Myofibrillar Damage Following Intense Eccentric Exercise in Man

Fridén, Jan; Sjöstróm, Michael; Ekblom, Björn

doi:10.1055/s-2008-1026030

Cited by 887 publications

(661 citation statements)

References 25 publications

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“…The present study used a cycling protocol that had previously been shown by Thomson et al ( 1979 ) to cause 95 % glycogen depletion in type I fibres in healthy men after 2 h. Assuming similar type I glycogen depletion occurred in this study, our participants would be expected to commence the RED downhill run, recruiting predominantly type II fibres, which are more prone to eccentric induced muscle damage (Fridén et al 1983 ). This would agree with an earlier study (Krustrup et al 2004 ), in which slow twitch fibre depletion led to greater fast twitch fibre recruitment and O for subsequent cycling exercise.…”

Section: Discussionmentioning

confidence: 82%

The effect of glycogen reduction on cardiorespiratory and metabolic responses during downhill running

2015

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PurposeExercise induced muscle damage and lowered glycogen are common during heavy training periods, and may prolong recovery. We examined the effects of lowered glycogen on cardiorespiratory, metabolic and perceptual responses to downhill running. AQ1 MethodsTwelve men performed two downhill runs (−12 % gradient, 12.1 ± 1.1 km h ) separated by 6 weeks, under normal (NORM) and reduced glycogen (RED) conditions in a crossover design. For RED, participants performed exhaustive cycling at 60 % O power (95 ± 13 min) in the evening, and the next morning completed a downhill run comprising of five stages of 8 min running, with 2 min recovery (1 % gradient, 8 km h ) between each stage. Expired gas, heart rate, rating of perceived exertion (RPE) and blood lactate (bLa) and glucose were measured for each stage.

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Section: Discussionmentioning

confidence: 82%

The effect of glycogen reduction on cardiorespiratory and metabolic responses during downhill running

2015

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“…Αμέσως μετά από την έκκεντρη άσκηση παρατηρείται διατάραξη των σαρκομερίων μέσα στα μυοϊνίδια, διαταραχές στην ευθυγράμμιση των γραμμών Ζ, βλάβες στα Τ σωληνάρια και αποδιοργάνωση των μυονηματίων (Brown & Hill, 1991;Close, Ashton, McArdle, & Maclaren, 2005;Friden, 1984;Friden, Sjostrom, & Ekblom, 1983). Πιο συγκεκριμένα, κατά την έκκεντρη συστολή του μυός, διατείνονται περισσότερο τα πιο αδύναμα σαρκομέρια των μυοϊνιδίων (Friden, et al, 1983).…”

Section: έκκεντρη άσκηση και μυϊκή βλάβηunclassified

“…Πιο συγκεκριμένα, κατά την έκκεντρη συστολή του μυός, διατείνονται περισσότερο τα πιο αδύναμα σαρκομέρια των μυοϊνιδίων (Friden, et al, 1983). Αποτέλεσμα αυτού είναι τα συγκεκριμένα μυοϊνίδια να γίνονται σταδιακά ασθενέστερα (Stauber, 1989) και όταν φτάσουν στο οριακό τους σημείο, να διαταθούν απότομα και ανεξέλεγκτα χωρίς να υπάρχει αλληλοκάλυψη μεταξύ της ακτίνης και της μυοσίνης.…”

Section: έκκεντρη άσκηση και μυϊκή βλάβηunclassified

“…Μερικά όμως από αυτά τα σαρκομέρια αποτυγχάνουν να επανέλθουν στο φυσιολογικό τους μήκος και καταστρέφονται (Brown & Hill, 1991;Friden, et al, 1983;McCully & Faulkner, 1985;Newham, et al, 1983) με παράλληλη ανεξέλεγκτη είσοδο ασβεστίου στο σαρκόπλασμα (McCully & Faulkner, 1985;Proske & Allen, 2005). Κατά τη διάρκεια επαναλαμβανόμενων έκκεντρων συστολών ο αριθμός των κατεστραμμένων σαρκομερίων μεγαλώνει μέχρι το σημείο όπου έχουμε καταστροφή σημαντικού αριθμού μυϊκών κυττάρων και συνεπώς πρόκληση μυϊκής βλάβης.…”

Section: έκκεντρη άσκηση και μυϊκή βλάβηunclassified

“…Συνεπώς, μπορεί να ειπωθεί ότι η μείωση που παρουσιάστηκε στην ολική χοληστερόλη και στην LDL χοληστερόλη οφείλεται στην εκροή της χοληστερόλης από το πλάσμα στο μυ, παρέχοντας έτσι ένα υπόστρωμα για τη σύνθεση νέων κυτταρικών μεμβρανών μετά τη μυϊκή βλάβη που προήλθε από την έκκεντρη άσκηση. Αυτό ενισχύεται και από το γεγονός ότι τα σημάδια αναδόμησης των μυϊκών κυττάρων αρχίζουν να εμφανίζονται μετά τις πρώτες 36 ώρες από το τέλος της άσκησης (Friden, et al, 1983). Επομένως, μετά και την τελευταία συνεδρία όπου η μυϊκή βλάβη ήταν σημαντικά περιορισμένη σε σχέση με την 1 η συνεδρία, η μείωση που παρουσιάστηκε στη ολική χοληστερόλη και στην LDL χοληστερόλη ήταν επίσης περιορισμένη αφού μικρότερη ποσότητα χοληστερόλης και φωσφολιπιδίων χρειάζεται για την αναγέννηση του κατεστραμμένου μυϊκού ιστού.…”

Section: επίδραση της άσκησηςunclassified

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Η Επίδραση Της Έκκεντρης Προπόνησης Σε Δείκτες Μυϊκής Βλάβης Και Οξειδωτικού Στρες

Θεοδώρου¹

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Anastasios A. Theodorou : The effect of eccentric training on muscle damage and redox status indices (Under the supervision of Athanasios Jamurtas, Assistand Professor)Antioxidant supplementation is quite often among athletes in an attempt to counteract the increased production of free radicals during exercise and especially after exerciseinduced muscle damage (eccentric). Recently an increasing number of studies reported negative effects of antioxidant supplementation on the training and cellular adaptations to chronic exercise. The aim of the present study was to investigate the effects of vitamin C and E supplementation on muscle performance, blood and muscle redox status, hemolysis and blood lipid profile in both trained and untrained individuals after acute and chronic exercise. After previous investigations of our group, a specific type of exercise was applied (eccentric) in order to produce long lasting and extensive changes in all biomarkers and examine more easily any effects of antioxidant supplementation. In a double-blinded fashion, participants received either a daily oral supplementation of vitamin C and vitamin E (n=14) or placebo (n=14) for eleven weeks. Following baseline tests, volunteers performed an eccentric exercise session two times per week for four weeks. Before and after the chronic eccentric exercise volunteers were subjected to one session of acute eccentric exercise, and physiological measurements were performed as well as blood samples and muscle biopsies (from 8 participants) were collected. The present results failed to support any effect of antioxidant supplementation; eccentric exercise similarly modified muscle damage and performance, blood redox status, hemolysis and lipid profile in both supplemented and non-supplemented groups. This is despite the fact that eccentric exercise induced marked changes in muscle damage and performance as well as redox status and lipid profile for several days after exercise. The complete lack of any effect on the physiological and biochemical outcome measures employed questions the validity of using orally antioxidant supplementation as redox modulators of muscle and redox status in healthy humans. Moreover, the lack of any effect of antioxidant supplementation on training and cellural adaptation to exercise observed in this study, opposed previous studies suggesting that antioxidant may block training adaptations.

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Lack of effect of combined low intensity laser therapy/phototherapy (CLILT) on delayed onset muscle soreness in humans

Barron

Walsh

et al. 1999

Lasers Surg. Med.

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Background and Objectives This study, which was approved by the University's Ethical committee, was conducted to investigate the effectiveness of Combined Low Intensity Laser Therapy/Phototherapy (CLILT) in alleviating the signs and symptoms of Delayed Onset Muscle Soreness (DOMS) over an 11‐day period. Study Design/Materials and Methods Thirty‐six subjects (18 M:18 F) were randomly allocated, under strictly controlled double‐blind conditions, to one of three experimental conditions: Control, Placebo, and CLILT (660–950 nm; 11 J/cm2; pulsed at 73 Hz). DOMS was induced in a standardised fashion in the non‐dominant elbow flexors using repeated eccentric contractions until exhaustion was reached. Subjects returned on five consecutive days, and two days during the following week, for treatment according to group, and assessment of outcome variables including range of motion, pain, and tenderness. Results While analysis of results using repeated measures and one factor ANOVA with post‐hoc tests showed significant changes in all variables over time (P < 0.05) as a result of the induction procedure, there were no significant differences observed between groups. Conclusions CLILT failed to show any beneficial treatment effect on DOMS, at least at the parameters used here. These results therefore provide no evidence for the claimed biostimulating effects of such therapy. Lasers Surg. Med. 24:223–230, 1999. © 1999 Wiley‐Liss, Inc.

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Myofibrillar Damage Following Intense Eccentric Exercise in Man

Cited by 887 publications

References 25 publications

The effect of glycogen reduction on cardiorespiratory and metabolic responses during downhill running

The effect of glycogen reduction on cardiorespiratory and metabolic responses during downhill running

Η Επίδραση Της Έκκεντρης Προπόνησης Σε Δείκτες Μυϊκής Βλάβης Και Οξειδωτικού Στρες

Lack of effect of combined low intensity laser therapy/phototherapy (CLILT) on delayed onset muscle soreness in humans

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