An attempt to bridge muscle architecture dynamics and its instantaneous rate of force development using ultrasonography

The association between force–time characteristics of isometric leg press (ILP) and countermovement jump (CMJ) with vastus lateralis (VL) muscle architecture, was examined in 19 female athletes (aged 23.2 ± 5.4 years). Peak force (PF), average rate of force development (ARFD) and rate of force development (RFD) at different time epochs were calculated from the force–time curve, as well as CMJ jump height and power. Significant correlations were found between ILP-PF and CMJ power (r = 0.658, p < 0.01), while both variables were correlated with VL thickness and fascicle length (r = 0.471 to 0.648, p < 0.05). Significant correlations were also observed between ILP-RFD epochs and VL fascicle length (r = 0.565 to 0.646, p < 0.05) and between CMJ height with VL thickness (r = 0.523, p < 0.05). Furthermore, positive correlations were found between ILP and CMJ in ARFD (r = 0.625, p < 0.01) and RFD epochs (r = 0.464 to 0.566, p < 0.05). ILP-PF and muscle thickness accounted for 52.8% (p = 0.002) of the variance in CMJ power. These results suggest that isometric force time characteristics are associated with power generation during dynamic muscle actions. Furthermore, VL muscle thickness and fascicle length are associated with rapid force production in female athletes, irrespective of the type of muscle action.

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Rate of Force Development and Muscle Architecture after Fast and Slow Velocity Eccentric Training

Sports ◽

10.3390/sports7020041 ◽

2019 ◽

Vol 7 (2) ◽

pp. 41 ◽

Cited By ~ 15

Author(s):

Angeliki-Nikoletta Stasinaki ◽

Nikolaos Zaras ◽

Spyridon Methenitis ◽

Gregory Bogdanis ◽

Gerasimos Terzis

Keyword(s):

Resistance Training ◽

Vastus Lateralis ◽

Muscle Architecture ◽

Rate Of Force Development ◽

Vastus Lateralis Muscle ◽

Eccentric Training ◽

Fascicle Length ◽

Force Development ◽

Muscle Fascicle ◽

Slow Velocity

The aim of the study was to investigate the rate of force development (RFD) and muscle architecture early adaptations in response to training with fast- or slow-velocity eccentric squats. Eighteen young novice participants followed six weeks (two sessions/week) of either fast-velocity (Fast) or slow-velocity (Slow) squat eccentric-only training. Fast eccentric training consisted of nine sets of nine eccentric-only repetitions at 70% of 1-RM with <1 s duration for each repetition. Slow eccentric training consisted of five sets of six eccentric-only repetitions at 90% of 1-RM with ~4 sec duration for each repetition. Before and after training, squat 1-RM, countermovement jump (CMJ), isometric leg press RFD, and vastus lateralis muscle architecture were evaluated. Squat 1-RM increased by 14.5 ± 7.0% (Fast, p < 0.01) and by 5.4 ± 5.1% (Slow, p < 0.05). RFD and fascicle length increased significantly in the Fast group by 10–19% and 10.0 ± 6.2%, p < 0.01, respectively. Muscle thickness increased only in the Slow group (6.0 ± 6.8%, p < 0.05). Significant correlations were found between the training induced changes in fascicle length and RFD. These results suggest that fast eccentric resistance training may be more appropriate for increases in rapid force production compared to slow eccentric resistance training, and this may be partly due to increases in muscle fascicle length induced by fast eccentric training.

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Rate of Force Development, Muscle Architecture, and Performance in Young Competitive Track and Field Throwers

The Journal of Strength and Conditioning Research ◽

10.1519/jsc.0000000000001048 ◽

2016 ◽

Vol 30 (1) ◽

pp. 81-92 ◽

Cited By ~ 32

Author(s):

Nikolaos D. Zaras ◽

Angeliki-Nikoletta E. Stasinaki ◽

Spyridon K. Methenitis ◽

Argyro A. Krase ◽

Giorgos P. Karampatsos ◽

...

Keyword(s):

Muscle Architecture ◽

Rate Of Force Development ◽

Track And Field ◽

Force Development ◽

And Performance

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Effect of Inter-Repetition Rest vs. Traditional Strength Training on Lower Body Strength, Rate of Force Development, and Muscle Architecture

Applied Sciences ◽

10.3390/app11010045 ◽

2020 ◽

Vol 11 (1) ◽

pp. 45

Author(s):

Nikolaos Zaras ◽

Angeliki-Nikoletta Stasinaki ◽

Polyxeni Spiliopoulou ◽

Thomas Mpampoulis ◽

Marios Hadjicharalambous ◽

...

Keyword(s):

Strength Training ◽

Repeated Measures ◽

Muscle Architecture ◽

Rate Of Force Development ◽

Lower Body ◽

Fascicle Length ◽

Force Development ◽

Leg Press ◽

Body Strength ◽

Lower Body Strength

The purpose of the study was to investigate the effect of seven weeks inter-repetition rest vs. traditional strength training on lower body strength, rate of force development (RFD), and vastus lateralis (VL) muscle architecture. Sixteen male participants were assigned into two groups: the inter-repetition rest (IRRG) and the traditional (TG) group. Both groups performed the leg press exercise with four sets of six maximum repetitions (RM) for two training sessions per week. IRRG added a 20 s inter-repetition rest period between single repetitions. Before and after the training period, 1-RM in leg press, isometric leg press RFD, and peak force (PF), VL muscle architecture, vastus intermedius (VI) thickness, and quadriceps’ cross sectional area (CSA) with ultrasonography, were measured. Two way ANOVA for repeated measures was used for statistics. One-RM strength increased similarly for both groups (p < 0.05), while percentage increases in RFD were greater for IRRG compared to TG (p < 0.05). Isometric PF was increased similarly for both groups (p < 0.05). VL and VI thickness as well as CSA of the quadriceps increased similarly in both groups, while VL fascicle length increased more following IRRG compared to TG (IRRG: 4.8 ± 6.1% vs. TG: −3.9 ± 5.4%, p = 0.001). These results suggest that 20 s inter-repetition rest during strength training may effectively increase lower body explosive strength and muscle fascicle length without compromising muscle hypertrophy.

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