Muscle damage induced by stretch-shortening cycle exercise.
OBJECTIVE
Strenuous stretch-shortening cycle exercise was used as a model to study the leakage of proteins from skeletal muscle.


METHODS
The analysis included serum levels of creatine kinase (S-CK), myoglobin (S-Mb), and carbonic anhydrase (S-CA III). Blood samples from power- (N=11) and endurance-trained (N=10) athletes were collected before, 0, and 2 h after the exercise, which consisted of a total of 400 jumps.


RESULTS
The levels of all determined myocellular proteins increased immediately after the exercise (P < 0.05-0.001) among both subject groups. In the endurance group, the protein levels increased (P < 0.05-0.001) further during the following 2 h after the exercise, and the ratio of S-CA III and S-Mb decreased (P < 0.05) in a before-after comparison. This was not the case among the power group despite their greater mechanical work (P < 0.001) and higher ratio of eccentric and concentric EMG activity of the leg extensor muscles (P < 0.05).


CONCLUSIONS
The differences of the determined protein levels between the subject groups might be due to obvious differences in the muscle fiber distribution, differences in recruitment order of motor units, and/or differences in training background.
Kyröläinen
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Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, Finland. heikki@maila.jyu.fi
Takala
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TE
Komi
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PV
D000328:Adult; D000704:Analysis of Variance; D001265:Athletic Injuries / Q000097:blood*; D001696:Biomechanical Phenomena; D002256:Carbonic Anhydrases / Q000097:blood*; D003402:Creatine Kinase / Q000097:blood*; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D006801:Humans; D018482:Muscle, Skeletal / Q000293:injuries*; D009211:Myoglobin / Q000097:blood*; D013314:Stress, Mechanical
D009211:Myoglobin; D003402:Creatine Kinase; D002256:Carbonic Anhydrases