scholarly journals Exploring cardio-pulmonary interactions by examining the ventilatory, pulmonary gas exchange, and heart rate kinetics response to high-intensity cycle exercise in COPD patients

2015 ◽  
Vol 219 ◽  
pp. 103-105 ◽  
Author(s):  
Bruno-Pierre Dubé ◽  
Pierantonio Laveneziana
2010 ◽  
Vol 111 (2) ◽  
pp. 225-234 ◽  
Author(s):  
Pierantonio Laveneziana ◽  
Gabriele Valli ◽  
Paolo Onorati ◽  
Patrizia Paoletti ◽  
Alessandro Maria Ferrazza ◽  
...  

2001 ◽  
Vol 90 (6) ◽  
pp. 2081-2087 ◽  
Author(s):  
S. E. Bearden ◽  
R. J. Moffatt

The purpose of this study was to examine oxygen consumption (V˙o 2) and heart rate kinetics during moderate and repeated bouts of heavy square-wave cycling from an exercising baseline. Eight healthy, male volunteers performed square-wave bouts of leg ergometry above and below the gas exchange threshold separated by recovery cycling at 35%V˙o 2 peak.V˙o 2 and heart rate kinetics were modeled, after removal of phase I data by use of a biphasic on-kinetics and monoexponential off-kinetics model. Fingertip capillary blood was sampled 45 s before each transition for base excess, HCO[Formula: see text] and lactate concentration, and pH. Base excess and HCO[Formula: see text] concentration were significantly lower, whereas lactate concentration and pH were not different before the second bout. The results confirm earlier reports of a smaller mean response time in the second heavy bout. This was the result of a significantly greater fast-component amplitude and smaller slow-component amplitude with invariant fast-component time constant. A role for local oxygen delivery limitation in heavy exercise transitions with unloaded but not moderate baselines is presented.


2017 ◽  
Vol 49 (5S) ◽  
pp. 725
Author(s):  
Natasha G. Boyes ◽  
Josie T.J. Fries ◽  
Stephanie Fusnik ◽  
Paul J. Fadel ◽  
Corey R. Tomczak

1998 ◽  
Vol 85 (1) ◽  
pp. 310-317 ◽  
Author(s):  
Judith G. Regensteiner ◽  
Timothy A. Bauer ◽  
Jane E. B. Reusch ◽  
Suzanne L. Brandenburg ◽  
Jeffrey M. Sippel ◽  
...  

Persons with type II diabetes mellitus (DM), even without cardiovascular complications have a decreased maximal oxygen consumption (V˙o2 max) and submaximal oxygen consumption (V˙o2) during graded exercise compared with healthy controls. We evaluated the hypothesis that change in the rate ofV˙o2in response to the onset of constant-load exercise (measured byV˙o2-uptake kinetics) was slowed in persons with type II DM. Ten premenopausal women with uncomplicated type II DM, 10 overweight, nondiabetic women, and 10 lean, nondiabetic women had aV˙o2 maxtest. On two separate occasions, subjects performed 7-min bouts of constant-load bicycle exercise at workloads below and above the lactate threshold to enable measurements of V˙o2kinetics and heart rate kinetics (measuring rate of heart rate rise).V˙o2 maxwas reduced in subjects with type II DM compared with both lean and overweight controls ( P < 0.05). Subjects with type II DM had slowerV˙o2and heart rate kinetics than did controls at constant workloads below the lactate threshold. The data suggest a notable abnormality in the cardiopulmonary response at the onset of exercise in people with type II DM. The findings may reflect impaired cardiac responses to exercise, although an additional defect in skeletal muscle oxygen diffusion or mitochondrial oxygen utilization is also possible.


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