Anterior cruciate ligament: A brief narrative review of main risk factors for injury and re-injury.

Anterior cruciate ligament (ACL) injury is one of the main injuries in professional and amateur athletes of different sports. Hundreds of thousands of ACL ruptures occurs annually, and only 55% of the athletes return to competitive level, with a 15 times higher chance of suffering a second injury. 60% of these injuries occur without physical contact and since they occur in the acute process, they can cause joint effusion, muscle weakness and functional incapacity. In the long term, they can contribute to a premature process of osteoarthritis. This narrative review is of particular interest for clinicians, practitioners, coaches and athletes to understand the main factors that contribute to an injury and/or re-injury and thus, to optimize their training to reduce and/or prevent the risk of injury and/or reinjury of ACL. Therefore, we aimed reports a narrative overview of the literature surrounding communication and explore through a theoretical review, the main risk factors for an ACL injury and/or re-injury, as well as bringing practical and correct methods of training applications. The lack of theoretical/practical knowledge on the part of rehabilitation and/or training professionals may impair the treatment of an athlete and/or student. High-quality research that can testing different training methods approaches in randomized controlled trials is needed.

Effect of caffeine on mitochondrial biogenesis in the skeletal muscle - A narrative review.

Caffeine is one of the most widely used substances as recreational drug for performance-enhancement in sport, underpinned by a strong evidence base. Although the effects of caffeine are widely investigated within the scope of performance physiology, the molecular effects of caffeine within skeletal muscle remain unclear. Evidence from in vitro and in vivo models suggest that caffeine regulates the glucose metabolism in the skeletal muscle. Moreover, caffeine seems to stimulate CaMKII, PPARδ/ß, AMPK and PGC1α, classical markers of exercise-adaptations, including mitochondrial biogenesis and mitochondrial content. This review summarizes evidence to suggest caffeine-effects within skeletal muscle fibers, focusing on the putative role of caffeine on mitochondrial biogenesis to explore whether caffeine supplementation might be a strategy to enhance mitochondrial biogenesis.

Supra-physiological doses of testosterone affect membrane oxidation of human neutrophils monitored by the fluorescent probe C11-BODIPY58¹/59¹.

The purpose of this study was to determine the effects of supra-physiological doses of testosterone (TES) on membrane oxidation of activated human neutrophils in vitro using an innovative and sensitive technique: the real-time detection with the fluorescence probe C11-BODIPY(581/591). Methodological controls were performed with the lipid-soluble and powerful antioxidant astaxanthin at different neutrophil density cultures. Neutrophils from nine healthy young men (23.4 ± 2.5 years, 174.4 ± 7.0 cm height, and 78.3 ± 7.0 kg weight) were isolated and treated with 0.1 or 10 µM TES for 24 h and subsequently labeled with the free radical-sensitive probe C11-BODIPY(581/591) for monitoring membrane oxidation after neutrophil activation with phorbol-12-myristate-13-acetate (PMA). First-order exponential decay kinetic indicated that both 0.1 and 10 µM TES severely increased baseline membrane oxidation in non-activated human neutrophils (compared to control). However, similar kinetics of membrane oxidation were observed in control and 0.1 µM TES-treated neutrophils after PMA activation, whereas chemical activation did not alter the baseline higher rates of membrane oxidation in 10 µM TES-treated neutrophils. The data presented here support the hypothesis that TES exerts distinct effects on the membrane oxidation of human neutrophils, depending on its dose (here, 10(2) to 10(4)-fold higher than physiological levels in men) and on PMA activation of the oxidative burst. Furthermore, this paper also presents an innovative application of the free radical-sensitive probe C11-BODIPY(581/591) for monitoring (auto-induced) membrane oxidation as an important parameter of viability and, thus, responsiveness of immune cells in inflammatory processes.