Serum creatine kinase and lactate dehydrogenase changes following an eighty kilometer race. Relationship to lipid peroxidation.

Pre and post race serum malondialdehyde (MDA), creatine kinase (CK) and lactate dehydrogenase (LDH) levels were studied in runners following an 80 km (50 mile) race. MDA is an indicator of lipid peroxidation. Subjects averaged 47.4 years (range 35-60), had a mean maximal oxygen uptake (VO2max) of 48.2 ml/kg, and averaged 121 km (75 miles) per week in training. Throughout the race, runners maintained a pace approximating 72% of VO2max. Previous data from our laboratory indicated a high correlation between resting MDA and total CK and CK-MB. Present resting data confirms prior results (r = 0.84 and 0.69 respectively). In addition, the relationship established at rest persisted following exercise (r = 0.62 and 0.85 respectively). Post race CK, CK-MB, LDH and MDA values for all subjects were significantly greater than resting values (p less than 0.01). Mean post CK and CK-MB levels were nearly 10 and 4 times lower, respectively, than prior values from our laboratory in subjects following a 100 km (62 mile) race. It was concluded that post exercise serum enzyme elevations, universally accepted as a marker of tissue damage, correlate well and may be related to an exercise induced lipid peroxidation.