Lower Limb Sports Compression Garments Improve Muscle Blood Flow and Exercise Performance During Repeated-Sprint Cycling

2018 ◽  
Vol 13 (7) ◽  
pp. 882-890 ◽  
Author(s):  
James R. Broatch ◽  
David J. Bishop ◽  
Shona Halson
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Lower Limb ◽  
Base Excess ◽  
Vastus Lateralis ◽  
Cycling Performance ◽  
Compression Garments ◽  
Repeated Sprint ◽  
The Right ◽  
Limb Compression

Purpose: Evidence supporting the use of lower-limb compression garments during repeated-sprint exercise (RSE) with short rest periods, where performance will rely heavily on aerobic metabolism, is lacking. Methods: A total of 20 recreationally active participants completed 2 cycling RSE sessions, with and without lower-limb compression tights. The RSE session consisted of 4 sets of 10 × 6-s maximal sprints on a wind-braked cycle ergometer, interspaced by 24 s of recovery between bouts and 2 min of recovery between sets. Muscle oxygen consumption () of, and blood flow (mBF) to, the right vastus lateralis muscle was measured during exercise using near-infrared spectroscopy and venous/arterial occlusions of the right lower limb. Cycling performance, oxygen consumption (), heart rate, and capillary blood samples (lactate, pH, bicarbonate, and base excess) were also measured/taken throughout the session. Results: Compared with control, peak power (40.7 [19.9] W; mean ± 95% confidence intervals) and mBF (0.101 [0.061] mL·min−1·100 g−1) were higher, and heart rate (2  [1] beats/min) was lower, when participants wore compression (P < .05). , , blood lactate, and heart rate increased as a result of exercise (P < .05), with no differences between conditions. Similarly, blood pH, bicarbonate, and base excess decreased as a result of exercise (P < .05), with no difference between conditions. Conclusions: Wearing lower-limb compression tights during RSE with short intervals of rest improved cycling performance, vastus lateralis mBF, and heart rate. These results provide novel data to support the notion that lower-limb compression garments aid RSE performance, which may be related to local and/or central blood flow.

Positive inotropic response to inosine in the in situ canine heart

1977 ◽  
Vol 233 (4) ◽  
pp. H438-H443 ◽  
Author(s):  
C. E. Jones ◽  
J. X. Thomas ◽  
M. D. Devous ◽  
C. P. Norris ◽  
E. E. Smith
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Arterial Pressure ◽  
Substantial Effect ◽  
Contractile Force ◽  
Left Ventricular ◽  
Canine Heart ◽  
Inotropic State ◽  
Arterial Blood ◽  
The Right

Effects of inosine on left ventricular contractile force, circumflex blood flow, heart rate, and arterial pressure were investigated in mongrel dogs. Infusion of 50 ml of 10, 25, or 50 mM inosine into the right atrium over 5 min produced arterial blood inosine concentrations of 20-120 microM. Infusion of inosine concentrations of 10 mM or greater produced statistically significant increases in contractile force and circumflex blood flow (P less than 0.05). The increases in contractile force and circumflex blood flow caused by 50 inosine were approximately 40% and 110%, respectively. No statistically significant increases in heart rate or arterial pressure were observed during infusion of inosine at any concentration. Administration of propranolol (2 mg/kg) in no way altered the effects of inosine on contractile force or circumflex blood flow. Thus, the present study suggests that inosine in concentrations which may be produced in the myocardium during stressful conditions causes a substantial effect on the inotropic state of the heart and that the effects of inosine are not mediated through adrenergic mechanisms.

Acute Responses to On-Court Repeated-Sprint Training Performed With Blood Flow Restriction Versus Systemic Hypoxia in Elite Badminton Athletes

2019 ◽  
Vol 14 (9) ◽  
pp. 1280-1287 ◽  
Author(s):  
Pedro L. Valenzuela ◽  
Guillermo Sánchez-Martínez ◽  
Elaia Torrontegi ◽  
Javier Vázquez-Carrión ◽  
Manuela González ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Heart Rate Variability ◽  
Creatine Kinase ◽  
Perceived Exertion ◽  
Sprint Training ◽  
Flow Restriction ◽  
Repeated Sprint ◽  
Systemic Hypoxia ◽  
Acute Responses

Purpose: Repeated-sprint training (RS) is commonly conducted in normoxia, but its completion with localized (blood-flow restriction [BFR]) or systemic hypoxia has been proven effective for performance enhancement. Yet, few studies have applied these types of RS sessions in racket sports. The authors aimed to determine the acute responses to these types of training in elite badminton players. Methods: Eight male elite badminton players participated in this randomized crossover study. They performed 3 on-court RS sessions, each consisting of 3 sets of 10 repetitions of 10-s badminton-specific movements in normoxia (RSN), systemic normobaric hypoxia (RSH, FiO2 = 14%), or with BFR (RS-BFR, 40% arterial occlusion pressure). Performance, perceptual (ie, rating of perceived exertion), and physiological (ie, pulse saturation, muscle oxygenation, blood lactate, creatine kinase, heart-rate variability) responses were measured after each set and up to 48 h postsession. Results: RS-BFR induced a greater performance impairment (lower distance and accelerations) and a higher local perceived exertion in the legs than RSN and RSH (P < .05), whereas greater overall fatigue was reported with RSH (P < .05). RSH induced a lower saturation (P < .001), but no differences were observed in muscle oxygenation between conditions. No differences in creatine kinase or heart-rate variability were observed at any time point (from baseline up to 48 h after the session). Conclusions: RS-BFR—and, to a lower extent, RSH—resulted in impaired performance and a higher perceived strain than RSN. However, these 2 hypoxic methods do not seem to induce a long-lasting (post 24–48 h) physiological stress in elite badminton players.

Cerebral and systemic hemodynamic changes during cognitive and motor activation paradigms

2005 ◽  
Vol 288 (6) ◽  
pp. R1581-R1588 ◽  
Author(s):  
Michelle Moody ◽  
Ronney B. Panerai ◽  
Penelope J. Eames ◽  
John F. Potter
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Activation ◽  
Cortical Activation ◽  
Hemispheric Dominance ◽  
Metabolic Demand ◽  
Hemodynamic Changes ◽  
Word Generation ◽  
The Right

Cognitive and/or sensorimotor stimulations of the brain induce increases in cerebral blood flow that are usually associated with increased metabolic demand. We tested the hypothesis that changes in arterial blood pressure (ABP) and arterial Pco2 also take place during brain activation protocols designed to induce hemispheric lateralization, leading to a pressure-autoregulatory response in addition to the metabolic-driven changes usually assumed by brain stimulation paradigms. Continuous recordings of cerebral blood flow velocity [CBFV; bilateral, middle cerebral artery (MCA)], ABP, ECG, and end-tidal Pco2 (PetCO2) were performed in 15 right-handed healthy subjects (aged 21–43 yr), in the seated position, at rest and during 10 repeated presentations of a word generation and a constructional puzzle paradigm that are known to induce differential cortical activation. Derived variables included heart rate, cerebrovascular resistance, critical closing pressure, resistance area product, and the difference between the right and left MCA recordings (CBFVR-L). No adaptation of the CBFVR-L difference was detected for the repeated presentation of 10 activation tasks, for either paradigm. During activation with the word generation tasks, CBFV changed by (mean ± SD) 9.0 ± 3.7% (right MCA, P = 0.0007) and by 12.3 ± 7.6% (left MCA, P = 0.0007), ABP by 7.7 ± 6.0 mmHg ( P = 0.0007), heart rate by 7.1 ± 5.3 beats/min ( P = 0.0008), and PetCO2 by −2.32 ± 2.23 Torr ( P = 0.002). For the puzzle paradigm, CBFV changed by 13.9 ± 6.6% (right MCA, P = 0.0007) and by 11.5 ± 6.2% (left MCA, P = 0.0007), ABP by 7.1 ± 8.4 mmHg ( P = 0.0054), heart rate by 7.9 ± 4.6 beats/min ( P = 0.0008), and PetCO2 by −2.42 ± 2.59 Torr ( P = 0.001). The word paradigm led to greater left hemispheric dominance than the right hemispheric dominance observed with the puzzle paradigm ( P = 0.004). We concluded that significant changes in ABP and PetCO2 levels occur during brain activation protocols, and these contribute to the evoked change in CBFV. A pressure-autoregulatory response can be observed in addition to the hemodynamic changes induced by increases in metabolic demand. Simultaneous changes in Pco2 and heart rate add to the complexity of the response, indicating the need for more detailed modeling and better understanding of brain activation paradigms.

scholarly journals Functional impairment of skeletal muscle oxidative metabolism during knee extension exercise after bed rest

2011 ◽  
Vol 111 (6) ◽  
pp. 1719-1726 ◽  
Author(s):  
Desy Salvadego ◽  
Stefano Lazzer ◽  
Mauro Marzorati ◽  
Simone Porcelli ◽  
Enrico Rejc ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Oxidative Metabolism ◽  
Near Infrared ◽  
Vastus Lateralis ◽  
Bed Rest ◽  
Knee Extension ◽  
Functional Evaluation

A functional evaluation of skeletal muscle oxidative metabolism during dynamic knee extension (KE) incremental exercises was carried out following a 35-day bed rest (BR) (Valdoltra 2008 BR campaign). Nine young male volunteers (age: 23.5 ± 2.2 yr; mean ± SD) were evaluated. Pulmonary gas exchange, heart rate and cardiac output (by impedance cardiography), skeletal muscle (vastus lateralis) fractional O2 extraction, and brain (frontal cortex) oxygenation (by near-infrared spectroscopy) were determined during incremental KE. Values at exhaustion were considered “peak”. Peak heart rate (147 ± 18 beats/min before vs. 146 ± 17 beats/min after BR) and peak cardiac output (17.8 ± 3.3 l/min before vs. 16.1 ± 1.8 l/min after BR) were unaffected by BR. As expected, brain oxygenation did not decrease during KE. Peak O2 uptake was lower after vs. before BR, both when expressed as liters per minute (0.99 ± 0.17 vs. 1.26 ± 0.27) and when normalized per unit of quadriceps muscle mass (46.5 ± 6.4 vs. 56.9 ± 11.0 ml·min−1·100 g−1). Skeletal muscle peak fractional O2 extraction, expressed as a percentage of the maximal values obtained during a transient limb ischemia, was lower after (46.3 ± 12.1%) vs. before BR (66.5 ± 11.2%). After elimination, by the adopted exercise protocol, of constraints related to cardiovascular O2 delivery, a decrease in peak O2 uptake and muscle peak capacity of fractional O2 extraction was found after 35 days of BR. These findings suggest a substantial impairment of oxidative function at the muscle level, “downstream” with respect to bulk blood flow to the exercising muscles, that is possibly at the level of blood flow distribution/O2 utilization inside the muscle, peripheral O2 diffusion, and intracellular oxidative metabolism.

Comparison of Visual Function and Ocular Hemodynamics between Pre- and Post-Menopausal Women

2008 ◽  
Vol 18 (2) ◽  
pp. 320-323 ◽  
Author(s):  
B.A. Siesky ◽  
A. Harris ◽  
C. Patel ◽  
C.L. Klaas ◽  
M. Harris ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Intraocular Pressure ◽  
Contrast Sensitivity ◽  
Premenopausal Women ◽  
Menopausal Women ◽  
Post Menopausal ◽  
The Right ◽  
Ocular Hemodynamics

Purpose The incidence of eye disease increases with age and can often be linked to worsening cardiovascular function and increasing intraocular pressure. Estrogen is known to have vasodilatory effects in the systemic circulation. Decreased estrogen levels during menopause may therefore complicate or contribute to ocular pathologies as estrogen receptors are found in both retinal and choroidal tissue. The purpose of this investigation was to determine the effects of menopause on visual function and cardiovascular and ocular hemodynamics. Methods Twelve premenopausal and 24 postmenopausal women were evaluated at the Indiana University School of Medicine during a single study visit. Vision screening and ocular blood flow evaluations were performed, including blood pressure, heart rate, visual acuity, contrast sensitivity, intraocular pressure, and retinal capillary and retrobulbar blood flow imaging. Vision and ocular hemodynamics were compared using unpaired Student t-tests with pp<0.05 regarded as statistically significant. Results The premenopausal group had significantly lower heart rate (-16.1 b/m, p=0.0001) and systolic blood pressure (-17.7 mmHg, p=0.003) than postmenopausal subjects. Contrast sensitivity was significantly higher (measured in log units) in premenopausal women in both the right (0.25, p=0.039; 0.16, p=0.039) and left (0.45, p=0.001; 0.27, p=0.032) eyes at 9 and 18 cycles per degree, respectively. Premenopausal women also had significantly lower intraocular pressure in both the right (-2.19 mmHg, p=0.024) and left (-1.74 mmHg, p=0.035) eyes. Total ocular perfusion was not significantly different between groups. Conclusions This pilot work suggests that postmenopausal women have lower contrast sensitivity detection and elevated intraocular pressures compared to premenopausal women. Premenopausal women have lower cardiovascular risk factors, while total ocular circulation was similar to post-menopausal women.

scholarly journals Effect of lower limb compression on blood flow and performance in elite wheelchair rugby athletes

2016 ◽  
Vol 39 (2) ◽  
pp. 206-211 ◽  
Author(s):  
Joanna Vaile ◽  
Brad Stefanovic ◽  
Christopher D. Askew
Keyword(s):  
Blood Flow ◽  
Lower Limb ◽  
Wheelchair Rugby ◽  
And Performance ◽  
Limb Compression

The effect of vasopressin on fetal oxygenation in sheep

1984 ◽  
Vol 62 (1) ◽  
pp. 27-30 ◽  
Author(s):  
D. W. Rurak ◽  
N. C. Gruber
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Arterial Pressure ◽  
Oxygen Delivery ◽  
Oxygen Supply ◽  
Base Excess ◽  
Percentage Increase ◽  
Umbilical Blood ◽  
Umbilical Blood Flow ◽  
Fetal Oxygenation

To examine the effects of vasopressin on fetal oxygenation the hormone was infused intravenously for 1 h (1.4–3.5 mU∙min−1∙kg fetal weight−1) to chronically catheterized fetal lambs in utero (113–137 days gestation). Arterial pressure rose (48.3 to 59.6 mmHg) (1 mmHg = 133.322 Pa) and heart rate fell (185.3 to 141.0 beats/min) during the infusion. There was a significant increase in fetal arterial [Formula: see text] (20.0 to 23. 1 mmHg) and significant declines in pH (7.414 to 7.381) and base excess. Umbilical blood flow rose, and the percentage increase in flow (23%) was identical to the proportional rise in arterial pressure. Accompanying the rise in umbilical blood flow was a rise in umbilical oxygen delivery. But as there was no change in fetal oxygen consumption, fractional oxygen extraction by the fetus fell significantly (0.31 to 0.25). These data indicate that the vasopressin-induced rise in fetal vascular [Formula: see text] results from an increase in umbilical oxygen delivery and concomitant fall in fractional extraction. Fetal vasopressin levels are greatly elevated during hypoxia, and under conditions of reduced oxygen supply, the effects of the hormone on umbilical oxygen delivery and vascular [Formula: see text] could have definite survival value.

Sex differences in muscle excitation and oxygenation, but not in force fluctuations or active hyperemia resulting from a fatiguing, bilateral isometric task

2021 ◽  
Author(s):  
Joshua L Keller ◽  
John Paul Vance Anders ◽  
Tyler J Neltner ◽  
Terry J Housh ◽  
Richard J Schmidt ◽  
...  
Keyword(s):  
Blood Flow ◽  
Sex Difference ◽  
Near Infrared ◽  
Task Force ◽  
Vastus Lateralis ◽  
Muscle Blood Flow ◽  
Rate Of Change ◽  
Force Fluctuations ◽  
Rate Of Increase ◽  
The Right

Abstract It remains to be fully elucidated if there are sex-specific physiological adjustments within the human neuromuscular and vascular systems that contribute to symptoms of fatigue during a sustained bilateral task. This, in part, is likely due to various limitations in experimental design such as an inability to independently record force fluctuations from each limb. Objective: Therefore, the purpose of the current study was to examine the fatigue-induced changes in muscle excitation, force fluctuations, skeletal muscle tissue saturation (StO2), and muscle blood flow resulting from a sustained, bilateral task. Approach: Thirty healthy, college-aged adults (15 males, 15 females) performed a bilateral leg task at 25% of maximum voluntary isometric (MVIC). Before and after the task, MVICs were completed. Resting and post-task femoral artery blood flow (FABF) were determined. Muscle excitation was quantified as electromyographic amplitude (EMG AMP) from the right and left vastus lateralis. During the task, force fluctuations were determined independently from each leg. The StO2 signal was collected with a near-infrared spectroscopy device attached to the right vastus lateralis. The rate of change in these variables was calculated via simple linear regression. The exercise-induced magnitude of change in MVIC (i.e., performance fatigability) and FABF (i.e., active hyperemia) was determined. Main results: There was no sex difference in the percent decline in MVIC (20.5±20.1% vs. 16.4± 3.5%; p>0.05). There were no inter-leg differences in EMG AMP or force fluctuations. The males exhibited a faster rate of increase in EMG AMP (b=0.13 vs. b=0.08; p<0.001), whereas the females exhibited a slower rate of decline in StO2 (b=-0.049 vs. b=-0.080). There was no sex difference in force fluctuations or change in FABF. Significance: Males and females likely have different neuromuscular strategies and muscle characteristics, but these did not elicit a sex difference in performance fatigability.

Chemical activation of thin-fiber phrenic afferents. 2. Cardiovascular responses

1991 ◽  
Vol 70 (1) ◽  
pp. 77-86 ◽  
Author(s):  
S. N. Hussain ◽  
A. Chatillon ◽  
A. Comtois ◽  
C. Roussos ◽  
S. Magder
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Chemical Activation ◽  
Cardiovascular Responses ◽  
Arterial Flow ◽  
Aortic Blood Flow ◽  
Thin Fiber ◽  
The Right

To assess the effects of groups III and IV (thin-fiber) phrenic afferents on arterial pressure, heart rate, and distribution of cardiac output, we injected capsaicin into phrenic arteries of in situ isolated and innervated left diaphragms of dogs anesthetized with chloralose, vagotomized, and mechanically ventilated. Blood flow in the ascending aorta, common carotid, renal, superior mesenteric, and femoral arteries was measured by electromagnetic and Doppler flow probes. Injection of 1 mg capsaicin into the left phrenic artery produced congruent to 15% increase in mean arterial pressure and congruent to 7% increase in heart rate with no change in aortic flow. Phrenic arterial flow decreased by 64%, renal arterial flow by 16%, and superior mesenteric arterial flow by 10%, whereas carotid flow increased by 13% and flow to the right gastrocnemius muscle did not change. Mean arterial pressure, heart rate, and blood flow distribution (with the exception of the decline in phrenic blood flow) returned to baseline within 60 s of the injection. Injection of 1.5 mg capsaicin into the right isolated and innervated gastrocnemius produced congruent to 35% increase in mean arterial pressure, 17% rise in heart rate, and no change in aortic blood flow. Phrenic and carotid arterial flow rose by 240 and 41%, respectively, whereas renal and superior mesenteric flow declined by 50 and 20%, respectively. In conclusion, thin-fiber phrenic afferents have an excitatory effect on arterial pressure and heart rate. They redistribute blood flow away from the renal and intestinal vascular beds and toward the carotid vascular bed. On the other hand, the cardiovascular reflex from thin-fiber phrenic afferents seems less potent than that from limb muscle afferents.

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