scholarly journals Models for Oxygen Consumption and Cardiac Output as Response to Treadmill Exercise

Author(s):  
Milan Stork ◽  
Jaroslav Novak
1987 ◽  
Vol 253 (6) ◽  
pp. R890-R895 ◽  
Author(s):  
J. M. Weber ◽  
G. P. Dobson ◽  
W. S. Parkhouse ◽  
D. Wheeldon ◽  
J. C. Harman ◽  
...  

This study characterizes the effects of exercise on the cardiac output (Q) and the metabolic rate (VO2) of trained Thoroughbred racehorses. Heart rate, Q, and arteriovenous (a-v)O2 difference were measured at rest and at three levels of submaximal treadmill exercise (1.6 m/s walk and 3-4 m/s trot at 6% incline, and 6.5 m/s horizontal canter). Heart rate and (a-v)O2 difference were also measured during maximal exercise (12.5 m/s gallop, 5% incline) to obtain an estimate of maximum O2 uptake (VO2max). The walk, trot, and canter represented 25, 45, and 55% VO2max. Mean heart rate went from 48.9 (rest) to 197 beats/min (gallop). Q ranged from 106 (rest) to 571 ml.min-1.kg-1 (canter), and stroke volume went from 1.34 (rest) to a maximum of 1.58 liters (walk). Thoroughbreds were able to bring hematocrit from 38 (rest) to 63% (gallop), and this adjustment allowed them to reach an impressive (a-v)O2 difference of 23 vol%, which represents a fivefold increase over resting values. These outstanding athletes probably support an aerobic scope of 40-fold.


2015 ◽  
Vol 36 (03) ◽  
pp. e11-e18 ◽  
Author(s):  
G. Mendonca ◽  
J. Vaz ◽  
P. Pezarat-Correia ◽  
B. Fernhall

AbstractThis study determined the influence of walking with blood flow restriction (BFR) on the excess post-exercise oxygen consumption (EPOC) of healthy young men. 17 healthy young men (22.1±2.9 years) performed graded treadmill exercise to assess VO2peak. In a randomized fashion, each participant performed 5 sets of 3-min treadmill exercise at their optimal walking speed with 1-min interval either with or without BFR. Participants were then seated in a chair and remained there for 30 min of recovery. Expired gases were continuously monitored during exercise and recovery. BFR increased the O2 cost of walking as well as its relative intensity and cumulative O2 deficit (p<0.05). The EPOC magnitude after walking with BFR was greater than in the non-BFR condition (p<0.05). No differences between conditions were seen for the duration of EPOC. The EPOC magnitude was no longer different between conditions after controlling for the differences in relative intensity and in the cumulative O2 deficit (p>0.05). These data indicate that walking with BFR increases the magnitude of EPOC. Moreover, they also demonstrate that such increment in EPOC is likely explained by the effects of BFR on walking relative intensity and cumulative O2 deficit.


2020 ◽  
Vol 1 (1) ◽  
pp. 72-9
Author(s):  
Alfan Mahdi Nugroho ◽  
Yusmein Uyun ◽  
Annemarie Chrysantia Melati

Analgesia epidural telah diperkenalkan secara rutin sebagai salah satu modalitas analgesia pada proses persalinan sejak lama. Hubungan antara analgesia epidural persalinan dengan demam intrapartum pada maternal sudah disebutkan pada beberapa literatur. Demam didefinisikan sebagai peningkatan suhu tubuh lebih dari 38 oC yang didapat dari dua kali pemeriksaan. Beberapa teori yang disebutkan antara lain perubahan termoregulasi, infeksi pada ibu-janin dan inflamasi non-infeksi yang dimediasi oleh sitokin proinflamasi. Namun demikian berbagai mekanisme analgesia epidural dapat menyebabkan demam masih terus diteliti. Identifikasi demam pada ibu saat persalinan merupakan hal yang penting untuk dilakukan karena memiliki konsekuensi klinis pada ibu dan neonatus. Pada ibu ditemukan suhu yang meningkat dikaitkan dengan peningkatan denyut jantung ibu, curah jantung, konsumsi oksigen, dan produksi katekolamin. Sedangkan pada janin demam intrapartum dapat menyebabkan sepsis, perubahan skor APGAR, peningkatan kebutuhan bantuan napas dan kejadian kejang. Efek demam pada ibu dan janin masih terus dipelajari, sehingga suatu saat didapatkan cara pencegahan yang paling baik yang pada akhirnya menghindarkan keraguan untuk melakukan analgesia persalinan.   Fever during labour epidural analgesia Abstract Epidural analgesia has been routinely introduced as one of the analgesia modalities during labour. Literature has mentioned the relationship between epidural analgesia and intrapartum fever among mothers. Fever is defined as increased temperature above 38 oC in more than two measurements. Several theories have been proposed, inculing thermoregulation changes, mother-fetal infection, and non-infectious inflammation mediated by proinflammatory cytokines. However, these mechanisms have been continued to evolve. Fever identification in pregnant women is essential to recognize clinical consequences to both mothers and neonates. Increased temperature in mothers is associated with increased heart rate, cardiac output, oxygen consumption, and catecholamines production. Meanwhile, in neonates intrapartum fever is related to sepsis, APGAR score changes, the need of respiratory support and incidence of neonatal seizure. Therefore, these consequences are extensively studied in order to determine the appropriate prevention.


1963 ◽  
Vol 41 (1) ◽  
pp. 1949-1953 ◽  
Author(s):  
Margaret Beznák ◽  
P. Hacker

Subcutaneous injection of 40 mg/kg isoproterenol is followed within 2 minutes by a fall in blood pressure and peripheral resistance, by tachycardia, and by an increase in cardiac output. It seems likely that these hemodynamic changes are a consequence of a direct action of isoproterenol on the myocardium. Isoproterenol also causes a significant increase in the oxygen consumption of the rats. The increased oxygen demand of the tissues may play a role in maintaining the hemodynamic changes for periods of more than an hour after isoproterenol. Signs of histological damage in the myocardium begin to appear without affecting the function of the cardiovascular system, as measured by the tests used.


1988 ◽  
Vol 9 (3) ◽  
pp. 337-342 ◽  
Author(s):  
A. H KENDRICK ◽  
J. WEST ◽  
M. PAPOUCHADO ◽  
A. ROZKOVEC

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