TECHNICAL AND PHYSIOLOGICAL RESPONSES OF SWIMMING CRAWLSTROKE USING HAND PADDLES, FINS AND SNORKEL IN SWIMMING FLUME: A PILOT STUDY

We evaluated the effect on front-crawl during a 5 minutes effort in a swimming flume, at a speed 95% of 400m wearing swimming paddles, fins or frontal snorkel. It was evaluated measuring changes on stroke frequency, stroke length, ERP, lactate concentration and pulse rate post-effort. An one-way repeated measures ANOVA showed the stroke frequency was significantly affected F(2.3, 27.6) = 20.69

Postactivation potentiation on 50-meter freestyle

Postactivation potentiation (PAP) is a phenomenon which improves muscle contractility, strength and speed in sporting performances through previously applied maximal or submaximal loads on the muscle system. This study aimed to assess the effects of two types of activation protocols based on PAP, on sprint swimming performance. A repeated-measures design was used to compare three different scenarios prior to a 50-m race. First, all of the participants performed a standard warm-up (SWU), consisting of a 400-m swim followed by dynamic stretching. This protocol acted as the control. Subsequently, the swimmers were randomly assigned into two groups: the swimmers in the first group performed the SWU followed by a PAP one-repetition warm-up (RMWU), consisting of three “lunge” and three “arm stroke” repetitions, both at 85% of the one-repetition maximum. The swimmers in the second group performed the SWU followed by a PAP eccentric flywheel warm-up (EWU), consisting of one set of four repetitions of exercises of both the lower and upper limbs on an adapted eccentric flywheel at the maximal voluntary contraction. The time required for the swimmers to swim 5 and 10 m was shorter with the PAP protocols. The swimming velocity of the swimmers who underwent the EWU and RMWU protocols were faster at 5 and 10 m. The best total swimming time was not influenced by any of the protocols. When isolating swimming (excluding start performance and turn), best time was achieved with the SWU and RMWU compared with EWU (SWU: 20.86 ± 0.95 s; EWU: 21.25 ± 1.12 s; RMWU: 20.97 ± 1.22 s). In conclusion, a warm up based on PAP protocols might exert an influence on performance in the first meters of a 50-m race. Nevertheless, other factors, such as fatigue, could modify swimming patterns and yield results contradictory to those of the desired task.CTS-527: Actividad física y deportiva en el medio acuátic

SHORT COURSE 50M MALE FREESTYLE PERFORMANCE COMPARISON BETWEEN NATIONAL AND REGIONAL SPANISH SWIMMERS

We aimed to analyse and compare the race components of national (47) and regional (158) male swimmers taking part in 50 m freestyle short course event. The relative contribution of each component, the split differences and relative splits were considered. A swimming race analysis system and an automatic swimming performance analysis (ASPA) were applied in the study. National male swimmers obtained significantly shorter times than regional: T10, 3.65 ± 0.14 s vs 4.56 ± 0.43 s; T15, 6.11 ± 0.18 s vs 7.47 ± 0.62 s; TTV15m, 6.99 ± 0.22 s vs 8.42 ± 0.71 s; T50, 23.25 ± 0.57 s vs 27.70 ± 2.16 s; higher SR (cyc•min-1) 60.2 ± 4.13 vs 57.6 ± 5.51; longer SL(m) 1.97 ± 0.15 vs 1.78 ± 0.15; and higher SI(m2•s-1) 3.89 ± 0.36 vs 3.011 ± 0.37. Differences in performances between national and regional Spanish groups were explained by the absolute split times, stroke length and stroke index. These differences were not found analysing the relative splits and indicates a similar race strategy regardless of the swimmers level

Extracellular vesicles from pristane-treated CD38-deficient mice express an antiinflammatory neutrophil protein signature, which reflects the mild lupus severity elicited in these mice

In CD38-deficient (Cd38-/-) mice intraperitoneal injection of pristane induces a lupus-like disease, which is milder than that induced in WT mice, showing significant differences in the inflammatory and autoimmune processes triggered by pristane. Extracellular vesicles (EV) are present in all body fluids. Shed by cells, their molecular make-up reflects that of their cell of origin and/or tissue pathological situation. The aim of this study was to analyze the protein composition, protein abundance, and functional clustering of EV released by peritoneal exudate cells (PECs) in the pristane experimental lupus model, to identify predictive or diagnostic biomarkers that might discriminate the autoimmune process in lupus from inflammatory reactions and/or normal physiological processes. In this study, thanks to an extensive proteomic analysis and powerful bioinformatics software, distinct EV subtypes were identified in the peritoneal exudates of pristane-treated mice: 1) small EV enriched in the tetraspanin CD63 and CD9, which are likely of exosomal origin; 2) small EV enriched in CD47 and CD9, which are also enriched in plasma-membrane, membrane-associated proteins, with an ectosomal origin; 3) small EV enriched in keratins, ECM proteins, complement/coagulation proteins, fibrin clot formation proteins, and endopetidase inhibitor proteins. This enrichment may have an inflammation-mediated mesothelial-tomesenchymal transition origin, representing a protein corona on the surface of peritoneal exudate EV; 4) HDL-enriched lipoprotein particles. Quantitative proteomic analysis allowed us to identify an anti-inflammatory, Annexin A1- enriched pro-resolving, neutrophil protein signature, which was more prominent in EV from pristane-treated Cd38-/- mice, and quantitative differences in the protein cargo of the ECM-enriched EV from Cd38-/- vs WT mice. These differences are likely to be related with the distinct inflammatory outcome shown by Cd38-/- vs WT mice in response to pristane treatment. Our results demonstrate the power of a hypothesis-free and data-driven approach to transform the heterogeneity of the peritoneal exudate EV from pristanetreated mice in valuable information about the relative proportion of different EV in a given sample and to identify potential protein markers specific for the different small EV subtypes, in particular those proteins defining EV involved in the resolution phase of chronic inflammation.Proyecto del plan estatal, Ministerio de Ciencia e Innovacion PT13/0001/011CSIC PT17/0019/0010 PID2020-119567RB-I0