engleski

Skeletal muscle contraction time is an important factor in the muscle damage response in kickboxing athletes

Background and Study Aim: Combat sports athletes strive to improve their muscle performance, however, they also habitually attempt to reduce their body-mass before the competition voluntarily. The cognitive purpose of this study was the knowledge about combined effects of voluntary body-mass loss and the influence of exercise induced muscle damage (EIMD) markers on the mechanical muscle properties in real-life settings. Materials and Methods: Ten elite kickboxing athletes (all males, age 22.1 +/- 4.1 years) were tested at the beginning of the tapering period (t-1) and two days before the competition (t-2). Muscle mechanical properties (contraction time Tc ; the maximum amplitude of radial displacement Dm) of the biceps femoris (BF), vastus lateralis (VL) and vastus medialis (VM) of each athlete's dominant leg were assessed using tensiomyography, while blood and urine samples were collected to address biochemical response and hydration status. Results: Body-mass decreased by -1.3%, plasma volume decreased -0.9 +/- 1.5%, while EIMD markers decreased by -74.4% and -29.4% (p< 0.05) for creatine kinase (CK) and lactate dehydrogenases (LDH), respectively. Tc of the VL and BF decreased by -22.2% and -9.9% (p< 0.001), respectively, while the Dm decreased only in BF by -20.7% (p< 0.001). This study also found a moderate correlation between the average Tc of all three muscles and the CK activity (rs= -0.70 ; p= 0.03). Conclusions: Apparently, after a tapering period that was paralleled by gradual body-mass loss, kick boxers decreased their EIMD markers and improved their contractile muscle performance. According to present correlation findings, Tensiomyography assessment could be used as a surrogate method to denote local muscle fatigue. However, these data also suggest that the CK activity decreases were lower in athletes with lower averaged Tc, an indirect measure of myosin heavy chain type-I proportion

blood analysis ; combat sports athletes ; contractile characteristics ; hydration ; muscle function ; training load

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