Cardiovascular Responses to Submaximal Concentric and Eccentric Isokinetic Exercise in Older Adults

1999 ◽  
Vol 7 (1) ◽  
pp. 20-31 ◽  
Author(s):  
Elizabeth Thompson ◽  
Theo H. Versteegh ◽  
Tom J. Overend ◽  
Trevor B. Birmingham ◽  
Anthony A. Vandervoort

Our purpose was to describe heart rate (HR), mean arterial blood pressure (MAP), and perceived exertion (RPE) responses to submaximal isokinetic concentric (CON) and eccentric (ECC) exercise at the same absolute torque output in older adults. Peak torques for ECC and CON knee extension were determined in healthy older males (n = 13) and females (n = 7). Subjects then performed separate, randomly ordered, 2-min bouts of CON and ECC exercise. Heart rate and MAP increased (p < .001) from resting values throughout both exercise bouts. CON exercise elicited a significantly greater cardiovascular response than ECC exercise after 60 s. Peak HR, MAP, and RPE after CON exercise were greater than after ECC exercise (p < .01). At the same absolute torque output, isokinetic CON knee extension exercise resulted in a significantly greater level of cardiovascular stress than ECC exercise. These results are relevant to resistance testing and exercise in older people.

2008 ◽  
Vol 16 (1) ◽  
pp. 14-23 ◽  
Author(s):  
David R. Dolbow ◽  
Richard S. Farley ◽  
Jwa K. Kim ◽  
Jennifer L. Caputo

The purpose of this study was to examine the cardiovascular responses to water treadmill walking at 2.0 mph (3.2 km/hr), 2.5 mph (4.0 km/hr), and 3.0 mph (4.8 km/hr) in older adults. Responses to water treadmill walking in 92 °F (33 °C) water were compared with responses to land treadmill walking at 70 °F (21 °C) ambient temperature. After an accommodation period, participants performed 5-min bouts of walking at each speed on 2 occasions. Oxygen consumption (VO2), heart rate (HR), systolic blood pressure (SBP), and rating of perceived exertion (RPE) were significantly higher during therapeutic water treadmill walking than during land treadmill walking. Furthermore, VO2, HR, and RPE measures significantly increased with each speed increase during both land and water treadmill walking. SBP significantly increased with each speed during water treadmill walking but not land treadmill walking. Thus, it is imperative to monitor HR and blood pressure for safety during this mode of activity for older adults.


1998 ◽  
Vol 274 (3) ◽  
pp. R814-R821 ◽  
Author(s):  
James C. Schadt ◽  
Eileen M. Hasser

Chronically instrumented, conscious rabbits were used to test the hypothesis that sensory stimulation with an air jet or oscillation produces differential hemodynamic changes that may be appropriate for an active or a passive behavioral response, respectively. Both stressors increased arterial pressure, central venous pressure, and hindquarters blood flow and produced visceral vasoconstriction. Neither stimulus altered hindquarters conductance. Although air jet increased heart rate and cardiac output, oscillation did not. The two stressors affected arterial baroreflex control of heart rate differently. Oscillation reset arterial pressure to a higher level with no change in heart rate maximum or minimum, whereas air jet reset both heart rate and arterial pressure to higher levels. Neither stressor affected baroreflex sensitivity. We conclude that the conscious rabbit shows at least two distinct cardiovascular responses when exposed to acute stressors. Air jet produces a cardiovascular response including tachycardia, which resembles the defense reaction and appears appropriate for active defense or flight. The response to oscillation, on the other hand, appears better suited for a passive response such as “freezing” behavior. During exposure to either stressor, the baroreflex is altered to allow simultaneous increases in heart rate and arterial blood pressure, but the sensitivity is maintained, allowing normal moment to moment control of heart rate.


2020 ◽  
Vol 91 (8) ◽  
pp. 621-627
Author(s):  
Nandini Deshpande ◽  
Steven S. Laurie ◽  
Stuart M. C. Lee ◽  
Chris A. Miller ◽  
Ajitkumar P. Mulavara ◽  
...  

BACKGROUND: The vestibulo-sympathetic reflex operates during orthostatically challenging movements to initiate cardiovascular responses in advance of a baroreceptor-mediated response. The objective of this study was to determine whether there was an association between changes in vestibular function and cardiovascular responses during a prone-to-stand movement in astronauts after return from long-duration spaceflight.METHODS: Thirteen crewmembers who participated in International Space Station missions were tested before spaceflight and 1 d after landing. Vestibular function was evaluated by computerized dynamic posturography while their head was erect and while they performed dynamic head tilts. Heart rate and mean arterial blood pressure were measured while the subjects were in prone and standing positions.RESULTS: The 21.4% increase in the astronauts’ heart rate during the prone to stand maneuver after spaceflight correlated significantly with their spaceflight-induced 48.7% decrease in postural stability during dynamic head tilts. The larger mean arterial pressure in the prone position after spaceflight compared to preflight (+7%) also correlated with the postflight decrease in postural stability during dynamic head tilts.CONCLUSION: These results indicate that an appropriate vestibular function is important to evoke optimum vestibulo-sympathetic response during orthostatically challenging voluntary movements performed after spaceflight. They also suggest that there may be a greater need to generate an anticipatory cardiovascular response after spaceflight.Deshpande N, Laurie SS, Lee SMC, Miller CA, Mulavara AP, Peters BT,Reschke MF, Stenger MB, Taylor LC, Wood SJ, Clément GR, Bloomberg JJ. Vestibular and cardiovascular responses after long-duration spaceflight. Aerosp Med Hum Perform. 2020; 91(8):621–627.


1965 ◽  
Vol 43 (2) ◽  
pp. 327-337
Author(s):  
M. A. Chiong ◽  
J. D. Hatcher

Cardiovascular responses to the intravenous administration of adrenaline were measured as a means of assessing cardiovascular reactivity in intact anaesthetized dogs, before and at 3 hours and 3 days after the rapid production of anaemia by a dextran-for-blood exchange. Three types of experiments were carried out. In experiments A and B, 2.0 and 5.0 μg/kg of adrenaline (respectively) were injected intravenously before and at both periods after exchange, and the changes in arterial blood pressure were assessed. In experiment B the changes in the arterial plasma concentration of potassium and sodium were also measured. In experiment C, several cardiovascular parameters, including cardiac output (Fick method), arterial pressure, and heart rate, were measured before and at the end of a 15-minute infusion of adrenaline in a dose of 0.2 μg/kg minute. In all three experiments, evidence of a reduced cardiovascular response to adrenaline was found when the dogs were anaemic; and in experiment B the adrenaline-induced hyperkalaemia and hyponatraemia were found to be significantly reduced during anaemia.The mechanism of the hyporeactivity to adrenaline during anaemia is not clear, but may include changes in blood volume, electrolyte disturbances, and severe anoxia.


2018 ◽  
Vol 3 (4) ◽  
pp. 60 ◽  
Author(s):  
Ramires Tibana ◽  
Nuno de Sousa ◽  
Jonato Prestes ◽  
Fabrício Voltarelli

The aim of this study was to analyze blood lactate concentration (LAC), heart rate (HR), and rating perceived exertion (RPE) during and after shorter and longer duration CrossFit® sessions. Nine men (27.7 ± 3.2 years; 11.3 ± 4.6% body fat percentage and training experience: 41.1 ± 19.6 months) randomly performed two CrossFit® sessions (shorter: ~4 min and longer: 17 min) with a 7-day interval between them. The response of LAC and HR were measured pre, during, immediately after, and 10, 20, and 30 min after the sessions. RPE was measured pre and immediately after sessions. Lactate levels were higher during the recovery of the shorter session as compared with the longer session (shorter: 15.9 ± 2.2 mmol/L/min, longer: 12.6 ± 2.6 mmol/L/min; p = 0.019). There were no significant differences between protocols on HR during (shorter: 176 ± 6 bpm or 91 ± 4% HRmax, longer: 174 ± 3 bpm or 90 ± 3% HRmax, p = 0.387). The LAC was significantly higher throughout the recovery period for both training sessions as compared to pre-exercise. The RPE was increased immediately after both sessions as compared to pre-exercise, while there was no significant difference between them (shorter: 8.7 ± 0.9, longer: 9.6 ± 0.5; p = 0.360). These results demonstrated that both shorter and longer sessions induced elevated cardiovascular responses which met the recommendations for gains in cardiovascular fitness. In addition, both training sessions had a high metabolic and perceptual response, which may not be suitable if performed on consecutive days.


1993 ◽  
Vol 264 (1) ◽  
pp. R79-R84 ◽  
Author(s):  
J. N. Stinner ◽  
D. L. Ely

The pressor response to normal daily behaviors and acute stress was studied in black racer snakes (Coluber constrictor) at 30 degrees C. In addition, hematological changes during the stress response were assessed. Mean nighttime systemic arterial blood pressure (SABP) in undisturbed snakes was lower than daytime pressure (26 +/- 3 vs. 32 +/- 9 mmHg, P < 0.001). When snakes were fed mice, SABP increased 3.5- to 4-fold and heart rate increased approximately 3-fold above resting values within approximately 30 s (peak SABP, 99 +/- 18 mmHg; peak heart rate, 99 +/- 12 beats/min). Killing and ingesting the mice required 6-15 min, during which time mean SABP and heart rate were 84 +/- 16 mmHg and 92 +/- 12 beats/min. Pulmonary blood pressure also increased but remained 40-50 mmHg lower than SABP. During stress elicited by tapping the snakes for 5-8 min, heart rate was 94 +/- 6 beats/min but SABP averaged only 44 +/- 11 mmHg. Plasma norepinephrine and epinephrine increased 51- and 26-fold. Plasma glucose increased 58%, hematocrit increased 19%, and plasma volume decreased 19%. It is concluded that blood pressure is markedly affected by behavior and that the sympathetic nervous system appears to play a key role.


1987 ◽  
Vol 62 (3) ◽  
pp. 1186-1191 ◽  
Author(s):  
J. W. Kozelka ◽  
G. W. Christy ◽  
R. D. Wurster

The ascending spinal pathways mediating somatocardiovascular reflexes during exercise were studied in unanesthetized dogs by placing lesions in the lumbar spinal cord. After training to run on a treadmill with hindlimbs only, 20 dogs were anesthetized and instrumented using sterile surgical techniques. To chronically record heart rate and arterial blood pressure, the aorta was cannulated via the omocervical artery. To test the intactness of descending spinal sympathetic pathways, reflex pressor responses to baroreceptor hypotension were produced by bilateral carotid arterial occlusion using pneumatic vessel occluders placed around the common carotid arteries. To generate transient ischemic exercise (120 s), a pneumatic occluder was placed around the left iliac artery. Eight to 10 days after instrumentation, blood pressure and heart rate were monitored at rest and during hindlimb running with and without simultaneous iliac arterial occlusion. The modest pressor response and tachycardia elicited by hindlimb exercise were markedly augmented by simultaneous hindlimb ischemia (i.e., iliac arterial occlusion). Lesion placement in the dorsolateral sulcus area and the dorsolateral funiculus at L2 significantly reduced the blood pressure and heart rate responses to simultaneous exercise occlusion. The cardiovascular responses to nonischemic exercise and bilateral carotid arterial occlusion were not altered by such spinal sections. It is concluded that in the dog the ascending spinal pathways mediating cardiovascular responses to ischemic exercise are located in the lateral funiculus, including the dorsolateral sulcus area and dorsolateral funiculus.


2014 ◽  
Vol 116 (11) ◽  
pp. 1371-1381 ◽  
Author(s):  
James P. Mendoza ◽  
Rachael J. Passafaro ◽  
Santhosh M. Baby ◽  
Alex P. Young ◽  
James N. Bates ◽  
...  

Exposure to hypoxia elicits changes in mean arterial blood pressure (MAP), heart rate, and frequency of breathing (fr). The objective of this study was to determine the role of nitric oxide (NO) in the cardiovascular and ventilatory responses elicited by brief exposures to hypoxia in isoflurane-anesthetized rats. The rats were instrumented to record MAP, heart rate, and fr and then exposed to 90 s episodes of hypoxia (10% O2, 90% N2) before and after injection of vehicle, the NO synthase inhibitor NG-nitro-l-arginine methyl ester (l-NAME), or the inactive enantiomer d-NAME (both at 50 μmol/kg iv). Each episode of hypoxia elicited a decrease in MAP, bidirectional changes in heart rate (initial increase and then a decrease), and an increase in fr. These responses were similar before and after injection of vehicle or d-NAME. In contrast, the hypoxia-induced decreases in MAP were attenuated after administration of l-NAME. The initial increases in heart rate during hypoxia were amplified whereas the subsequent decreases in heart rate were attenuated in l-NAME-treated rats. Finally, the hypoxia-induced increases in fr were virtually identical before and after administration of l-NAME. These findings suggest that NO factors play a vital role in the expression of the cardiovascular but not the ventilatory responses elicited by brief episodes of hypoxia in isoflurane-anesthetized rats. Based on existing evidence that NO factors play a vital role in carotid body and central responses to hypoxia in conscious rats, our findings raise the novel possibility that isoflurane blunts this NO-dependent signaling.


2013 ◽  
Vol 21 (3) ◽  
pp. 335-347 ◽  
Author(s):  
Mandy L. Gault ◽  
Richard E. Clements ◽  
Mark E.T. Willems

Cardiovascular responses of older adults to downhill (DTW, –10% incline) and level treadmill walking (0%) at self-selected walking speed (SSWS) were examined. Fifteen participants (age 68 ± 4 yr, height 1.69 ± 0.08 m, body mass 74.7 ± 8.1 kg) completed two 15-min walks at their SSWS (4.6 ± 0.6 km/hr). Cardiovascular responses were estimated using an arterial-volume finger clamp and infrared plethysmography. Oxygen consumption was 25% lower during DTW and associated with lower values for stroke volume (9.9 ml/beat), cardiac output (1.0 L/min), arteriovenous oxygen difference (a-v O2 diff, 2.4 ml/L), and systolic blood pressure (10 mmHg), with no differences in heart rate or diastolic and mean arterial blood pressure. Total peripheral resistance (TPR) was higher (2.11 mmHg) during DTW. During downhill walking, an exercise performed with reduced cardiac strain, endothelial changes, and reduced metabolic demand may be responsible for the different responses in TPR and a-v O2 diff. Future work is warranted on whether downhill walking is suitable for higher risk populations.


1991 ◽  
Vol 261 (2) ◽  
pp. R420-R426
Author(s):  
M. Inoue ◽  
J. T. Crofton ◽  
L. Share

We have examined in conscious rats the interaction between centrally acting prostanoids and acetylcholine in the stimulation of vasopressin secretion. The intracerebroventricular (icv) administration of carbachol (25 ng) resulted in marked transient increases in the plasma vasopressin concentration and mean arterial blood pressure and a transient reduction in heart rate. Central cyclooxygenase blockade by pretreatment icv with either meclofenamate (100 micrograms) or indomethacin (100 micrograms) virtually completely blocked these responses. Prostaglandin (PG) D2 (20 micrograms icv) caused transient increases in the plasma vasopressin concentration (much smaller than after carbachol) and heart rate, whereas mean arterial blood pressure rose gradually during the 15-min course of the experiment. Pretreatment with the muscarinic antagonist atropine (10 micrograms icv) decreased the peak vasopressin response to icv PGD2 by approximately one-third but had no effect on the cardiovascular responses. We conclude that the stimulation of vasopressin release by centrally acting acetylcholine is dependent on increased prostanoid biosynthesis. On the other hand, stimulation of vasopressin release by icv PGD2 is partially dependent on activation of a cholinergic pathway.


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