Brown, Day and Donnelly (1999) Indirect evidence of human skeletal muscle damage and collagen breakdown after eccentric muscle actions

getCITED

Home Search Add Content Reports Help

Edit Publication | Edit Contributors | Delete Publication | Edit References | Edit Citations

Add to Bookstack | Show Bookstack | Change Bookstack

Indirect evidence of human skeletal muscle damage and collagen breakdown after eccentric muscle actions

Post a Comment

CONTRIBUTORS:

	Author:	Brown, S.
	Author:	Day, S.
	Author:	Donnelly, A.

JOURNAL:

Journal of Sports Sciences (JSS), 17(5), ?? - ??.

YEAR:

1999

PUB TYPE:

Journal Article

SUBJECT(S):

MUSCLE-CONTRACTION; MUSCLE; INJURY; COLLAGEN; CREATINE-KINASE

DISCIPLINE:

No discipline assigned

HTTP:

LANGUAGE:

English

PUB ID:

103-366-642 (Last edited on 2002/02/27 18:44:59 US/Mountain)

SPONSOR(S):

ABSTRACT:
Indirect markers of muscle damage and collagen breakdown were recorded for up to 9 days after a bout of concentric, followed by a bout of eccentric, muscle actions. Nine untrained participants performed two bouts of 50 maximum effort repetitions on an isokinetic dynamometer (angular velocity 1.05 rad.s-1, range of motion 1.75 rad). An initial concentric bout of muscle actions were followed by an eccentric bout 21 days later, using the same knee extensors. Concentric actions induced no changes in maximum voluntary isometric contraction force (MVC), nor induced any changes in the serum enzyme activities of creatine kinase, a lactate dehydrogenase isoenzyme (LDH-1), or alkaline phosphatase. Similarly, concentric actions induced no change in markers of collagen breakdown, namely plasma hydroxyproline and serum type 1 collagen concentration. In contrast, eccentric actions induced a 23.5 +/- 19.0 % (mean +/1 s) decrease in MVC immediately post-exercise, and increased the serum enzyme activities of creatine kinase and LDH-1 to 486 +/- 792 and 90 +/- IU.1-1 respectively on day 3 post-exercise, and to 189 +/- 159 and 96 +/- 12 IU.1-1 respectively on day 7 post-exercise. Eccentric actions induced no significant changes in plasma hydroxyproline, but increased collagen concentration on days 1 and 9 post-exercise (48.6 % and 44.3 % increases above pre-exercise on days 1 and 9 respectively; both). We conclude that eccentric but not concentric actions may result in temporary muscle damage, and that collagen breakdown may also be affected by eccentric actions. With caution, indices of collagen breakdown may be used to identify exercise-induced damage to connective tissue.

STATISTICS

Click on # to view
Citations		0
References		0
Comments		0
Quality		0/0.00
Interest		0/0.00
View(er)s		1/342

Quality
	N/A
High
	7
	6
	5
	4
	3
	2
	1
Low

Interest
	N/A
High
	7
	6
	5
	4
	3
	2
	1
Low

Prev | Next