Intramuscular fiber conduction velocity, isometric force and explosive performance

Abstract

Conduction of electrical signals along the surface of muscle fibers is acknowledged as an essential neuromuscular component which is linked with muscle force production. However, it remains unclear whether muscle fiber conduction velocity (MFCV) is also linked with explosive performance. The aim of the present study was to investigate the relationship between vastus lateralis MFCV and countermovement jumping performance, the rate of force development and maximum isometric force. Fifteen moderately-trained young females performed countermovement jumps as well as an isometric leg press test in order to determine the rate of force development and maximum isometric force. Vastus lateralis MFCV was measured with intramuscular microelectrodes at rest on a different occasion. Maximum MFCV was significantly correlated with maximum isometric force (r = 0.66, p < 0.01), nevertheless even closer with the leg press rate of force development at 100 ms, 150 ms, 200 ms, and 250 ms (r = 0.85, r = 0.89, r = 0.91, r = 0.92, respectively, p < 0.01). Similarly, mean MFCV and type II MFCV were better correlated with the rate of force development than with maximum isometric leg press force. Lower, but significant correlations were found between mean MFCV and countermovement jump power (r = 0.65, p < 0.01). These data suggest that muscle fiber conduction velocity is better linked with the rate of force development than with isometric force, perhaps because conduction velocity is higher in the larger and fastest muscle fibers which are recognized to contribute to explosive actions.

Changes in Muscle Power and Muscle Morphology with Different Volumes of Fast Eccentric Half-Squats

“…Participants warmed-up for 5 minutes on a stationary bicycle at 50 Watt before performing three CMJs with submaximal intensity. Subsequently, they performed 3threemaximal CMJs with arms akimbo, with 2 min rest between each jump, on a force platform (WP1000kg weighting platform, Applied Measurements Ltd Co. UK, sampling frequency 1 kHz) as previously described [16,17,20]). Force platform data were recorded and analyzed (Kyowa sensor interface PCD-320A) to calculate the following variables [16,39]: Jump height (cm) = ((0.5 × flight time) 2 × 2 −1 ) × 9.81 and Maximum Power (W) = (body weight + Fmax) × 9.81 × flight time.…”

“…Power resistance training involves primarily high-velocity movements with body weight or with additional external loads, e.g., jumps [3], ballistic movements [7], eccentric actions [11,14] or a combination of the above [9,12]. The ability for high muscle power production seems to depend on many biological parameters, including muscle mass, muscle architecture, muscle fiber type composition neural activation and rate of force development [4,5,11,15,16,17,18,19,20,21,22]. Effective power training programs promote at least some of these neuromuscular adaptations.…”

The Importance of Lean Body Mass for the Rate of Force Development in Taekwondo Athletes and Track and Field Throwers

“…Two-minute rest was allowed between attempts. Data from the force platform were recorded and analysed (Kyowa sensor interface PCD-320A; Kyowa Electronic Instruments Co., Ltd., Chofu, Tokyo, Japan) to calculate the maximum vertical jump height, the power output, the velocity, and the average rate of force development [ARFD (N·s −1 ) = (Max force − Body weight) × [(Time of maximum force − Time at which force reach the body weight) −1 ]] during the push off phase (Time of maximum force − Time at which force reach the body weight) [ 29 , 30 ]. The highest jump was used for further analysis (Intraclass Correlation Coefficients (ICC) = 0.91, 95% Confidence Intervals (CI; Lower = 0.90, Upper = 0.99, n = 13), coefficient of variation (CV) = 8.1%.…”

Efecto de un programa de actividad física polimotor sobre el consumo máximo de oxígeno, la condición física antropométrica y la atención en una población escolar de Bogotá

“…Una de las consideraciones más interesantes que tiene siempre un reflejo en la bibliografía sobre la velocidad, es el carácter más o menos hereditario o innato de esta capacidad (86).…”

“…Un individuo que realiza actividad física, activa todos los sistemas corporales y muestra cambios significativos que desencadenan en hábitos saludables alejándolos del sedentarismo, liberando beta-endorfina que genera una situación placentera(138). Es indispensable que cada uno de los participantes del PAFP cambie su comportamiento de pasivo a activo con respecto a la actividad física 86. Efectos de un programa de actividad física Polimotor sobre el consumo máximo de oxígeno, la condición física y antropométrica y la atención en una población escolar de Bogota.Tabla 27 Comportamiento de las Variables.Los resultados alcanzados por el grupo intervenido mostraron comportamientos satisfactorios en la condición física.…”