The Effects of a Long Distance Run on Creatine Kinase Levels 24, 48, and 72 Hours Post-Run

Distance runners often complete a long duration run in their regular training program. This training run may cause muscle damage. Creatine Kinase (CK), an enzyme in the blood, is a marker of muscle damage. Delayed onset muscle soreness (DOMS) often accompanies elevations in CK. Together, these variable may negatively affect a runner’s performance. PURPOSE: To determine whether a long distance run evokes DOMS and increased CK levels. METHODS: Subjects (n=10) were recruited from various running clubs around the Seacoast area and visited the lab 5 times. Visits 1,3, 4 and 5 involved flexibility, muscle power, and muscle soreness tests, as well as a blood draw to measure CK levels. Visit 2 involved a 16 mile road run through Durham and Dover. RESULTS: A repeated measures ANOVA analysis of the Creatine Kinase values revealed that CK was significantly higher (p=0.0053) 24 and 48 hours post run. Although it was not significant, CK levels were still increased at 72 hours. DOMS was not significant at any time post run. CONCLUSIONS: The results from this study show that CK levels are in fact increased 24 and 48 hours after a 16 mile run, suggesting muscle damage. However, the muscle damage that takes place is not enough to elicit a DOMS reaction