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 en zyme activities, the effects of short duration intense exercise on enz yme 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 lo ng-distance runners or cyclists (no. = 33), and matched healthy contro l subjects (no. = 30). Immediately before and 6 h after the tests, blo od samples were taken to assess the effects of exercise on serum creat ine 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 te st (p < 0.001), as were ALS activities (p < 0.01 before and p < 0.05 a fter the test), whereas LD activities were significantly higher (p < 0 .05) in the athletes only after the test. Following the test, increase s in LD activities (p < 0.01) were observed in athletes and rises in C K activities (p < 0.05) were seen in the controls. Significant correla tions between pre- and post-exercise serum enzyme activities were esta blished for both groups. In conclusion, following a supramaximal exerc ise test, increases in serum LD activities of athletes and in CK activ ities of controls appear to be more pronounced, and increases in serum CK, LD and ALS activities seem to depend more on the duration of exer cise than on its intensity.