ECSS Paris 2023: CP-AP20
INTRODUCTION: This study forms part of a systematic review and meta-analysis examining the effects of exercise training on the performance of racket sports athletes. In this section, we compare the impact of resistance training, plyometric training, and complex training on change-of-direction ability, whilst exploring sources of heterogeneity within the current evidence—particularly concerning factors such as training duration and frequency. METHODS: The protocol was prospectively registered ( PROSPERO CRD420251267647 ). We systematically searched seven electronic databases, including CNKI, PubMed, Web of Science, Scopus, SPORTDiscus, the Cochrane Library, and Embase, to identify randomized controlled trials (RCTs) that met the inclusion criteria. Ultimately, 17 studies involving 512 athletes were included. A random-effects model was employed to calculate standardized mean differences (SMDs), supplemented by subgroup analyses to explore the impact of factors such as training mode, duration, and frequency on outcomes. RESULTS: The overall analysis revealed that all three intervention methods significantly improved change-of-direction ability, with a pooled effect size of SMD = −0.96 [−1.37, −0.55], demonstrating high statistical significance (P < 0.0001). However, substantial heterogeneity existed between studies (I² = 77.40%). Sensitivity analyses indicated that excluding any single study had minimal impact on the overall effect size, suggesting robust results. Subgroup analyses revealed greater effects for interventions involving an 8-week training period and twice- or thrice-weekly training sessions. Training mode and training frequency exerted minimal explanatory influence on heterogeneity. CONCLUSION: The meta analysis findings of this study indicate that exercise training interventions can generally significantly improve the change-of-direction ability of racquet sports athletes. However, considerable heterogeneity exists between studies, and the current evidence has not yet established a stable and directly generalizable effect pattern. Subgroup analyses suggest that training duration and frequency may be key moderating factors influencing the consistency of training effects. Conversely, training modality and total training volume failed to significantly account for inter-study heterogeneity, indicating these factors may exert relatively consistent or negligible effects on agility enhancement. Future research should employ more standardized designs to further validate these findings and elucidate the training characteristics influencing agility performance.
Read CV CHUAN ZE LIECSS Paris 2023: CP-AP20
INTRODUCTION: Agility is fundamental to volleyball, particularly in defensive and transitional actions requiring rapid braking, reorientation, and re‑acceleration. As the distal link of the lower limb kinetic chain, the plantar flexor muscles operate under tight time constraints and rely heavily on stretch‑shortening cycle (SSC) efficiency and rapid force production. However, direct comparisons between “static reserve” capacity (peak force, PF; force symmetry rate, FSR) and “SSC‑related” qualities (reactive strength index, RSI; rate of force development, RFD) in explaining agility performance remain scarce, and strength‑agility profiles is poorly understood. This study aimed to quantify the relative contributions of plantar flexor strength measures to pre‑planned (modified agility T‑test, MAT) and reactive (digging agility test, DAT) agility METHODS: 19 male elite volleyball players from the Chinese Volleyball Super League (age 24.95 ± 3.54 yrs, height 195.3 ± 10.6 cm, mass 89.3 ± 8.7 kg) performed: (i) seated isometric plantar flexion testing to obtain bilateral PF, FSR, and RFD at 0–50/100/150/200/250 ms; (ii) 40 cm drop jumps to determine RSI, eccentric RFD, and surface EMG root mean square (RMS) of the soleus, gastrocnemius medialis and lateralis; (iii) MAT and DAT. Normality was assessed with Shapiro–Wilk tests. Pearson/Spearman correlations and multiple linear regression (covariates: height, mass, age, training experience) were used to examine relationships between strength measures and agility performance. RESULTS: MAT correlated moderately with RSI (r=–0.517, p=0.023), left‑leg RFD at 0–100 ms (r=–0.552, p=0.014), and right‑leg RFD at 0–200 ms (r=–0.550, p=0.015). RSI independently explained 37.2% of MAT variance (β=–0.651, p=0.006). Neither PF nor FSR showed significant independent prediction for MAT or DAT. DAT was not significantly associated with any strength or EMG variable. CONCLUSION: MAT is primarily determined by plantar flexor SSC efficiency (RSI) and early neural drive (0–100 ms RFD), with only minimal contribution from PF or FSR. The underlying reason lies in the time constraints of cutting tasks: ground contact time during directional changes is typically below 250 ms—far shorter than the time required to reach peak force—thereby limiting the translation of strength reserves into effective braking and re‑acceleration impulse. In contrast, DAT cannot be adequately explained by isolated strength measures; its performance appears more dependent on perceptual‑decision efficiency and motor coordination, suggesting that strength‑only training is insufficient to improve this task domain. From a practical standpoint, training emphasis should be placed on enhancing RSI and early RFD, with position‑specific interventions guided by individual strength profiles. PF and FSR are better reserved as monitoring tools for strength reserve and rehabilitation progress. Collectively，these findings establish a clear hierarchy of strength qualities for guiding agility training in volleyball.
Read CV Xuan QiECSS Paris 2023: CP-AP20
INTRODUCTION: Basketball performance depends on reactive agility—the ability to rapidly perceive stimuli and execute effective directional changes in both pre-planned and reactive situations. This ability integrates perceptual, decision-making, and physical components and distinguishes players of different levels. Reliable assessment of reactive agility is essential for talent identification and monitoring training adaptations. However, many existing tests rely on simple, limited-choice tasks that do not reflect basketball’s complex, multidirectional demands. To address this limitation, a light-based reactive agility wall test was developed, incorporating short-distance, multidirectional, and defensive-specific movements triggered by multiple stimuli. This study evaluated the test’s reliability and examined whether body height influences reactive agility performance in basketball players. METHODS: Thirty-two male university amateur basketball players participated (age 22.3 ± 2.2 years; height 190.7 ± 8.2 cm; weight 80.1 ± 10.9 kg). The standardized test used eight trigger lights symmetrically positioned on horizontal arms mounted on a 2.2-m vertical frame, placed 1.5 m from the starting line (Witty SEM, Bolzano, Italy). Players consecutively deactivated eight illuminated lights by stepping forward and then returning backward to the starting line before responding to the next stimulus. Across three laboratory sessions (conducted every other day), participants completed pre-planned and reactive trials to assess test–retest reliability and anthropometric influences. Each session included eight trials: four reactive (unknown sequence) and four pre-planned (numbered sequence). The four trials per condition were averaged for analysis. The reactivity index was calculated as the difference between reactive and pre-planned completion times. Reliability was assessed using intraclass correlation coefficients (ICC), and multiple regression analyses examined anthropometric effects. RESULTS: Pre-planned trials were completed faster than reactive trials (p < 0.001). Pre-planned and reactive trials demonstrated good test–retest reliability (ICC = 0.895 and 0.848, respectively), as did the reactivity index (ICC = 0.891). Performance improved on Day 2 in both conditions, indicating a learning effect, whereas the reactivity index remained stable. Regression analyses indicated that height modestly explained task completion time (5–11% of the variance) but did not meaningfully influence the reactivity index. CONCLUSION: The newly developed test is a reliable measure of reactive agility. The reactivity index appears independent of participants’ height, suggesting that perceptual-cognitive components of performance are not substantially influenced by anthropometric differences. However, because height explains part of the variance in task completion times, scaling for height should be considered when pre-planned or reactive completion time is the primary outcome.
Read CV Audrius SNIECKUSECSS Paris 2023: CP-AP20