Michał Nowak

The single-leg countermovement jump (SL CMJ) is widely used to assess limb-specific neuromuscular function, with interpretation commonly centred on inter-limb asymmetry. However, contextualising unilateral performance relative to bilateral capacity remains less clearly defined. This retrospective cross-sectional study aimed to develop exploratory descriptive benchmarks for SL CMJ kinetic, kinematic, and temporal variables expressed as a percentage of bilateral CMJ performance in a heterogeneous athletic cohort. A total of 348 athletes completed bilateral and unilateral CMJs using dual force plate sampling at 1000 Hz. The best trials were selected using the modified reactive strength index (mRSI), and averaged unilateral variables were expressed relative to bilateral potential. Unilateral-to-bilateral transfer was non-uniform across metric domains. Median relative jump height and the mRSI were 44.8% and 39.4%, respectively, whereas median average relative braking and propulsive force values were 76.0% and 75.4%, respectively. Gross impulse measures were retained to a greater extent than power- and rate-dependent variables, while temporal metrics showed prolonged unilateral phase durations. Exploratory sex-based analyses indicated trivial-to-small differences in selected variables; however, these findings should be interpreted cautiously because of unequal group sizes and the descriptive nature of the dataset. These results provide broad exploratory percentile benchmarks that may help practitioners contextualise SL CMJ performance relative to bilateral execution. However, the values should not be interpreted as universal clinical thresholds, injury-risk markers, or sport-specific normative standards without consideration of sex, sport discipline, competitive level, injury history, and longitudinal athlete context.

Background: Practitioners increasingly seek proxy metrics that allow key neuromuscular qualities to be monitored using field-based tests. However, the extent to which countermovement jump (CMJ), sprint-based deceleration tasks, and isometric strength tests share underlying constructs remains unclear. Purpose: To examine relationships between metrics derived from CMJ, assisted 30 m acceleration-deceleration (ADA30), and isometric belt squat (IBS) tests, and to identify candidate proxy metrics for acceleration, peak sprint velocity, and braking. Methods: Twenty-four American football players completed CMJ no-arms-swing, ADA30 in assisted mode, and IBS at ∼120° knee flexion. From exports, 30 CMJ, 8 ADA30 phase 1a, and 9 IBS variables were retained. Spearman rank correlations were computed between CMJ–ADA30, CMJ–IBS, and ADA30–IBS pairs. False discovery rate was controlled using the Benjamini-Hochberg procedure (q = 0.10). Results: Phase 1a peak assisted sprint velocity was associated with CMJ propulsive metrics (ρ = 0.61–0.81). CMJ braking phase variables were associated with IBS relative peak force, including relative braking force metrics (ρ = 0.63–0.66) and braking phase duration (ρ = −0.61). Braking phase duration and stiffness were associated with phase 1a peak deceleration (ρ = −0.58 and −0.57). Peak IBS rate of force development was counterintuitively associated with early assisted acceleration metrics, comprising phase 1a 0–5 m time (ρ = 0.58) and phase 1a peak acceleration (ρ = −0.57). Conclusions: CMJ propulsive metrics appear to be robust proxy candidates for assisted peak sprint velocity, whereas CMJ braking phase variables and IBS force outputs may reflect indirectly neuromuscular capacities related to horizontal deceleration. Further work, including unassisted sprint and deceleration tasks, is required.

The fast-paced nature of 3x3 basketball requires simple performance metrics that support quick decision-making. This study aimed to validate a new Team Performance Index (TPI) for predicting match outcomes, using data from all 34 men’s games at the Paris 2024 Olympics. TPI was defined as points scored divided by a composite error term (missed shots + team fouls + turnovers – offensive rebounds + 1). We compared TPI against two established metrics – shooting efficiency (S-EFF) and a statistical value index (S-VAL) – to evaluate their predictive power using ROC-AUC, classification accuracy (with cross-validation), and effect sizes. Results showed that winning teams had significantly higher TPI (mean 1.11 vs 0.68, p<0.001, very large effect size). TPI achieved excellent discrimination between wins and losses (AUC ~0.91, accuracy ~81%), comparable to S-VAL (AUC ~0.93) and superior to S-EFF (AUC ~0.81). No significant difference in AUC was found between TPI and S-VAL, while both outperformed S-EFF. Preliminary “traffic-light” thresholds indicated that TPI 1.05 (green) to near-certain victory (~94% wins). Sensitivity analysis (MCDA) revealed missed shots and team fouls as the dominant drivers of TPI (~74% combined importance), underscoring shooting accuracy and foul discipline as key success factors. In conclusion, TPI is a practical and interpretable index that effectively signals likely outcomes and supports real-time coaching decisions; however, it’s not deterministic and should be further validated in diverse competitions.

Background: Mixed martial arts (MMA) is becoming increasingly popular and is developing dynamically in terms of training methods and number of participants involved, while weightlifting, powerlifting, and other kinds of strength disciplines are well established. In this study, the aim was to compare the body composition, as an anthropometric effect of training in MMA fighters and strength athletes, and then analyze and find reasoning for observed differences. Methods: Thirty-four young healthy male participants (body weight 84.9 ± 10.2 kg, body height 182.0 ± 6.8 cm, BMI 25.8 ± 2.51 kg/m², tier 2/3 in McKay’s sports level classification) represented two groups: MMA (n = 17) and powerlifting athletes (STR, n = 17). The measured anthropometric characteristics were skeletal muscle mass (SMM), percentage of body fat (PBF), body fat mass (FM) and visceral fat mass (VFM). Phase angle (º) was measured as an indicator of tissue quality and we performed detailed investigations of soft fat-free tissue mass (SLM) and of fat mass in body parts separately in each lower and upper limb and trunk. Results: The groups did not differ in terms of body weight, height, BMI, SMM, PBF, FM, VFM, SLM in upper limbs and trunk, FM in the body parts, or the phase angle (all p > 0.05). The statistically significant differences were only observed in the SLM of both lower limbs (greater in STR, p < 0.05) but, after statistical correction with the Holm’s method, these parameters also did not show statistically significant differences despite high effect sizes. Conclusions: The MMA athletes do not differ significantly from strength training athletes in measured anthropometric parameters despite distinct differences in training methodology. The reasons for these observations need future research, combining anthropometric measurements with training and competing load monitoring.

The study presents an innovative approach to analyzing and optimizing 2-point shooting strategies in 3x3 basketball, using newly defined parameters and multi-criteria decision analysis (MCDA). A comparative analysis of the results of the Polish and Serbian national teams from the Olympic Games in Tokyo 2020 allowed us to identify key factors influencing the effectiveness of shots, such as the location of the shot, interaction with the defender, and the time of the action. It was shown that the Serbian team was more effective, which translated into a better result. Differences in shooting strategies were identified, especially in the crucial second half of the match, emphasizing the importance of tactical flexibility. Multi-criteria modeling showed that two factors – the effectiveness of shots and the average duration of an action – could be used to optimize game strategy. To leverage these findings, we emphasize the need for individualized training measures focused on generating shooting opportunities for oneself and teammates, which in turn increases decision-making effectiveness in key moments (e.g., when trailing in score). 3x3 basketball offers a unique opportunity to analyze strategies that rely more on cooperation, creativity, and improvisation than on the strictly defined tactical systems of 5x5. Research into this format can contribute to a deeper understanding of decision-making processes, shooting efficiency, and adaptive responses of players in high-intensity situations, which may also apply to other fast-paced team sports. This study proposes to continue the research with larger numbers of teams to develop new models for a more detailed understanding of shooting efficiency in this discipline, including the influence of fatigue, tactical adjustments, and partial automation of measurements. These further studies will fill existing research gaps and positively impact the development of this new Olympic discipline. This is one of the first studies to apply multi-criteria decision analysis to 3x3 basketball tactics.

Introduction: This study aimed to assess the development of speed, endurance and power in young football players and to create percentile charts and tables for standardized assessment.Methods: Cross-sectional data were collected from 495 male players aged 12–16 years at RKS Raków Częstochowa Academy in 2018–2022. Players participated in a systematic training in which running time 5 m, 10 m, 30 m, lower limb power (standing long jump), and Maximum Aerobic Speed (MAS) were measured using the 30–15 Intermittent Fitness Test. All tests were performed under constant environmental conditions by qualified personnel. Statistical analysis included ANOVA and percentile distribution for P3, P10, P25, P50, P75, P90, P97.Results: Results indicated that the most significant improvements occurred between the ages of 13 and 14, with increased speed over all distances and a significant increase in power. Percentile tables were developed, highlighting improvements in speed 5 m: 0.087–0.126 s; 10 m 0.162–0.215 s; 30 m: 0.438–0.719 s and power in the long jump test: 31–48 cm. Improvements in MAS ranged from 0.3 to 0.6 m/s across the percentiles.Discussion: The results highlight the need for individual training programs tailored to the biological maturity of players. The developed percentile charts and tables offer a valuable tool for coaches and sports scientists to monitor progress, optimize training loads, and minimize the risk of injury, providing a frame of reference for assessing the physical development of young soccer players. Future research should focus on extending these charts and tables to other age groups and genders to refine training methodologies further.

GNSS systems are widely used in many sports. Lastly observed increase of popularity of this kind of monitoring is observed by new equipment appearing on the market. Our aim in this study was to assess validity and reliability of TITAN2 GNSS equipment. Two protocols were used: protocol one consisted of 9 laps of 400(m) long athletes track where the devices were carried on an electric car with constant velocity, protocol two was using gold standard proposed by Coutts & Duffield (2010) consisting 128,5m track of different move patterns including 20m sprint with photocells which was covered by 19 male adult professional football players. Results: total distance (TD) CV% was ranging from 0.32 to 0.55%, TD at maximum speed CV% was ranging from 0.45% to 0.78%, maximum speed CV% was 0.206% to 0.609%, TD on 128.5(m) track had CV% of 1.4%. These results prove that TITAN2 GNSS is a reliable device providing valid data to the users.

Objectives: Rupture of the anterior cruciate ligament (ACL) is a severe injury common in sports. It also has a high rate of re-injury. The aim of this work was to assess hamstring muscle fatigue in active football players after ACL reconstruction who were cleared to play and to determine symmetry between the lateral and medial hamstring muscles. Methods: In professional football players post ACL reconstruction (n = 25) and non-injured players (n = 26), the bioelectrical activity of the medial (biceps femoris—BF) and lateral (semimembranosus and semitendinosus—SEM) hamstring muscles was measured during 60 s of isometric contraction. The fatigue variables were calculated using the Continuous Wavelet Transform (CWT) tool. Results: The football players following ACL reconstruction demonstrated significant asymmetry in fatigue of the lateral and medial hamstring muscles, with greater fatigue in the SEM compared to the BF muscle. Moreover, in those after reconstruction, the changes are more pronounced, with higher muscle fatigue in both limbs (they have lower MDF than non-injured players) and more severe SEM muscle insufficiency (noted in both limbs but with greater intensity in the non-operated one). Conclusions: The higher SEM muscle fatigue observed in this study influenced the lateral-to-medial activation ratio within the hamstring muscle, which may be a probable cause of this muscle’s insufficiency in laterally stabilizing the knee in the frontal and transverse plane. Furthermore, the hamstring muscles after reconstruction were more fatigued in both limbs, which may be another risk factor for ACL graft rupture. Therefore, increased fatigue in specific hamstring muscles may indicate the direction in which knee stabilization is compromised due to ACL overload. A muscle that becomes fatigued and inefficient more quickly also becomes ineffective in performing its function sooner, which can lead to increased overloading forces acting on the ACL graft.