Search results for "Concentric"

Changes induced by eccentric training on force-velocity relationships of the elbow flexor muscles.

1995

The aim of this study was to examine the effects of a short term eccentric training period on force-velocity relationships of the elbow flexor muscles. From a muscle model, the maximal shortening velocity Vo(x) and the af parameter which varies according to the curvature of the force-velocity relationship of the muscle were determined. Sixteen volunteer subjects divided into 2 groups participated in this study (Group Eccentric GE, n = 8; Group Control GC, n = 8). The subjects performed, on an isokinetic ergometer, 2 maximal concentric elbow flexions at different angular velocities (60, 120, 180, 240, 300, 360 degrees s-1) and held maximal and submaximal isometric actions at an elbow flexion…

Greater Strength Gains after Training with Accentuated Eccentric than Traditional Isoinertial Loads in Already Strength-Trained Men

2016

As training experience increases it becomes more challenging to induce further neuromuscular adaptation. Consequently, strength trainers seek alternative training methods in order to further increase strength and muscle mass. One method is to utilize accentuated eccentric loading, which applies a greater external load during the eccentric phase of the lift as compared to the concentric phase. Based upon this practice, the purpose of this study was to determine the effects of 10 weeks of accentuated eccentric loading vs. traditional isoinertial resistance training in strength-trained men. Young (22 ± 3 years, 177 ± 6 cm, 76 ± 10 kg, n = 28) strength-trained men (2.6 ± 2.2 years experience) w…

Maximal strength and power characteristics in isometric and dynamic actions of the upper and lower extremities in middle-aged and older men

1999

Muscle cross-sectional area of the quadriceps femoris (CSAQF), maximal isometric strength (handgrip test and unilateral knee extension/flexion), the shape of isometric force-time curves, and power-load curves during concentric and stretch-shortening cycle (SSC) actions with loads ranging from 15 to 70% of one repetition maximum half-squat (1RMHS) and bench-press (1RMBP) were examined in 26 middle-aged men in the 40-year-old (M40) (mean age 42, range 35-46) and 21 elderly men in the 65-year-old age group (M65) (mean age 65, range 60-74). Maximal bilateral concentric (1RMHS and 1RMBP), unilateral knee extension (isometric; MIFKE and concentric; 1RMKE) strength and muscle CSA in M65 were lower…

Moderate-Load Muscular Endurance Strength Training Did Not Improve Peak Power or Functional Capacity in Older Men and Women

2017

The present study determined the effects of muscular endurance strength training on maximum strength and power, functional capacity, muscle activation and hypertrophy in older men and women. Eighty-one men and women acted as an intervention group while 22 acted as non-training controls (age range 64–75 y). Intervention training included super-sets (i.e., paired exercises, immediately performing the second exercises following completion of the first) with short rest intervals (30–60 s between sets) at an intensity of 50–60% one-repetition maximum (1-RM) for 15–20 repetitions. Concentric leg press actions measured maximum strength (1-RM) and concentric peak power. Functional capacity was asse…

[OP.4B.03] CIRCULATING ALDOSTERONE LEVELS ARE ASSOCIATED WITH CONCENTRIC LEFT VENTRICULAR GEOMETRY IN ESSENTIAL HYPERTENSIVE PATIENTS

2016

OBJECTIVE: Sound evidence indicates that aldosterone has a fundamental role in determining functional and structural changes in the heart. Moreover, it has been observed that high plasma aldosterone concentration (PAC) is related to the development of congestive heart failure and to cardiovascular mortality. However, previous studies on the association between circulating aldosterone levels and left ventricular (LV) mass (LVM) and LV geometry, in subjects without primary aldosteronism yielded conflicting results. The aim of our study was to evaluate in patients with essential hypertension the relationships of PAC with LV mass and geometry, and to asses the influence of gender on these relat…

Plyometric muscular action tests in judo- and non-judo athletes

2011

The majority of explosive actions during the Judo fight occur when the athlete is trying to overcome his/her adversary via rapid execution(s) of (isolated or chained) technical manoeuvres. The aim of this study was to compare the results of two plyometric muscular action tests (i.e., Squat Jump – SJ, and Countermovement Jump – CMJ) between judoand non-judoathletes. The investigation involved a cross-sectional examination of 102 subjects (age, 21.9 ± 3.4 years) divided into 3 performance groups: a) Senior top elite judo athletes (n = 50), b) Junior elite judo athletes (n = 26) and c) Adult non-judo athletes (n = 26). Thirteen biomechanical variables (including jump height, velocity, power, f…

The function of neuromuscular system in maximal stretch-shortening cycle exercises: Comparison between power- and endurance-trained athletes.

1994

Abstract Differences in neuromuscular function between power athletes ( n = 10) and endurance athletes ( n = 10) were investigated in six different experimental conditions. In drop jumps and in stretch-shortening cycle (SSC) exercises on the sledge (sledge jumps), the subjects performed about 10 maximal jumps from the optimum dropping height (O) as well as from the dropping height of optimum −40 cm (O − 40) and optimum +40 cm (O + 40). The five to six best jumps were taken for further analysis. In every condition the power group had better physical performance compared to their endurance counterparts. During the pre-activity, the rate of electromyographic (EMG) development of the power athl…

Electrohysterogram Signals from Patients with Threatened Preterm Labor: Concentric Ring Electrode Vs Disk Electrode Recordings

2017

Activation and torque deficits in ACL-reconstructed patients 4 months post-operative

2001

This study compares knee extension and flexion torques and electromyographic (EMG) activity of normal and anterior cruciate ligament (ACL)-reconstructed knees during maximal unilateral isometric and isokinetic tests performed 4–5 months after ACL reconstruction. The subjects consisted of 3 age- and activity-matched groups of 6 subjects: a healthy control group (Ctrl) and 2 groups of patients, with Kenneth-Jones technique using autologous patellar-ligament graft (KJ group) and autologous graft from the semitendinosus tendon (ST group). When compared to the Ctrl group values, each patient group had significant bilateral extension torque deficits in isometric and at slow velocity concentric co…

Effects of power training on neuromuscular performance and mechanical efficiency

2007

Effects of power training with stretch-shortening cycle (SSC) exercises on mechanical efficiency (ME) were investigated with 9 young women who trained 3 times a week for 4 months. The training included various types of jumping exercises. Before and after the training as well as after the detraining (2 months) the subjects performed 6 different submaximal exercises with a special sledge apparatus. Each exercise involved 60 muscle actions lasting for a total of 3 min per testing condition. The work intensities were determined individually according to the recordings of distance obtained during the single maximal concentric exercises. The training caused the greatest changes of ME in condition…