Impact of 60 days of 6° head down tilt bed rest on muscular oxygen uptake and heart rate kinetics: efficacy of a reactive sledge jump countermeasure

2018 ◽  
Vol 118 (9) ◽  
pp. 1885-1901 ◽  
Author(s):  
J. Koschate ◽  
L. Thieschäfer ◽  
U. Drescher ◽  
U. Hoffmann
2019 ◽  
Vol 51 (Supplement) ◽  
pp. 465
Author(s):  
Uwe Hoffmann ◽  
Uwe Drescher ◽  
Lutz Thieschäfer ◽  
Jessica Koschate

2006 ◽  
Vol 38 (Supplement) ◽  
pp. S325
Author(s):  
Robert G. Haennel ◽  
Corey R. Tomczak ◽  
Russell J. Down ◽  
Bharath Krishnan

2017 ◽  
Vol 125 (05) ◽  
pp. 275-281 ◽  
Author(s):  
Jessica Koschate ◽  
Uwe Drescher ◽  
Klaus Baum ◽  
Christian Brinkmann ◽  
Thorsten Schiffer ◽  
...  

AbstractThe aim of this pilot study was to investigate whether there are differences in heart rate and oxygen uptake kinetics in type 2 diabetes patients, considering their cardiovascular medication. It was hypothesized that cardiovascular medication would affect heart rate and oxygen uptake kinetics and that this could be detected using a standardized exercise test. 18 subjects were tested for maximal oxygen uptake. Kinetics were measured in a single test session with standardized, randomized moderate-intensity work rate changes. Time series analysis was used to estimate kinetics. Greater maxima in cross-correlation functions indicate faster kinetics. 6 patients did not take any cardiovascular medication, 6 subjects took peripherally acting medication and 6 patients were treated with centrally acting medication. Maximum oxygen uptake was not significantly different between groups. Significant main effects were identified regarding differences in muscular oxygen uptake kinetics and heart rate kinetics. Muscular oxygen uptake kinetics were significantly faster than heart rate kinetics in the group with no cardiovascular medication (maximum in cross-correlation function of muscular oxygen uptake vs. heart rate; 0.32±0.08 vs. 0.25±0.06; p=0.001) and in the group taking peripherally acting medication (0.34±0.05 vs. 0.28±0.05; p=0.009) but not in the patients taking centrally acting medication (0.28±0.05 vs. 0.30±0.07; n.s.). It can be concluded that regulatory processes for the achievement of a similar maximal oxygen uptake are different between the groups. The used standardized test provided plausible results for heart rate and oxygen uptake kinetics in a single measurement session in this patient group.


1993 ◽  
Vol 25 (Supplement) ◽  
pp. S55
Author(s):  
S. M. McCue ◽  
L. R. Reider ◽  
J. E. Graves ◽  
L. B. Panton ◽  
L. Garzarella ◽  
...  

2008 ◽  
Vol 85 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Corey R. Tomczak ◽  
Darren E.R. Warburton ◽  
Kenneth J. Riess ◽  
Nicholas G. Jendzjowsky ◽  
Ben T. Esch ◽  
...  

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.


2010 ◽  
Vol 111 (2) ◽  
pp. 225-234 ◽  
Author(s):  
Pierantonio Laveneziana ◽  
Gabriele Valli ◽  
Paolo Onorati ◽  
Patrizia Paoletti ◽  
Alessandro Maria Ferrazza ◽  
...  

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