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.

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 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.

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.

Kinetics of oxygen uptake at the onset of exercise near or above peak oxygen uptake

2000 ◽  
Vol 88 (5) ◽  
pp. 1812-1819 ◽  
Author(s):  
R. L. Hughson ◽  
D. D. O'Leary ◽  
A. C. Betik ◽  
H. Hebestreit
Keyword(s):  
Oxygen Uptake ◽  
Cardiovascular System ◽  
Time Constant ◽  
Exponential Model ◽  
Peak Oxygen Uptake ◽  
Phase 2 ◽  
Heavy Exercise ◽  
The Difference ◽  
Kinetics Of ◽  
Model Phase

We tested the hypothesis that kinetics of O2 uptake (V˙o 2) measured in the transition to exercise near or above peakV˙o 2(V˙o 2 peak) would be slower than those for subventilatory threshold exercise. Eight healthy young men exercised at ∼57, ∼96, and ∼125%V˙o 2 peak. Data were fit by a two- or three-component exponential model and with a semilogarithmic transformation that tested the difference between required V˙o 2 and measuredV˙o 2. With the exponential model, phase 2 kinetics appeared to be faster at 125% V˙o 2 peak[time constant (τ2) = 16.3 ± 8.8 (SE) s] than at 57%V˙o 2 peak(τ2 = 29.4 ± 4.0 s) but were not different from that at 96%V˙o 2 peakexercise (τ2 = 22.1 ± 2.1 s).V˙o 2 at the completion of phase 2 was 77 and 80%V˙o 2 peak in tests predicted to require 96 and 125%V˙o 2 peak. WhenV˙o 2 kinetics were calculated with the semilogarithmic model, the estimated τ2 at 96%V˙o 2 peak (49.7 ± 5.1 s) and 125%V˙o 2 peak (40.2 ± 5.1 s) were slower than with the exponential model. These results are consistent with our hypothesis and with a model in which the cardiovascular system is compromised during very heavy exercise.

The Effect of Prior Moderate- and Heavy-Intensity Running on the VO2 Response to Exhaustive Severe-Intensity Running

2006 ◽  
Vol 1 (4) ◽  
pp. 361-374 ◽  
Author(s):  
Stephen B. Draper ◽  
Dan M. Wood ◽  
Jo Corbett ◽  
David V.B. James ◽  
Christopher R. Potter
Keyword(s):  
Oxygen Uptake ◽  
Slow Component ◽  
Maximum Oxygen Uptake ◽  
Moderate Intensity ◽  
Time To Exhaustion ◽  
Heavy Exercise ◽  
Square Wave ◽  
Severe Intensity ◽  
The Difference ◽  
Trained Runners

We tested the hypothesis that prior heavy-intensity exercise reduces the difference between asymptotic oxygen uptake (VO2) and maximum oxygen uptake (VO2max) during exhaustive severe-intensity running lasting ≍2 minutes. Ten trained runners each performed 2 ramp tests to determine peak VO2 (VO2peak) and speed at venti-latory threshold. They performed exhaustive square-wave runs lasting ≍2 minutes, preceded by either 6 minutes of moderate-intensity running and 6 minutes rest (SEVMOD) or 6 minutes of heavy-intensity running and 6 minutes rest (SEVHEAVY). Two transitions were completed in each condition. VO2 was determined breath by breath and averaged across the 2 repeats of each test; for the square-wave test, the averaged VO2 response was then modeled using a monoexponential function. The amplitude of the VO2 response to severe-intensity running was not different in the 2 conditions (SEVMOD vs SEVHEAVY; 3925 ± 442 vs 3997 ± 430 mL/min, P = .237), nor was the speed of the response (τ; 9.2 ± 2.1 vs 10.0 ± 2.1 seconds, P = .177). VO2peak from the square-wave tests was below that achieved in the ramp tests (91.0% ± 3.2% and 92.0% ± 3.9% VO2peak, P < .001). There was no difference in time to exhaustion between conditions (110.2 ± 9.7 vs 111.0 ± 15.2 seconds, P = .813). The results show that the primary VO2 response is unaffected by prior heavy exercise in running performed at intensities at which exhaustion will occur before a slow component emerges.

scholarly journals Oxygen Uptake Kinetics in Endurance Trained Youth and Adult Cyclists

2021 ◽  
pp. 398-403
Author(s):  
Bernhard Prinz ◽  
Manfred Zöger ◽  
Harald Tschan ◽  
Alfred Nimmerichter
Keyword(s):  
Oxygen Uptake ◽  
Time Constant ◽  
Oxygen Uptake Kinetics ◽  
Primary Response ◽  
Uptake Kinetics ◽  
Repeated Measure ◽  
Adult Age ◽  
Mean Response Time ◽  
Training History ◽  
Rate Intensity

Previous studies reported faster pulmonary oxygen uptake kinetics at the onset of exercise in untrained youth compared with adults. Whether or not these differences are identical for trained groups have not been examined. The purpose of this study was to compare ̇VO2 kinetics of youth and adult cyclists at moderate and heavy-intensity exercise. Thirteen adult (age: 23.2 ± 4.8 years; ̇VO2peak 68.4 ± 6.8 mL·min-1.kg-1) and thirteen youth cyclists (age: 14.3 ± 1.5 years; ̇VO2peak 61.7 ± 4.3 mL·min-1.kg-1) completed a series of 6-min square wave exercises at moderate and heavy-intensity exercise at 90 rev·min-1. A two-way repeated-measure ANOVA was conducted to identify differences between groups and intensities. The time constant, time delay and the mean response time were not significantly different between youth and adult cyclists (p > 0.05). We found significant differences between intensities, with a faster time constant during moderate than heavy-intensity exercise in youth (24.1 ± 7.0 s vs. 31.8 ± 5.6 s; p = 0.004) and adults (22.7 ± 5.6 s vs. 28.6 ± 5.7 s; p < 0.001). The present data suggest that the effect of training history in adult cyclists compensate for the superior primary response of the oxygen uptake kinetics typically seen in youth compared to adults. Furthermore, the ̇VO2 response is dependent of work rate intensity in trained youth and adult cyclists.

Oxygen uptake kinetics in treadmill running and cycle ergometry: a comparison

2000 ◽  
Vol 89 (3) ◽  
pp. 899-907 ◽  
Author(s):  
Helen Carter ◽  
Andrew M. Jones ◽  
Thomas J. Barstow ◽  
Mark Burnley ◽  
Craig A. Williams ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Slow Component ◽  
Maximal Oxygen Consumption ◽  
Exponential Model ◽  
Oxygen Uptake Kinetics ◽  
Treadmill Running ◽  
Tension Development ◽  
Exercise Transitions ◽  
The Difference ◽  
Power Outputs

The purpose of the present study was to comprehensively examine oxygen consumption (V˙o 2) kinetics during running and cycling through mathematical modeling of the breath-by-breath gas exchange responses to moderate and heavy exercise. After determination of the lactate threshold (LT) and maximal oxygen consumption (V˙o 2 max) in both cycling and running exercise, seven subjects (age 26.6 ± 5.1 yr) completed a series of “square-wave” rest-to-exercise transitions at running speeds and cycling power outputs that corresponded to 80% LT and 25, 50, and 75%Δ (Δ being the difference between LT andV˙o 2 max).V˙o 2 responses were fit with either a two- (<LT) or three-phase ( >LT) exponential model. The parameters of theV˙o 2 kinetic response were similar between exercise modes, except for the V˙o 2 slow component, which was significantly ( P < 0.05) greater for cycling than for running at 50 and 75%Δ (334 ± 183 and 430 ± 159 ml/min vs. 205 ± 84 and 302 ± 154 ml/min, respectively). We speculate that the differences between the modes are related to the higher intramuscular tension development in heavy cycle exercise and the higher eccentric exercise component in running. This may cause a relatively greater recruitment of the less efficient type II muscle fibers in cycling.

Letters to the Editor

1998 ◽  
Vol 85 (4) ◽  
pp. 1593-1600
Author(s):  
Guido Ferretti
Keyword(s):  
Slow Component ◽  
Oxygen Uptake Kinetics ◽  
Work Rate ◽  
Hot Water ◽  
Muscle Temperature ◽  
Appreciable Effect ◽  
Heavy Exercise ◽  
Letters To The Editor ◽  
Heavy Work ◽  
The Difference

The following is the abstract of the article discussed in the subsequent letter: 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 O2delivery 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 ofV˙o 2 during heavy exercise.

Kinetics of oxygen uptake during supine and upright heavy exercise

1999 ◽  
Vol 87 (1) ◽  
pp. 253-260 ◽  
Author(s):  
Shunsaku Koga ◽  
Tomoyuki Shiojiri ◽  
Manabu Shibasaki ◽  
Narihiko Kondo ◽  
Yoshiyuki Fukuba ◽  
...  
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Supine Position ◽  
Slow Component ◽  
Fast Component ◽  
Heavy Exercise ◽  
The Difference ◽  
Early Rise ◽  
Kinetics Of ◽  
State Increase

It is presently unclear how the fast and slow components of pulmonary oxygen uptake (V˙o 2) kinetics would be altered by body posture during heavy exercise [i.e., above the lactate threshold (LT)]. Nine subjects performed transitions from unloaded cycling to work rates representing moderate (below the estimated LT) and heavy exercise (V˙o 2 equal to 50% of the difference between LT and peakV˙o 2) under conditions of upright and supine positions. During moderate exercise, the steady-state increase in V˙o 2was similar in the two positions, butV˙o 2 kinetics were slower in the supine position. During heavy exercise, the rate of adjustment ofV˙o 2 to the 6-min value was also slower in the supine position but was characterized by a significant reduction in the amplitude of the fast component ofV˙o 2, without a significant slowing of the phase 2 time constant. However, the amplitude of the slow component was significantly increased, such that the end-exerciseV˙o 2 was the same in the two positions. The changes inV˙o 2 kinetics for the supine vs. upright position were paralleled by a blunted response of heart rate at 2 min into exercise during supine compared with upright heavy exercise. Thus the supine position was associated with not only a greater amplitude of the slow component forV˙o 2 but also, concomitantly, with a reduced amplitude of the fast component; this latter effect may be due, at least in part, to an attenuated early rise in heart rate in the supine position.

scholarly journals Excessive oxygen uptake during exercise and recovery in heavy exercise

2007 ◽  
pp. 721-725
Author(s):  
T Yano ◽  
T Yunoki ◽  
R Matsuura ◽  
T Arimitsu ◽  
T Kimura
Keyword(s):  
Time Delay ◽  
Oxygen Uptake ◽  
Power Output ◽  
High Ratio ◽  
Moderate Exercise ◽  
Heavy Exercise ◽  
Vo2 Kinetics ◽  
Recovery Exercise ◽  
The Difference ◽  
Excessive Oxygen

The aim of this study was to determine whether excessive oxygen uptake (Vo2) occurs not only during exercise but also during recovery after heavy exercise. After previous exercise at zero watts for 4 min, the main exercise was performed for 10 min. Then recovery exercise at zero watts was performed for 10 min. The main exercises were moderate and heavy exercises at exercise intensities of 40 % and 70 % of peak Vo2, respectively. Vo2 kinetics above zero watts was obtained by subtracting Vo2 at zero watts of previous exercise (DeltaVo2). Delta Vo2 in moderate exercise was multiplied by the ratio of power output performed in moderate and heavy exercises so as to estimate the Delta Vo2 applicable to heavy exercise. The difference between Delta Vo2 in heavy exercise and Delta Vo2 estimated from the value of moderate exercise was obtained. The obtained Vo2 was defined as excessive Vo2. The time constant of excessive Vo2 during exercise (1.88+/-0.70 min) was significantly shorter than that during recovery (9.61+/-6.92 min). Thus, there was excessive Vo2 during recovery from heavy exercise, suggesting that O2/ATP ratio becomes high after a time delay in heavy exercise and the high ratio continues until recovery.

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