Effects of a single bout of eccentric exercise on muscle swelling, imaging and mechanical properties in upper limb: Application of vibration

The α7β1-integrin is a heterodimeric transmembrane protein that adheres to laminin in the extracellular matrix, representing a critical link that maintains structure in skeletal muscle. In addition to preventing exercise-induced skeletal muscle injury, the α7-integrin has been proposed to act as an intrinsic mechanosensor, initiating cellular growth in response to mechanical strain. The purpose of this study was to determine the extent to which the α7-integrin regulates muscle hypertrophy following eccentric exercise. Wild-type (WT) and α7-integrin transgenic (α7Tg) mice completed a single bout of downhill running exercise (−20°, 17 m/min, 60 min), and gastrocnemius-soleus complexes were collected 1, 2, 4, and 7 days (D) postexercise (PE). Maximal isometric force was maintained and macrophage accumulation was suppressed in α7Tg muscle 1D PE. Mean fiber cross-sectional area was unaltered in WT mice but increased 40% in α7Tg mice 7D PE. In addition, a rapid and striking fivefold increase in embryonic myosin heavy chain-positive fibers appeared in α7Tg mice 2D PE. Although Pax7-positive satellite cells were increased in α7Tg muscle 1D PE, the number of nuclei per myofiber was not altered 7D PE. Phosphorylation of mammalian target of rapamycin (mTOR) was significantly elevated in α7Tg 1D PE. This study provides the first demonstration that the presence of the α7β1-integrin in skeletal muscle increases fiber hypertrophy and new fiber synthesis in the early time course following a single bout of eccentric exercise. Further studies are necessary to elucidate the precise mechanism by which the α7-integrin can enhance muscle hypertrophy following exercise.

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Whey protein supplementation does not accelerate recovery from a single bout of eccentric exercise

Journal of Sports Sciences ◽

10.1080/02640414.2020.1820184 ◽

2020 ◽

pp. 1-10

Author(s):

Luuk Hilkens ◽

Jolien De Bock ◽

Joris Kretzers ◽

Alwine F. M. Kardinaal ◽

Esther G. Floris-Vollenbroek ◽

...

Keyword(s):

Whey Protein ◽

Eccentric Exercise ◽

Protein Supplementation ◽

Single Bout

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Regional Differences of Mechanical Properties in a Biceps Brachii Following Eccentric Exercise

Exercise Science ◽

10.15857/ksep.2021.30.3.327 ◽

2021 ◽

Vol 30 (3) ◽

pp. 327-335

Author(s):

Choun-sub Kim ◽

Maeng-kyu Kim

Keyword(s):

Mechanical Properties ◽

Muscle Damage ◽

Eccentric Exercise ◽

Muscle Function ◽

Elbow Joint ◽

Muscle Soreness ◽

Biceps Brachii ◽

Dynamic Stiffness ◽

Significant Difference ◽

Regional Muscle

PURPOSE: This study aimed to examine the effects of eccentric exercise (ECC) on the indices of mechanical properties together with markers of exercise-induced muscle damage (EIMD) in different sites of the biceps brachii (BB) muscle.METHODS: ECC using an elbow joint was performed in 13 non-trained, college men. Global symptoms of EIMD were identified through changes in muscle soreness and serum creatine kinase (CK) activity, including muscle function following ECC. To evaluate regional EIMD, muscle swelling and tenderness as well as muscular echo intensity were measured at distal (4 cm above the elbow joint) and middle (30% of the distance from the antecubital crease to the acromion) sites within the BB muscle. A handheld myotonometer was used to estimate changes in mechanical properties, that is, oscillation frequency (F), dynamic stiffness (S), and relaxation time (R), of BB muscles after ECC.RESULTS: A significant difference in the major markers of EIMD, such as muscle soreness and serum CK activity, along with parameters of muscle function, was observed after ECC compared to baseline. Although all indirect markers of regional muscle damage demonstrated meaningful differences between before and after ECC, no statistically significant interaction between the distal and middle sites was observed in any of the markers. After ECC, both distal and middle sites showed significant changes in F, S, and R, but no statistical differences in changes in muscle mechanical properties were observed between localized muscle sites within BB muscles.CONCLUSIONS: Changes in mechanical properties, including regional muscle damage, seem to be uniformly influenced by different anatomical locations within the BB muscle, such as elbow flexors, following ECC.

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Effect of muscle energy technique on calf muscle stiffness increased after eccentric exercise in athletes

Journal of Kinesiology and Exercise Sciences ◽

10.5604/01.3001.0012.7985 ◽

2018 ◽

Vol 28 (81) ◽

pp. 21-29

Author(s):

Aleksandra Kisilewicz ◽

Marcin Urbaniak ◽

Adam Kawczyński

Keyword(s):

Eccentric Exercise ◽

Soft Tissues ◽

Muscle Stiffness ◽

Calf Muscle ◽

P Value ◽

Muscle Energy Technique ◽

Digital Palpation ◽

Single Bout ◽

Muscle Energy ◽

Post Hoc

Aim. The study aimed to assess changes in calf muscle stiffness after eccentric exercise (ECC), followed by Muscle Energy Technique (MET). Our second goal was to evaluate the reliability of novel MyotonPRO device for measurements of calf muscle stiffness in athletes. Basic procedures. The study was conducted on 18 athletes form University School of Physical Education in Wrocław, practicing various sport disciplines. Stiffness measurements were obtained five times, bilaterally over calf muscle: 1) test for the relative and absolute reliability, 2) re-test, 3) before single bout of ECC, 4) after ECC but before MET, 5) after application of MET. The results were evaluated using RM-ANOVA and Bonferroni post-hoc test. P-value < 0.05 was considered significant. Main Findings. Measurements of calf muscle were obtained with a reliable, hand-held and easy to use in filed conditions MyotonPRO device. Myoton Technology provides an accurate and sensitive way for the objective and non-invasive digital palpation of soft tissues, what may find many uses in professional sport. Results. The test-retest relative reliability was found to be almost perfect, with ICC of 0.898 (95% Confidence Interval: form 0.851 to 0.930). The average SEM was 21.81 N/m and average MDC equated 60.42 N/m. There was a significant increase of right calf muscle stiffness after single bout of eccentric exercise, comparing to its initial values (P<0,001), and the left leg (P=0,002). There was a significant decrease of muscle stiffness after performing MET (P=0,001). Initially and after MET there was no difference between left and right leg (P=0,06). Conclusions. The study showed that a single application of MET restores the normal stiffness level increased after a single bout of ECC significantly. It also proved MyotonPRO to be a reliable tool to assess calf muscle stiffness in athletes.

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Changes in the mechanical properties of human and amphibian muscle after eccentric exercise

European Journal of Applied Physiology ◽

10.1007/s004210050208 ◽

1997 ◽

Vol 76 (1) ◽

pp. 21-31 ◽

Cited By ~ 77

Author(s):

C. Jones ◽

T. Allen ◽

J. Talbot ◽

D. L. Morgan ◽

U. Proske

Keyword(s):

Mechanical Properties ◽

Eccentric Exercise

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Attenuation of Protective Effect Against Eccentric Exercise-Induced Muscle Damage

Canadian Journal of Applied Physiology ◽

10.1139/h05-139 ◽

2005 ◽

Vol 30 (5) ◽

pp. 529-542 ◽

Cited By ~ 34

Author(s):

Kazunori Nosaka ◽

Michael J. Newton ◽

Paul Sacco

Keyword(s):

Creatine Kinase ◽

Protective Effect ◽

Range Of Motion ◽

Eccentric Exercise ◽

Repeated Measures ◽

Muscle Soreness ◽

Isometric Strength ◽

Arm Circumference ◽

Single Bout ◽

Exercise Induced

A single bout of eccentric exercise confers a long-lasting protective effect against subsequent bouts of the same exercise. This study investigated how the protective effect was lessened when the interval between the initial and secondary exercise bouts was increased from 4 to 12 weeks. Thirty young men performed two bouts of 12 maximal eccentric actions of the elbow flexors of the nondominant arm separated by either 4 (n = 9), 8 (n = 10), or 12 (n = 11) weeks. Maximal isometric strength, flexed and relaxed elbow joint angles, range of motion, upper arm circumference, muscle soreness, plasma creatine kinase (CK), and myoglobin (Mb) were measured before, immediately after, and for 4 days after exercise. Changes in criterion measures were compared between bouts for each group and among groups by two-way repeated-measures ANOVA. There were no significant differences among groups in the changes in all measures following the first bout. Significantly (p < 0.05) smaller responses in all measures were observed after the second bout as compared with first bout for the 4 and 8 weeks, but only in strength, muscle soreness, CK, and Mb for the 12 weeks. It was concluded that some aspects of the protective effect were attenuated after 8 weeks, and the factors responsible for the effect vary among the measures. Key words: maximal isometric strength, creatine kinase, myoglobin, range of motion, muscle soreness

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