Isotonic muscle function is selectively reduced after muscle damage induced by isometric exercise at a long muscle length

2007 ◽  
Vol 15 (2) ◽  
pp. 69-75 ◽  
Author(s):  
A. Philippou ◽  
G.C. Bogdanis ◽  
M. Maridaki
Keyword(s):  
Muscle Damage ◽  
Muscle Function ◽  
Isometric Exercise ◽  
Muscle Length

Angle-specific impairment of elbow flexors strength after isometric exercise at long muscle length

2003 ◽  
Vol 21 (10) ◽  
pp. 859-865 ◽  
Author(s):  
Anastassios Philippou ◽  
Maria Maridaki ◽  
Gregory C. Bogdanis
Keyword(s):  
Isometric Exercise ◽  
Muscle Length ◽  
Elbow Flexors

scholarly journals Geniohyoid muscle function in awake canines

2003 ◽  
Vol 95 (2) ◽  
pp. 810-817 ◽  
Author(s):  
M. Yokoba ◽  
H. G. Hawes ◽  
P. A. Easton
Keyword(s):  
Muscle Function ◽  
Breathing Pattern ◽  
Muscle Length ◽  
Upper Airway ◽  
Mechanical Action ◽  
Emg Activity ◽  
Airway Occlusion ◽  
Lateral Decubitus ◽  
The Right ◽  
Emg Electrodes

The geniohyoid (Genio) upper airway muscle shows phasic, inspiratory electrical activity in awake humans but no activity and lengthening in anesthetized cats. There is no information about the mechanical action of the Genio, including length and shortening, in any awake, nonanesthetized mammal during respiration (or swallowing). Therefore, we studied four canines, mean weight 28.8 kg, 1.5 days after Genio implantation with sonomicrometry transducers and bipolar electromyogram (EMG) electrodes. Awake recordings of breathing pattern, muscle length and shortening, and EMG activity were made with the animal in the right lateral decubitus position during quiet resting, CO2-stimulated breathing, inspiratory-resisted breathing (80 cmH2O · l-1 · s), and airway occlusion. Genio length and activity were also measured during swallowing, when it shortened, showing a 9.31% change from resting length, and its EMG activity increased 6.44 V. During resting breathing, there was no phasic Genio EMG activity at all, and Genio showed virtually no movement during inspiration. During CO2-stimulated breathing, Genio showed minimal lengthening of only 0.07% change from resting length, whereas phasic EMG activity was still absent. During inspiratory-resisted breathing and airway occlusion, Genio showed phasic EMG activity but still lengthened. We conclude that the Genio in awake, nonanesthetized canines shows active contraction and EMG activity only during swallowing. During quiet or stimulated breathing, Genio is electrically inactive with passive lengthening. Even against resistance, Genio is electrically active but still lengthens during inspiration.

scholarly journals Improved recovery from skeletal muscle damage is largely unexplained by myofibrillar protein synthesis or inflammatory and regenerative gene expression pathways

2020 ◽  
Author(s):  
George Frederick Pavis ◽  
Tom SO Jameson ◽  
Marlou L. Dirks ◽  
Benjamin P. Lee ◽  
Doaa Reda Abdelrahman ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Muscle Damage ◽  
Muscle Function ◽  
Nutritional Intervention ◽  
Myofibrillar Protein ◽  
Skeletal Muscle Damage ◽  
Amino Acid Availability ◽  
Expression Pathways ◽  
Myofibrillar Protein Synthesis

The contribution of myofibrillar protein synthesis (MyoPS) to recovery from skeletal muscle damage in humans is unknown. Recreationally active males and females consumed a daily protein-polyphenol beverage targeted at increasing amino acid availability and reducing inflammation (PPB; n=9), both known to affect MyoPS, or an isocaloric placebo (PLA; n=9) during 168 h of recovery from 300 maximal unilateral eccentric contractions (EE). Muscle function was assessed daily. Muscle biopsies were collected 24, 27, 36, 72 and 168 h for MyoPS measurements using 2H2O and expression of 224 genes using RT-qPCR and pathway analysis. PPB improved recovery of muscle function, which was impaired for five days following EE in PLA (interaction; P<0.05). Acute postprandial MyoPS rates were unaffected by nutritional intervention (24-27 h). EE increased overnight (27-36 h) MyoPS versus control leg (PLA: 33±19%; PPB: 79±25%; leg P<0.01), and PPB tended to increase this further (interaction P=0.06). Daily MyoPS rates were greater with PPB between 72-168 h after EE, albeit after function had recovered. Inflammatory and regenerative signaling pathways were dramatically upregulated and clustered following EE but were unaffected by nutritional intervention. These results suggest that accelerated recovery from EE is not explained by elevated MyoPS or suppression of inflammation.

scholarly journals Muscle damage and inflammation during recovery from exercise

2017 ◽  
Vol 122 (3) ◽  
pp. 559-570 ◽  
Author(s):  
Jonathan M. Peake ◽  
Oliver Neubauer ◽  
Paul A. Della Gatta ◽  
Kazunori Nosaka
Keyword(s):  
Muscle Strength ◽  
Muscle Damage ◽  
Muscle Tissue ◽  
Time Course ◽  
Inflammatory Responses ◽  
Large Body ◽  
Clinical Signs ◽  
Muscle Length ◽  
Signs And Symptoms ◽  
Exercise Induced

Unaccustomed exercise consisting of eccentric (i.e., lengthening) muscle contractions often results in muscle damage characterized by ultrastructural alterations in muscle tissue, clinical signs, and symptoms (e.g., reduced muscle strength and range of motion, increased muscle soreness and swelling, efflux of myocellular proteins). The time course of recovery following exercise-induced muscle damage depends on the extent of initial muscle damage, which in turn is influenced by the intensity and duration of exercise, joint angle/muscle length, and muscle groups used during exercise. The effects of these factors on muscle strength, soreness, and swelling are well characterized. By contrast, much less is known about how they affect intramuscular inflammation and molecular aspects of muscle adaptation/remodeling. Although inflammation has historically been viewed as detrimental for recovery from exercise, it is now generally accepted that inflammatory responses, if tightly regulated, are integral to muscle repair and regeneration. Animal studies have revealed that various cell types, including neutrophils, macrophages, mast cells, eosinophils, CD8 and T-regulatory lymphocytes, fibro-adipogenic progenitors, and pericytes help to facilitate muscle tissue regeneration. However, more research is required to determine whether these cells respond to exercise-induced muscle damage. A large body of research has investigated the efficacy of physicotherapeutic, pharmacological, and nutritional interventions for reducing the signs and symptoms of exercise-induced muscle damage, with mixed results. More research is needed to examine if/how these treatments influence inflammation and muscle remodeling during recovery from exercise.

Comparison of Carbohydrate and Milk-Based Beverages on Muscle Damage and Glycogen Following Exercise

2001 ◽  
Vol 11 (4) ◽  
pp. 406-419 ◽  
Author(s):  
Janet R. Wojcik ◽  
Janet Walberg-Rankin ◽  
Lucille L. Smith ◽  
F.C. Gwazdauskas
Keyword(s):  
Muscle Damage ◽  
Eccentric Exercise ◽  
Muscle Glycogen ◽  
Muscle Function ◽  
Muscle Protein ◽  
Serum Insulin ◽  
Peak Torque ◽  
Group Differences ◽  
Protein Breakdown ◽  
Post Exercise

This study examined effects of carbohydrate (CHO), milk-based carbohydrate-protein (CHO-PRO), or placebo (P) beverages on glycogen resynthesis, muscle damage, inflammation, and muscle function following eccentric resistance exercise. Untrained males performed a cycling exercise to reduce muscle glycogen 12 hours prior to performance of 100 eccentric quadriceps contractions at 120% of 1-RM (day 1) and drank CHO (n = 8), CHO-PRO (n = 9; 5 kcal/kg), or P (n = 9) immediately and 2 hours post-exercise. At 3 hours post-eccentric exercise, serum insulin was four times higher for CHO-PRO and CHO than P (p < .05). Serum creatine kinase (CK) increased for all groups in the 6 hours post-eccentric exercise (p < .01), with the increase tending to be lowest for CHO-PRO (p < .08) during this period. Glycogen was low post-exercise (33 ± 3.7 mmol/kg ww), increased 225% at 24 hours, and tripled by 72 hours, with no group differences. The eccentric exercise increased muscle protein breakdown as indicated by urinary 3-methylhistidine and increased IL-6 with no effect of beverage. Quadriceps isokinetic peak torque was depressed similarly for all groups by 24% 24 hours post-exercise and remained 21 % lower at 72 hours (p < .01). In summary, there were no influences of any post-exercise beverage on muscle glycogen replacement, inflammation, or muscle function.

Biochemical impact of soccer: an analysis of hormonal, muscle damage, and redox markers during the season

2014 ◽  
Vol 39 (4) ◽  
pp. 432-438 ◽  
Author(s):  
João Renato Silva ◽  
António Rebelo ◽  
Franklim Marques ◽  
Laura Pereira ◽  
André Seabra ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Glutathione Reductase ◽  
Muscle Damage ◽  
Muscle Function ◽  
Biochemical Markers ◽  
Reductase Activity ◽  
Recovery Period ◽  
Soccer Players ◽  
Professional Soccer ◽  
And Oxidative Stress

This study aimed to analyze changes in performance, muscle function, and stress-related biochemical markers in professional soccer players (n = 14) at 4 timepoints (3 for performance and 4 for stress-related biochemical markers) during the soccer season [Formula: see text] preseason (E1), midseason (E2), end of the season (E3) [Formula: see text] and after the end of the recovery period (E4). Performance in 5- and 30-m sprints, countermovement jump, and agility, and maximal isokinetic knee extension and knee flexion strength were measured (E1 to E3). We observed increased in-season levels of myoglobin (E2 > E1 and E4; p < 0.05), a higher testosterone/cortisol ratio (T/C), and increased levels of creatine kinase (CK), C-reactive protein, superoxide dismutase (SOD), protein sulfhydryls (–SH), and malondialdehyde (E2 and E3 > E1 and E4; p < 0.05). Lower cortisol concentrations (E3 < E1 and E4; p < 0.05) and glutathione reductase activity (E3 < E2 and E4; p < 0.05) were observed at the end of the season. T/C, CK, SOD, –SH, and malondialdehyde decreased during the off-season, and cortisol and glutathione reductase increased (E3 < E4; p < 0.05). Agility increased in E2 and E3 (p < 0.01). Significant correlations were found during the season between hormonal and muscle function parameters (r = 0.56–0.86; p < 0.05). In addition, in E2, significant associations were observed between match-accumulated time (MATE2; minutes played by each player during the competition period), performance, and hormonal and redox parameters (r = 0.456–0.615; p < 0.05). In conclusion, this study shows that soccer players face significant changes in biomarkers of physiologic strain (muscle damage and oxidative stress-related markers) during the season, but values return to normal during the off-season. Additionally, MAT influences physical, hormonal, and oxidative stress-related parameters in professional soccer players.

Etiology of Exercise-Induced Muscle Damage

1999 ◽  
Vol 24 (3) ◽  
pp. 234-248 ◽  
Author(s):  
Priscilla M. Clarkson ◽  
Stephen P. Sayers
Keyword(s):  
Muscle Damage ◽  
Eccentric Exercise ◽  
Muscle Function ◽  
Stress Proteins ◽  
Repair Process ◽  
Cellular Level ◽  
Muscle Stiffness ◽  
Damage Repair ◽  
Exercise Induced ◽  
Shock Proteins

Muscle damage is caused by strenuous and unaccustomed exercise, especially exercise involving eccentric muscle contractions, where muscles lengthen as they exert force. Damage can be observed both directly at the cellular level and indirectly from changes in various indices of muscle function. Several mechanisms have been offered to explain the etiology of the damage/repair process, including mechanical factors such as tension and strain, disturbances in calcium homeostasis. the inflammatory response, and the synthesis of stress proteins (heat shock proteins). Changes in muscle function following eccentric exercise have been observed at the cellular level as an impairment in the amount and action of transport proteins for glucose and lactate/H+, and at the systems level as an increase in muscle stiffness and a prolonged loss in the muscle's ability to generate force. This paper will briefly review factors involved in the damage/repair process and alterations in muscle function following eccentric exercise. Key words: eccentric exercise, inflammation, stress proteins, muscle function

scholarly journals Physiological and Neural Adaptations to Eccentric Exercise: Mechanisms and Considerations for Training

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Nosratollah Hedayatpour ◽  
Deborah Falla
Keyword(s):  
Muscle Damage ◽  
Motor Unit ◽  
Muscle Weakness ◽  
Eccentric Exercise ◽  
Muscle Function ◽  
Muscle Hypertrophy ◽  
Eccentric Contractions ◽  
Neural Adaptations ◽  
Neuromuscular Adaptations ◽  
Exercise Induced

Eccentric exercise is characterized by initial unfavorable effects such as subcellular muscle damage, pain, reduced fiber excitability, and initial muscle weakness. However, stretch combined with overload, as in eccentric contractions, is an effective stimulus for inducing physiological and neural adaptations to training. Eccentric exercise-induced adaptations include muscle hypertrophy, increased cortical activity, and changes in motor unit behavior, all of which contribute to improved muscle function. In this brief review, neuromuscular adaptations to different forms of exercise are reviewed, the positive training effects of eccentric exercise are presented, and the implications for training are considered.

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

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.

scholarly journals The effects of cocoa flavanols on indices of muscle recovery and exercise performance: a narrative review

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Liam D. Corr ◽  
Adam Field ◽  
Deborah Pufal ◽  
Tom Clifford ◽  
Liam D. Harper ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Muscle Damage ◽  
Exercise Performance ◽  
Muscle Function ◽  
Muscle Soreness ◽  
Narrative Review ◽  
Muscle Recovery ◽  
Exercise Induced ◽  
The Impact ◽  
Cocoa Flavanols

Abstract Exercise-induced muscle damage (EIMD) is associated with oxidative stress and inflammation, muscle soreness, and reductions in muscle function. Cocoa flavanols (CF) are (poly)phenols with antioxidant and anti-inflammatory effects and thus may attenuate symptoms of EIMD. The purpose of this narrative review was to collate and evaluate the current literature investigating the effect of CF supplementation on markers of exercise-induced oxidative stress and inflammation, as well as changes in muscle function, perceived soreness, and exercise performance. Acute and sub-chronic intake of CF reduces oxidative stress resulting from exercise. Evidence for the effect of CF on exercise-induced inflammation is lacking and the impact on muscle function, perceived soreness and exercise performance is inconsistent across studies. Supplementation of CF may reduce exercise-induced oxidative stress, with potential for delaying fatigue, but more evidence is required for any definitive conclusions on the impact of CF on markers of EIMD. Graphic abstract

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