@article{ChaabeneMarkovPrieskeetal.2022,
  author    = {Chaabene, Helmi and Markov, Adrian and Prieske, Olaf and Moran, Jason and Behrens, Martin and Negra, Yassine and Ramirez-Campillo, Rodrigo and Koch, Ulrike and Mkaouer, Bessem},
  title     = {Effect of flywheel versus traditional resistance training on change of direction performance in male athletes},
  series = {International journal of environmental research and public health : IJERPH},
  volume    = {19},
  journal   = {International journal of environmental research and public health : IJERPH},
  number    = {12},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1661-7827},
  doi       = {10.3390/ijerph19127061},
  pages     = {17},
  year      = {2022},
  abstract  = {Objective: This study aimed to systematically review and meta-analyze the effect of flywheel resistance training (FRT) versus traditional resistance training (TRT) on change of direction (CoD) performance in male athletes. Methods: Five databases were screened up to December 2021. Results: Seven studies were included. The results indicated a significantly larger effect of FRT compared with TRT (standardized mean difference [SMD] = 0.64). A within-group comparison indicated a significant large effect of FRT on CoD performance (SMD = 1.63). For TRT, a significant moderate effect was observed (SMD = 0.62). FRT of <= 2 sessions/week resulted in a significant large effect (SMD = 1.33), whereas no significant effect was noted for >2 sessions/week. Additionally, a significant large effect of <= 12 FRT sessions (SMD = 1.83) was observed, with no effect of >12 sessions. Regarding TRT, no significant effects of any of the training factors were detected (p > 0.05). Conclusions: FRT appears to be more effective than TRT in improving CoD performance in male athletes. Independently computed single training factor analyses for FRT indicated that <= 2 sessions/week resulted in a larger effect on CoD performance than >2 sessions/week. Additionally, a total of <= 12 FRT sessions induced a larger effect than >12 training sessions. Practitioners in sports, in which accelerative and decelerative actions occur in quick succession to change direction, should regularly implement FRT.},
  language  = {en}
}
@article{BehmAlizadehDruryetal.2021,
  author    = {Behm, David G. and Alizadeh, Shahab and Drury, Ben and Granacher, Urs and Moran, Jason},
  title     = {Non-local acute stretching effects on strength performance in healthy young adults},
  series = {European journal of applied physiology},
  volume    = {121},
  journal   = {European journal of applied physiology},
  number    = {6},
  publisher = {Springer},
  address   = {Berlin ; Heidelberg},
  issn      = {1439-6319},
  doi       = {10.1007/s00421-021-04657-w},
  pages     = {1517 -- 1529},
  year      = {2021},
  abstract  = {Background Static stretching (SS) can impair performance and increase range of motion of a non-exercised or non-stretched muscle, respectively. An underdeveloped research area is the effect of unilateral stretching on non-local force output. Objective The objective of this review was to describe the effects of unilateral SS on contralateral, non-stretched, muscle force and identify gaps in the literature. Methods A systematic literature search following preferred reporting items for systematic review and meta-analyses Protocols guidelines was performed according to prescribed inclusion and exclusion criteria. Weighted means and ranges highlighted the non-local force output response to unilateral stretching. The physiotherapy evidence database scale was used to assess study risk of bias and methodological quality. Results Unilateral stretching protocols from six studies involved 6.3 +/- 2 repetitions of 36.3 +/- 7.4 s with 19.3 +/- 5.7 s recovery between stretches. The mean stretch-induced force deficits exhibited small magnitude effect sizes for both the stretched (-6.7 +/- 7.1\%, d = -0.35: 0.01 to -1.8) and contralateral, non-stretched, muscles (-4.0 +/- 4.9\%, d = , 0.22: 0.08 to 1.1). Control measures exhibited trivial deficits. Conclusion The limited literature examining non-local effects of prolonged SS revealed that both the stretched and contralateral, non-stretched, limbs of young adults demonstrate small magnitude force deficits. However, the frequency of studies with these effects were similar with three measures demonstrating deficits, and four measures showing trivial changes. These results highlight the possible global (non-local) effects of prolonged SS. Further research should investigate effects of lower intensity stretching, upper versus lower body stretching, different age groups, incorporate full warm-ups, and identify predominant mechanisms among others.},
  language  = {en}
}
@article{DaviesDruryRamirezCampilloetal.2021,
  author    = {Davies, Michael J. and Drury, Benjamin and Ramirez-Campillo, Rodrigo and Chaabene, Helmi and Moran, Jason},
  title     = {Effect of plyometric training and biological maturation on jump and change of direction ability in female youth},
  series = {Journal of strength and conditioning research : the research journal of the NSCA / National Strength \& Conditioning Association},
  volume    = {35},
  journal   = {Journal of strength and conditioning research : the research journal of the NSCA / National Strength \& Conditioning Association},
  number    = {10},
  publisher = {Lippincott Williams \& Wilkins},
  address   = {Philadelphia},
  issn      = {1064-8011},
  doi       = {10.1519/JSC.0000000000003216},
  pages     = {2690 -- 2697},
  year      = {2021},
  abstract  = {Biological maturation has been shown to affect male youths' responses to plyometric training (PT). However, to date, no researcher has examined the effect of maturation on the effects of PT in female youth. We undertook the first controlled intervention study to examine this, focusing on adaptive responses to countermovement jump (CMJ), reactive strength index (RSI), and change of direction (COD) performance in groups of female youth divided by maturation status (years from peak height velocity [PHV]). The training program lasted 7 weeks with subjects undertaking 2 sessions of PT per week. In the mid-PHV group, there was a small increase (effect size; 90\% confidence interval = 0.40; -0.23 to 1.03) in CMJ performance. No changes were observed in the post-PHV group (0.02; -0.68 to 0.72). For RSI, there was a moderate increase in the mid-PHV group (0.94; 0.29-1.59) with only a trivial increase in the post-PHV group (0.06; -0.65 to 0.76). The intervention exerted no positive effect on COD performance in any group. Plyometric training seems to enhance CMJ and RSI in female youth, although the magnitude of adaptation could be affected by maturation status. A twice-per-week program of multidirectional jumping and hopping, with bilateral and unilateral components, can be used as a preparatory precursor to physical education classes or recreational sport.},
  language  = {en}
}
@article{PalmaMunozRamirezCampilloAzocarGallardoetal.2021,
  author    = {Palma-Mu{\~n}oz, Ignacio and Ram{\´i}rez-Campillo, Rodrigo and Azocar-Gallardo, Jairo and {\´A}lvarez, Cristian and Asadi, Abbas and Moran, Jason and Chaabene, Helmi},
  title     = {Effects of progressed and nonprogressed volume-based overload plyometric training on components of physical fitness and body composition variables in youth male basketball players},
  series = {Journal of strength and conditioning research : the research journal of the NSCA},
  volume    = {35},
  journal   = {Journal of strength and conditioning research : the research journal of the NSCA},
  number    = {6},
  publisher = {Lippincott Williams \& Wilkins},
  address   = {Philadelphia},
  issn      = {1064-8011},
  doi       = {10.1519/JSC.0000000000002950},
  pages     = {1642 -- 1649},
  year      = {2021},
  abstract  = {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.},
  language  = {en}
}
@article{PrieskeChaabeneMoranetal.2022,
  author    = {Prieske, Olaf and Chaabene, Helmi and Moran, Jason and Saeterbakken, Atle Hole},
  title     = {Adaptations to Advanced Resistance Training Strategies in Youth and Adult Athletes},
  series = {Frontiers in physiology / Frontiers Research Foundation},
  volume    = {13},
  journal   = {Frontiers in physiology / Frontiers Research Foundation},
  publisher = {Frontiers Media},
  address   = {Lausanne},
  issn      = {1664-042X},
  doi       = {10.3389/fphys.2022.888118},
  pages     = {3},
  year      = {2022},
  language  = {en}
}
@article{ChaabeneNegraMoranetal.2021,
  author    = {Chaabene, Helmi and Negra, Yassine and Moran, Jason and Prieske, Olaf and Sammoud, Senda and Ramirez-Campillo, Rodrigo and Granacher, Urs},
  title     = {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},
  series = {Journal of strength and conditioning research : the research journal of the NSCA},
  volume    = {35},
  journal   = {Journal of strength and conditioning research : the research journal of the NSCA},
  number    = {8},
  publisher = {Lippincott Williams \& Wilkins},
  address   = {Philadelphia},
  issn      = {1064-8011},
  doi       = {10.1519/JSC.0000000000003128},
  pages     = {2230 -- 2235},
  year      = {2021},
  abstract  = {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.},
  language  = {en}
}
@article{MoranValiDruryetal.2022,
  author    = {Moran, Jason and Vali, Norodin and Drury, Ben and Hammami, Raouf and Tallent, Jamie and Chaabene, Helmi and Ramirez-Campillo, Rodrigo},
  title     = {The effect of volume equated 1-versus 2-day formats of Nordic hamstring exercise training on fitness in youth soccer players},
  series = {PLOS ONE},
  volume    = {17},
  journal   = {PLOS ONE},
  number    = {12},
  publisher = {PLOS},
  address   = {San Francisco, California, US},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0277437},
  pages     = {13},
  year      = {2022},
  abstract  = {Purpose This randomised controlled trial examined the effect of an 8-week volume-equated programme of Nordic hamstring exercise (NHE) training, executed at frequencies of 1- or 2-days per week, on fitness (10 m and 40 m sprint, '505' change of direction [COD] and standing long jump [SLJ]) in male youth soccer players (mean age: 16.4 0.81 years). Method Players were divided into an experimental group (n = 16) which was further subdivided into 1-day (n = 8) and 2-day (n = 8) per week training groups and a control group (n = 8). Results There were significant group-by-time interactions for 10-m sprint (p<0.001, eta(2) = 0.120, d = 2.05 [0.57 to 3.53]), 40-m sprint (p = 0.001, eta(2) = 0.041, d = 1.09 [-0.23 to 2.4]) and COD (p = 0.002, eta(2) = 0.063, d = 1.25 [-0.09 to 2.59). The experimental group demonstrated a 'very large' effect size (d = 3.02 [1.5 to 4.54]) in 10-m sprint, and 'large' effect sizes in 40-m sprint (d = 1.94 [0.98 to 2.90]) and COD (d = 1.84 [0.85 to 2.83). The control group showed no significant changes. There were no significant differences between the 1-day and 2-day training groups. In three of the four tests (40 m, COD, SLJ) the 2-day group demonstrated larger effect sizes. Ratings of perceived exertion (RPE) were significantly lower in the 2-day group (p<0.001, 3.46 [1.83 to 5.04). Conclusion The NHE increases fitness in youth soccer players and there may be advantages to spreading training over two days instead of one.},
  language  = {en}
}
@article{NegraChaabeneSammoudetal.2020,
  author    = {Negra, Yassine and Chaabene, Helmi and Sammoud, Senda and Prieske, Olaf and Moran, Jason and Ramirez-Campillo, Rodrigo and Nejmaoui, Ali and Granacher, Urs},
  title     = {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},
  series = {International journal of sports physiology and performance : IJSSP},
  volume    = {15},
  journal   = {International journal of sports physiology and performance : IJSSP},
  number    = {2},
  publisher = {Human Kinetics},
  address   = {Champaign, Ill.},
  issn      = {1555-0265},
  doi       = {10.1123/ijspp.2018-0866},
  pages     = {189 -- 195},
  year      = {2020},
  abstract  = {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.},
  language  = {en}
}
@article{MoranPaxtonJonesetal.2020,
  author    = {Moran, Jason and Paxton, Kevin and Jones, Ben and Granacher, Urs and Sandercock, Gavin Rh and Hope, Edward and Ramirez-Campillo, Rodrigo},
  title     = {Variable long-term developmental trajectories of short sprint speed and jumping height in English Premier League academy soccer players: an applied case study},
  series = {Journal of sports sciences},
  volume    = {38},
  journal   = {Journal of sports sciences},
  number    = {22},
  publisher = {Routledge, Taylor \& Francis Group},
  address   = {London},
  issn      = {0264-0414},
  doi       = {10.1080/02640414.2020.1792689},
  pages     = {2525 -- 2531},
  year      = {2020},
  abstract  = {Growth and maturation affect long term physical performance, making the appraisal of athletic ability difficult. We sought to longitudinally track youth soccer players to assess the developmental trajectory of athletic performance over a 6-year period in an English Premier League academy. Age-specific z-scores were calculated for sprint and jump performance from a sample of male youth soccer players (n = 140). A case study approach was used to analyse the longitudinal curves of the six players with the longest tenure. The trajectories of the sprint times of players 1 and 3 were characterised by a marked difference in respective performance levels up until peak height velocity (PHV) when player 1 achieved a substantial increase in sprint speed and player 3 experienced a large decrease. Player 5 was consistently a better performer than player 2 until PHV when the sprint and jump performance of the former markedly decreased and he was overtaken by the latter. Fluctuations in players' physical performance can occur quickly and in drastic fashion. Coaches must be aware that suppressed, or inflated, performance could be temporary and selection and deselection decisions should not be made based on information gathered over a short time period.},
  language  = {en}
}
@article{ChaabenePrieskeMoranetal.2020,
  author    = {Chaabene, Helmi and Prieske, Olaf and Moran, Jason and Negra, Yassine and Attia, Ahmed and Granacher, Urs},
  title     = {Effects of resistance training on Change-of-Direction speed in youth and young physically active and athletic adults: a systematic review with meta-analysis},
  series = {Sports medicine : the world's premier sports medicine preview journal},
  volume    = {50},
  journal   = {Sports medicine : the world's premier sports medicine preview journal},
  number    = {8},
  publisher = {Springer},
  address   = {Berlin [u.a.]},
  issn      = {0112-1642},
  doi       = {10.1007/s40279-020-01293-w},
  pages     = {1483 -- 1499},
  year      = {2020},
  abstract  = {Background Change-of-direction (CoD) speed is a physical fitness attribute in many field-based team and individual sports. To date, no systematic review with meta-analysis available has examined the effects of resistance training (RT) on CoD speed in youth and adults. Objective To aggregate the effects of RT on CoD speed in youth and young physically active and athletic adults, and to identify the key RT programme variables for training prescription. Data sources A systematic literature search was conducted with PubMed, Web of Science, and Google Scholar, with no date restrictions, up to October 2019, to identify studies related to the effects of RT on CoD speed. Study Eligibility Criteria Only controlled studies with baseline and follow-up measures were included if they examined the effects of RT (i.e., muscle actions against external resistances) on CoD speed in healthy youth (8-18 years) and young physically active/athletic male or female adults (19-28 years). Study Appraisal and Synthesis Methods A random-effects model was used to calculate weighted standardised mean differences (SMD) between intervention and control groups. In addition, an independent single training factor analysis (i.e., RT frequency, intensity, volume) was undertaken. Further, to verify if any RT variable moderated effects on CoD speed, a multivariate random-effects meta-regression was conducted. The methodological quality of the included studies was assessed using the physiotherapy evidence database (PEDro) scale. Results Fifteen studies, comprising 19 experimental groups, were included. The methodological quality of the studies was acceptable with a median PEDro score of 6. There was a significant large effect size of RT on CoD speed across all studies (SMD = - 0.82 [- 1.14 to - 0.49]). Subgroup analyses showed large effect sizes on CoD speed in males (SMD = - 0.95) contrasting with moderate improvements in females (SMD = - 0.60). There were large effect sizes on CoD speed in children (SMD = - 1.28) and adolescents (SMD = - 1.21) contrasting with moderate effects in adults (SMD = - 0.63). There was a moderate effect in elite athletes (SMD = - 0.69) contrasting with a large effect in subelite athletes (SMD = - 0.86). Differences between subgroups were not statistically significant. Similar improvements were observed regarding the effects of independently computed training variables. In terms of RT frequency, our results indicated that two sessions per week induced large effects on CoD speed (SMD = - 1.07) while programmes with three sessions resulted in moderate effects (SMD = - 0.53). For total training intervention duration, we observed large effects for <= 8 weeks (SMD = - 0.81) and > 8 weeks (SMD = - 0.85). For single session duration, we found large effects for <= 30 min and >= 45 min (both SMD = - 1.00). In terms of number of training sessions, we identified large effects for <= 16 sessions (SMD = - 0.83) and > 16 sessions (SMD = - 0.81). For training intensity, we found moderate effects for light-to-moderate (SMD = - 0.76) and vigorous-to-near maximal intensities (SMD = - 0.77). With regards to RT type, we observed large effects for free weights (SMD = - 0.99) and machine-based training (SMD = - 0.80). For combined free weights and machine-based training, moderate effects were identified (SMD = - 0.77). The meta-regression outcomes showed that none of the included training variables significantly predicted the effects of RT on CoD speed (R-2 = 0.00). Conclusions RT seems to be an effective means to improve CoD speed in youth and young physically active and athletic adults. Our findings indicate that the impact of RT on CoD speed may be more prominent in males than in females and in youth than in adults. Additionally, independently computed single factor analyses for different training variables showed that higher compared with lower RT intensities, frequencies, and volumes appear not to have an advantage on the magnitude of CoD speed improvements. In terms of RT type, similar improvements were observed following machine-based and free weights training.},
  language  = {en}
}