Maximal Voluntary Contraction Force and Rate of Force Development are Decreased in Human Creatine Depletion

The purpose of the study was to examine the effect of prolonged tonic vibration applied to a single synergist muscle on maximal voluntary contraction (MVC) and maximal rate of force development (dF/d t max). The knee extension MVC force and surface electromyogram (EMG) from the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) during MVC were recorded before and after vibration of RF muscle at 30 Hz for 30 min. MVC, dF/d t max, and the integrated EMG (iEMG) of RF decreased significantly after prolonged tonic vibration in spite of no changes in iEMG of VL and VM. The present results indicate that MVC and dF/d t max may be influenced by the attenuated Ia afferent functions of a single synergist muscle.

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Maximal voluntary contraction force, SR function and glycogen resynthesis during the first 72 h after a high-level competitive soccer game

European Journal of Applied Physiology ◽

10.1007/s00421-011-1919-y ◽

2011 ◽

Vol 111 (12) ◽

pp. 2987-2995 ◽

Cited By ~ 70

Author(s):

Peter Krustrup ◽

Niels Ørtenblad ◽

Joachim Nielsen ◽

Lars Nybo ◽

Thomas P. Gunnarsson ◽

...

Keyword(s):

Maximal Voluntary Contraction ◽

Voluntary Contraction ◽

Contraction Force ◽

Glycogen Resynthesis ◽

Soccer Game ◽

High Level

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Metabolism of Exercising and Resting Human Skeletal Muscle, in the Post-Prandial and Fasting States

Clinical Science ◽

10.1042/cs0440479 ◽

1973 ◽

Vol 44 (5) ◽

pp. 479-491 ◽

Cited By ~ 14

Author(s):

Patricia G. B. Baker ◽

R. F. Mottram

Keyword(s):

Carbon Dioxide ◽

Skeletal Muscle ◽

Oxygen Uptake ◽

Glucose Uptake ◽

Maximal Voluntary Contraction ◽

Human Skeletal Muscle ◽

Voluntary Contraction ◽

Contraction Force ◽

Carbon Dioxide Output

1. Methods are described for study of metabolism of human skeletal muscle in situ, at rest and during mild sustained contraction in the fed and fasted states. 2. At rest the average oxygen uptake was 0.29 ml min−1 100 ml of muscle−1 and the carbon dioxide output was 0.22 ml. Glucose uptake was 0.49 mg min−1 100 ml of muscle−1. The respiratory quotient was 0.75, indicating that most of the glucose was being stored. 3. When subjects made hand-grips of 5% of their maximal voluntary contraction force (5% MVC) the oxygen and carbon dioxide exchanges both increased by six times while the glucose uptake increased by 70% of the resting value. 4. A 7 h fast before the observations were made severely decreased both resting and exercising glucose uptake but produced no other alteration in the metabolism of the muscle.

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Age- and Sex-Related Differences in the Maximum Muscle Performance and Rate of Force Development Scaling Factor of Precision Grip Muscles

Motor Control ◽

10.1123/mc.2019-0021 ◽

2020 ◽

Vol 24 (2) ◽

pp. 274-290

Author(s):

Talyene G.C. Corrêa ◽

Stephanie V.S. Donato ◽

Kauê C.A. Lima ◽

Ronaldo V. Pereira ◽

Mehmet Uygur ◽

...

Keyword(s):

Grip Force ◽

Isometric Force ◽

Maximum Voluntary Contraction ◽

Precision Grip ◽

Voluntary Contraction ◽

Scaling Factor ◽

Rate Of Force Development ◽

Muscle Performance ◽

Force Development ◽

Age And Sex

The aim of this study was to explore the effects of age and sex on the rate of force development scaling factor (RFD-SF) and maximum performance (i.e., maximum grip force [GFMax] and maximum rate of grip force development [RGFDMax]) of precision handgrip muscles. Sixty-four subjects, allocated in four groups according to their age and sex, were asked to hold an instrumented handle with the tip of the digits and perform two tests: maximum voluntary contraction and RFD-SF tests. In the maximum voluntary contraction test, GFMax and RGFDMax were assessed. In the RFD-SF test, the subjects generated quick isometric force pulses to target amplitudes varying between 20% and 100% of their GFMax. The RFD-SF and R2 values were obtained from the linear relationship between the peak values of the force pulses and the corresponding peak values of the rate of force development. Younger adults and males produced higher GFMax and RGFDMax and presented higher R2 and RFD-SF than older adults and females, respectively. No correlations between GFMax and RFD-SF and between RGFDMax and RFD-SF were observed.

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Early Detection of Prolonged Decreases in Maximal Voluntary Contraction Force after Eccentric Exercise of the Knee Extensors

Medicine & Science in Sports & Exercise ◽

10.1249/mss.0000000000002797 ◽

2021 ◽

Vol Publish Ahead of Print ◽

Author(s):

Cassio V. Ruas ◽

Christopher Latella ◽

Janet L. Taylor ◽

G. Gregory Haff ◽

Kazunori Nosaka

Keyword(s):

Early Detection ◽

Eccentric Exercise ◽

Maximal Voluntary Contraction ◽

Voluntary Contraction ◽

Knee Extensors ◽

Contraction Force

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NMR and analytic biochemical evaluation of CrP and nucleotides in the human calf during muscle contraction

Journal of Applied Physiology ◽

10.1152/jappl.1993.74.4.2034 ◽

1993 ◽

Vol 74 (4) ◽

pp. 2034-2039 ◽

Cited By ~ 54

Author(s):

J. Bangsbo ◽

L. Johansen ◽

B. Quistorff ◽

B. Saltin

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Maximal Voluntary Contraction ◽

Work Load ◽

Voluntary Contraction ◽

Isometric Contractions ◽

Contraction Force ◽

Biochemical Evaluation ◽

Male Subjects ◽

Human Calf

This study compared biochemical and 31P-nuclear magnetic resonance (NMR) determinations of energy metabolites during isometric contractions of the human calf muscle at various exercise intensities. Seven male subjects performed one-legged isometric contractions at a work load of 28, 64, and 90% of maximal voluntary contraction force (28-, 64-, and 90%-CON, respectively) for 3 min, 40 s, and 40 s, respectively, in a magnet and in an exact model of the magnet with an arrangement for rapid muscle biopsy sampling from the gastrocnemius. The decrease in phosphocreatine (CrP) determined by NMR was 20, 33, and 71% for 28%-, 64%-, and 90%-CON, respectively. These decreases were the same as those determined biochemically (25, 34, and 61%, respectively). Muscle CrP 1 min after 90%-CON was also found to be similar between NMR and biochemical determinations (88 and 74% of resting value, respectively). Although no significant change in muscle ATP was found by NMR, a decrease of 29% was observed biochemically at 90%-CON. The ratio between muscle CrP and ATP was the same between NMR and biochemical determinations except for 90%-CON (1.98 and 0.78, respectively). The increase in muscle ADP determined by NMR was two-, five-, and eightfold higher than that found biochemically for 28%-, 64%-, and 90%-CON, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

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