properties which was absent after VOL (p<0.05). Regarding the effects on oxygen uptake kinetics, the appearance of the Slow Component was delayed after EMS and its amplitude was lower than those obtained in VOL and NFP conditions (0.48+/-0.07 vs. 0.75+/-0.09 and 0.69+/-0.08 L . min (-1), respectively; p<0.05). It can thus be concluded that exercises dedicated to preferentially fatiguing type II fibres may alter V.O (2) kinetics.

  • Effects of two types of fatigue on the VO(2) Slow Component.
    International Journal of Sports Medicine, 2006
    Co-Authors: Gaelle Deley, Fabio Borrani, Guillaume Y. Millet, G Lattier, L Brondel
    Abstract:

    The aim of the study was to test the hypothesis of the involvement of type II fibres in the V.O (2) Slow Component phenomenon by using two prior fatiguing protocols on the knee extensor muscles. Nine subjects performed three constant-load cycling exercises at a work rate corresponding to 80 % of their V.O (2) max: (i) preceded by a 20-min fatiguing protocol using electromyostimulation (EMS), (ii) preceded by a 20-min fatiguing protocol using voluntary contractions (VOL), and (iii) without fatiguing protocol (NFP). Voluntary and evoked neuromuscular properties of the knee extensor muscles were tested before (PRE) and after (POST) the two fatiguing protocols. Results show a significant reduction in voluntary force after both fatiguing protocols (-19.9 % and -11.8 %, in EMS and VOL, respectively p

  • Does the mechanical work in running change during the VO2 Slow Component
    Medicine & Science in Sports & Exercise, 2003
    Co-Authors: Fabio Borrani, Robin Candau, Stéphane Perrey, Guillaume Y. Millet, Grégoire P. Millet, Jean-denis Rouillon
    Abstract:

    ABSTRACTBORRANI, F., R. CANDAU, S. PERREY, G. Y. MILLET, G. P. MILLET, and J.-D. ROUILLON. Does the Mechanical Work in Running Change during the VO2 Slow Component? Med. Sci. Sports Exerc., Vol. 35, No. 1, pp. 50–57, 2003.PurposeThe origin of the Slow Component is not fully understood. The mechanic

  • Is the V˙o 2 Slow Component dependent on progressive recruitment of fast-twitch fibers in trained runners?
    Journal of Applied Physiology, 2001
    Co-Authors: Fabio Borrani, Robin Candau, Stéphane Perrey, Guillaume Y. Millet, Jörg Fuchslocher, J. D. Rouillon
    Abstract:

    The goal of this study was to use spectral analysis of EMG data to test the hypothesis that the O2 uptake (V˙o 2) Slow Component is due to a recruitment of fast fibers. Thirteen runners carried out...

  • is the v o 2 Slow Component dependent on progressive recruitment of fast twitch fibers in trained runners
    Journal of Applied Physiology, 2001
    Co-Authors: Fabio Borrani, Robin Candau, Stéphane Perrey, Guillaume Y. Millet, Jörg Fuchslocher, J. D. Rouillon
    Abstract:

    The goal of this study was to use spectral analysis of EMG data to test the hypothesis that the O2 uptake (V˙o 2) Slow Component is due to a recruitment of fast fibers. Thirteen runners carried out...

Michael C Hogan - One of the best experts on this subject based on the ideXlab platform.

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