Changes in serum creatine kinase, lactate dehydrogenase and aldolase activities following supramaximal exercise in athletes.

While it is well known that prolonged intense exercise raises serum enzyme activities, the effects of short duration intense exercise on enzyme activity changes have not been clearly described. Three successive standard 30 s Wingate anaerobic cycle ergometer tests separated by 6-8 min rest intervals were performed by competitive male middle- and long-distance runners or cyclists (no. = 33), and matched healthy control subjects (no. = 30). Immediately before and 6 h after the tests, blood samples were before and 6 h after the tests, blood samples were taken to assess the effects of exercise on serum creatine kinase (CK), lactate dehydrogenase (LD) and aldolase (ALS) enzyme activities. Serum CK activities were found to be significantly higher in athletes than in the controls, both before and 6 hours after the test (p < 0.001), as were ALS activities (p < 0.01 before and p < 0.05 after the test), whereas LD activities were significantly higher (p < 0.05) in the athletes only after the test. Following the test, increases in LD activities (p < 0.01) were observed in athletes and rises in CK activities (p < 0.05) were seen in the controls. Significant correlations between pre- and post-exercise serum enzyme activities were established for both groups. In conclusion, following a supramaximal exercise test, increases in serum LD activities of athletes and in CK activities of controls appear to be more pronounced, and increases in serum CK, LD and ALS activities seem to depend more on the duration of exercise than on its intensity.