Biochemical Response Comparisons of a Competitive Microcycle Vs. Congested Fixture Periods in Elite Level European Champions League Soccer Players

Across the course of an elite soccer season, the continual training, playing demands and additional stressors imposed upon players can lead to significant changes in haematological profiles [1]. Soccer is characterized by high intensity intermittent activity patterns. Players perform numerous intensive accelerations and decelerations in conjunction with high-intensity activities including sprinting, jumping, kicking and changing direction [2,3]. Such activity can cause muscle fiber damage. In the literature, CK is commonly used to examine exercise severity and exercise-induced muscle damage [4-6]. A soccer-game impose on players to repeat high numbers of very intensive accelerations and decelerations [7] that involve both concentric and eccentric contractions of the lower limb muscles, which may induce micro damages and structure changes to the muscles [8,9]. CK values have been shown to increase between 24-48h post-competitive soccer play, and to return to baseline approximately 72h or more [10-13], however, interestingly the variation across a typical competitive week of CK values linked to training load (TL) distribution have to date not been investigated. The presence of muscle damage after a soccer match could potentially impair subsequent training and competition performances, however further research is needed.