Sodium bicarbonate ingestion does not alter the slow component of oxygen uptake kinetics in professional cyclists

2003 ◽  
Vol 21 (1) ◽  
pp. 39-47 ◽  
Author(s):  
ALFREDO SANTALLA ◽  
MARGARITA PÉREZ ◽  
MANUEL MONTILLA ◽  
LÁZARO VICENTE ◽  
RICHARD DAVISON ◽  
...  
2015 ◽  
Vol 40 (9) ◽  
pp. 918-923 ◽  
Author(s):  
Kelly de Jesus ◽  
Ana Sousa ◽  
Karla de Jesus ◽  
João Ribeiro ◽  
Leandro Machado ◽  
...  

Swimming and training are carried out with wide variability in distances and intensities. However, oxygen uptake kinetics for the intensities seen in swimming has not been reported. The purpose of this study was to assess and compare the oxygen uptake kinetics throughout low-moderate to severe intensities during incremental swimming exercise. We hypothesized that the oxygen uptake kinetic parameters would be affected by swimming intensity. Twenty male trained swimmers completed an incremental protocol of seven 200-m crawl swims to exhaustion (0.05 m·s−1 increments and 30-s intervals). Oxygen uptake was continuously measured by a portable gas analyzer connected to a respiratory snorkel and valve system. Oxygen uptake kinetics was assessed using a double exponential regression model that yielded both fast and slow components of the response of oxygen uptake to exercise. From low-moderate to severe swimming intensities changes occurred for the first and second oxygen uptake amplitudes (P ≤ 0.04), time constants (P = 0.01), and time delays (P ≤ 0.02). At the heavy and severe intensities, a notable oxygen uptake slow component (>255 mL·min−1) occurred in all swimmers. Oxygen uptake kinetics whilst swimming at different intensities offers relevant information regarding cardiorespiratory and metabolic stress that might be useful for appropriate performance diagnosis and training prescription.


1997 ◽  
Vol 83 (4) ◽  
pp. 1333-1338 ◽  
Author(s):  
Shunsaku Koga ◽  
Tomoyuki Shiojiri ◽  
Narihiko Kondo ◽  
Thomas J. Barstow

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.


2011 ◽  
Vol 589 (3) ◽  
pp. 727-739 ◽  
Author(s):  
Daniel T. Cannon ◽  
Ailish C. White ◽  
Melina F. Andriano ◽  
Fred W. Kolkhorst ◽  
Harry B. Rossiter

2014 ◽  
Vol 39 (3) ◽  
pp. 308-317 ◽  
Author(s):  
Alan R. Barker ◽  
Emily Trebilcock ◽  
Brynmor Breese ◽  
Andrew M. Jones ◽  
Neil Armstrong

This study used priming exercise in young boys to investigate (i) how muscle oxygen delivery and oxygen utilization, and muscle activity modulate oxygen uptake kinetics during exercise; and (ii) whether the accelerated oxygen uptake kinetics following priming exercise can improve exercise tolerance. Seven boys that were aged 11.3 ± 1.6 years completed either a single bout (bout 1) or repeated bouts with 6 min of recovery (bout 2) of very heavy-intensity cycling exercise. During the tests oxygen uptake, muscle oxygenation, muscle electrical activity and exercise tolerance were measured. Priming exercise most likely shortened the oxygen uptake mean response time (change, ±90% confidence limits; –8.0 s, ±3.0), possibly increased the phase II oxygen uptake amplitude (0.11 L·min−1, ±0.09) and very likely reduced the oxygen uptake slow component amplitude (–0.08 L·min−1, ±0.07). Priming resulted in a likely reduction in integrated electromyography (–24% baseline, ±21% and –25% baseline, ±19) and a very likely reduction in Δ deoxyhaemoglobin/Δoxygen uptake (–0.16, ±0.11 and –0.09, ±0.05) over the phase II and slow component portions of the oxygen uptake response, respectively. A correlation was present between the change in tissue oxygenation index during bout 2 and the change in the phase II (r = –0.72, likely negative) and slow component (r = 0.72, likely positive) oxygen uptake amplitudes following priming exercise, but not for muscle activity. Exercise tolerance was likely reduced (change –177 s, ±180) following priming exercise. The altered phase II and slow component oxygen uptake amplitudes in boys following priming exercise are linked to an improved localised matching of muscle oxygen delivery to oxygen uptake and not muscle electrical activity. Despite more rapid oxygen uptake kinetics following priming exercise, exercise tolerance was not enhanced.


2008 ◽  
Vol 22 (6) ◽  
pp. 2018-2026 ◽  
Author(s):  
Moh H Malek ◽  
Terry J Housh ◽  
Larry D Crouch ◽  
Glen O Johnson ◽  
C Russell Hendrix ◽  
...  

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