Effects of caffeine supplementation on physical performance and mood dimensions in elite and trained-recreational athletes.

Background: Caffeine supplementation (CAFF) has an established ergogenic effect on physical performance and the psychological response to exercise. However, few studies have compared the response to CAFF intake among athletes of different competition level. This study compares the acute effects of CAFF on anaerobic performance, mood and perceived effort in elite and moderately-trained recreational athletes. Methods: Participants for this randomized, controlled, crossover study were 8 elite athletes (in the senior boxing national team) and 10 trained-recreational athletes. Under two experimental conditions, CAFF supplementation (6 mg/kg) or placebo (PLAC), the athletes completed a Wingate test. Subjective exertion during the test was recorded as the rating of perceived exertion (RPE) both at the general level (RPEgeneral) and at the levels muscular (RPEmuscular) and cardiorespiratory (RPEcardio). Before the Wingate test, participants completed the questionnaires Profiles of Moods States (POMS) and Subjective Vitality Scale (SVS). Results: In response to CAFF intake, improvements were noted in Wpeak (11.22 ± 0.65 vs 10.70 ± 0.84; p = 0.003; η2 p =0.44), Wavg (8.75 ± 0.55 vs 8.41 0.46; p = 0.001; η2 p =0.53) and time taken to reach Wpeak (7.56 ± 1.58 vs 9.11 ± 1.53; p < 0.001; η2 p =0.57) both in the elite and trained-recreational athletes. However, only the elite athletes showed significant increases in tension (+ 325%), vigor (+ 31%) and SVS (+ 28%) scores after the intake of CAFF compared to levels recorded under the condition PLAC (p < 0.05). Similarly, levels of vigor after consuming CAFF were significantly higher in the elite than the trained-recreational athletes (+ 5.8%). Conclusions: CAFF supplementation improved anaerobic performance in both the elite and recreational athletes. However, the ergogenic effect of CAFF on several mood dimensions and subjective vitality was greater in the elite athletes.post-print700 K

Tetanus toxin Hc fragment induces the formation of ceramide platforms and protects neuronal cells against oxidative stress

Tetanus toxin (TeTx) is the protein, synthesized by the anaerobic bacteria Clostridium tetani, which causes tetanus disease. TeTx gains entry into target cells by means of its interaction with lipid rafts, which are membrane domains enriched in sphingomyelin and cholesterol. However, the exact mechanism of host membrane binding remains to be fully established. In the present study we used the recombinant carboxyl terminal fragment from TeTx (Hc-TeTx), the domain responsible for target neuron binding, showing that Hc-TeTx induces a moderate but rapid and sustained increase in the ceramide/sphingomyelin ratio in primary cultures of cerebellar granule neurons and in NGF-differentiated PC12 cells, as well as induces the formation of ceramide platforms in the plasma membrane. The mentioned increase is due to the promotion of neutral sphingomyelinase activity and not to the de novo synthesis, since GW4869, a specific neutral sphingomyelinase inhibitor, prevents neutral sphingomyelinase activity increase and formation of ceramide platforms. Moreover, neutral sphingomyelinase inhibition with GW4869 prevents Hc-TeTx-triggered signaling (Akt phosphorylation), as well as the protective effect of Hc-TeTx on PC12 cells subjected to oxidative stress, while siRNA directed against nSM2 prevents protection by Hc-TeTx of NSC-34 cells against oxidative insult. Finally, neutral sphingomyelinase activity seems not to be related with the internalization of Hc-TeTx into PC12 cells. Thus, the presented data shed light on the mechanisms triggered by TeTx after membrane binding, which could be related with the events leading to the neuroprotective action exerted by the Hc-TeTx fragment

Evaluación del estado nutricional de un grupo de adultos mayores de 50 años mediante parámetros dietéticos y de composición corporal Assessment of the nutritional status of a group of people older than 50 years by means of dietary and body composition parameters

Objetivo: Valorar el estado nutricional de adultos mayores mediante parámetros dietéticos y de composición corporal. Metodología: La muestra está formada por 49 adultos mayores de 50 años (23 hombres y 26 mujeres) con una media de edad de 54,84 ± 4,56 años, empleados de una universidad privada. La composición corporal se analizó usando parámetros antropométricos. La ingesta de energía y nutrientes se recogió mediante un registro de todos los alimentos y bebidas consumidos durante 3 días, realizado por cada encuestado (previamente instruido) y estimando las cantidades a través de modelos fotográficos. Las necesidades energéticas totales se estimaron por las fórmulas de Harris-Benedict y FAO/OMS. Resultados: El índice de masa corporal fue similar (p = 0,018) en hombres y mujeres (26,1 ± 1,9 y 24,4 ± 2,8 kg/m²). El porcentaje de grasa obtenido por antropometría fue 29,6 ± 3,6 y 36,8 ± 3,1% (p = 0,000) en hombres y mujeres respectivamente. La actividad física fue muy ligera-ligera. La ingesta diaria de energía se adecuaba a las necesidades totales cuando estas se determinaron por las fórmulas propuestas por la FAO/OMS. El perfil calórico indicaba un desequilibrio con un alto aporte de proteínas y lípidos y bajo de carbohidratos. Respecto a los micronutrientes las dietas evaluadas indicaron un aporte deficitario de ácido fólico y vitaminas D y E en ambos sexos y cinc y selenio también en mujeres. Conclusiones y recomendaciones: Se han encontrado problemas de sobrepeso juzgados por el IMC y la circunferencia de la cintura y de obesidad según el porcentaje de grasa corporal con el potencial riesgo de desarrollar alguna complicación derivada de ello. Sería recomendable mejorar la calidad de las dietas consumidas aumentando algunos micronutrientes y fibra y promover un aumento de la actividad física.Objective: To assess the nutritional status of elder adults by means of dietary and body composition parameters. Methodology: The sample comprised 49 adults, older than 50 years (23 men and 26 women) with a mean age of 54.84 ± 4.56 years, working at a private university. The body composition was analyzed by using anthropometric parameters. The energy and nutrients intake was gathered by means of a registry of all the foods and beverages consumed during 3 days that was filled-up by each (previously instructed) participant and estimating the amounts through photographic models. Total energy requirements were estimated by the Harris-Benedict and FAO/WHO calculations. Results: The body mass index was similar (p = 0.018) in both men and women (26.1 ± 1.9 and 24.4 ± 2.8 kg/m²). The percentage of fat obtained by anthropometrics was 29.6 ± 3.6 and 36.8 ± 3.1% (p = 0.000) in men and women, respectively. The level of physical activity was very light to light. Daily energy intake was appropriate for total energy demands when these were calculated by the calculations proposed by FAO/WHO. The caloric profile indicated an unbalance with high proteins and lipids and low carbohydrates intake. As for the micronutrients, the diets assessed indicated a deficient intake of folic acid and vitamins D and E, in both genders, and zinc and selenium also in women. Conclusions and recommendations: We have found overweight problems according to the BMI and the waist circumference, and obesity according to the body fat percentage, with the potential risk for the development of an associated complication. It would be advisable to improve the quality of the diets consumed by increasing the amount of some micronutrients and fiber, and by promoting an increase in the physical activity

Umbral láctico y umbral ventilatorio en ejercicios empleados en el entrenamiento con contrarresistencias

SIN FINANCIACIÓNNo data (2015

Cardiorrespiratory responses at threshold intensity. Comparative between half squat vs cycle ergometer

Objetivo: Comparar las respuestas respiratorias, de frecuencia cardíaca (FC) y lactato a intensidad de umbral láctico (UL) en media sentadilla (MS) vs cicloergómetro. Métodos: 24 hombres (21,5±1,8 años, 180,1±5,2 cm, 81,9±8,7 kg) con experiencia en el entrenamiento de fuerza realizaron un test incremental progresivo en MS y cicloergómetro para determinar el UL. Durante los test se midieron las concentraciones de lactato, FC, consumo de oxígeno (VO2), producción de dióxido de carbono (VCO2), ventilación pulmonar (VE), equivalente ventilatorio del oxígeno (VE·VO2-1) y del dióxido de carbono (VE·VCO2-1). Una t student valoró las diferencias entre las dos modalidades de ejercicio. Resultados: las concentraciones de lactato, FC, VE, VE·VCO2-1 y VE·VO2-1 fueron superiores en MS vs cicloergómetro (p<0,05). Conclusiones: el UL puede ser detectado en el ejercicio de MS. Además, la realización de sesiones de entrenamiento contrarresistencias, a intensidad de UL, podrían ser utilizadas para mejorar la resistencia cardiovascular y la fuerza muscular.Objective: To compare respiratory responses, heart rate (HR) and lactate at the intensity of the lactate threshold (LT) between half squat (HS) and cycloergometer. Methods: 24 men (21.5±1.8 years, 180.1 ± 5.2 cm, 81.9±8.7 kg) with experience in resitance performed a progressive incremental test in HS and cycloergometer to determine LT. During such test, the following parameters were measured: blood lactate concentrations, HR, oxygen consumption (VO2), carbon dioxide production (VCO2), pulmonary ventilation (PV), ventilatory equivalent of oxygen (PV·VO2-1) and ventilatory equivalent of carbon dioxide (PV·VCO2-1). A t student evaluated the variables analysed among the two exercise modalities. Results: blood lactate concentrations, HR, PV, and PV·VO2-1 and PV·VCO2-1 were higher in HS than in cycloergometer (p <0.05). Conclusions: LT can be detected in HS exercise. Furthermore, the resistance training sessions to the intensity of LT might be used in training sessions which seek to improve cardiovascular endurance and muscle strength.Sin financiación1.031 JCR (2018) Q4, 71/83 Sport Sciences0.400 SJR (2018) Q3, 96/209 Physical Therapy, Sports Therapy and Rehabilitation, 89/125 Sports Science1.243 IDR (2018) C1, 5/43 DeporteUE