scholarly journals Recovery kinetics of creatine in mild plantar flexion exercise using 3D creatine CEST imaging at 7 Tesla

2020 ◽  
Vol 85 (2) ◽  
pp. 802-817
Author(s):  
Dushyant Kumar ◽  
Ravi Prakash Reddy Nanga ◽  
Deepa Thakuri ◽  
Neil Wilson ◽  
Abigail Cember ◽  
...  
Keyword(s):  
Plantar Flexion ◽  
7 Tesla ◽  
Cest Imaging ◽  
Kinetics Of ◽  
Plantar Flexion Exercise

scholarly journals Behavior of Aponeurosis and External Tendon of the Gastrocnemius Muscle During Dynamic Plantar Flexion Exercise

2005 ◽  
Vol 3 (Special_Issue_2) ◽  
pp. 235-244 ◽  
Author(s):  
Norihide Sugisaki ◽  
Hiroaki Kanehisa ◽  
Yasuo Kawakami ◽  
Tetsuo Fukunaga
Keyword(s):  
Gastrocnemius Muscle ◽  
Plantar Flexion ◽  
Plantar Flexion Exercise

MUSCLE OXYGENATION AND FEMORAL ARTERY FLOW DURING DYNAMIC PLANTAR FLEXION EXERCISE

1999 ◽  
Vol 31 (Supplement) ◽  
pp. S246
Author(s):  
V. Quaresima ◽  
S. Homma ◽  
K. Azuma ◽  
S. Shimizu ◽  
M. Ferrari ◽  
...  
Keyword(s):  
Femoral Artery ◽  
Plantar Flexion ◽  
Muscle Oxygenation ◽  
Artery Flow ◽  
Plantar Flexion Exercise

Effects of Respiratory Alkalosis on Phosphocreatine Kinetics During Moderate-Intensity Plantar Flexion Exercise

2006 ◽  
Vol 38 (Supplement) ◽  
pp. S520
Author(s):  
Sean C. Forbes ◽  
John M. Kowalchuk ◽  
R. Terry Thompson ◽  
Gregory D. Marsh ◽  
Donald H. Paterson
Keyword(s):  
Plantar Flexion ◽  
Respiratory Alkalosis ◽  
Moderate Intensity ◽  
Plantar Flexion Exercise

scholarly journals Enhanced muscle blood flow with intermittent pneumatic compression of the lower leg during plantar flexion exercise and recovery

2018 ◽  
Vol 124 (2) ◽  
pp. 302-311 ◽  
Author(s):  
K. A. Zuj ◽  
C. N. Prince ◽  
R. L. Hughson ◽  
S. D. Peterson
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Exercise Performance ◽  
Muscle Blood Flow ◽  
Plantar Flexion ◽  
Intermittent Pneumatic Compression ◽  
Muscle Pump ◽  
Intermittent Compression ◽  
Postexercise Recovery ◽  
Plantar Flexion Exercise

This study tested the hypothesis that intermittent compression of the lower limb would increase blood flow during exercise and postexercise recovery. Data were collected from 12 healthy individuals (8 men) who performed 3 min of standing plantar flexion exercise. The following three conditions were tested: no applied compression (NoComp), compression during the exercise period only (ExComp), and compression during 2 min of standing postexercise recovery. Doppler ultrasound was used to determine superficial femoral artery (SFA) blood flow responses. Mean arterial pressure (MAP) and cardiac stroke volume (SV) were assessed using finger photoplethysmography, with vascular conductance (VC) calculated as VC = SFA flow/MAP. Compared with the NoComp condition, compression resulted in increased MAP during exercise [+3.5 ± 4.1 mmHg (mean ± SD)] but not during postexercise recovery (+1.6 ± 5.9 mmHg). SV increased with compression during both exercise (+4.8 ± 5.1 ml) and recovery (+8.0 ± 6.6 ml) compared with NoComp. There was a greater increase in SFA flow with compression during exercise (+52.1 ± 57.2 ml/min) and during recovery (+58.6 ± 56.7 ml/min). VC immediately following exercise was also significantly greater in the ExComp condition compared with the NoComp condition (+0.57 ± 0.42 ml·min−1·mmHg−1), suggesting the observed increase in blood flow during exercise was in part because of changes in VC. Results from this study support the hypothesis that intermittent compression applied during exercise and recovery from exercise results in increased limb blood flow, potentially contributing to changes in exercise performance and recovery. NEW & NOTEWORTHY Blood flow to working skeletal muscle is achieved in part through the rhythmic actions of the skeletal muscle pump. This study demonstrated that the application of intermittent pneumatic compression during the diastolic phase of the cardiac cycle, to mimic the mechanical actions of the muscle pump, accentuates muscle blood flow during exercise and elevates blood flow during the postexercise recovery period. Intermittent compression during and after exercise might have implications for exercise performance and recovery.

Skeletal muscle oxidative metabolism in sedentary humans: 31P-MRS assessment of O2 supply and demand limitations

2004 ◽  
Vol 97 (3) ◽  
pp. 1077-1081 ◽  
Author(s):  
Luke J. Haseler ◽  
Alexander P. Lin ◽  
Russell S. Richardson
Keyword(s):  
Gastrocnemius Muscle ◽  
Supply And Demand ◽  
Plantar Flexion ◽  
Submaximal Exercise ◽  
Resonance Spectroscopy ◽  
O2 Supply ◽  
Sedentary Subjects ◽  
Mitochondrial Capacity ◽  
Oxidative Rate ◽  
Plantar Flexion Exercise

Previously, it was demonstrated in exercise-trained humans that phosphocreatine (PCr) recovery is significantly altered by fraction of inspired O2 (FiO2), suggesting that in this population under normoxic conditions, O2 availability limits maximal oxidative rate. Haseler LJ, Hogan ML, and Richardson RS. J Appl Physiol 86: 2013–2018, 1999. To further elucidate these population-specific limitations to metabolic rate, we used 31P-magnetic resonance spectroscopy to study the exercising human gastrocnemius muscle under conditions of varied FiO2 in sedentary subjects. To test the hypothesis that PCr recovery from submaximal exercise in sedentary subjects is not limited by O2 availability, but rather by their mitochondrial capacity, six sedentary subjects performed three bouts of 6-min steady-state submaximal plantar flexion exercise followed by 5 min of recovery while breathing three different FiO2 (0.10, 0.21, and 1.00). PCr recovery time constants were significantly longer in hypoxia (47.0 ± 3.2 s), but there was no difference between hyperoxia (31.8 ± 1.9 s) and normoxia (30.0 ± 2.1 s) (mean ± SE). End-exercise pH was not significantly different across treatments. These results suggest that the maximal muscle oxidative rate of these sedentary subjects, unlike their exercise-trained counterparts, is limited by mitochondrial capacity and not O2 availability in normoxia. Additionally, the significant elongation of PCr recovery in these subjects in hypoxia illustrates the reliance on O2 supply at the other end of the O2 availability spectrum in both sedentary and active populations.

scholarly journals Dynamic multivoxel-localized31P MRS during plantar flexion exercise with variable knee angle

2018 ◽  
Vol 31 (6) ◽  
pp. e3905 ◽  
Author(s):  
Fabian Niess ◽  
Georg B. Fiedler ◽  
Albrecht I. Schmid ◽  
Elmar Laistler ◽  
Roberta Frass-Kriegl ◽  
...  
Keyword(s):  
Plantar Flexion ◽  
Knee Angle ◽  
Plantar Flexion Exercise

pH heterogeneity during exercise in localized spectra from single human muscles

1993 ◽  
Vol 265 (5) ◽  
pp. C1332-C1339 ◽  
Author(s):  
K. Vandenborne ◽  
G. Walter ◽  
J. S. Leigh ◽  
G. Goelman
Keyword(s):  
Steady State ◽  
Line Width ◽  
Maximal Exercise ◽  
Fiber Type ◽  
Plantar Flexion ◽  
Fiber Types ◽  
Lateral Gastrocnemius ◽  
Human Muscles ◽  
Metabolic Heterogeneity ◽  
Plantar Flexion Exercise

We investigated whether pH heterogeneity in skeletal muscle during exercise, observed with 31P nuclear magnetic resonance, represents muscle fiber type heterogeneity. Localized spectra were simultaneously acquired from the soleus, medial, and lateral gastrocnemius using a multivolume localization technique, the Hadamard spectroscopic imaging (HSI) technique. Contamination of nonselected regions to the localized volumes was < 5%. HSI-localized spectra were obtained from the calf muscles of untrained subjects and a small group of athletes. Two plantar flexion exercise protocols were implemented: a "maximal" high frequency protocol and a "steady-state" protocol at low contraction frequency (0.25 Hz). pH heterogeneity was observed in localized spectra of single muscles during both exercise protocols, as indicated by the large Pi line width. During maximal exercise the Pi line width was up to three times wider than the phosphocreatine line width, covering an entire pH unit. During the steady-state exercise, in three subjects the Pi peak clearly resolved into two distinct peaks, one at low pH and one at high pH. As pH heterogeneity was observed in localized spectra of single muscles during both exercise protocols, it most likely reflects the metabolic heterogeneity between fiber types.

scholarly journals Sex-specific impact of aging on the blood pressure response to exercise

2018 ◽  
Vol 314 (1) ◽  
pp. H95-H104 ◽  
Author(s):  
Joel D. Trinity ◽  
Gwenael Layec ◽  
Corey R. Hart ◽  
Russell S. Richardson
Keyword(s):  
Blood Pressure ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Young Women ◽  
Blood Pressure Response ◽  
Plantar Flexion ◽  
Pressure Response ◽  
Old Men ◽  
Response To Exercise ◽  
Plantar Flexion Exercise

An exaggerated blood pressure (BP) response to exercise has been linked to cardiovascular disease, but little is known about the impact of age and sex on this response. Therefore, this study examined the hemodynamic and skeletal muscle metabolic response to dynamic plantar flexion exercise, at 40% of maximum plantar flexion work rate, in 40 physical activity-matched young (23 ± 1 yr, n = 20) and old (73 ± 2 yr, n = 20), equally distributed, male and female subjects. Central hemodynamics and BP (finometer), popliteal artery blood flow (Doppler ultrasound), and skeletal muscle metabolism (31P-magnetic resonance spectroscopy) were measured during 5 min of plantar flexion exercise. Popliteal artery blood flow and high-energy phosphate responses to exercise were not affected by age or sex, whereas aging, independent of sex, attenuated stroke volume and cardiac output responses. Systolic BP and mean arterial pressure responses were exaggerated in old women (Δ42 ± 4 and Δ28 ± 3 mmHg, respectively), with all other groups exhibiting similar increases in systolic BP (old men: Δ27 ± 8 mmHg, young men: Δ27 ± 3 mmHg, and young women: Δ22 ± 3 mmHg) and mean arterial pressure (old men: Δ15 ± 4 mmHg, young men: Δ19 ± 2 mmHg, and young women: Δ17 ± 2 mmHg). Interestingly, the exercise-induced change in systemic vascular resistance in old women (∆0.8 ± 1.0 mmHg·l−1·min−1) was augmented compared with young women and young and old men (∆−2.8 ± 0.5, ∆−1.6 ± 0.6, and ∆−3.18 ± 1.4 mmHg·l−1·min−1, respectively, P < 0.05). Thus, in combination, advancing age and female sex results in an exaggerated BP response to exercise, likely the result of a failure to reduce systemic vascular resistance. NEW & NOTEWORTHY An exaggerated blood pressure response to exercise has been linked to cardiovascular disease; however, little is known about how age and sex impact this response in healthy individuals. During dynamic exercise, older women exhibited an exaggerated blood pressure response driven by an inability to lower systemic vascular resistance.

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