scholarly journals Effect of creatine supplementation on oxygen uptake kinetics during submaximal cycle exercise

2002 ◽  
Vol 92 (6) ◽  
pp. 2571-2577 ◽  
Author(s):  
Andrew M. Jones ◽  
Helen Carter ◽  
Jamie S. M. Pringle ◽  
Iain T. Campbell
Keyword(s):  
Oxygen Uptake ◽  
Ventilatory Threshold ◽  
Vastus Lateralis ◽  
Creatine Supplementation ◽  
Oxygen Uptake Kinetics ◽  
Primary Component ◽  
Heavy Exercise ◽  
Cycle Exercise ◽  
Oral Consumption ◽  
Type Ii Fibers

The purpose of this study was to test the effect of oral creatine (Cr) supplementation on pulmonary oxygen uptake (V˙o 2) kinetics during moderate [below ventilatory threshold (VT)] and heavy (above VT) submaximal cycle exercise. Nine subjects (7 men; means ± SD: age 28 ± 3 yr, body mass 73.2 ± 5.6 kg, maximalV˙o 2 46.4 ± 8.0 ml · kg−1 · min−1) volunteered to participate in this study. Subjects performed transitions of 6-min duration from unloaded cycling to moderate (80% VT; 8–12 repeats) and heavy exercise (50% change; i.e., halfway between VT and maximal V˙o 2; 4–6 repeats), both in the control condition and after Cr loading, in a crossover design. The Cr loading regimen involved oral consumption of 20 g/day of Cr monohydrate for 5 days, followed by a maintenance dose of 5 g/day thereafter. V˙o 2 was measured breath by breath and modeled by using two (moderate) or three (heavy) exponential terms. For moderate exercise, there were no differences in the parameters of the V˙o 2 kinetic response between control and Cr-loaded conditions. For heavy exercise, the time-based parameters of the V˙o 2response were unchanged, but the amplitude of the primary component was significantly reduced with Cr loading (means ± SE: control 2.00 ± 0.12 l/min; Cr loaded 1.92 ± 0.10 l/min; P < 0.05) as was the end-exerciseV˙o 2 (control 2.19 ± 0.13 l/min; Cr loaded 2.12 ± 0.14 l/min; P < 0.05). The magnitude of the reduction in submaximalV˙o 2 with Cr loading was significantly correlated with the percentage of type II fibers in the vastus lateralis ( r = 0.87; P < 0.01; n = 7), indicating that the effect might be related to changes in motor unit recruitment patterns or the volume of muscle activated.

Oxygen uptake kinetics in endurance-trained and untrained postmenopausal women

2013 ◽  
Vol 38 (2) ◽  
pp. 154-160 ◽  
Author(s):  
Shilpa Dogra ◽  
Matthew D. Spencer ◽  
Juan M. Murias ◽  
Donald H. Paterson
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Older Women ◽  
Near Infrared ◽  
Ventilatory Threshold ◽  
Vastus Lateralis ◽  
Hemoglobin Concentration ◽  
Oxygen Uptake Kinetics ◽  
Moderate Intensity ◽  
Moderate Intensity Exercise

The rate of adjustment for pulmonary oxygen uptake (τV̇O2p) is slower in untrained and in older adults. Near-infrared spectroscopy (NIRS) has shed light on potential mechanisms underlying this in young men and women and in older men; however, there is no such data available in older women. The purpose of this study was to gain a better understanding of the mechanisms of slower τV̇O2p in older women who were either endurance-trained or untrained. Endurance-trained (n = 10; age, 62.6 ± 1.0 years) and untrained (n = 9; age, 69.1 ± 2.2 years) older women attended 2 maximal and 2 submaximal (90% of ventilatory threshold) exercise sessions. Oxygen uptake (V̇O2) was measured breath by breath, using a mass spectrometer, and changes in deoxygenated hemoglobin concentration of the vastus lateralis ([HHb]) were measured using NIRS. Heart rate was measured continuously with a 3-lead electrocardiogram. τV̇O2p was faster in trained (35.1 ± 5.5 s) than in untrained (57.0 ± 8.1 s) women. The normalized [HHb] to V̇O2 ratio, an indicator of muscle O2 delivery to O2 utilization, indicated a smaller overshoot in trained (1.09 ± 0.1) than in untrained (1.39 ± 0.1) women. Heart rate data indicated a faster adjustment of heart rate in trained (33.0 ± 13.0) than in untrained (68.7 ± 14.1) women. The pairing of V̇O2p data with NIRS-derived [HHb] data indicates that endurance-trained older women likely have better matching of O2 delivery to O2 utilization than older untrained women during moderate-intensity exercise, leading to a more rapid adjustment of V̇O2p.

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 Effect of pedal rate on primary and slow-component oxygen uptake responses during heavy-cycle exercise

2003 ◽  
Vol 94 (4) ◽  
pp. 1501-1507 ◽  
Author(s):  
Jamie S. M. Pringle ◽  
Jonathan H. Doust ◽  
Helen Carter ◽  
Keith Tolfrey ◽  
Andrew M. Jones
Keyword(s):  
Power Output ◽  
Ventilatory Threshold ◽  
Slow Component ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Motor Units ◽  
Primary Component ◽  
Heavy Exercise ◽  
Cycle Exercise ◽  
Pedal Rate

We hypothesized that a higher pedal rate (assumed to result in a greater proportional contribution of type II motor units) would be associated with an increased amplitude of the O2 uptake (V˙o 2) slow component during heavy-cycle exercise. Ten subjects (mean ± SD, age 26 ± 4 yr, body mass 71.5 ± 7.9 kg) completed a series of square-wave transitions to heavy exercise at pedal rates of 35, 75, and 115 rpm. The exercise power output was set at 50% of the difference between the pedal rate-specific ventilatory threshold and peakV˙o 2, and the baseline power output was adjusted to account for differences in the O2 cost of unloaded pedaling. The gain of the V˙o 2primary component was significantly higher at 35 rpm compared with 75 and 115 rpm (mean ± SE, 10.6 ± 0.3, 9.5 ± 0.2, and 8.9 ± 0.4 ml · min−1 · W−1, respectively; P < 0.05). The amplitude of theV˙o 2 slow component was significantly greater at 115 rpm (328 ± 29 ml/min) compared with 35 rpm (109 ± 30 ml/min) and 75 rpm (202 ± 38 ml/min) ( P < 0.05). There were no significant differences in the time constants or time delays associated with the primary and slow components across the pedal rates. The change in blood lactate concentration was significantly greater at 115 rpm (3.7 ± 0.2 mM) and 75 rpm (2.8 ± 0.3 mM) compared with 35 rpm (1.7 ± 0.4 mM) ( P < 0.05). These data indicate that pedal rate influences V˙o 2 kinetics during heavy exercise at the same relative intensity, presumably by altering motor unit recruitment patterns.

Chronic Omega-3 Fatty Acid Supplementation And Oxygen Uptake Kinetics During Heavy Exercise

2016 ◽  
Vol 48 ◽  
pp. 12
Author(s):  
Chad C. Wiggins ◽  
Shane A. Bielko ◽  
Allison J. Campbell ◽  
Timothy D. Mickleborough ◽  
Robert F. Chapman
Keyword(s):  
Fatty Acid ◽  
Oxygen Uptake ◽  
Oxygen Uptake Kinetics ◽  
Uptake Kinetics ◽  
Omega 3 ◽  
Heavy Exercise ◽  
Fatty Acid Supplementation ◽  
Acid Supplementation ◽  
Omega 3 Fatty Acid

Circadian Rhythm Affects Oxygen Uptake Kinetics In Moderate Not Heavy Exercise

2008 ◽  
Vol 40 (Supplement) ◽  
pp. S116
Author(s):  
Azmy Faisal ◽  
Andrew D. Robertson ◽  
Keith R. Beavers ◽  
Richard L. Hughson
Keyword(s):  
Circadian Rhythm ◽  
Oxygen Uptake ◽  
Oxygen Uptake Kinetics ◽  
Uptake Kinetics ◽  
Heavy Exercise

Muscle Glycogen Depletion Alters Oxygen Uptake Kinetics during Heavy Exercise

2004 ◽  
Vol 36 (6) ◽  
pp. 965-972 ◽  
Author(s):  
HELEN CARTER ◽  
JAMIE S. M. PRINGLE ◽  
LES BOOBIS ◽  
ANDREW M. JONES ◽  
JONATHAN H. DOUST
Keyword(s):  
Oxygen Uptake ◽  
Muscle Glycogen ◽  
Oxygen Uptake Kinetics ◽  
Uptake Kinetics ◽  
Glycogen Depletion ◽  
Heavy Exercise

scholarly journals A Single Bout of Constant-Load Exercise Test for Estimating the Time Constant of Oxygen Uptake Kinetics in Individuals With Stroke

2021 ◽  
Vol 45 (4) ◽  
pp. 304-313
Author(s):  
Kazuaki Oyake ◽  
Yasuto Baba ◽  
Yuki Suda ◽  
Jun Murayama ◽  
Ayumi Mochida ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Time Constant ◽  
Ventilatory Threshold ◽  
Exercise Bout ◽  
Relative Difference ◽  
Constant Load ◽  
Oxygen Uptake Kinetics ◽  
Uptake Kinetics ◽  
Single Bout ◽  
The Relationship

Objective To examine the relationship between the time constant of oxygen uptake kinetics during the onset of exercise (τVO2) estimated from a single exercise bout and that obtained from three averaged exercise bouts in individuals with stroke.Methods Twenty participants with stroke performed three bouts of a constant-load pedaling exercise at approximately 80% of the workload corresponding to the ventilatory threshold to estimate τVO2. The VO2 data from the first trial of three bouts were used to estimate τVO2 for a single bout. Additionally, data collected from three bouts were ensemble-averaged to obtain τVO2 for three averaged bouts as the criterion.Results There was a very high correlation between τVO2 for a single bout (34.8±14.0 seconds) and τVO2 for three averaged bouts (38.5±13.4 seconds) (r=0.926, p<0.001). However, τVO2 for a single bout was smaller than that for three averaged bouts (p=0.006).Conclusion τVO2 for a single bout could reflect the relative difference in τVO2 for three averaged bouts among individuals with stroke. However, it should be noted that τVO2 for a single bout may be underestimated compared to τVO2 for three averaged bouts.

The effects of creatine loading on oxygen uptake kinetics during heavy exercise

2013 ◽  
Vol 27 (S1) ◽  
Author(s):  
Cory L Butts ◽  
Heather Adamus ◽  
David M Keller ◽  
Paul McDonough
Keyword(s):  
Oxygen Uptake ◽  
Oxygen Uptake Kinetics ◽  
Uptake Kinetics ◽  
Heavy Exercise

Methodological validation of the dynamic heterogeneity of muscle deoxygenation within the quadriceps during cycle exercise

2011 ◽  
Vol 301 (2) ◽  
pp. R534-R541 ◽  
Author(s):  
Shunsaku Koga ◽  
David C. Poole ◽  
Yoshiyuki Fukuoka ◽  
Leonardo F. Ferreira ◽  
Narihiko Kondo ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Near Infrared ◽  
Continuous Wave ◽  
Vastus Lateralis ◽  
Relative Concentration ◽  
Primary Component ◽  
Dynamic Heterogeneity ◽  
Cycle Exercise ◽  
Muscle Deoxygenation ◽  
The Absolute

The conventional continuous wave near-infrared spectroscopy (CW-NIRS) has enabled identification of regional differences in muscle deoxygenation following onset of exercise. However, assumptions of constant optical factors (e.g., path length) used to convert the relative changes in CW-NIRS signal intensity to values of relative concentration, bring the validity of such measurements into question. Furthermore, to justify comparisons among sites and subjects, it is essential to correct the amplitude of deoxygenated hemoglobin plus myoglobin [deoxy(Hb+Mb)] for the adipose tissue thickness (ATT). We used two time-resolved NIRS systems to measure the distribution of the optical factors directly, thereby enabling the determination of the absolute concentrations of deoxy(Hb+Mb) simultaneously at the distal and proximal sites within the vastus lateralis (VL) and the rectus femoris muscles. Eight subjects performed cycle exercise transitions from unloaded to heavy work rates (>gas exchange threshold). Following exercise onset, the ATT-corrected amplitudes (Ap), time delay (TDp), and time constant (τp) of the primary component kinetics in muscle deoxy(Hb + Mb) were spatially heterogeneous (intersite coefficient of variation range for the subjects: 10–50 for Ap, 16–58 for TDp, 14–108% for τp). The absolute and relative amplitudes of the deoxy(Hb+Mb) responses were highly dependent on ATT, both within subjects and between measurement sites. The present results suggest that regional heterogeneity in the magnitude and temporal profile of muscle deoxygenation is a consequence of differential matching of O2 delivery and O2 utilization, not an artifact caused by changes in optical properties of the tissue during exercise or variability in the overlying adipose tissue.

Sign in / Sign up

Export Citation Format

Share Document