Does fatigue affect the kinematics of endurance running? / ¿Afecta la fatiga a la cinemática de la carrera de resistencia?

The purpose of this study was to determine the foot strike pattern (FSP), inversion (INV) and spatial-temporal variables in a large sample of recreational runners during a long-distance competition, according to sex and changes in the classification race. A total of 368 men and 67 women, who participated in the XVII International Half Marathon of Cordoba (Spain) were analysed. It was recorded at km 5 and km 15, where high-speed camcorder and 2D-photogrammetric techniques were used to measure FSP, INV, contact time (CT) and flight time (FT). The group that worsened their classification at km 15 increase RFS prevalence and INV asymmetry. A Pearson analysis indicates that variation of the classification in the race between the marks km 5 and km 15 is related with CT (r=0.429, p<0.001) and FT (r=-0.360, p<0.001). RFS prevalence and spatial-temporal parameters showed different patterns depending on whether the runners improved or worsened their ranking. (AU)

El objetivo de este estudio fue determinar el patrón de pisada, inversión y variables espaciotemporales para una amplia muestra de corredores amateurs, durante una carrera de larga distancia, según sexo y posición de clasificación. Se analizaron 368 hombres y 67 mujeres, que participaron en la XVII Media Maratón Internacional de Córdoba (España). Se registró el km 5 y km 15, utilizando técnicas de fotogrametría 2D de alta velocidad para medir la pisada, la inversión, el tiempo de contacto (TC) y el tiempo de vuelo (TV). El grupo que empeoró su clasificación en el km 15 aumentó la prevalencia de FSP y la asimetría del INV. Un análisis de Pearson indica que la variación de la clasificación en la carrera está relacionada con TC (r=0,429, p<0,001) y TV (r=-0,360, p<0,001). La prevalencia de retropié y los parámetros espaciotemporales mostraron diferentes patrones dependiendo de si los corredores mejoraron o empeoraron su clasificación. (AU)

Asociación entre función ejecutiva, madurez intelectual y condición física en niños preescolares / Association between Executive Function, Intellectual Maturity and Physical Fitness in Preschool Children

El objetivo principal de este estudio fue conocer el perfil evolutivo de la función ejecutiva (FE) y la madurez intelectual (MI) en relación con la condición físico-motora en niños preescolares. Han participado 81 niños, de edades comprendidas entre 3 a 6 años, 44 niños y 37 niñas. Se realizaron pruebas de condición física de fuerza, equilibrio, velocidad, resistencia y tiempo de reacción. Se analizaron las FE y la MI con los test de Laberintos de Porteus y el test de Goodenough respectivamente. En la evolución de las variables cognitivas y de condición física según la edad de los niños, se observan diferencias significativas entre los grupos de edad. La velocidad de desplazamiento junto con la dinamometría manual y el tiempo de reacción son variables que se asocian a las FE y a la MI. Por tanto, existe un paralelismo evolutivo entre el desarrollo de la FE y MI con el desarrollo de la condición física

The main aim of this study is to understand the evolutionary profile of the executive function (EF) and the intellectual maturity (IM) in relation to the physical-motor condition in preschool children. A group of 81 children, 3-6 years old, participated in the project (44 boys and 37 girls). Regarding the testing protocol, tests for assessing physical fitness were included (i.e., strength, balance, speed, resistance and reaction time). The EF and the IM were analyzed with the Porteus Maze test and the Goodenough test, respectively. The results showed an age effect on both cognitive variables and physical fitness, with significant differences between those variables between age groups. Additionally, the regression analysis reported a significant association between physical fitness (i.e., sprint, handgrip strength and reaction time) and the FE and the MI. In summary, the results obtained suggest a parallelism between the EF and IM with the development of physical fitness

Effects of a physical activity programme in the school setting on physical fitness in preschool children.

AIM: The purpose of this study was to examine the effects of a 10-week aerobic games programme on physical fitness. METHODS: One hundred eleven children, aged 3 to 6 years, participated in this study; 60 children were male (age: 4.28 ± 0.61 years old), and 51 were female (age 4.59 ± 0.49 years old). Participants were randomly assigned to an experimental group (EG; n = 56) and a control group (CG; n = 55). A fitness test battery previously validated for preschoolers was used. The children in the EG performed 3 weekly training sessions of physical activity in a classroom during a 10-week period. Every EG session lasted about 30 min. RESULTS: There were no significant differences in any variable in the pretest between groups. In the posttest, the EG achieved better results in horizontal jump and sprint. In relation to posttest-pretest differences, the EG showed a greater increase in horizontal jump, sprint, and endurance. CONCLUSION: An aerobic games programme in the school setting improved physical fitness in preschool children.

Physical fitness in preschool children: association with sex, age and weight status.

BACKGROUND: Because fitness level is a potent biomarker of health from an early age, the improvements of physical fitness performance through the promotion of physical activity could be important for the health of preschool children, particularly in obesity prevention. OBJECTIVE: The purpose of this study is to determine the physical fitness in children aged 3-6 years, discriminating performance by sex, age and body mass index (BMI). METHOD: A total of 3868 children from 3 to 6 years agreed voluntarily to participate. Demographic characteristics revealed that 1961 children were male (age: 55.71 ± 11.11 months old, BMI = 16.03 ± 1.93 kg/m2 ), and 1907 were female (age 56.16 ± 0.97 months old, BMI = 15.85 ± 1.89 kg/m2 ), and they were selected from 51 schools in southern Spain. RESULTS: Significant differences were found between sexes: boys showed a greater performance on cardio respiratory endurance, reaction time, strength and running speed. We found significant differences by sex in the different age groups (3, 4, 5 and 6 years old). CONCLUSIONS: Sex differences in physical fitness are evident at an early age; in addition, the relationship between physical fitness and BMI is inconsistent in preschool children. The improvements of physical fitness performance and its association with physical activity could be important for the health of children, particularly in obesity prevention.

Acute effects of high-intensity intermittent training on kinematics and foot strike patterns in endurance runners.

The main purpose of this study was to evaluate running kinematic characteristics and foot strike patterns (FSP) during early and late stages of actual and common high-intensity intermittent training (HIIT): 5 × 2000 m with 120-s recovery between runs. Thirteen healthy, elite, highly trained male endurance runners participated in this study. They each had a personal record in the half-marathon of 70 ± 2.24 min, and each had a minimum experience of 4 years of training and competition. Heart rate (HR) and rate of perceived exertion (RPE) were monitored during HIIT. High levels of exhaustion were reached by the athletes during HIIT (HRpeak: 174.30 bpm; RPE: 17.23). There was a significant increase of HRpeak and RPE during HIIT; nevertheless, time for each run remained unchanged. A within-protocol paired t-test (first vs. last run) revealed no significant changes (P ≥ 0.05) in kinematics variables and FSP variables during HIIT. There were no substantial changes on kinematics and FSP characteristics in endurance runners after fatigue induced by a HIIT. Only the minimum ankle alignment showed a significant change. The author suggests that these results might be due to both the high athletic level of participants and their experience in HIIT.

The Utility of a High-intensity Exercise Protocol to Prospectively Assess ACL Injury Risk.

This study investigated the utility of a 5-min high-intensity exercise protocol (SAFT(5)) to include in prospective cohort studies investigating ACL injury risk. 15 active females were tested on 2 occasions during which their non-dominant leg was analysed before SAFT(5) (PRE), immediately after (POST0), 15 min after (POST15), and 30 min after (POST30). On the first occasion, testing included 5 maximum isokinetic contractions for eccentric and concentric hamstring and concentric quadriceps and on the second occasion, 3 trials of 2 landing tasks (i. e., single-leg hop and drop vertical jump) were conducted. Results showed a reduced eccentric hamstring peak torque at POST0, POST15 and POST30 (p<0.05) and a reduced functional HQ ratio (Hecc/Qcon) at POST15 and POST30 (p<0.05). Additionally, a more extended knee angle at POST30 (p<0.05) and increased knee internal rotation angle at POST0 and POST15 (p<0.05) were found in a single-leg hop. SAFT(5) altered landing strategies associated with increased ACL injury risk and similar to observations from match simulations. Our findings therefore support the utility of a high-intensity exercise protocol such as SAFT(5) to strengthen injury screening tests and to include in prospective cohort studies where time constraints apply.

Influence of shod/unshod condition and running speed on foot-strike patterns, inversion/eversion, and vertical foot rotation in endurance runners.

The aim of this study was to determine the influence of barefoot running on foot-strike patterns, eversion-inversion, running speed and vertical foot rotation in endurance runners. Eighty healthy recreational runners (age = 34.11 ± 12.95 years old, body mass index = 22.56 ± 2.65 kg · m(-2)) performed trials in shod/unshod running conditions on a treadmill at comfortable and competitive self-selected speeds. Data were collected by systematic observation of lateral and back recordings at 240 Hz. McNemar's test indicated significant differences between shod/unshod conditions and foot strike at comfortable and competitive speeds (P < 0.001). Speed was related to vertical foot rotation type for shod (P < 0.01) and unshod conditions (P < 0.05). Significant differences were found between shod/unshod conditions in foot rotation at comfortable running speeds (P < 0.001) and competitive running speeds (P < 0.01). No significant difference was found in inversion or eversion (P ≥ 0.05). In conclusion, the results suggest that running kinematics, in terms of foot-strike patterns and vertical foot rotation, differ between shod/unshod conditions, while the inversion or eversion degree remains unchanged.

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.

Relationship between sex, body composition, gait speed and body satisfaction in elderly people.

UNLABELLED: The purpose of this study is to analyzebody satisfaction in non-institutionalized old people and its association with sex, body mass index (BMI) and gait speed. METHODS: Hundred six people have participated, 38 men (age=74.60 ±6.67 years old) and 68 women (age=72.76 ±4.68 years old). The Body Shape Questionnaire (BSQ) has been used together with body composition and a gait speed test. RESULTS: Prevalence of body dissatisfaction in old people is about 5.6 %. Women have higher body fat percentage and less muscle mass. Significant differences were not found (p≥0.05) in the BSQ relating with sex. Obese old people with less gait speed showed higher score in BSQ. The Total BSQ is positively correlated with BMI (r=0.487, p<0.01), fat percentage (r=0.371, p<0.01) and negatively correlated with gait speed (r=-0.215 p<0.05)and perceived health status (r=-0.269, p<0.05). CONCLUSION: Older people's body satisfaction is positively associated with the perception of health and gait speed and negatively with BMI.

El objetivo de este estudio es analizar la satisfacción corporal en personas mayores no institucionalizados y su asociación con el sexo, el índice de masa corporal (IMC) y la velocidad de la marcha. Métodos: Ciento seis personas participaron en el estudio, 38 hombres (edad =74.60 ±6.67 años) y 68 mujeres (edad =72.76 ±4.68 años). Se empleó el Cuestionario de forma física (CFF) junto con un test de la composición corporal y la velocidad de la marcha. Resultados: La prevalencia de insatisfacción corporal en ancianos se sitúa entorno al 5.6 %. Las mujeres tienen un mayor porcentaje de masa corporal y menos masa muscular. No se encontraron diferencias significativas (p≥0.05) en el CFF en relación al sexo. Los ancianos obesos con menor velocidad de la marcha mostraron un resultado superior en el CFF. El total del CFF está positivamente relacionado con el IMC (r=0.487, p.

Relationship between sex, body composition, gait speed and body satisfaction in elderly people / Relación entre sexo, composición corporal, velocidad de la marcha y satisfacción corporal en ancianos

The purpose of this study is to analyze body satisfaction in non-institutionalized old people and its association with sex, body mass index (BMI) and gait speed. Methods: Hundred six people have participated,38 men (age=74.60 ±6.67 years old) and 68 women(age=72.76 ±4.68 years old). The Body Shape Questionnaire(BSQ) has been used together with body composition and a gait speed test. Results: Prevalence of body dissatisfaction in old people is about 5.6 %. Women have higher body fat percentage and less muscle mass. Significant differences were not found (p≥0.05) in the BSQ relating with sex. Obese old people with less gait speed showed higher score in BSQ. The Total BSQ is positively correlated with BMI (r = 0.487, p < 0.01), fat percentage (r = 0.371, p < 0.01) and negatively correlated with gait speed (r = -0.215 p < 0.05) and perceived health status (r = -0.269, p < 0.05). Conclusion: Older people's body satisfaction is positively associated with the perception of health and gait speed and negatively with BMI (AU)

El objetivo de este estudio es analizar la satisfacción corporal en personas mayores no institucionalizados y su asociación con el sexo, el índice de masa corporal (IMC) y la velocidad de la marcha. Métodos: Ciento seis personas participaron en el estudio,38 hombres (edad =74.60 ±6.67 años) y 68 mujeres (edad =72.76 ±4.68 años). Se empleó el Cuestionario de forma física (CFF) junto con un test de la composición corporal y la velocidad de la marcha. Resultados: La prevalencia de insatisfacción corporal en ancianos se sitúa en torno al 5.6 %. Las mujeres tienen un mayor porcentaje de masa corporal y menos masa muscular. No se encontraron diferencias significativas (p≥0.05) en el CFF en relación al sexo. Los ancianos obesos con menor velocidad de la marcha mostraron un resultado superior en el CFF. El total del CFF está positivamente relacionado con el IMC (r=0.487, p<0.01), porcentaje de grasa (r=0.371,p<0.01) y negativamente relacionado con la velocidad dela marcha (r=-0.215 p<0.05) y el estado de salud percibido (r=-0.269, p<0.05).Conclusión: La satisfacción corporal de los ancianos está positivamente relacionada con la percepción de la salud y la velocidad de la marcha y negativamente con el IMC (AU)