title: Variations in serum myoglobin after a 2-min isokinetic exercise test and the effects of training.
abstract: Serum-myoglobin was measured after the completion of three different types of exercise i.e., dynamic, isometric, and isokinetic. The maximal rises in serum-myoglobin levels were 20%, 70%, and 300%, respectively. On the basis of this finding a 2-min isokinetic test was developed and standardized for the purpose of studying conditions in vivo that may affect myoglobin leakage from skeletal muscle cells. Fourteen healthy men performed the 2-min isokinetic test. Blood lactate increased on average eight times with maximal levels obtained 4 min after completed work. S-Myoglobin levels obtained 4 min after completed work. S-Myoglobin was raised approximately five times after 2 h. The rise in S-myoglobin was significantly (P less than 0.01) related to the loss in muscle strength (torque decline) during the test. After a training period of 3 weeks comprising 4 min of maximal isokinetic exercise three times a week the rise in S-myoglobin after a 2-min isokinetic test was reduced from on average 240 micrograms X 1(-1) to 96 micrograms X 1(-1) (P less than 0.001). The rise in blood lactate was not related to the variations in S-myoglobin or affected by training. The 2-min isokinetic exercise test is an easily standardized exercise test which in combination with measurements of serum-myoglobin should prove valuable in the study of conditions affecting leakage from muscle cells.
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000328:Adult; D005080:Exercise Test; D006801:Humans; D007537:Isometric Contraction; D007773:Lactates / Q000097:blood; D019344:Lactic Acid; D008297:Male; D008954:Models, Biological; D009119:Muscle Contraction; D009132:Muscles / Q000378:metabolism; D009211:Myoglobin / Q000097:blood* / Q000378:metabolism; D010806:Physical Education and Training; D005082:Physical Exertion
chemical_list: D007773:Lactates; D009211:Myoglobin; D019344:Lactic Acid; D000255:Adenosine Triphosphate