Creatine Phosphokinase and Urea as Biochemical Markers of Muscle Injuries in Professional Football Players

Abstract

Background: Although biochemical markers have been used to monitor training loads (TL), it is unknown if they can be used to predict muscle injuries (MI) in professional football (soccer) players (PFP). Objectives: To evaluate the relationship between the incidence of MI, serum concentration of creatine phosphokinase (CPK) and urea, as well as TL in PFP. Methods: Twenty-three PFP from a Colombian first-division team were enrolled in a retrospective cohort study. CPK, urea, TL and new MI were measured during 19 weeks. CPK and urea serum levels within 4 weeks before a diagnosed MI were compared to those measured preseason. CPK and urea relationship with TL were analyzed using a mixed-effects model. Results: The subjects had an age of 25.3 ± 4.2 years. Nine subjects presented with MI during follow-up, 66.6% of which were localized to hamstrings. Serum CPK and urea profiles were constructed for each player along the season. Injured players had a significant elevation of these markers within 4 weeks before the injury was clinically evident when compared to their own preseason values. Expected individual increases in CPK and urea according to TL during the season were estimated. Conclusions: Since CPK and urea values rose several weeks before the MI became overt, constructing CPK and urea profiles for each player during the whole preseason and season may help identify peaks in their concentration as early markers of MI. A tight biochemical control of training may become a preventive strategy for MI, but the use of published reference values is discouraged.

Exercise-associated muscle cramps and creatine kinase responses after workload spikes in a professional soccer player: a case study

“…Thus, when recording and interpreting the level of muscle damage from CK concentrations, the occurrence of any EAMC episode should be noted as a factor that may interfere. Another caution to be considered would be the training workload that an athlete can tolerate on the days following an EAMC episode because if they are exposed to an inadequate training workload on the days after an EAMC episode, the probabilities of another EAMC episode [5,9,14] and other injuries [11] may be importantly increased.…”

“…EAMCs can result in increased skeletal muscle damage [9], which, in turn, raises the permeability of the plasmatic membrane, therefore releasing creatine kinase (CK) into the bloodstream [10]. The monitoring of CK concentrations in soccer players is a common practice because of its association with muscle damage and injury [11]. Some previous evidence suggested that EAMC could increase muscle damage [9], which has been largely associated with changes in CK concentrations after soccer activities [12].…”