TY  - JOUR
A1  - Ramirez-Campillo, Rodrigo
A1  - Andrade, David C.
A1  - Nikolaidis, Pantelis T.
A1  - Moran, Jason
A1  - Clemente, Filipe Manuel
A1  - Chaabene, Helmi
A1  - Comfort, Paul
T1  - Effects of plyometric jump training on vertical jump height of volleyball players: a systematic review with meta-analysis of randomized-controlled trial
JF  - Journal of Sports Science and Medicine
N2  - This meta-analysis aimed to assess the effects of plyometric jump training (PJT) on volleyball players’ vertical jump height (VJH), comparing changes with those observed in a matched control group. A literature search in the databases of PubMed, MEDLINE, Web of Science, and SCOPUS was conducted. Only randomized-controlled trials and studies that included a pre-to-post intervention assessment of VJH were included. They involved only healthy volleyball players with no restrictions on age or sex. Data were independently extracted from the included studies by two authors. The Physiotherapy Evidence Database scale was used to assess the risk of bias, and methodological quality, of eligible studies included in the review. From 7,081 records, 14 studies were meta-analysed. A moderate Cohen’s d effect size (ES = 0.82, p <0.001) was observed for VJH, with moderate heterogeneity (I2 = 34.4%, p = 0.09) and no publication bias (Egger’s test, p = 0.59). Analyses of moderator variables revealed no significant differences for PJT program duration (≤8 vs. >8 weeks, ES = 0.79 vs. 0.87, respectively), frequency (≤2 vs. >2 sessions/week, ES = 0.83 vs. 0.78, respectively), total number of sessions (≤16 vs. >16 sessions, ES = 0.73 vs. 0.92, respectively), sex (female vs. male, ES = 1.3 vs. 0.5, respectively), age (≥19 vs. <19 years of age, ES = 0.89 vs. 0.70, respectively), and volume (>2,000 vs. <2,000 jumps, ES = 0.76 vs. 0.79, respectively). In conclusion, PJT appears to be effective in inducing improvements in volleyball players’ VJH. Improvements in VJH may be achieved by both male and female volleyball players, in different age groups, with programs of relatively low volume and frequency. Though PJT seems to be safe for volleyball players, it is recommended that an individualized approach, according to player position, is adopted with some players (e.g. libero) less prepared to sustain PJT loads.
KW  - human physical conditioning
KW  - resistance training
KW  - stretch-shortening cycle
KW  - physical fitness
KW  - exercise therapy
KW  - team sports
Y1  - 2020
VL  - 19
PB  - Wiley-Blackwell
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Ramirez-Campillo, Rodrigo
A1  - Alvarez, Cristian
A1  - Garcia-Pinillos, Felipe
A1  - Sanchez-Sanchez, Javier
A1  - Yanci, Javier
A1  - Castillo, Daniel
A1  - Loturco, Irineu
A1  - Chaabene, Helmi
A1  - Moran, Jason
A1  - Izquierdo, Mikel
T1  - Optimal reactive strength index
BT  - is it an accurate variable to optimize plyometric training effects on measures of physical fitness in young soccer players?
JF  - Journal of strength and conditioning research : the research journal of the NSCA
N2  - Ramirez-Campillo, R, Alvarez, C, García-Pinillos, F, Sanchez-Sanchez, J, Yanci, J, Castillo, D, Loturco, I, Chaabene, H, Moran, J, and Izquierdo, M. Optimal reactive strength index: is it an accurate variable to optimize plyometric training effects on measures of physical fitness in young soccer players? J Strength Cond Res 32(4): 885–893, 2018—This study aimed to compare the effects of drop-jump training using a fixed drop-box height (i.e., 30-cm [FIXED]) vs. an optimal (OPT) drop-box height (i.e., 10-cm to 40-cm: generating an OPT reactive strength index [RSI]) in youth soccer players' physical fitness. Athletes were randomly allocated to a control group (n = 24; age = 13.7 years), a fixed drop-box height group (FIXED, n = 25; age = 13.9 years), or an OPT drop-box height group (OPT, n = 24; age = 13.1 years). Before and after 7 weeks of training, tests for the assessment of jumping (countermovement jump [CMJ], 5 multiple bounds), speed (20-m sprint time), change of direction ability (CODA [Illinois test]), strength {RSI and 5 maximal squat repetition test (5 repetition maximum [RM])}, endurance (2.4-km time trial), and kicking ability (maximal kicking distance) were undertaken. Analyses revealed main effects of time for all dependent variables (p < 0.001, d = 0.24–0.72), except for 20-m sprint time. Analyses also revealed group × time interactions for CMJ (p < 0.001, d = 0.51), depth jump (DJ) (p < 0.001, d = 0.30), 20-m sprint time (p < 0.001, d = 0.25), CODA (p < 0.001, d = 0.22), and 5RM (p < 0.01, d = 0.16). Post hoc analyses revealed increases for the FIXED group (CMJ: 7.4%, d = 0.36; DJ: 19.2%, d = 0.49; CODA: −3.1%, d = −0.21; 5RM: 10.5%, d = 0.32) and the OPT group (CMJ: 16.7%, d = 0.76; DJ: 36.1%, d = 0.79; CODA: −4.4%, d = −0.34; 5RM: 18.1%, d = 0.47). Post hoc analyses also revealed increases for the OPT group in 20-m sprint time (−3.7%, d = 0.27). Therefore, to maximize the effects of plyometric training, an OPT approach is recommended. However, using adequate fixed drop-box heights may provide a rational and practical alternative.
KW  - football
KW  - stretch-shortening cycle
KW  - maturity
KW  - training optimization
KW  - change of direction
KW  - jumping
Y1  - 2018
U6  - https://doi.org/10.1519/JSC.0000000000002467
SN  - 1064-8011
SN  - 1533-4287
VL  - 32
IS  - 4
SP  - 885
EP  - 893
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Prieske, Olaf
A1  - Mühlbauer, Thomas
A1  - Krüger, Tom
A1  - Kibele, A.
A1  - Behm, David George
A1  - Granacher, Urs
T1  - Sex-Specific effects of surface instability on drop jump and landing biomechanics
JF  - International journal of sports medicine
N2  - This study investigated sex-specific effects of surface instability on kinetics and lower extremity kinematics during drop jumping and landing. Ground reaction forces as well as knee valgus and flexion angles were tested in 14 males (age: 23 +/- 2 years) and 14 females (age: 24 +/- 3 years) when jumping and landing on stable and unstable surfaces. Jump height was found to be significantly lower (9 %, p < 0.001) when drop jumps were performed on unstable vs. stable surface. Significantly higher peak ground reaction forces were observed when jumping was performed on unstable vs. stable surfaces (5 %, p = 0.022). Regarding frontal plane kinematics during jumping and landing, knee valgus angles were higher on unstable compared to stable surfaces (1932 %, p < 0.05). Additionally, at the onset of ground contact during landings, females showed higher knee valgus angles than males (222 %, p = 0.027). Sagittal plane kinematics indicated significantly smaller knee flexion angles (6-35 %, p < 0.05) when jumping and landing on unstable vs. stable surfaces. During drop jumps and landings, women showed smaller knee flexion angles at ground contact compared to men (27-33 %, p < 0.05). These findings imply that knee motion strategies were modified by surface instability and sex during drop jumps and landings.
KW  - stretch-shortening cycle
KW  - ground reaction force
KW  - knee joint angle
KW  - injury risk
Y1  - 2015
U6  - https://doi.org/10.1055/s-0034-1384549
SN  - 0172-4622
SN  - 1439-3964
VL  - 36
IS  - 1
SP  - 75
EP  - 81
PB  - Thieme
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Prieske, Olaf
A1  - Chaabene, Helmi
A1  - Puta, Christian
A1  - Behm, David George
A1  - Büsch, Dirk
A1  - Granacher, Urs
T1  - Effects of Drop Height on Jump Performance in Male and Female Elite Adolescent Handball Players
JF  - International journal of sports physiology and performance
N2  - Purpose: To examine the effects of drop height on drop-jump (DJ) performance and on associations between DJ and horizontal-jump/sprint performances in adolescent athletes. Methods: Male (n = 119, 2.5 [0.6] y post-peak-height velocity) and female (n = 120, 2.5 [0.5] y post-peak-height velocity) adolescent handball players (national level) performed DJs in randomized order using 3 drop heights (20, 35, and 50 cm). DJ performance (jump height, reactive strength index [RSI]) was analyzed using the Optojump Next system. In addition, correlations were computed between DJ height and RSI with standing-long-jump and 20-m linear-sprint performances. Results: Statistical analyses revealed medium-size main effects of drop height for DJ height and RSI (P <.001, 0.63 <= d <= 0.71). Post hoc tests indicated larger DJ heights from 20 to 35 and 35 to 50 cm (P <=.031, 0.33 <= d <= 0.71) and better RSI from 20- to 35-cm drop height (P <.001, d = 0.77). No significant difference was found for RSI between 35- and 50-cm drop height. Irrespective of drop height, associations of DJ height and RSI were small with 5-m-split time (-.27 <= r <=.05), medium with 10-m-split time (-.44 <= r <=.14), and medium to large with 20-m sprint time and standing-long-jump distance (-.57 <= r <=.22). Conclusions: The present findings indicate that, irrespective of sex, 35-cm drop heights are best suited to induce rapid and powerful DJ performance (ie, RSI) during reactive strength training in elite adolescent handball players. Moreover, training-related gains in DJ performance may at least partly translate to gains in horizontal jump and longer sprint distances (ie, >= 20-m) and/or vice versa in male and female elite adolescent athletes, irrespective of drop height.
KW  - stretch-shortening cycle
KW  - plyometric training
KW  - strength training
KW  - tendon stiffness
KW  - young athletes
Y1  - 2019
U6  - https://doi.org/10.1123/ijspp.2018-0482
SN  - 1555-0265
SN  - 1555-0273
VL  - 14
IS  - 5
SP  - 674
EP  - 680
PB  - Human Kinetics Publ.
CY  - Champaign
ER  - 
TY  - JOUR
A1  - Palma-Muñoz, Ignacio
A1  - Ramírez-Campillo, Rodrigo
A1  - Azocar-Gallardo, Jairo
A1  - Álvarez, Cristian
A1  - Asadi, Abbas
A1  - Moran, Jason
A1  - Chaabene, Helmi
T1  - Effects of progressed and nonprogressed volume-based overload plyometric training on components of physical fitness and body composition variables in youth male basketball players
JF  - Journal of strength and conditioning research : the research journal of the NSCA
N2  - This study examined the effect of 6 weeks of progressed and nonprogressed volume-based overload plyometric training (PT) on components of physical fitness and body composition measures in young male basketball players, compared with an active control group. Subjects were randomly assigned to a progressed PT (PPT, n = 7; age = 14.6 +/- 1.1 years), a non-PPT (NPPT, n = 8, age = 13.8 +/- 2.0 years), or a control group (CG, n = 7, age = 14.0 +/- 2.0 years). Before and after training, body composition measures (muscle mass and fat mass), countermovement jump with arms (CMJA) and countermovement jump without arms (CMJ), horizontal bilateral (HCMJ) and unilateral jump with right leg (RJ) and left leg (LJ), 20-cm drop jump (DJ20), sprint speed (10 m sprint), and change of direction speed (CODS [i.e., T-test]) were tested. Significant effects of time were observed for muscle and fat mass, all jump measures, and CODS (all p < 0.01; d = 0.37-0.83). Significant training group x time interactions were observed for all jump measures (all p < 0.05; d = 0.24-0.41). Post hoc analyses revealed significant pre-post performance improvements for the PPT (RJ and LJ: increment 18.6%, d = 0.8 and increment 22.7%, d = 0.9, respectively; HCMJ: increment 16.4%, d = 0.8; CMJ: increment 22.4%, d = 0.7; CMJA: increment 23.3%, d = 0.7; and DJ20: increment 39.7%, d = 1.1) and for the NPPT group (LJ: increment 14.1%, d = 0.4; DJ20: increment 32.9%, d = 0.8) with greater changes after PPT compared with NPPT for all jump measures (all p < 0.05; d = 0.21-0.81). The training efficiency was greater (p < 0.05; d = 0.22) after PPT (0.015% per jump) compared with NPPT (0.0053% per-jump). The PPT induced larger performance improvements on measures of physical fitness as compared to NPPT. Therefore, in-season progressive volume-based overload PT in young male basketball players is recommended.
KW  - stretch-shortening cycle
KW  - young
KW  - team sports
KW  - athletic performance
KW  - anthropometry
Y1  - 2021
U6  - https://doi.org/10.1519/JSC.0000000000002950
SN  - 1064-8011
SN  - 1533-4287
VL  - 35
IS  - 6
SP  - 1642
EP  - 1649
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Negra, Yassine
A1  - Chaabene, Helmi
A1  - Sammoud, Senda
A1  - Prieske, Olaf
A1  - Moran, Jason
A1  - Ramirez-Campillo, Rodrigo
A1  - Nejmaoui, Ali
A1  - Granacher, Urs
T1  - The increased effectiveness of loaded versus unloaded plyometric jump training in improving muscle power, speed, change of direction, and kicking-distance performance in prepubertal male soccer players
JF  - International journal of sports physiology and performance : IJSSP
N2  - Purpose: To examine the effects of loaded (LPJT) versus unloaded plyometric jump training (UPJT) programs on measures of muscle power, speed, change of direction (CoD), and kicking-distance performance in prepubertal male soccer players. Methods: Participants (N = 29) were randomly assigned to a LPJT group (n = 13; age = 13.0 [0.7] y) using weighted vests or UPJT group (n = 16; age = 13.0 [0.5] y) using body mass only. Before and after the intervention, tests for the assessment of proxies of muscle power (ie, countermovement jump, standing long jump); speed (ie, 5-, 10-, and 20-m sprint); CoD (ie, Illinois CoD test, modified 505 agility test); and kicking-distance were conducted. Data were analyzed using magnitude-based inferences. Results: Within-group analyses for the LPJT group showed large and very large improvements for 10-m sprint time (effect size [ES] = 2.00) and modified 505 CoD (ES = 2.83) tests, respectively. For the same group, moderate improvements were observed for the Illinois CoD test (ES = 0.61), 5- and 20-m sprint time test (ES = 1.00 for both the tests), countermovement jump test (ES = 1.00), and the maximal kicking-distance test (ES = 0.90). Small enhancements in the standing long jump test (ES = 0.50) were apparent. Regarding the UPJT group, small improvements were observed for all tests (ES = 0.33-0.57), except 5- and 10-m sprint time (ES = 1.00 and 0.63, respectively). Between-group analyses favored the LPJT group for the modified 505 CoD (ES = 0.61), standing long jump (ES = 0.50), and maximal kicking-distance tests (ES = 0.57), but not for the 5-m sprint time test (ES = 1.00). Only trivial between-group differences were shown for the remaining tests (ES = 0.00-0.09). Conclusion: Overall, LPJT appears to be more effective than UPJT in improving measures of muscle power, speed, CoD, and kicking-distance performance in prepubertal male soccer players.
KW  - young
KW  - football
KW  - stretch-shortening cycle
KW  - maturity
KW  - athletic
KW  - performance
Y1  - 2020
U6  - https://doi.org/10.1123/ijspp.2018-0866
SN  - 1555-0265
SN  - 1555-0273
VL  - 15
IS  - 2
SP  - 189
EP  - 195
PB  - Human Kinetics
CY  - Champaign, Ill.
ER  - 
TY  - JOUR
A1  - Negra, Yassine
A1  - Chaabene, Helmi
A1  - Sammoud, Senda
A1  - Bouguezzi, Raja
A1  - Mkaouer, Bessem
A1  - Hachana, Younes
A1  - Granacher, Urs
T1  - EFFECTS OF PLYOMETRIC TRAINING ON COMPONENTS OF PHYSICAL FITNESS IN PREPUBERAL MALE SOCCER ATHLETES: THE ROLE OF SURFACE INSTABILITY
JF  - Journal of strength and conditioning research : the research journal of the NSCA
N2  - Previous studies contrasted the effects of plyometric training (PT) conducted on stable vs. unstable surfaces on components of physical fitness in child and adolescent soccer players. Depending on the training modality (stable vs. unstable), specific performance improvements were found for jump (stable PT) and balance performances (unstable PT). In an attempt to combine the effects of both training modalities, this study examined the effects of PT on stable surfaces compared with combined PT on stable and unstable surfaces on components of physical fitness in prepuberal male soccer athletes. Thirty-three boys were randomly assigned to either a PT on stable surfaces (PTS; n = 17; age = 12.1 +/- 0.5 years; height = 151.6 +/- 5.7 cm; body mass = 39.2 +/- 6.5 kg; and maturity offset = 22.3 +/- 0.5 years) or a combined PT on stable and unstable surfaces (PTC; n = 16; age = 12.2 +/- 0.6 years; height = 154.6 +/- 8.1 cm; body mass = 38.7 +/- 5.0 kg; and maturity offset = 22.2 +/- 0.6 years). Both intervention groups conducted 4 soccer-specific training sessions per week combined with either 2 PTS or PTC sessions. Before and after 8 weeks of training, proxies of muscle power (e.g., countermovement jump [CMJ], standing long jump [SLJ]), muscle strength (e.g., reactive strength index [RSI]), speed (e.g., 20-m sprint test), agility (e.g., modified Illinois change of direction test [MICODT]), static balance (e.g., stable stork bal-ance test [SSBT]), and dynamic balance (unstable stork balance test [USBT]) were tested. An analysis of covariance model was used to test between-group differences (PTS vs. PTC) at posttest using baseline outcomes as covariates. No significant between-group differences at posttest were observed for CMJ (p > 0.05, d = 0.41), SLJ (p > 0.05, d = 0.36), RSI (p > 0.05, d = 0.57), 20-m sprint test (p > 0.05, d = 0.06), MICODT (p > 0.05, d = 0.23), and SSBT (p > 0.05, d = 0.20). However, statistically significant between-group differences at posttest were noted for the USBT (p < 0.01, d = 1.49) in favor of the PTC group. For most physical fitness tests (except RSI), significant pre-to-post improvements were observed for both groups (p < 0.01, d = 0.55-3.96). Eight weeks of PTS or PTC resulted in similar performance improvements in components of physical fitness except for dynamic balance. From a performance-enhancing perspective, PTC is recommended for pediatric strength and conditioning coaches because it produced comparable training effects as PTS on proxies of muscle power, muscle strength, speed, agility, static balance, and additional effects on dynamic balance.
KW  - youth
KW  - football
KW  - stretch-shortening cycle
KW  - athletic performance
KW  - balance
Y1  - 2017
SN  - 1064-8011
SN  - 1533-4287
VL  - 31
SP  - 3295
EP  - 3304
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Negra, Yassine
A1  - Chaabene, Helmi
A1  - Fernandez-Fernandez, Jaime
A1  - Sammoud, Senda
A1  - Bouguezzi, Raja
A1  - Prieske, Olaf
A1  - Granacher, Urs
T1  - Short-term plyometric Jump training improves repeated-sprint ability in prepuberal male soccer players
JF  - Journal of strength and conditioning research : the research journal of the NSCA
N2  - This study examined the effects of a short-term (i.e., 8 weeks) combined horizontal and vertical plyometric jump training (PJT) program in combination with regular soccer-specific training as compared with soccer-specific training only on jump and change of direction (CoD) performances, speed, and repeated-sprint ability (RSA) in prepuberal male soccer players. Twenty-four players were recruited and randomly assigned to either a PJT group (PJT(G); n = 13; 12.7 +/- 0.2 years) or an active control group (CONG; n = 11; 12.7 +/- 0.2 years). The outcome measures included tests for the assessment of jump performance (drop jump from 20- to 40-cm height [DJ20 and DJ40] and 3-hop test [THT]), speed (20-m sprint), CoD (T-test), and RSA (20-m repeated shuttle sprint). Data were analyzed using magnitude-based inferences. Within-group analyses revealed large performance improvements in the T-test (d = -1.2), DJ20 (d = 3.7), DJ40 (d = 3.6), THT (d = 0.6), and the RSA(total) (d = -1.6) in the PJT(G). Between-group analyses showed greater performance improvements in the T-test (d = -2.9), 20-m sprint time (d = -2.0), DJ20 (d = 2.4), DJ40 (d = 2.0), THT (d = 1.9), RSA(best) (d = -1.9), and the RSA(total) (d = -1.9) in the PJT(G) compared with CONG. Eight weeks of an in-season PJT in addition to regular soccer-specific training induced larger increases in measures of physical fitness in prepuberal male soccer players compared with regular soccer-specific training only. More specifically, PJT was effective in improving RSA performance.
KW  - youth
KW  - stretch-shortening cycle
KW  - athletic performance
KW  - soccer
Y1  - 2020
U6  - https://doi.org/10.1519/JSC.0000000000002703
SN  - 1064-8011
SN  - 1533-4287
VL  - 34
IS  - 11
SP  - 3241
EP  - 3249
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Chaabene, Helmi
A1  - Negra, Yassine
A1  - Moran, Jason
A1  - Prieske, Olaf
A1  - Sammoud, Senda
A1  - Ramirez-Campillo, Rodrigo
A1  - Granacher, Urs
T1  - Plyometric training improves not only measures of linear speed, power, and change-of-direction speed but also repeated sprint ability in young female handball players
JF  - Journal of strength and conditioning research : the research journal of the NSCA
N2  - This study examined the effects of an 8-week plyometric training (PT) program on components of physical fitness in young female handball players. Twenty-one female adolescent handball players were assigned to an experimental group (EG, n = 12; age = 15.9 +/- 0.2 years) or an active control group (CG, n = 9, age = 15.9 +/- 0.3 years). While EG performed plyometric exercises in replacement of some handball-specific drills, CG maintained the regular training schedule. Baseline and follow-up tests were performed for the assessment of linear speed (i.e., 5-, 10-, and 20-m time), change-of-direction (CoD) speed (i.e., T-test time), muscle power (i.e., countermovement jump [CMJ] height and reactive strength index [RSI]), and repeated sprint ability (RSA) (RSA total time [RSA(total)], RSA best time [RSA(best)], and RSA fatigue index [RSA(FI)]). Data were analyzed using magnitude-based inferences. Within-group analyses for the EG revealed moderate-to-large improvements for the 5-m (effect size [ES] = 0.81 [0.1-1.5]), 10-m sprint time (ES = 0.84 [0.1-1.5]), RSI (ES = 0.75 [0.1-1.4]), RSA(FI) (ES = 0.65 [0.0-1.3]), and T-test time (ES = 1.46 [0.7-2.2]). Trivial-to-small ES was observed for RSA(best) (ES = 0.18 [-0.5 to 0.9]), RSA(total) (ES = 0.45 [-0.2 to 1.1]), 20-m sprint time (ES = 0.56 [-0.1 to 1.2]), and CMJ height (ES = 0.57 [-0.1 to 1.3]). For the CG, within-group analyses showed a moderate performance decline for T-test time (ES = -0.71 [-1.5 to 0.1]), small decreases for 5-m sprint time (ES = -0.46 [-1.2 to 0.3]), and a trivial decline for 10-m (ES = -0.10 [-0.9 to 0.7]) and 20-m sprint times (ES = -0.16 [-0.9 to 0.6]), RSA(total) (ES = 0.0 [-0.8 to 0.8]), and RSA(best) (ES = -0.20 [-0.9 to 0.6]). The control group achieved trivial-to-small improvements for CMJ height (ES = 0.10 [-0.68 to 0.87]) and RSI (ES = 0.30 [-0.5 to 1.1]). In conclusion, a short-term in-season PT program, in replacement of handball-specific drills, is effective in improving measures of physical fitness (i.e., linear/CoD speed, jumping, and RSA) in young female handball players.
KW  - stretch-shortening cycle
KW  - physical fitness
KW  - young athletes
Y1  - 2021
U6  - https://doi.org/10.1519/JSC.0000000000003128
SN  - 1064-8011
SN  - 1533-4287
VL  - 35
IS  - 8
SP  - 2230
EP  - 2235
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  -