scholarly journals Effects of prior heavy exercise on phase II pulmonary oxygen uptake kinetics during heavy exercise

2000 ◽  
Vol 89 (4) ◽  
pp. 1387-1396 ◽  
Author(s):  
Mark Burnley ◽  
Andrew M. Jones ◽  
Helen Carter ◽  
Jonathan H. Doust
Keyword(s):  
Oxygen Uptake ◽  
Phase Ii ◽  
Slow Component ◽  
Exercise Bout ◽  
Oxygen Uptake Kinetics ◽  
Cycle Ergometer ◽  
Moderate Exercise ◽  
Heavy Exercise ◽  
Mean Response Time ◽  
The Mean

We tested the hypothesis that heavy-exercise phase II oxygen uptake (V˙o 2) kinetics could be speeded by prior heavy exercise. Ten subjects performed four protocols involving 6-min exercise bouts on a cycle ergometer separated by 6 min of recovery: 1) moderate followed by moderate exercise; 2) moderate followed by heavy exercise; 3) heavy followed by moderate exercise; and 4) heavy followed by heavy exercise. The V˙o 2 responses were modeled using two (moderate exercise) or three (heavy exercise) independent exponential terms. Neither moderate- nor heavy-intensity exercise had an effect on the V˙o 2 kinetic response to subsequent moderate exercise. Although heavy-intensity exercise significantly reduced the mean response time in the second heavy exercise bout (from 65.2 ± 4.1 to 47.0 ± 3.1 s; P < 0.05), it had no significant effect on either the amplitude or the time constant (from 23.9 ± 1.9 to 25.3 ± 2.9 s) of theV˙o 2 response in phase II. Instead, this “speeding” was due to a significant reduction in the amplitude of the V˙o 2 slow component. These results suggest phase II V˙o 2 kinetics are not speeded by prior heavy exercise.

Cardiovascular and Oxygen Uptake Kinetics During Sequential Heavy Cycling Exercises

2003 ◽  
Vol 28 (2) ◽  
pp. 283-298 ◽  
Author(s):  
Stéphane Perrey ◽  
Jodie Scott ◽  
Laurent Mourot ◽  
Jean-Denis Rouillon
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Time Constant ◽  
Impedance Cardiography ◽  
Ventilatory Threshold ◽  
Slow Component ◽  
Oxygen Uptake Kinetics ◽  
Cycle Ergometer ◽  
Fast Component ◽  
Heavy Exercise

The purpose of the present study was to assess the relationship between the rapidity of increased oxygen uptake [Formula: see text] and increased cardiac output (CO) during heavy exercise. Six subjects performed repeated bouts on a cycle ergometer above the ventilatory threshold (∼80% of peak [Formula: see text]) separated by 10-min recovery cycling at 35% peak [Formula: see text]. [Formula: see text] was determined breath-by-breath and CO was determined continuously by impedance cardiography. CO and [Formula: see text] values were significantly higher during the 2-min period preceding the second bout. The overall responses for [Formula: see text] and CO were significantly related and were faster during the second bout. Prior heavy exercise resulted in a significant increase in the amplitude of the fast component of [Formula: see text] with no change in the time constant and a decrease in the slow component. Under these circumstances, the amplitude of the fast component was more sensitive to prior heavy exercise than was the associated time constant. Key words: impedance cardiography, exercise transitions, cardiac output, prior exercise

scholarly journals Oxygen uptake kinetics during treadmill running in boys and men

2001 ◽  
Vol 90 (5) ◽  
pp. 1700-1706 ◽  
Author(s):  
Craig A. Williams ◽  
Helen Carter ◽  
Andrew M. Jones ◽  
Jonathan H. Doust
Keyword(s):  
Oxygen Uptake ◽  
Time Constant ◽  
Slow Component ◽  
Oxygen Uptake Kinetics ◽  
Primary Response ◽  
Treadmill Running ◽  
Initial Increase ◽  
Moderate Exercise ◽  
Heavy Exercise ◽  
The Difference

The purpose of this study was to compare the kinetics of the oxygen uptake (V˙o 2) response of boys to men during treadmill running using a three-phase exponential modeling procedure. Eight boys (11–12 yr) and eight men (21–36 yr) completed an incremental treadmill test to determine lactate threshold (LT) and maximum V˙o 2. Subsequently, the subjects exercised for 6 min at two different running speeds corresponding to 80% of V˙o 2 at LT (moderate exercise) and 50% of the difference betweenV˙o 2 at LT and maximumV˙o 2 (heavy exercise). For moderate exercise, the time constant for the primary response was not significantly different between boys [10.2 ± 1.0 (SE) s] and men (14.7 ± 2.8 s). The gain of the primary response was significantly greater in boys than men (239.1 ± 7.5 vs. 167.7 ± 5.4 ml · kg−1 · km−1; P < 0.05). For heavy exercise, theV˙o 2 on-kinetics were significantly faster in boys than men (primary response time constant = 14.9 ± 1.1 vs. 19.0 ± 1.6 s; P < 0.05), and the primary gain was significantly greater in boys than men (209.8 ± 4.3 vs. 167.2 ± 4.6 ml · kg−1 · km−1; P < 0.05). The amplitude of theV˙o 2 slow component was significantly smaller in boys than men (19 ± 19 vs. 289 ± 40 ml/min; P < 0.05). The V˙o 2responses at the onset of moderate and heavy treadmill exercise are different between boys and men, with a tendency for boys to have faster on-kinetics and a greater initial increase inV˙o 2 for a given increase in running speed.

Pulmonary oxygen uptake kinetics

2017 ◽  
Author(s):  
Alan R Barker ◽  
Neil Armstrong
Keyword(s):  
Oxygen Uptake ◽  
Oxidative Phosphorylation ◽  
Children And Adolescents ◽  
Phase Ii ◽  
Slow Component ◽  
Moderate Intensity ◽  
Heavy Exercise ◽  
Moderate Intensity Exercise ◽  
Pulmonary Oxygen Uptake ◽  
Age Related

The pulmonary oxygen uptake (pV̇O2) kinetic response to exercise provides valuable non-invasive insight into the control of oxidative phosphorylation and determinants of exercise tolerance in children and adolescents. Few methodologically robust studies have investigated pV̇O2 kinetics in children and adolescents, but age- and sex-related differences have been identified. There is a clear age-related slowing of phase II pV̇O2 kinetics during heavy and very heavy exercise, with a trend showing during moderate intensity exercise. During heavy and very heavy exercise the oxygen cost is higher for phase II and the pV̇O2 component is truncated in children. Sex-related differences occur during heavy, but not moderate, intensity exercise, with boys having faster phase II pV̇O2 kinetics and a smaller pV̇O2 slow component compared to girls. The mechanisms underlying these differences are likely related to changes in phosphate feedback controllers of oxidative phosphorylation, muscle oxygen delivery, and/or muscle fibre recruitment strategies.

scholarly journals Prior moderate and heavy exercise accelerate oxygen uptake and cardiac output kinetics in endurance athletes

2009 ◽  
Vol 106 (5) ◽  
pp. 1553-1563 ◽  
Author(s):  
Azmy Faisal ◽  
Keith R. Beavers ◽  
Andrew D. Robertson ◽  
Richard L. Hughson
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Phase Ii ◽  
Exercise Bout ◽  
Endurance Athletes ◽  
Heavy Exercise ◽  
Cycling Exercise ◽  
Warm Up ◽  
Exercise Onset ◽  
Finger Pulse

Cardiorespiratory interactions at the onset of dynamic cycling exercise are modified by warm-up exercises. We tested the hypotheses that oxygen uptake (V̇o2) and cardiac output (Q̇) kinetics would be accelerated at the onset of heavy and moderate cycling exercise by warm-up. Nine male endurance athletes (peak V̇o2: 60.5 ± 3.2 ml·min−1·kg−1) performed multiple rides of two different 36-min cycling protocols, involving 6-min bouts at moderate and heavy intensities. Breath-by-breath V̇o2 and beat-by-beat stroke volume (SV) and Q̇, estimated by Modelflow from the finger pulse, were measured simultaneously with kinetics quantified from the phase II time constant (τ2). One novel finding was that both moderate (M) and heavy (H) warm-up bouts accelerated phase II V̇o2 kinetics during a subsequent bout of heavy exercise (τ2: after M = 22.5 ± 2.7 s, after H = 22.1 ± 2.9 vs. 26.2 ± 3.2 s; P < 0.01). Q̇ kinetics in heavy exercise were accelerated by both warm-up intensities (τ2: M = 22.0 ± 4.1 s, H = 23.8 ± 5.6 s vs. 27.4 ± 7.2 s; P < 0.05). During moderate exercise, prior heavy-intensity warm-up (one or two bouts) accelerated V̇o2 kinetics and elevated Q̇ at exercise onset, with no changes in Q̇ kinetics. A second novel finding was a significant overshoot in the estimate of SV from Modelflow in the first minutes of each moderate and heavy exercise bout. These findings suggest that the acceleration of V̇o2 kinetics during heavy exercise was enabled by the acceleration of Q̇ kinetics, and that rapid increases in Q̇ at the onset of moderate and heavy exercise might result, in part, from an overshoot of SV.

Oxygen Uptake Kinetics in Children and Adolescents: A Review

2009 ◽  
Vol 21 (2) ◽  
pp. 130-147 ◽  
Author(s):  
Neil Armstrong ◽  
Alan R. Barker
Keyword(s):  
Oxygen Uptake ◽  
Children And Adolescents ◽  
Phase Ii ◽  
Slow Component ◽  
Fiber Type ◽  
Muscle Metabolism ◽  
Oxygen Uptake Kinetics ◽  
Exponential Phase ◽  
Future Research ◽  
Age Related

The pulmonary oxygen uptake (pVO2) kinetic response at the onset of exercise provides a noninvasive window into the metabolic activity of the muscle and a valuable means of increasing our understanding of developmental muscle metabolism. However, to date only limited research has been devoted to investigating the pVO2 kinetic response during exercise in children and adolescents. From the rigorous studies that have been conducted, both age- and sex-related differences have been identified. Specifically, children display a faster exponential rise in the phase II pVO2 kinetics, which are purported to reflect the rise in muscle O2 consumption, during moderate, heavy and very heavy intensity exercise compared with adults. Furthermore, for heavy and very heavy exercise, the O2 cost of exercise is higher for the exponential phase and the magnitude of the pVO2 slow component is smaller in young children. Sex-related differences have been identified during heavy, but not moderate exercise, with prepubertal boys displaying a faster exponential phase II pVO2 kinetic response and a smaller pVO2 slow component compared with prepubertal girls. The mechanisms underlying these differences are currently poorly understood, and form the basis for future research in this area. However, it is hypothesized that an age-related modulation of the muscle phosphate feedback controllers to signal an increased rate of oxidative phosphorylation and/or altered muscle fiber type recruitment strategies have the potential to play an important role. Overall, the data support the view that at the onset of exercise children have an enhanced potential for oxidative metabolism in the myocyte compared with adults.

The influence of priming exercise on oxygen uptake, cardiac output, and muscle oxygenation kinetics during very heavy-intensity exercise in 9- to 13-yr-old boys

2010 ◽  
Vol 109 (2) ◽  
pp. 491-500 ◽  
Author(s):  
Alan R. Barker ◽  
Andrew M. Jones ◽  
Neil Armstrong
Keyword(s):  
Cardiac Output ◽  
Phase Ii ◽  
Near Infrared ◽  
Slow Component ◽  
Exercise Bout ◽  
Muscle Oxygenation ◽  
Heavy Exercise ◽  
Total Phase ◽  
Priming Exercise ◽  
Component Amplitude

The present study examined the effect of priming exercise on O2 uptake (V̇o2) kinetics during subsequent very heavy exercise in eight 9- to 13-yr-old boys. We hypothesised that priming exercise would 1) elevate muscle O2 delivery prior to the subsequent bout of very heavy exercise, 2) have no effect on the phase II V̇o2 τ, 3) elevate the phase II V̇o2 total amplitude, and 4) reduce the magnitude of the V̇o2 slow component. Each participant completed repeat 6-min bouts of very heavy-intensity cycling exercise separated by 6 min of light pedaling. During the tests V̇o2, muscle oxygenation (near infrared spectroscopy), and cardiac output (Q̇) (thoracic impedance) were determined. Priming exercise increased baseline muscle oxygenation and elevated Q̇ at baseline and throughout the second exercise bout. The phase II V̇o2 τ was not altered by priming exercise ( bout 1: 22 ± 7 s vs. bout 2: 20 ± 4 s; P = 0.30). However, the time constant describing the entire V̇o2 response from start to end of exercise was accelerated ( bout 1: 43 ± 8 s vs. bout 2: 36 ± 5 s; P = 0.002) due to an increased total phase II V̇o2 amplitude ( bout 1: 1.73 ± 0.33 l/min vs. bout 2: 1.80 ± 0.59 l/min; P = 0.002) and a reduced V̇o2 slow component amplitude ( bout 1: 0.18 ± 0.08 l/min vs. bout 2: 0.12 ± 0.09 l/min; P = 0.048). These results suggest that phase II V̇o2 kinetics in young boys is principally limited by intrinsic muscle metabolic factors, whereas the V̇o2 total phase II and slow component amplitudes may be O2 delivery sensitive.

Slow component of O2 uptake during heavy exercise: adaptation to endurance training

1995 ◽  
Vol 79 (3) ◽  
pp. 838-845 ◽  
Author(s):  
C. J. Womack ◽  
S. E. Davis ◽  
J. L. Blumer ◽  
E. Barrett ◽  
A. L. Weltman ◽  
...  
Keyword(s):  
Heart Rate ◽  
Power Output ◽  
Slow Component ◽  
Exercise Bout ◽  
Cycle Ergometer ◽  
O2 Uptake ◽  
Heavy Exercise ◽  
Absolute Power ◽  
Exercise Adaptation ◽  
Male Subjects

Seven untrained male subjects [age 25.6 +/- 1.5 (SE) yr, peak O2 uptake (VO2) 3.20 +/- 0.19 l/min] trained on a cycle ergometer 4 days/wk for 6 wk, with the absolute training workload held constant for the duration of training. Before and at the end of each week of training, the subjects performed 20 min of constant-power exercise at a power designed to elicit a pronounced slow component of VO2 (end-exercise VO2-VO2 at minute 3 of exercise) in the pretraining session. An additional 20-min exercise bout was performed after training at this same absolute power output during which epinephrine (Epi) was infused at a rate of 100 ng.kg-1.min-1 between minutes 10 and 20. After 2 wk of training, significant decreases in VO2 slow component, end-exercise VO2, blood lactate ([La-] and glucose concentrations, plasma Epi ([Epi]) and norepinephrine concentrations, ventilation (VE), and heart rate (HR) were observed (P < 0.05). Although the rapid attenuation of the VO2 slow component coincided temporally with reductions in plasma [Epi], blood [La-], and VE, the infusion of Epi after training significantly increased plasma [Epi] (delta 2.22 ng/ml), blood [La-] (delta 2.4 mmol/l) and VE (delta 10.0 l/min) without any change in exercise VO2. We therefore conclude that diminution of the VO2 slow component with training is attributable to factors other than the reduction in plasma [Epi], blood [La-] and VE.

scholarly journals Effect of muscle mass on V˙o 2kinetics at the onset of work

2001 ◽  
Vol 90 (2) ◽  
pp. 461-468 ◽  
Author(s):  
Shunsaku Koga ◽  
Thomas J. Barstow ◽  
Tomoyuki Shiojiri ◽  
Tetsuo Takaishi ◽  
Yoshiyuki Fukuba ◽  
...  
Keyword(s):  
Muscle Mass ◽  
Ventilatory Threshold ◽  
Slow Component ◽  
Cycle Ergometer ◽  
Muscle Recruitment ◽  
Heavy Exercise ◽  
Mean Response Time ◽  
Heavy Work ◽  
Exercise Transitions ◽  
Recruitment Patterns

The dependence of O2 uptake (V˙o 2) kinetics on the muscle mass recruited under conditions when fiber and muscle recruitment patterns are similar following the onset of exercise has not been determined. We developed a motorized cycle ergometer that facilitated one-leg (1L) cycling in which the electromyographic (EMG) profile of the active muscles was not discernibly altered from that during two-leg (2L) cycling. Six subjects performed 1L and 2L exercise transitions from unloaded cycling to moderate [<ventilatory threshold (VT)] and heavy (>VT) exercise. The 1L condition yielded kinetics that was unchanged from the 2L condition [the phase 2 time constants (τ1, in s) for <VT were as follows: 1L = 16.8±8.4 (SD), 2L = 18.4 ± 8.1, P > 0.05; for >VT: 1L = 26.8 ± 12.0; 2L = 27.8 ± 16.1, P > 0.05]. The overall V˙o 2 kinetics (mean response time) was not significantly different for the two exercise conditions. However, the gain of the fast component (the amplitude/work rate) during the 1L exercise was significantly higher than that for the 2L exercise for both moderate and heavy work rates. The slow-component responses evident for heavy exercise were temporally and quantitatively unaffected by the 1L condition. These data demonstrate that, when leg muscle recruitment patterns are unchanged as assessed by EMG analysis, on-transient V˙o 2 kinetics for both moderate and heavy exercise are not dependent on the muscle mass recruited.

Influence of exercise intensity on pulmonary oxygen uptake kinetics in young and late middle-aged adults

2012 ◽  
Vol 303 (8) ◽  
pp. R791-R798 ◽  
Author(s):  
Melitta A. McNarry ◽  
Michael I. C. Kingsley ◽  
Michael J. Lewis
Keyword(s):  
Gas Exchange ◽  
Oxygen Uptake ◽  
Phase Ii ◽  
Slow Component ◽  
Primary Component ◽  
Oxygen Availability ◽  
Large Sample Size ◽  
Heavy Exercise ◽  
Middle Aged ◽  
Pulmonary Oxygen Uptake

It is unclear whether pulmonary oxygen uptake (V̇o2) kinetics demonstrate linear, first-order behavior during supra gas exchange threshold exercise. Resolution of this issue is pertinent to the elucidation of the factors regulating oxygen uptake (V̇o2) kinetics, with oxygen availability and utilization proposed as putative mediators. To reexamine this issue with the advantage of a relatively large sample size, 50 young (24 ± 4 yr) and 15 late middle-aged (54 ± 3 yr) participants completed repeated bouts of moderate and heavy exercise. Pulmonary gas exchange, heart rate (HR), and cardiac output (Q̇) variables were measured throughout. The phase II τ was slower during heavy exercise in both young (moderate: 22 ± 9; heavy: 29 ± 9 s; P ≤ 0.001) and middle-aged (moderate: 22 ± 9; heavy: 30 ± 8 s; P ≤ 0.001) individuals. The HR τ was slower during heavy exercise in young (moderate: 33 ± 10; heavy: 44 ± 15 s; P ≤ 0.05) and middle-aged (moderate: 30 ± 12; heavy: 50 ± 20 s; P ≤ 0.05) participants, and the Q̇ τ showed a similar trend (young moderate: 21 ± 13; heavy: 28 ± 16 s; middle-aged moderate: 32 ± 13; heavy: 40 ± 15 s; P ≥ 0.05). There were no differences in primary component V̇o2 kinetics between age groups, but the middle-aged group had a significantly reduced V̇o2 slow component amplitude in both absolute (young: 0.25 ± 0.09; middle-aged: 0.11 ± 0.06 l/min; P ≤ 0.05) and relative terms (young: 15 ± 10; middle-aged: 9 ± 4%; P ≤ 0.05). Thus V̇o2 kinetics do not demonstrate dynamic linearity during heavy intensity exercise. Speculatively, the slower phase II τ during heavy exercise might be attributable to reduced oxygen availability. Finally, the primary and slow components of V̇o2 kinetics appear to be differentially influenced by middle age.

Effect of increased muscle temperature on oxygen uptake kinetics during exercise

1997 ◽  
Vol 83 (4) ◽  
pp. 1333-1338 ◽  
Author(s):  
Shunsaku Koga ◽  
Tomoyuki Shiojiri ◽  
Narihiko Kondo ◽  
Thomas J. Barstow
Keyword(s):  
Oxygen Uptake ◽  
Slow Component ◽  
Oxygen Uptake Kinetics ◽  
Work Rate ◽  
Uptake Kinetics ◽  
Hot Water ◽  
Muscle Temperature ◽  
Appreciable Effect ◽  
Heavy Exercise ◽  
The Difference

Koga, Shunsaku, Tomoyuki Shiojiri, Narihiko Kondo, and Thomas J. Barstow. Effect of increased muscle temperature on oxygen uptake kinetics during exercise. J. Appl. Physiol. 83(4): 1333–1338, 1997.—To test whether increased muscle temperature (Tm) would improve O2 uptake (V˙o 2) kinetics, seven men performed transitions from rest to a moderate work rate [below the estimated lactate threshold (LTest)] and a heavy work rate (V˙o 2 = 50% of the difference between LTest and peakV˙o 2) under conditions of normal Tm (N) and increased Tm (H), produced by wearing hot water-perfused pants before exercise. Quadriceps Tm was significantly higher in H, but rectal temperature was similar for the two conditions. There were no significant differences in the amplitudes of the fast component ofV˙o 2 or in the time constants of the on and off transients for moderate and heavy exercise between the two conditions. The increment inV˙o 2 between the 3rd and 6th min of heavy exercise was slightly but significantly smaller for H than for N. These data suggest that elevated Tm before exercise onset, which would have been expected to increase O2 delivery and off-loading to the muscle, had no appreciable effect on the fast exponential component ofV˙o 2 kinetics (invariant time constant). These data further suggest that elevated Tm does not contribute to the slow component of V˙o 2 during heavy exercise.

Sign in / Sign up

Export Citation Format

Share Document