Comparison of the inflammatory and stress response between sprint interval swimming and running.

The aim of the study was to compare myocellular damage, metabolic stress, and inflammatory responses as well as circulating sodium (Na+ ) and potassium (K+ ) between a single sprint swimming and running training. Eighteen subjects regularly involved in swimming and running training for at least 2 years were recruited. The subjects performed 8 × 30 seconds "all out" exercise on different days either by running or by swimming in a random order. Blood was collected before each training session, after the cessation of exercise (post) and after 2 hours of rest (2 hours). We then analyzed tumor necrosis factor alpha (TNF-α), interleukin 10 (IL-10), interleukin 6 (IL-6), cortisol, creatine kinase MB isoform (CK-MB), lactate dehydrogenase (LDH), K+ , and Na+ . Neither TNF-α nor IL-10 differed between swimming and running. Most of the subjects showed a non-statistically significant increase of LDH and CK-MB after swimming. On the other hand, IL-6 (P < .05) and cortisol (P < .05) were significantly lower after 2 hours of swimming than after running. In addition, post-exercise K+ was significantly lower (P < .001) for swimming than for running. Our results provide evidence of similar inflammatory responses between exercise modes but lower metabolic stress in response to swimming than in response to running.

Influencia de la práctica deportiva sobre la huella plantar en atletas españoles / Influence of sport practice on the footprint in Spanish athletes

El objetivo de este estudio fue conocer la asociación entre el entrenamiento de atletas con las características de cada pie. Se midieron y compararon las huellas plantares de tres grupos de deportistas (28 velocistas, 29 fondistas, 47 nadadores) y de 67 sujetos no entrenados (GC). Para la captura de parámetros plantares se empleó una plataforma de escaneado podálico Podoscanalycer®. El índice podálico, metatarsal, medio podálico, y calcáneo fue inferior en GC respecto a corredores de velocidad, fondo, y nadadores (p<0.001). El riesgo relativo de tener un pie cavo o un tipo de pié específico por pertenecer a una determinada modalidad atlética no resulto significativo (todos p>0.05). Se concluye que los años de entrenamiento y la edad en atletas españoles no se asocian significativamente con la curvatura y tipología del pie ni sobre ningún índice plantar específico. Sin embargo, sexo e IMC se asocia significativamente con los índices plantares según la modalidad atlética (AU)

The aim of the present study was to determine the association between athletic training and characteristics of each foot. Plantar foot print of three groups of athletes (28 sprinters, 29 distance runners, 47 swimmers) and 67 sedentary subjects (CG) were measured and compared. A scanning platform breech Podoscanalyzer was employed to obtain plantar pressure measurements. The breech, metatarsal, middle breech, and calcaneus index, were lower in CG compared to sprinters, long-distance runners, and swimmers (p<0.001). The relative risk of having a cavus foot or any specific type of foot as a result of practicing a particular athletic discipline was not significant (all p>0.05). We conclude that the years of training and the age are not significantly associated neither with the curvature and the type of the foot nor with any specific plantar arch index in Spanish athletes. Nevertheless, sex and BMI are significantly associated with the plantar arch indexes according to the athletic discipline (AU)

Impact of limited hamstring flexibility on vertical jump, kicking speed, sprint, and agility in young football players.

This study aims to analyse the impact of limited hamstring flexibility (HF) on specific football skills, such as sprinting and jumping ability, agility, and kicking speed in young football players. Forty-three male football players (aged 14-18) from a semi-professional football academy participated voluntarily in this study. Data about anthropometric measurements, HF (unilateral passive straight-leg raise test: PSLR), vertical jumping ability (countermovement jump: CMJ), sprinting ability (5, 10, 20 m: S5 m, S10 m, S20 m), agility (Balsom agility test: BAT), and kicking speed in terms of ball speed (dominant and non-dominant leg: KSdom and KSnon-dom) were collected. Cluster analysis grouped according to HF, dividing participants into a flexible group (FG, n = 24) and a non-flexible group (NFG, n = 19) in relation to performances on the PSLR test. Despite finding no significant differences between groups in body composition and age, the FG performed better in terms of sprint scores (S5 m: 6.12%, S10 m: 4.09%, S20 m: 3.29%), BAT score (4.11%), CMJ score (10.49%), and scores for KSdom (6.86%) and KSnon-dom (8%) than the NFG. The results suggest that HF is a key factor for performing football-specific skills, such as sprinting, jumping, agility, and kicking in young football players. These results support the rationale that muscle flexibility must be specifically trained in football players beginning at early ages.