Eight male collegiate weightlifters (age: 21.2 ± 0.9 years; height: 177.6 ± 2.3 cm; and body mass: 85.1 ± 3.3 kg) participated in this study to compare isometric to dynamic force-time dependent variables. Subjects performed the isometric and dynamic mid-thigh clean pulls at 30–120% of their one repetition maximum (1RM) power clean (118.4 ± 5.5 kg) on a 61 X 121.9–cm AMTI forceplate. Variables such as peak force (PF) and peak rate of force development (PRFD) were calculated and were compared between isometric and dynamic conditions. The relationships between force-time dependent variables and vertical jump performances also were examined. The data indicate that the isometric PF had no significant correlations with the dynamic PF against light loads. On the one hand, there was a general trend toward stronger relationships between the isometric and dynamic PF as the external load increased for dynamic muscle actions. On the other hand, the isometric and dynamic PRFD had no significant correlations regardless of the external load used for dynamic testing. In addition, the isometric PF and dynamic PRFD were shown to be strongly correlated with vertical jump performances, whereas the isometric PRFD and dynamic PF had no significant correlations with vertical jump performances. In conclusion, it appears that the isometric and dynamic measures of force-time curve characteristics represent relatively specific qualities, especially when dynamic testing involves small external loads. Additionally, the results suggest that athletes who possess greater isometric maximum strength and dynamic explosive strength tend to be able to jump higher. Eight male collegiate weightlifters (age: 21.2 ± 0.9 years; height: 177.6 ± 2.3 cm; and body mass: 85.1 ± 3.3 kg) participated in this study to compare isometric to dynamic force-time dependent variables. Subjects performed the isometric and dynamic mid-thigh clean pulls at 30–120% of their one repetition maximum (1RM) power clean (118.4 ± 5.5 kg) on a 61 X 121.9–cm AMTI forceplate. Variables such as peak force (PF) and peak rate of force development (PRFD) were calculated and were compared between isometric and dynamic conditions. The relationships between force-time dependent variables and vertical jump performances also were examined. The data indicate that the isometric PF had no significant correlations with the dynamic PF against light loads. On the one hand, there was a general trend toward stronger relationships between the isometric and dynamic PF as the external load increased for dynamic muscle actions. On the other hand, the isometric and dynamic PRFD had no significant correlations regardless of the external load used for dynamic testing. In addition, the isometric PF and dynamic PRFD were shown to be strongly correlated with vertical jump performances, whereas the isometric PRFD and dynamic PF had no significant correlations with vertical jump performances. In conclusion, it appears that the isometric and dynamic measures of force-time curve characteristics represent relatively specific qualities, especially when dynamic testing involves small external loads. Additionally, the results suggest that athletes who possess greater isometric maximum strength and dynamic explosive strength tend to be able to jump higher.

PURPOSE: The purpose of the study was to examine the relationship between bat swing velocity and lower extremity strength and power in NCAA Division-I softball athletes. METHODS: Twenty-nine softball athletes (age = 19.8 ± 1.3 years, height = 167.9 ± 6.8 cm, mass = 76.4 ± 18.1 kg) participated in the study. Athletes were tested on unloaded and loaded (20kg) squat and countermovement jump peak force, peak power, and jump height performed on a force platform sampling at 1000Hz. During practice, athletes were tested on swing velocity using a timing gate system. Pearson-product moment zero-order correlations were calculated between bat swing velocity and lower extremity strength and power. Statistical significance was set at p≤0.05. RESULTS: Moderate to strong relationships were observed between swing velocity and peak force at all conditions: SJ 0kg (r= 0.51, p= 0.005), SJ 20kg (r= 0.50, p= 0.006), CMJ 0kg (r= 0.44, p= 0.016), CMJ 20kg (r= 0.43, p= 0.022). Additionally, relationships were observed between swing velocity and peak power at all conditions: SJ 0kg (r= 0.45, p= 0.015), SJ 20kg (r= 0.40, p= 0.031), CMJ 0kg (r= 0.53, p= 0.003), CMJ 20kg (r= 0.45, p= 0.015). No statistically significant relationships were observed between swing velocity and jump height. CONCLUSIONS: Swing velocity was related to lower extremity force and power variables. Considering the known effects of strength training on lower extremity strength and power production, these results provide background for inclusion of lower extremity strength training for the development of swing velocity in NCAA Division-I softball athletes.

Power-generating capacity should be a primary training outcome for football athletes. The ability to be explosive and use high levels of strength seems to differentiate between athletes and teams. Developing training interventions that can improve both strength- and power-generating capacity would therefore be considered a paramount endeavor when attempting to optimize the physiological and performance adaptations necessary for competitive success. Too often, strength and conditioning coaches forget that the foundation of powergenerating capacity is in fact high levels of muscular strength. When the development of strength is minimized or excluded from the training plan, the ability to express high-power outputs is compromised. In addition, a failure to use sequenced and integrated training programs decreases the possibility of successfully increasing strength- and power-generating capacity, thus decreasing the potential for competitive success. Therefore, this brief review attempts to explain how strength- and powergenerating capacity can be enhanced to increase the potential for developing the physiological and performance foundation necessary for competitive success with the football athlete.

Darbo objektas – 9 – 11 klasių berniukų staigiosios jėgos ir fizinio pajėgumo ryšys. Tyrimo tikslas – nustatyti 9-11 klasių berniukų fizinio pajėgumo ir staigiosios jėgos ryšį. Tyrimo uždaviniai: 1. Nustatyti 9-11 klasių berniukų fizinį pajėgumą. 2. Nustatyti 9-11 klasių berniukų staigiąją jėgą. 3. Nustatyti berniukų fizinio pajėgumo ir staigiosios jėgos ryšį. Hipotezė – tarp fizinio pajėgumo ir staigiosios jėgos yra ryšys. Pagrindiniai tyrimo rezultatai. Naudojant EUROFIT (2002) orientacines vertinimo skales buvo orientuotasi kokiam vertinimo lygiui galima priskirti rezultatų vidurkius. Palyginus visus testų rezultatus, galime teigti, kad geriausiai išlavintas berniukų lankstumas – 5,7 balo (testas „Sėstis/siekti“). Vertinant pagal Lietuvos gyventojų fizinio pajėgumo testavimo ir fizinės būklės nustatymo metodiką (2007), lankstumas būtų patenkinamas, jei tai yra 25,8 cm. Blogiausiai išlavinta širdies ir kvėpavimo sistemos ištvermė - 3,9 balo (testas „20 m bėgimas šaudykle“). Išvados: 1. Nustatyta, kad tiriamųjų 9-11 klasių berniukų fizinio pajėgumo testų rezultatai buvo vidutiniai 5,1 balo vertinant pagal moksleivių fizinio pajėgumo moksleivių fizinio pajėgumo referencines skales: 10x5 m bėgimas šaudykle (vikrumas) – 5,4 balai, sėstis/gultis (liemens jėga) – 5,3 balai, sėstis/siekti (lankstumas) – 5,7 balai, 20 m bėgimas šaudykle (širdies ir kvėpimo sistemos ištvermės) – 3,9 balai. 2. 9-11 klasių berniukų šuolis į tolį iš vietos (staigioji jėga) testo rezultatas buvo... [toliau žr. visą tekstą] / The object of the research – the relation between the explosive strength and physical capacity for 9-11 grade boys. The purpose of the research – to identify the liaison between the explosive strength and physical capacity in the group of 9-11 grade boys. The objectives of the research: 1. To find out what is the physical capacity of the 9-11 grade boys. 2. To identify the level of the explosive strength of the 9-11 grade boys. 3. To identify the liaison between the explosive strength and physical capacity in the group of 9-11 grade boys. The hypothesis - that there is a liaison between physical capacity and explosive strength. The main results of the research. Using EUROFIT (2002) reference scales it was concentrated on which evaluation level we can attribute the averages of the results. After comparing the results of all the tests, we can see that the best educated skill of boys is flexibility – 5,7 points (test „Sit/Reach“). Based on „Lithuanian population physical fitness testing and physical methodologies, 2007“, the flexibility is average if it is 25,8 cm. The worst educated skill for boys is heart and breathing endurance – 3,9 points (test „20min shuttle run“). Conclusion: 1. It was found out that physical capcity tests results for the respondents in the group of 9-11 grade boys are in average 5,1 points based on the reference tables for students‘ physical capacity: 10x5 m shuttle run (agility) - 5.4 points, sit / lie (waist strength) - 5.3 points, to sit / reach... [to full text]

Abstract available in the Journal of Strength and Conditioning Research

No description available.

Title: Selected fitness aspects of professional firefighters competing in fire sport and TFA Objectives: The aim of the thesis was to find out the level and the difference in the parameters of body constitution, postural stability and muscular and explosive force of lower limbs with groups of professional firemen competing in fire sport and TFA Methods: The research sample was represented by two groups of professional firemen (17 fire sportsmen and 17 TFA competitors). We assessed chosen parameters of body constitution (Tanita MC-980MA), postural stability (RS Footscan), explosive force (Kistler) and muscular force (Cybex Humac Norm). Assessed parameters of body constitution were percentage of body fat and fatless matter. In the tests of postural stability we assessed total travel way of the centre of pressure (TTW), narrow stand (open and closed eyes) and one-leg stand (right, left). When testing explosive force, overall produced maximal force and height of the leap were assessed. Muscular force was assessed with the help of muscular force moment in concentric muscle activity with angular velocity 60ř·s-1. Results: We found out a significant difference between the two groups in the tests of postural stability - narrow stand with open and closed eyes (F1,32 = 9,94, p<0,01), in the tests of...

Title: Developing the explosive strength of the lower extremities of the players of the extra league team in volleyball. Subject: Measuring the jump height of twelve players of the extra league team. Objectives: Measure to see if it is possible, by systematically training the explosive strength of the lower extremities, to increase the jump height for volleyball players after a period of three months. Results: To compare the results of each single measurement with the first measurement performed prior to systematic training of the explosive strength of the lower extremities Key words: Development, explosive strenght, lower extremities, player, volleyball, team.

The purpose of this study was to identify a potentiation effect on 30 meter (m) fly sprint performance in collegiate sprinters and jumpers (M=21, W=5) following an acute bout of whole-body vibration. The WBV protocol consisted of one 30 second bout at 50 Hz, ~3 mm amplitude, and 60 seconds rest before a 30m fly sprint. Sprint times were measured using timing gates, and characteristics of strength and power were measured using a force plate. Analysis included measures of jump height, peak power, peak force, and rate of force development. Each subject participated in 3 separate trials using randomized treatment sessions over 3 months of preparation training. The control condition consisted of no vibration and WBV treatment 1 and 2 incorporated vibration. Statistics comparing the average sprint times showed no treatment effects. The results of this study indicate that WBV at 50 Hz and ~3 mm amplitude has no effect on sprint times.

Neural activation is thought to be essential for the expression of maximal muscle performance, but the exact contribution of neural mechanisms such as the level of agonist, antagonist and stabiliser muscle activation to muscle strength is not fully understood. Explosive neuromuscular performance, including the ability to initiate (the electromechanical delay, EMD) and develop force rapidly (termed, rate of force development, RFD) are considered essential for the performance of explosive sporting tasks and joint stabilisation and thus injury avoidance. The thesis aimed to improve our understanding of the contribution of neural factors to muscle performance, with a specific focus on explosive neuromuscular performance. The work in this thesis utilised a range of approaches to achieve this aim. Initially, the association between muscle activation and rate of force development and EMD was established. Comparison of unilateral and bilateral actions was then undertaken. Finally interventions with the aim to both negatively affect and improve muscle strength, which included fatigue and resistance training (RT), respectively was undertaken and the neural contributions to changes in performance established. Agonist activation during the early phase of voluntary force production was shown to be an important determinant of voluntary EMD, explaining 41% of its inter-individual variability. Agonist activation was an important determinant of early, but not late phase RFD. Use of bilateral actions resulted in a reduction in explosive strength, which was thought to be due to differences in postural stability between unilateral and bilateral strength tasks. The level of stabiliser activation was strongly related to the level of agonist activation during the early phase of explosive force development and had a high association with explosive force production. Task-specific adaptations following isoinertial RT, specifically, the greater increase in isoinertial lifting strength than maximal isometric strength were due to training-specific changes in the level of agonist activation. High-intensity fatigue achieved a more substantial decline in explosive than maximal isometric strength, and this was postulated to be due to neural mechanisms, specifically decreased agonist activation. This work provides an in depth analysis of the neural contributions to maximal muscle performance.