Effect of High-Intensity Interval Training and Intermittent Fasting on Body Composition and Physical Performance in Active Women.

Nutritional strategies may have an effect on body composition and physical performance. Intermittent fasting (IF) is an eating pattern that cycles between periods of eating and fasting in specified time periods. Moreover, it is a common strategy among members of the athlete population that are looking for weight loss. However, this strategy may negatively affect physical performance, as compared to other weight loss strategies. The main purpose of this research was to use a cross-over design to study the effects of HIIT, with or without intermittent fasting, on muscular and anaerobic performance in 14 active women (27 ± 6 y). To assess performance, body composition (anthropometry), hand-grip strength, and counter-movement jump (CMJ) height was measured, and a 30 s Wingate test was completed assessed. HIIT + IF reduced fat mass (1 kg, p < 0.05, d = 1.1; 1.5%, p < 0.01, d = 1.0) and increased CMJ height (6.2 cm, p < 0.001, d = 1.8). In addition, the change in CMJ height in HIIT + IF was higher over HIIT (5.2 cm, p < 0.001, d = 1.9). In conclusion, intermittent fasting could be a nutritional strategy to decrease fat mass and increase jumping performance. However, longer duration programs would be necessary to determine whether other parameters of muscle performance could be positively affected by IF.

Frequency of High Intensity Circuit Training and diet. Effects on performance and health in active adults: Randomized Controlled Trial / Efectos sobre rendimiento y salud en adultos activos: Ensayo Controlado Aleatorizado

Introduction: High intensity circuit training (HICT) has been proven to be one of the most efficient methods to improve physical and physiological parameters using short training sessions. The objective of this study was to discern the effects of a 6-week HICT program in active persons, modifying the training frequency. Methods: Group A trained two days a week (n=7), group B trained 3 days a week (n=7), while the control group did not perform any training (n=7). All groups followed a diet program adapted to the strength training requirements. The training sessions were comprised of 4 series of 10 self-loading exercises, including sprints and supporting materials, with 1-2 minute rests between series, exerting an 80-95% maximum cardiac frequency intensity. A 1:1 training load density was used, with 20-25 second intervals between work and recovery. Results: Groups A and B significantly improved in body composition and strength tests (bench press and back squats), compared to the control group as well as in the intragroup analysis when comparing before and after the intervention. However, no significant differences were observed when comparing the two experimental groups. No changes in blood pressure were observed in any inter- or intragroup analysis. Conclusion: An adapted nutritional program and a 2-day/week HICT program seems to be sufficient in order to obtain significant improvements in strength and body composition in healthy active subjects, although blood pressure was not affected

Introducción: El entrenamiento en circuito de alta intensidad (HICT) ha demostrado ser uno de los métodos de entrenamiento más eficaces por la mejora de parámetro físicos y fisiológicos utilizando cortos periodos de entrenamiento. El objetivo de este estudio fue conocer los efectos de un programa de 6 semanas de entrenamiento HICT en personas activas, modificando la frecuencia de entrenamiento. Método: El grupo A entrenó con una frecuencia de 2 días a la semana (n=7), el grupo B (n=7) 3 días a la semana y el grupo control no realizó ningún entrenamiento (n=7). Ambos grupos siguieron un programa dietético adaptado a los requerimientos de los entrenamientos de fuerza. Realizaron un mismo entrenamiento compuesto de 4 series de 10 ejercicios con auto-cargas, con material auxiliar y carreras, con descanso de 1 y 2 minutos entre las series, a una intensidad entre el 80-95% de la FC máx. Se utilizó una densidad de la carga de entrenamiento de 1:1 con intervalos de trabajo y recuperación de 20 a 25 segundos. Resultados: Los grupos A y B mostraron, en comparación al grupo control, mejoras en la composición corporal y en los test de fuerza (press de banca y sentadilla) antes y después de la intervención con HICT. Sin embargo, no se obtuvieron diferencias cuando se compararon los resultados obtenidos entre ambos grupos experimentales. Las diferencias se observaron frente al grupo control, ya que tanto el grupo A como el grupo B mostraron mejoras significativas en la composición corporal y la fuerza. La presión arterial no presentó diferencias en las comparaciones inter e intragrupo. Conclusión: Un programa dietético nutricional adaptado y una frecuencia de entrenamiento de HICT de dos días parece ser suficiente para obtener mejoras en la fuerza y la composición corporal, aunque no para mejorar la presión arterial en sujetos sanos activos