Search Results (36)

Background: Strength-Duration (S-D) assessment is commonly used in clinics to examine the excitability of peripheral nerves and muscles. Yet, how changes in neuromuscular excitability relate to improved athletic and muscular performance in healthy subjects remains poorly understood. Therefore, the aim of the study was to evaluate the electrophysiological changes in neuromuscular excitability in the vastus medialis (VM) muscle using the S-D assessment, following a back squat conditioning activity (BS-CA) protocol designed to elicit a post-activation potentiation (PAP)/post-activation performance enhancement (PAPE) effect in healthy athletic males. Methods: Eleven male physical education students were included in this study. All subjects performed two trials: one examining their BS one-repetition maximum (1-RM), and a main experiment. During the main experiment, baseline levels of rectangular rheobase (R-RIC), triangular rheobase (R-DIC), and chronaxie were collected from the VM muscle following a standard warmup. Subsequently, the subjects performed four warmup BS sets and executed a top set of five repetitions (reps) at 80% of 1-RM. Afterwards, R-RIC, R-DIC, and chronaxie were reassessed for pre and post analysis. Based on these S-D curve (SDC) parameters, the muscle adjustability quotient (MAQ) and threshold charge (Q) were also computed and compared. Results: The R-RIC, R-DIC and Q were all significantly higher following the BS-CA, compared to pre-intervention (p < 0.001). No significant differences were observed for the chronaxie and MAQ (p > 0.05), although an increasing trend was noted for the chronaxie (p = 0.054). Conclusions: Based on the findings from this study, the neuromuscular excitability in the VM muscle can be acutely altered following a BS-CA protocol. However, these changes seem to be more related to muscle fatigue than PAP/PAPE. Nevertheless, S-D assessment may broaden our understanding of the fatigue process during exercise. Full article

Background: Targeted training interventions, including neuromuscular warm-up protocols, eccentric resistance training, and dynamic stretching exercises, with limited and heterogeneous evidence on recovery strategies, have shown potential benefits for muscle performance and reductions in injury risk. Objective: To synthesize and structure contemporary evidence on exercise-based interventions spanning the pre-activity warm-up through post-activity recovery, emphasizing performance outcomes, injury-related effects, reported dose–response patterns, and implementation characteristics. Methods: This systematic review with structured qualitative synthesis was based on a systematic database search and eligibility screening process (n = 40 studies). Studies evaluating exercise-based interventions targeting injury prevention and/or performance in athletes were included. Data extraction included study design, population characteristics, intervention components, outcomes, and risk-of-bias assessments, which were summarized using comparative tables and descriptive analyses. Due to heterogeneity, results were synthesized qualitatively without meta-analysis. Results: Neuromuscular warm-ups (e.g., FIFA 11+) were frequently linked to reduced reported lower-extremity injury risk, alongside improvements in sprint, jump, and balance performance. Eccentric hamstring training was linked in several studies to lower reported hamstring injury rates and increased eccentric strength and fascicle length, while dynamic warm-ups may acutely improve sprint and jump performance. Evidence regarding recovery modalities was heterogeneous, supporting a cautious and individualized emphasis on sleep, nutrition, and hydration. However, heterogeneity in study designs, outcome measures, and populations limits the comparability and generalizability of the findings. Conclusions: Exercise-based interventions, including neuromuscular warm-ups, eccentric strengthening, dynamic stretching, and progressive load and recovery strategies, may support performance enhancement and injury-risk reduction in youth and adult athletes when appropriately implemented, although interpretation is limited by study heterogeneity. Full article

This case report documents the multi-season development of a 38-year-old elite F12 shot putter with macular degeneration (<10% functional vision) who improved from 13.00 m to a personal best of 14.41 m between 2021 and 2023. Athletes classified as F11–F13 compete with significant visual impairment that limits spatial feedback during rotational tasks, yet longitudinal evidence describing integrated training frameworks remains scarce. A 12-month macrocycle integrated phase-dependent velocity-based resistance training using mean concentric velocity targets (0.70–1.00 m·s⁻¹) monitored via linear position transducers with a 10% velocity loss threshold, combined with structured auditory and tactile cueing, including metronome pacing and environmental anchors. High-volume warm-ups and prehabilitation addressed a prior L4–L5 disk herniation. The athlete achieved 14.41 m at the 2023 U.S. Para Athletics Trials, with TrackMan^®-verified release velocity of 11.3 m·s⁻¹. Bench throw velocity improved by 35.4% (0.65 to 0.88 m·s⁻¹) and squat jump velocity improved by 22.9% (1.18 to 1.45 m·s⁻¹), while post-session RPE remained manageable, indicating improved neuromuscular readiness and training tolerance. No lumbar symptom recurrence occurred. This case illustrates that integrating velocity autoregulation, multisensory stabilization, and injury-informed preparation can support meaningful performance gains in visually impaired throwers and offers an applied framework for coaches working with F11–F13 athletes. Full article

The purpose of the present study was to examine whether countermovement vertical jump (CMJ) force-time metrics differ among teams with three ranking statuses competing within the same professional women’s handball league in Europe (i.e., SuperLeague). Following a standardized dynamic warm-up procedure, twenty-six professional female handball players (top-ranked: n = 8; mid-ranked: n = 8; bottom-ranked: n = 10) performed three CMJs on a uni-axial force plate sampling at 1000 Hz (VALD Performance). Nineteen force-time metrics were derived to characterize neuromuscular performance qualities during both the eccentric (i.e., braking) and concentric (i.e., propulsive) phases of the jumping motion. A one-way ANOVA revealed no statistically significant differences (p < 0.05) between the teams for any CMJ force-time metric of interest (i.e., peak and mean eccentric force and power, jump height, reactive strength index-modified, countermovement depth, eccentric and concentric duration) across ranking status in either phase of the movement, nor for anthropometric characteristics (i.e., height and body mass). Overall, the results indicate that CMJ force-time metrics did not differentiate team ranking status within this sample of professional female handball players. These findings suggest that, within a homogeneous cohort competing at the same level of play, CMJ-derived neuromuscular performance characteristics may have limited sensitivity for distinguishing between teams of different competitive rankings. While CMJ force-time analysis remains a useful tool for monitoring individual neuromuscular status, the present results do not allow conclusions regarding the role of other performance determinants (e.g., tactical or technical factors), which were not directly assessed in this study. Full article

Background and Objectives: The assessment of neuromuscular recovery after ACL reconstruction is crucial for safe return to sport (RTS) in professional soccer players. This retrospective cross-sectional study aimed to compare squat jump (SJ), bilateral countermovement jump (CMJ), and single-leg CMJ performance in three distinct groups: players at 6 months post-ACL reconstruction, players at 9 months post-ACL reconstruction, and healthy controls. Materials and Methods: Seventy-two male players (24 at 6 months post-ACL, 24 at 9 months post-ACL, 24 healthy controls) performed squat jump, bilateral countermovement jump, and single-leg CMJ tests using contact platforms following a controlled warm-up protocol. Results: Significant group differences were observed in all jump tests. At 6 months post-ACL reconstruction, players demonstrated significantly lower squat jump (45.13 ± 6.20 cm) and bilateral countermovement jump (49.67 ± 6.80 cm) heights compared to both 9-month players (SJ: 50.03 ± 5.30 cm; CMJ: 53.79 ± 4.85 cm) and controls (SJ: 51.12 ± 4.97 cm; CMJ: 55.49 ± 5.54 cm) (p ≤ 0.016, η² = 0.187 and η² = 0.156, respectively). No significant differences between 9-month and control groups were observed for the squat jump and the bilateral countermovement jump. Regarding the unilateral countermovement jump, the injured leg showed significant performance deficits compared to controls in both the 6-month and 9-month groups (p = 0.001, η² = 0.378). However, the non-injured leg exhibited deficits only in the 6-month group. Conclusions: Compared to the 6-month post-ACL reconstruction group, the 9-month group showed a marked improvement in bilateral jump performance, indicating substantial neuromuscular recovery over time. However, persistent unilateral deficits in the injured leg remained even at 9 months, underscoring the need for a routine and comprehensive jumping evaluation to identify residual neuromuscular impairments that may require targeted rehabilitation before returning to sport. Full article

A warm-up is a critical procedure in sports science for enhancing muscular performance and optimizing subsequent athletic activities. However, the physiological and athletic performance effects of a warm-up are often transient, diminishing rapidly during the period of inactivity after the warm-up, which is known as the warm-up transition phase. In this study, a multi-functional thermoregulation wearable composite film of graphene–MXene–bacterial cellulose/polyethylene glycol (G-M-BC/PEG) was developed by integrating MXene (a two-dimensional material with good photothermal conversion performance) and graphene into a bacterial cellulose aerogel framework, subsequently impregnated with polyethylene glycol (PEG-2000). The film showed stable structure, efficient solar photothermal conversion and storage (SPCS), and improved mechanical properties. Under 1 sun irradiation, the optimized G-M-BC/PEG wearable film showed excellent SPCS performance, sustaining a temperature plateau of 38–40 °C for 10 min after the xenon lamp was switched off under 1 sun irradiation, with a leakage rate of only 5.32% after five cycles. By constructing a biomimetic sports human body model, the composite aerogel was shown to significantly elevate muscle surface temperature and effectively mitigate heat loss during the transition phase. In the warm-up effectiveness and sports performance tests, the wearable film improved 200 m sprint performance by 0.8% ± 0.4% (p = 0.039). It also maintained subjective thermal sensation during the warm-up transition phase, with no significant decline at 5 or 10 min after the warm-up and a significant decrease only at 15 min (p = 0.02), while thermal comfort remained stable, suggesting improved neuromuscular readiness. This research provided a novel strategy for the fabrication of advanced aerogel-based wearable devices aimed at precision thermal management and athletic performance optimization. Full article

Background and Objectives: Percussive massage devices (PMDs) are increasingly used as warm-up tools to enhance neuromuscular performance; however, evidence regarding the optimal intensity and its interaction with circadian variation remains limited. This study examined the acute effects of two percussive massage intensities (low: 28 Hz; moderate: 35 Hz) compared with no massage on change-of-direction (COD) performance, vertical jump kinetics, and neuromuscular variables in trained male football players across morning and evening sessions. Materials and Methods: Eighteen trained male football players completed a randomized, counterbalanced crossover design involving three protocols (no massage, 28 Hz, and 35 Hz) performed in both morning (09:00–11:00) and evening (17:00–19:00) sessions following a standardized warm-up protocol. COD performance (T-Test and Illinois COD Test), countermovement jump height, and model-derived kinetic variables were assessed. Results: Significant main effects of the protocol were observed for T-test performance, jump height, velocity-related variables, and kinetic outcomes (p < 0.001; large effect sizes), with both percussive massage intensities outperforming the no-massage condition. Significant protocol × time-of-day interactions emerged for jump height, force, and impulse-related variables (p < 0.05), indicating greater morning-specific benefits following moderate-intensity (35 Hz) massage. The Illinois COD Test showed no significant protocol-related changes. Conclusions: Acute percussive massage enhances COD performance and vertical jump-related outcomes in trained football players. While both intensities are effective for general performance enhancement, moderate-intensity massage (35 Hz) appears to be more effective for optimizing force–time characteristics and attenuating morning-related performance decrements. These findings support the inclusion of intensity- and time-specific percussive massage strategies in warm-up routines. Full article

Background/Objectives: The front kick is among the most commonly used techniques in martial arts. This study aimed to analyze the range of motion during the mae-geri kick in advanced-level Kyokushin karate practitioners compared to an intermediate-level control group under three conditions: before warm-up, after warm-up, and after a shadow fight. Methods: The study group [N = 28, M: 27.6 years, body mass 81.9 kg, height 1.8 m] consisted of advanced-level Kyokushin karate practitioners (3rd kyu and higher), and the control group consisted of intermediate-level practitioners (6th to 4th kyu). A wireless surface electromyography (EMG) system was used to record muscle activity and an inertial measurement unit (IMU) was used to measure joint angles. Before the study began, the maximum voluntary contraction was determined for each muscle tested. Each participant performed three consecutive kicks in three conditions: before warm-up, after warm-up, and after a shadow fight. Results: The intermediate-level practitioners used the soleus muscle more than advanced practitioners during the front kick (48.92% vs. 35.94% before the warm-up kick, p = 0.042, η²_p = 0.27). After the warm-up, both groups began to use the soleus muscle more intensively (intermediate: 48.92% vs. 61.72% MVC, p = 0.046; advanced: 35.94% vs. 48.69% MVC, p = 0.045), and the advanced group’s activity in the medial gastrocnemius muscle increased compared to before the warm-up (58.23% vs. 39.20% MVC, p = 0.016). Conclusions: Advanced vs. intermediate Kyokushin karate practitioners display distinct neuro-muscular activation strategies in the mae-geri kick, particularly in soleus and gastrocnemius recruitment. Combined EMG and IMU systems can identify trends and in-form training feedback in Kyokushin karate training and effectively prepare the musculoskeletal system for rapid activity, which is important during sports competitions. Full article

Understanding the long-term effectiveness of warm-up strategies is essential for enhancing neuromuscular performance in youth soccer players. This study examined the long-term effects of integrating squat exercises into the final phase of the warm-up over nine weeks on sprint, jump, change-of-direction (COD), and aerobic performance in youth soccer players. Twenty-four male U17 players were randomly assigned to either a squat-based warm-up (experimental group [EG]) or a rondo-based warm-up (control group [CG]). The EG trained twice weekly using 3–4 sets of 4–12 repetitions at progressively increasing intensities (50–85% of 1-RM). Performance was assessed pre- and post-intervention using 10 and 30 m sprint, squat jump (SJ), countermovement (CMJ), standing long jump (SLJ), 5-jump (5JT), T-half (COD), and VAMEVAL tests. The EG showed small to large significant gains in sprint (10 m: −2.21%, Cohen’s d [d] = 1; 30 m: −1.6%, d = 0.58), jumping (SJ: +9.29%, d = 1.23; CMJ: +12.08%, d = 1.83; SLJ: +7.14%, d = 0.8; 5JT: +2.33%, d = 0.32), and COD (−1.41%, d = 0.32), while aerobic endurance showed no significant change (p > 0.05). The CG showed no significant improvements (p > 0.05). Overall, integrating brief, progressive squat exercises at the end of warm-ups twice weekly led to chronic improvements in explosive neuromuscular performance, with minimal impact on aerobic endurance. Full article

Background: The study examined sex differences in countermovement jump (CMJ) force plate metrics and neuromuscular responses to a standardized dynamic warm-up in physically active college students. Methods: Forty-one participants (21 males, 20 females) completed pre- and post-warm-up assessments of CMJ performance using a dual force plate system. Body composition was measured via bioelectrical impedance analysis, and performance metrics included force, velocity, power, and other jump metrics. Percent change scores were calculated for all metrics. Results: Males demonstrated significantly greater improvements in braking force metrics compared to females, including force at minimum displacement (11.4% Δ male vs. 5.7% Δ female, p = 0.043), average braking force (10.6% Δ male vs. 5.0% Δ female, p = 0.043), and peak braking force (11.5% Δ male vs. 5.7% Δ female, p = 0.043). No significant sex differences were found in velocity, power, propulsive force, or other general CMJ performance variables. Hierarchical regression analyses revealed that sex was a significant (p ≤ 0.043 for all) predictor of changes in braking force metrics, while lean body mass did not enhance model fit or independently predict force changes. The addition of lean body mass slightly attenuated the sex effect but did not contribute meaningfully to the models. Conclusions: Findings suggest males may experience greater braking force adaptation to a dynamic warm-up, while other performance outcomes appear similar between sexes. These results may inform sex-specific warm-up strategies targeting neuromuscular readiness and braking force development. Full article

Jumping exercises are widely applied in sport performance and conditioning due to their crucial role in enhancing neuromuscular function and lower-limb power. Acute effects related to contractile properties measured by tensiomyography (TMG) remain insufficiently explored. This study aimed to examine the acute effects of two jump types—bilateral countermovement jumps (CMJs) and stiffness jumps (STs)—on the contractile properties of the vastus medialis (VM) and medial gastrocnemius (GM) muscles. Twenty-nine kinesiology students (fourteen males, fifteen females; age 19.4 ± 0.7 years) performed CMJ and ST protocols in a randomized order. Muscle contractile characteristics were measured before and immediately after each protocol and analyzed using a mixed-model repeated-measures ANOVA. Significant pre–post changes were found in both muscles. In the VM, contraction (Tc) and delay (Td) times decreased (p < 0.01), indicating faster responses, whereas relaxation time (Tr) increased and sustain time (Ts) decreased (p < 0.05), suggesting temporary fatigue. Maximal displacement (Dm) increased (p < 0.01), indicating reduced stiffness. In contrast, the GM showed greater responsiveness after stiffness jumps, characterized by shorter Tc and Td (p < 0.01), and reduced endurance after CMJs. These findings highlight muscle specific neuromuscular adaptations and provide practical insights for optimizing warm-up, training, and rehabilitation protocols through targeted jump selection. Full article

As neuromuscular performance assessment has become a fundamental component of athlete monitoring, ensuring strong measurement reliability is essential for supporting accurate data-driven decision-making. Thus, the purpose of this study was twofold: (i) to examine the reliability of countermovement vertical jump (CMJ) force-time metrics obtained using a portable force plate system (Hawkin Dynamics) and (ii) to determine whether absolute and relative reliability scores differ between well-trained individuals (i.e., athletes) and those less familiar with CMJ force-plate testing (i.e., non-athletes). Seventy-four participants volunteered to take part in this investigation, of whom thirty-nine were NCAA Division-I baseball and track-and-field athletes and thirty-five age-matched non-athletes with no prior CMJ testing experience on force plates. After performing a standardized dynamic warm-up, participants performed three CMJs without arm swing while standing on a dual uniaxial force plate system sampling at 1000 Hz. Each jump trial was separated by a 30 s rest interval. Absolute and relative reliability were assessed using the coefficient of variation (CV) and intraclass correlation coefficient (ICC), respectively. The results revealed that 75% of the variables demonstrated excellent reliability. Specifically, absolute (CV < 10%) and relative (ICC > 0.750) reliability values were good to excellent for most force-time metrics of interest, including braking and propulsive phase duration, peak braking force, average propulsive power, reactive strength index-modified, countermovement depth, and jump height. In contrast, average and peak landing force and inter-limb asymmetry measures during the braking and propulsive phases displayed moderate to good reliability, whereas asymmetry-related variables during the landing phase exhibited poor reliability. In addition, athletes demonstrated lower CV and greater ICC across most metrics compared to non-athletes. Full article

During an unpredictable side-cut, this study examined how a sport-specific neuromuscular training program (NMTP) influenced electromyography responses in the lower limb posterior muscles, leg movement angles, maximum vertical ground reaction force (vGRF), and the rate of force development of vGRF. Thirty-eight adult female recreational hockey players were randomly allocated into an intervention group (INT) or a control group (CON). Before beginning training or matches, the INT carried out the NMTP three times per week for eight weeks, whereas the CON performed their routine warm-up. A 45° sidecut (dominant leg only) was performed at baseline and after eight-weeks and recorded with a motion capture system. The effect of group and time, and their interaction, was investigated using a mixed-design ANOVA. After landing, the participants in the INT had greater activation of their gastrocnemius lateralis, gastrocnemius medialis, and gluteus maximus muscles than those in the CON. INT participants showed significantly lower amounts of maximum knee abduction and knee excursion, while there was an increase in these variables for the CON. At week eight, the vGRF RFD decreased for the INT but increased for the CON. Although non-significant, the overall muscle activity showed an increasing trend for the INT when it came to supervised NMTP for eight weeks compared to the effect seen in the CON. This activity caused greater alterations in the motion and forces of the lower body for the INT than the CON. Full article

Objectives: This study evaluated how different distributions of isometric conditioning activity (ICA) durations affect countermovement jump (CMJ) performance in highly trained male volleyball players compared to a control condition (CTRL). Methods: Twelve participants performed CTRL and three ICA protocols in a half-back squat: 9 s (3 × 1 × 3 s), 27 s (3 × 3 × 3 s), and 45 s (3 × 5 × 3 s). CMJ height was measured before and at 3, 6, 9, and 12 min post ICA. Results: A two-way repeated measures ANOVA showed significant main effects of time (F = 3.820; p = 0.009) and condition (F = 6.451; p = 0.001), with no significant interaction (F = 1.484; p = 0.138). Post hoc analysis indicated significant CMJ height increases at 9 min [mean difference (MD) = 5.1 ± 0.6 cm; p = 0.045] and 12 min (MD = 6.0 ± 1.4 cm; p = 0.010) post ICA. Moreover, CMJ height was significantly greater in the 27 s (MD = 10.0 ± 0.6 cm; p = 0.002) and 45 s (MD = 7.3 ± 2.0 cm; p = 0.035) conditions compared to the 9 s protocol. Conclusions: Incorporating ICAs of 9 s or 45 s into warm-up routines can enhance CMJ performance, although these durations may elicit different neuromuscular adaptations and movement strategies. Full article

Background/Objectives: Post-activation performance enhancement (PAPE) is an acute neuromuscular phenomenon influenced by training status, yet evidence regarding its response to isometric conditioning activity (ICA) across different athletic populations remains inconclusive. This study investigated the acute effects of ICA on countermovement jump (CMJ) performance in trained (T) versus highly trained (HT) male participants. Methods: A total of 32 participants (T: n = 16; HT: n = 16) completed two randomized sessions: a control condition (CTRL) and an isometric protocol (ICA; three sets of three maximal isometric back squat contractions, 3 s each). CMJ height was assessed at baseline and at 3-, 6- and 9-min post-intervention using a force platform. Repeated-measures ANOVA examined interactions between time, condition, and training status. Results: A significant improvement in jump height was observed only in the HT-ISO group at 3 min post-ICA (mean difference: +3.0 ± 2.3 cm; p < 0.005; d = 0.65). No significant changes were detected in the T group across conditions. Peak power and modified reactive strength index showed no significant differences, though effect trends favored the HT group. Conclusions: ICA elicits short-term PAPE effects in highly trained, but not moderately trained, individuals. These findings underscore the importance of tailoring warm-up protocols to the athlete’s training level for optimal performance enhancement. Full article