TY  - JOUR
A1  - Chaouachi, Mehdi
A1  - Granacher, Urs
A1  - Makhlouf, Issam
A1  - Hammami, Raouf
A1  - Behm, David G.
A1  - Chaouachi, Anis
T1  - Within Session Sequence of Balance and Plyometric Exercises Does Not Affect Training Adaptations with Youth Soccer Athletes
JF  - Journal of sports science & medicine
N2  - The integration of balance and plyometric training has been shown to provide significant improvements in sprint, jump, agility, and other performance measures in young athletes. It is not known if a specific within session balance and plyometric exercise sequence provides more effective training adaptations. The objective of the present study was to investigate the effects of using a sequence of alternating pairs of exercises versus a block (series) of all balance exercises followed by a block of plyometric exercises on components of physical fitness such as muscle strength, power, speed, agility, and balance. Twenty-six male adolescent soccer players ( 13.9 +/- 0.3 years) participated in an 8-week training program that either alternated individual balance (e. g., exercises on unstable surfaces) and plyometric (e. g., jumps, hops, rebounds) exercises or performed a block of balance exercises prior to a block of plyometric exercises within each training session. Pre- and post-training measures included proxies of strength, power, agility, sprint, and balance such as countermovement jumps, isometric back and knee extension strength, standing long jump, 10 and 30-m sprints, agility, standing stork, and Y-balance tests. Both groups exhibited significant, generally large magnitude (effect sizes) training improvements for all measures with mean performance increases of approximately > 30%. There were no significant differences between the training groups over time. The results demonstrate the effectiveness of combining balance and plyometric exercises within a training session on components of physical fitness with young adolescents. The improved performance outcomes were not significantly influenced by the within session exercise sequence.
KW  - Power
KW  - strength
KW  - jumps
KW  - sprints
KW  - balance
KW  - children
Y1  - 2017
SN  - 1303-2968
VL  - 16
SP  - 125
EP  - 136
PB  - Department of Sports Medicine, Medical Faculty of Uludag University
CY  - Bursa
ER  - 
TY  - JOUR
A1  - Prieske, Olaf
A1  - Aboodarda, Saied J.
A1  - Sierra, Jose A. Benitez
A1  - Behm, David G.
A1  - Granacher, Urs
T1  - Slower but not faster unilateral fatiguing knee extensions alter contralateral limb performance without impairment of maximal torque output
JF  - European journal of applied physiology
N2  - The purpose of the present study was to examine the effects of unilateral fatigue of the knee extensors at different movement velocities on neuromuscular performance in the fatigued and non-fatigued leg. Unilateral fatigue of the knee extensors was induced in 11 healthy young men (23.7 +/- 3.8 years) at slower (60A degrees/s; FAT60) and faster movement velocities (240A degrees/s; FAT240) using an isokinetic dynamometer. A resting control (CON) condition was included. The fatigue protocols consisted of five sets of 15 maximal concentric knee extensions using the dominant leg. Before and after fatigue, peak isokinetic torque (PIT) and time to PIT (TTP) of the knee extensors as well as electromyographic (EMG) activity of vastus medialis, vastus lateralis, and biceps femoris muscles were assessed at 60 and 240A degrees/s movement velocities in the fatigued and non-fatigued leg. In the fatigued leg, significantly greater PIT decrements were observed following FAT60 and FAT240 (11-19%) compared to CON (3-4%, p = .002, d = 2.3). Further, EMG activity increased in vastus lateralis and biceps femoris muscle following FAT240 only (8-28%, 0.018 <= p <=.024, d = 1.8). In the non-fatigued leg, shorter TTP values were found after the FAT60 protocol (11-15%, p = .023, d = 2.4). No significant changes were found for EMG data in the non-fatigued leg. The present study revealed that both slower and faster velocity fatiguing contractions failed to show any evidence of cross-over fatigue on PIT. However, unilateral knee extensor fatigue protocols conducted at slower movement velocities (i.e., 60A degrees/s) appear to modulate torque production on the non-fatigued side (evident in shorter TTP values).
KW  - Electromyography
KW  - Cross-over fatigue
KW  - Isokinetic
KW  - Movement velocity
KW  - Motor function
KW  - Central activation
Y1  - 2017
U6  - https://doi.org/10.1007/s00421-016-3524-6
SN  - 1439-6319
SN  - 1439-6327
VL  - 117
SP  - 323
EP  - 334
PB  - Springer
CY  - New York
ER  -