Using blood lactate concentration to predict muscle damage and jump performance response to maximal stretch-shortening cycle exercise.

BACKGROUND

It is well known that eccentric muscle contractions induce delayed onset muscle soreness (DOMS) and exertional rhabdomyolysis (ERB), both of which are related to high blood levels of muscle damage markers after exercise. Creatine kinase (CK) is, together with some other markers (i.e. myoglobin, α-actin, skeletal troponin), widely used in determination of muscle damage. Moreover, DOMS after eccentric exercise has been shown to be associated with altered blood lactate concentration after subsequent submaximal or maximal cycling exercise. However, it is unknown whether blood lactate can predict muscle damage levels after maximal stretch-shortening cycle (SSC) exercise, as due to the differences in types of contractions between the eccentric and SSC protocol. Additionally, we determined the association between blood lactate concentration and CMJ performance after such a protocol.

METHODS

Forty-three healthy, physically active young men completed a plyometric training session consisting of maximal countermovement jumps (CMJ) to failure. The blood creatine kinase (CK), myoglobin (Mb) and aspartate aminotransferase (AST) samples were taken pre- and 48 hours post-exercise. Blood lactate concentration was determined directly post-exercise.

RESULTS

There was a significant correlation between blood lactate concentration (post) and blood CK (P=0.027), Mb (P=0.007) and AST (P=0.024) (48 hours post), which means that higher blood lactate concentration is associated with higher muscle damage values after exercise. No correlation was found between blood lactate concentration (post) and performance loss which was expressed by the decrease in maximum CMJ height 5 minutes post-exercise.

CONCLUSIONS

Blood lactate concentration could be used as a predictor of muscle damage levels after maximal SSC exercise, which supports the results found in other studies, although after eccentric exercise. However, it cannot predict acute performance loss in jump height.