Muscle contraction-blood flow interactions during upright knee extension exercise in humans

2005 ◽  
Vol 98 (4) ◽  
pp. 1575-1583 ◽  
Author(s):  
Barbara J. Lutjemeier ◽  
Akira Miura ◽  
Barry W. Scheuermann ◽  
Shunsaku Koga ◽  
Dana K. Townsend ◽  
...  
Keyword(s):  
Blood Flow ◽  
Steady State ◽  
Muscle Contraction ◽  
Muscle Blood Flow ◽  
Knee Extension ◽  
Work Rate ◽  
Early Recovery ◽  
Muscle Pump ◽  
Significant Difference ◽  
Knee Extension Exercise

To test for evidence of a muscle pump effect during steady-state upright submaximal knee extension exercise, seven male subjects performed seven discontinuous, incremental exercise stages (3 min/stage) at 40 contractions/min, at work rates ranging to 60–75% peak aerobic work rate. Cardiac cycle-averaged muscle blood flow (MBF) responses and contraction-averaged blood flow responses were calculated from continuous Doppler sonography of the femoral artery. Net contribution of the muscle pump was estimated by the difference between mean exercise blood flow (MBFM) and early recovery blood flow (MBFR). MBFM rose in proportion with increases in power output with no significant difference between the two methods of calculating MBF. For stages 1 and 5, MBFM was greater than MBFR; for all others, MBFM was similar to MBFR. For the lighter work rates ( stages 1–4), there was no significant difference between exercise and early recovery mean arterial pressure (MAP). During stages 5–7, MAP was significantly higher during exercise and fell significantly early in recovery. From these results we conclude that 1) at the lightest work rate, the muscle pump had a net positive effect on MBFM, 2) during steady-state moderate exercise ( stages 2–4) the net effect of rhythmic muscle contraction was neutral (i.e., the impedance due to muscle contraction was exactly offset by the potential enhancement during relaxation), and 3) at the three higher work rates tested ( stages 5–7), any enhancement to flow during relaxation was insufficient to fully compensate for the contraction-induced impedance to muscle perfusion. This necessitated a higher MAP to achieve the MBFM.

Vascular function is related to blood flow during high-intensity, but not low-intensity, knee extension exercise

2020 ◽  
Vol 128 (3) ◽  
pp. 698-708 ◽  
Author(s):  
Brady E. Hanson ◽  
Meagan Proffit ◽  
Jayson R. Gifford
Keyword(s):  
Blood Flow ◽  
High Intensity ◽  
Vascular Function ◽  
Knee Extension ◽  
Work Rate ◽  
Microvascular Function ◽  
Blood Flow Response ◽  
Low Intensity ◽  
Flow Response ◽  
Knee Extension Exercise

While vascular function, assessed as the ability of the vasculature to dilate in response to a stimulus, is related to cardiovascular health, its relationship to exercise hyperemia is unclear. This study sought to determine if blood flow during submaximal and maximal exercise is related to vascular function. Nineteen healthy adults completed multiple assessments of vascular function specific to the leg, including passive leg movement (PLM), rapid onset vasodilation (ROV), reactive hyperemia (RH), and flow-mediated dilation (FMD). On a separate day, exercise blood flow (Doppler ultrasound) was assessed in the same leg during various intensities of single-leg, knee-extension (KE) exercise. Vascular function, determined by PLM, ROV, and RH, was related to exercise blood flow at high intensities, including maximum work rate (WRmax) ( r = 0.58–0.77, P < 0.001), but not low intensities, like ~21% WRmax ( r = 0.12–0.34, P = 0.12–0.62). Relationships between multiple indices of vascular function and peak exercise blood flow persisted when controlling for quadriceps mass and exercise work rate ( P < 0.05), indicating vascular function is independently related to the blood flow response to intense exercise. When divided into two groups based upon the magnitude of the PLM response, subjects with a lower PLM response exhibited lower exercise flow at several absolute work rates, as well as lower peak flow ( P < 0.05). In conclusion, leg flow during dynamic exercise is independently correlated with multiple different indices of microvascular function. Thus microvascular function appears to modulate the hyperemic response to high-intensity, but not low-intensity, exercise. NEW & NOTEWORTHY While substantial evidence indicates that individuals with lower vascular function are at greater risk for cardiovascular disease, with many redundant vasodilator pathways present during exercise, it has been unclear if low vascular function actually impacts blood flow during exercise. This study provides evidence that vascular function, assessed by multiple noninvasive methods, is related to the blood flow response to high-intensity leg exercise in healthy young adults. Importantly, healthy young adults with lower levels of vascular function, particularly microvascular function, exhibit lower blood flow during high-intensity, and maximal knee extension exercise. Thus it appears that in addition to increasing one’s risk of cardiovascular disease, lower vascular function is also related to a blunted blood flow response during high-intensity exercise.

Effect of contraction frequency on leg blood flow during knee extension exercise in humans

2001 ◽  
Vol 91 (2) ◽  
pp. 671-679 ◽  
Author(s):  
Brian D. Hoelting ◽  
Barry W. Scheuermann ◽  
Thomas J. Barstow
Keyword(s):  
Blood Flow ◽  
Doppler Ultrasound ◽  
Femoral Artery ◽  
Supine Position ◽  
Muscle Blood Flow ◽  
Muscle Tension ◽  
Knee Extension ◽  
Contraction Frequency ◽  
Knee Extension Exercise ◽  
Exercise In Humans

Previous studies in isolated muscle preparations have shown that muscle blood flow becomes compromised at higher contraction frequencies. The purpose of this study was to examine the effect of increases in contraction frequency and muscle tension on mean blood flow (MBF) during voluntary exercise in humans. Nine male subjects [23.6 ± 3.7 (SD) yr] performed incremental knee extension exercise to exhaustion in the supine position at three contraction frequencies [40, 60, and 80 contractions/min (cpm)]. Mean blood velocity of the femoral artery was determined beat by beat using Doppler ultrasound. MBF was calculated by using the diameter of the femoral artery determined at rest using echo Doppler ultrasound. The work rate (WR) achieved at exhaustion was decreased ( P< 0.05) as contraction frequency increased (40 cpm, 16.2 ± 1.4 W; 60 cpm, 14.8 ± 1.4 W; 80 cpm, 13.2 ± 1.3 W). MBF was similar across the contraction frequencies at rest and during the first WR stage but was higher ( P < 0.05) at 40 than 80 cpm at exercise intensities >5 W. MBF was similar among contraction frequencies at exhaustion. In humans performing knee extension exercise in the supine position, muscle contraction frequency and/or muscle tension development may appreciably affect both the MBF and the amplitude of the contraction-to-contraction oscillations in muscle blood flow.

Muscle use during dynamic knee extension: implication for perfusion and metabolism

1998 ◽  
Vol 85 (3) ◽  
pp. 1194-1197 ◽  
Author(s):  
Chester A. Ray ◽  
Gary A. Dudley
Keyword(s):  
Blood Flow ◽  
Muscle Mass ◽  
Muscle Blood Flow ◽  
Knee Extension ◽  
Magnetic Resonance Images ◽  
Quadriceps Femoris ◽  
Work Rate ◽  
Quadriceps Femoris Muscle ◽  
Total Muscle ◽  
Femoris Muscle

Dynamic one-legged knee extension (DKE) is commonly used to examine physiological responses to “aerobic” exercise. Muscle blood flow during DKE is often expressed relative to quadriceps femoris muscle mass irrespective of work rate. This is contrary to the notion that increased force is achieved by recruitment in large muscles. The purpose of this study, therefore, was to determine muscle use during DKE. Six subjects had magnetic resonance images taken of their quadriceps femoris before and after 4 min of DKE at 20 and 40 W. Muscle use was determined by shifts in T2. The cross-sectional area of quadriceps femoris that had an elevated T2 was 16 ± 1% (mean ± SE) preexercise, and 54 ± 5 and 94 ± 4% after 20- and 40-W DKE, respectively. Volume of quadriceps femoris increased 11.4 ± 0.2% ( P = 0.006), from 2,230 ± 233 cm3before exercise to 2,473 ± 232 cm3 after 40-W DKE. Extrapolation of these data indicates that 1,301 ± 111 cm3 of quadriceps femoris were engaged during 20-W DKE compared with 2,292 ± 154 cm3 during 40-W DKE. By using muscle blood flow data for submaximal DKE at 20 W [P. Andersen and B. Saltin. J. Physiol. (Lond.)366: 233–249, 1985; and L. B. Rowell, B. Saltin, B. Kiens, and N. J. Christensen. Am. J. Physiol. 251 ( Heart Circ. Physiol. 20): H1038–H1044, 1986] and estimating muscle use in those studies from our data (total muscle mass × 0.54), extrapolated blood flow to active muscle (263 and 278 ml ⋅ min−1 ⋅ 100 g−1, respectively) is comparable to that obtained during peak aerobic DKE when expressed relative to total muscle mass (243 and 250 ml ⋅ min−1 ⋅ 100 g−1, respectively). These findings indicate that increased power during aerobic DKE is achieved by recruitment. Additionally, they suggest that blood flow to the active quadriceps femoris muscle does not increase with increases in submaximal work rate but instead is maximal to support aerobic metabolism. Thus increases in muscle blood flow are directed to newly recruited muscle, not to increased perfusion of muscle already engaged.

Is rapid rise in vascular conductance at onset of dynamic exercise due to muscle pump?

1993 ◽  
Vol 265 (4) ◽  
pp. H1227-H1234 ◽  
Author(s):  
D. D. Sheriff ◽  
L. B. Rowell ◽  
A. M. Scher
Keyword(s):  
Blood Flow ◽  
Muscle Blood Flow ◽  
Venous Pressure ◽  
Work Rate ◽  
Dynamic Exercise ◽  
Aortic Flow ◽  
Vascular Conductance ◽  
Muscle Pump ◽  
Autonomic Blockade ◽  
Metabolic Vasodilation

We tested the hypothesis that rapid increases in muscle blood flow and vascular conductance (C) at onset of dynamic exercise are caused by the muscle pump. We measured arterial (AP) and central venous pressure (CVP) in nine awake dogs, eight with atrioventricular block, pacemakers, and ascending aortic flow probes for control of cardiac output (CO) (2 also had terminal aortic flow probes). One dog had only an iliac artery probe. At exercise onset (0 and 10% grade, 4 mph) C and CVP rose to early plateaus, and AP reached a nadir, all in 2-5 s. At 20% grade and 4 mph, C increased continuously after its initial sudden rise. Timing and magnitude of initial change in conductance (delta C) were independent of CO, AP, work rate (change in grade at constant speed), or autonomic function (blocked by hexamethonium). Speed of initial delta C and its independence from work rate and blood flow ruled out metabolic vasodilation as its cause; insensitivity to AP and autonomic blockade ruled out myogenic relaxation and sympathetic vasodilation as causes of sudden delta C. Sensitivity to contraction frequency (not work per se) implicates the muscle pump. When reflexes were blocked, a large secondary rise in C, presumably caused by metabolic vasodilation, began after 10 s of mild exercise. When reflexes were intact in mild exercise, C was lowered below its initial plateau by sympathetic vasoconstriction, which partially raised AP from its nadir toward its preexercise level. Our conclusion is that dynamic exercise has a large rapid effect on C that is not explained by known neural, metabolic, myogenic, or hydrostatic influences.(ABSTRACT TRUNCATED AT 250 WORDS)

Skeletal muscle blood flow capacity: role of muscle pump in exercise hyperemia

1987 ◽  
Vol 253 (5) ◽  
pp. H993-H1004 ◽  
Author(s):  
M. H. Laughlin
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Muscle Contraction ◽  
Perfusion Pressure ◽  
Muscle Blood Flow ◽  
Dynamic Exercise ◽  
Vascular Conductance ◽  
Muscle Pump ◽  
Blood Flows ◽  
Flow Capacity

An appreciation for the potential of skeletal muscle vascular beds for blood flow (blood flow capacity) is required if one is to understand the limits of the cardiorespiratory system in exercise. To assess this potential, an index of blood flow capacity that can be objectively measured is required. One obvious index would be to measure maximal muscle blood flow (MBF). However, a unique value for maximal MBF cannot be measured, since once maximal vasodilation is attained MBF is a function of perfusion pressure. Another approach would be to measure maximal or peak vascular conductance. However, peak vascular conductance is different among skeletal muscles composed of different fiber types and is a function of perfusion pressure during peak vasodilation within muscle composed of a given fiber type. Also, muscle contraction can increase or decrease blood flow and/or the apparent peak vascular conductance depending on the experimental preparation and the type of muscle contraction. Blood flows and calculated values of conductance appear to be greater during rhythmic contractions (with the appropriate frequency and duration) than observed in resting muscle during what is called "maximal" vasodilation. Moreover, dynamic exercise in conscious subjects produces the greatest skeletal muscle blood flows. The purpose of this review is to consider the interaction of the determinants of muscle blood flow during locomotory exercise. Emphasis is directed toward the hypothesis that the "muscle pump" is an important determinant of perfusion of active skeletal muscle. It is concluded that, during normal dynamic exercise, MBF is determined by skeletal muscle vascular conductance, the perfusion pressure gradient, and the efficacy of the muscle pump.

scholarly journals Role of Alpha‐1 Adrenergic Vasoconstriction in Regulating Skeletal Muscle Blood Flow during Single Leg Knee Extension Exercise with Advancing Age

2018 ◽  
Vol 32 (S1) ◽  
Author(s):  
Jeremy L. Theisen ◽  
Stephen M. Ratchford ◽  
Heather L. Clifton ◽  
Kanokwan Bunsawat ◽  
Zachary Barret‐O'keefe ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Muscle Blood Flow ◽  
Knee Extension ◽  
Skeletal Muscle Blood Flow ◽  
Knee Extension Exercise

Relationship between muscle blood flow and oxygen uptake during exercise in endurance-trained and untrained men

2005 ◽  
Vol 98 (1) ◽  
pp. 380-383 ◽  
Author(s):  
Kari K. Kalliokoski ◽  
Juhani Knuuti ◽  
Pirjo Nuutila
Keyword(s):  
Blood Flow ◽  
Oxygen Uptake ◽  
Regional Blood Flow ◽  
Muscle Blood Flow ◽  
Knee Extension ◽  
Large Individual ◽  
Mean Values ◽  
The Mean ◽  
Similar Good ◽  
Knee Extension Exercise

A recent study showed good correlation between regional blood flow (BF) and oxygen uptake (V̇o2) 30 min after exhaustive exercise. The question that remains open is whether there is similar good correlation between BF and V̇o2 also during exercise. We reanalyzed our previous data from a study in which BF and V̇o2 was measured in different quadriceps femoris muscles in seven healthy endurance-trained and seven healthy untrained men at rest and during low-intensity intermittent static knee-extension exercise (Kalliokoski KK, Oikonen V, Takala TO, Sipila H, Knuuti J, and Nuutila P. Am J Physiol Endocrinol Metab 280: E1015–E1021, 2001). When the mean values of each muscle were considered, there was good correlation between BF and V̇o2 during exercise in both groups ( r2 = 0.82 in untrained and 0.97 in trained). However, when calculated individually, the correlations were poorer, and the mean correlation coefficient ( r2) was significantly higher in the trained men (0.71 ± 0.07 vs. 0.40 ± 0.11, P = 0.03). These results suggest that there is large individual variation in matching BF to V̇o2 in human skeletal muscles during exercise, ranging from very poor to excellent. Furthermore, this matching seems to be better in the endurance-trained than in untrained men.

Vasodilation and muscle pump contribution to immediate exercise hyperemia

1996 ◽  
Vol 271 (4) ◽  
pp. H1697-H1701 ◽  
Author(s):  
M. E. Tschakovsky ◽  
J. K. Shoemaker ◽  
R. L. Hughson
Keyword(s):  
Blood Flow ◽  
Muscle Contraction ◽  
Peak Flow ◽  
Muscle Blood Flow ◽  
Cuff Inflation ◽  
Early Exercise ◽  
Muscle Pump ◽  
Exercise Hyperemia ◽  
Human Forearm

A rapid (within 0-5 s) increase in skeletal muscle blood flow has been demonstrated following muscle contraction, yet the mechanism remains unresolved. Recently, it was suggested that the entire rapid exercise hyperemia could be attributed to the mechanical muscle pump effect. Other evidence indicates that the muscle pump cannot increase arterial flow. We measured human forearm blood flow with the arm positioned above or below heart level during 1) simulation of rhythmic muscle pump function via repeated inflation/deflation of a forearm cuff to 100 mmHg to achieve mechanical emptying of forearm veins, and 2) 1-s single-cuff inflations, 1-s voluntary forearm contractions, and 1-s contractions performed within a cuff inflation. Rhythmic cuff inflation increased blood flow with the arm below heart level (P < 0.05) but not above. Flow following single contractions was higher than flow following cuff inflation within 2 s (P < 0.05). Peak flow increases due to a single mechanical venous emptying (7.7 +/- 0.7 ml.100 ml(-1) min(-1)) could account for 60% of the peak flow increase due to muscle contraction (12.8 +/- 1.0 ml.100 ml(-1).min(-1)) with the arm below heart level, whereas above heart level mechanical venous emptying accounted for 46% of the flow increase due to contraction (3.0 +/- 0.4 vs. 6.5 +/- 0.6 ml.100 ml(-1).min(-1)). We conclude that a functional muscle pump does exist in the human forearm in vivo, but that a rapid vasodilation detectable within 2 s also contributes to the early exercise hyperemia.

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