Search Results (31)

Background/Objectives: Peak force (PF) reflects maximal strength, while early rate of force development (RFD; 0–100 ms) indicates explosive neuromuscular output. The Athletic Shoulder (ASH) test is gaining popularity in overhead athlete profiling, but its use for assessing explosive strength in various shoulder positions is underexplored. This study compared PF and RFD at shoulder abductions of 180° (ASH-I), 135° (ASH-Y), and 90° (ASH-T) in baseball players. Methods: Seventeen male athletes (age 22.7 ± 4.2 years; height 186.3 ± 7.3 cm; body mass 83.9 ± 10.1 kg) performed isometric ASH tests with the dominant arm. PF, PF relative to body mass (PF/BM), and early RFD were analysed. Results: ASH I showed 25% significantly higher PF (182 ± 41 N), PF/BM (2.15 ± 0.39 N/kg), and 40% higher RFD (545 N/s) than ASH Y or T (all p < 0.001), which did not differ significantly. PF showed excellent reliability (ICC = 0.86–0.93); RFD showed moderate-to-good reliability (ICC = 0.75–0.81). Smallest worthwhile changes were ~5% for PF and ~15% for RFD. Conclusions: Maximal isometric shoulder strength and explosiveness were highest at 180° abduction in baseball athletes, with no significant difference between 135° and 90°. PF demonstrated excellent reliability, while early RFD showed moderate to good reliability and higher variability, highlighting the need for repeated measures. These findings provide specific position reference values and support the inclusion of multiple abduction angles in shoulder strength assessment to detect neuromuscular deficits and monitor training adaptations in baseball athletes. Full article

Objectives: This randomized controlled trial investigated the effects of an 8-week, volume-equated eccentric training program comprising Nordic hamstring and reverse Nordic exercises performed either once or twice per week on measures of physical fitness in pubertal male soccer players. Methods: A total of 34 participants were randomly assigned into a 1-day (n = 16; age = 14.58 ± 0.28 years) or 2-day (n = 18; age = 14.84 ± 0.22 years) per week training group. Physical fitness was assessed using 5 m and 10 m sprints, the 505 change in direction (CiD) speed test, Y-shaped agility test, countermovement jump (CMJ), and standing long jump (SLJ). Results: Significant group-by-time interactions were observed for the 505 CiD test, agility, and CMJ performance (effect sizes [ES] = 0.80 to 1.13). However, no significant interactions were found for the 5 and 10 m sprints or for SLJ (p > 0.05). Compared to the 1-day group, the 2-day training group showed greater improvements in CiD speed (∆7.36%; p < 0.001; ES = 0.92), agility (∆7.91%; p < 0.001; ES = 1.68), and CMJ (∆7.44%; p < 0.01; ES = 0.35), while no differences were observed in 5 and 10 m linear sprints or SLJ performance. According to individual response analysis, improvements across the physical fitness parameters beyond the smallest worthwhile change (SWC_0.2) were observed in 22–83% of players in the 1-day group and 77–100% in the 2-day group. Conclusions: In summary, the findings suggest that when training volume is matched, distributing the eccentric training regimen over two days per week may lead to greater improvements in CiD speed, agility, and CMJ performance compared to a single-day approach. Full article

Background: Change of direction (COD) and sprint abilities are essential in soccer, while reactive agility involves decision-making and perceptual/cognitive skills. This study aimed to examine the relationships between sprint speed, COD, and reactive agility in U12 soccer players. Methods: Thirty-three male players (age 10.40 ± 0.32 years) completed sprint tests (5 m, 10 m, 15 m), the Modified Agility T-Test (MAT), and the Y-Shaped Reactive Agility (Y-RSA) test, across two sessions. Results: The sprint, COD, and reactive agility tests showed high reliability. The Y-RSA test demonstrated strong reliability in regard to the initial sprint, COD-phase time, and total time. Significant correlations were found between sprint, COD, and reactive agility metrics. The sprint times were positively associated with the MAT and reactive agility times (e.g., sprint 15 m vs. total Y-RSA time: r = 0.740, p < 0.01). The smallest worthwhile changes (SWCs) indicated that these tests effectively detect performance improvements. Conclusions: This study demonstrated significant correlations between sprint speed, change of direction, and reactive agility in U12 soccer players, with the 15 m sprint showing the strongest association with reactive agility. These findings support the combined use of physical and perceptual/cognitive assessments to better inform soccer-specific training and evaluate the performance of youth players. Full article

Background: This study examined external intensity and acute neuromuscular responses across multiple games played during a single-day official 3 × 3 basketball tournament. Methods: Twelve male players (Tier 2–3; age: 24.7 ± 4.5 years; height: 186.4 ± 8.5 cm; body mass: 86.5 ± 13.0 kg) were monitored with microsensors (Movement Intensity (MI), while countermovement jump (CMJ) variables—jump height (JH); time to takeoff (TTTO); and Modified Reactive Strength Index (RSI_mod)—were obtained before the start of the tournament and after each game. Linear mixed models examined differences in MI and CMJ variables across tournament phases. Additionally, the smallest worthwhile change (SWC) calculations were applied to all comparisons. Results: No statistical differences were found across tournament stages for MI (p = 0.466), JH (p = 0.762), TTTO (p = 0.990), or RSI_mod (p = 0.951). SWC comparisons showed that MI was higher in GG1 than GG2, GG3, and QF; higher in GG2 than GG3; and lower in G3 than QF and SF. Regarding JH, the post-QF value was higher than the baseline and post-GG2. For TTTO, post-QF was higher than post-GG1. RSI_mod post-GG2 was lower than post-GG3 and post-SF. Conclusions: While no significant changes were observed, MI showed a practically meaningful decline in GG3 and recovery in QF, while RSI_mod initially declined before improving post-SF. These findings highlight the importance of pacing and recovery strategies in 3 × 3 basketball tournaments. Full article

Sprint acceleration is critical for success in team sports. This study aimed to (a) establish the test–retest reliability of a novel method for assessing 20 m sprint performance and (b) determine the magnitude of meaningful change in 20 m sprint times. Thirty highly trained male team sport athletes completed sprint testing (2 × 20 m [separated by 5 min]) on two separate occasions, separated by 7 days. Sprint times (0–20, 0–10, 10–20 m) were recorded using infrared timing gates (Brower Timing Systems, West Valley City, UT, USA) connected to a motion start sensor positioned at the participant’s rear leg while in a 2-point starting stance. 0–20, 0–10, and 10–20 m sprint times demonstrated acceptable reliability (CV = 0.52–1.36%, ICC = 0.89–0.95). Additionally, the smallest worthwhile change (SWC) was greater than the typical error (TE [95% CI]) for 0–20 (0.025 s) and 0–10 m (0.016 s) sprint times, indicating that meaningful changes can be reliably detected between testing sessions. However, the SWC was less than the TE for 10–20 m sprint times. This suggests the method may not reliably detect meaningful changes in sprint performance over this distance. As such, the minimal detectable change (95% CI) should be considered the threshold for meaningful change (0.033 s). The consistent and low TE across sprint distances highlights the test–retest reliability of the method for assessing 0–20 m sprint times in this population of highly trained male team sport athletes. Full article

This study aimed to examine the intra- and inter-session reliability of kinetic variables in the isometric mid-thigh pull (IMTP) and isometric belt squat test (IBSqT) in strength-trained individuals. Fifteen men (26.9 ± 8.9 years; 1.78 ± 0.05 m; 86.9 ± 10.5 kg) and six women (23.8 ± 4.6 years; 1.66 ± 0.06 m; 65.8 ± 10.3 kg), experienced in strength training, completed a familiarization session followed by two experimental sessions. The peak force (PF) and relative peak force to body weight (RPF), were collected for both isometric tests. Additionally, force (F), impulse (I), and rate of force development (RFD) were analyzed across different time windows (50, 100, 150, 200, and 250 ms). The intraclass correlation coefficient (ICC), coefficient of variation (CV), standard error of measurement (SEM), smallest worthwhile change (SWC) and Bland-Altman plots were calculated and displayed. Intra-session reliability was excellent for PF and RPF (ICC ≥ 0.98, CV ≤ 10%) in both IMTP and IBSqT. However, RFD and IMP displayed higher variability (CV > 10%), with low to good reliability depending on time frames. Inter-session reliability was excellent for PF and RPF (ICC ≥ 0.96, CV ≤ 5.3%) in both tests. Force at various time points exhibited moderate to excellent reliability (ICC = 0.70–0.90). PF and RPF demonstrated the highest sensitivity to performance changes, with SWC0.2 values exceeding SEM. In contrast, RFD and impulse showed larger variabilities. These findings indicate that PF and RPF are the most reliable and sensitive metrics for monitoring performance. Coaches and practitioners can use IMTP and IBSqT to detect meaningful changes in maximal isometric force production. Full article

RaceRunning is a sport for disabled people and successful performance depends on reducing the amount of time spent travelling a specific distance. Performance analysis in RaceRunning athletes is based on traditional methods such as recording race time, distances travelled and frequency (sets and reps) that are not sufficient for monitoring training loads. The aims of this study were to monitor training loads in typical training sessions and evaluate technical adaptations in RaceRunning performance by acquiring sensor metrics. Five elite and competitive RaceRunning athletes (18.2 ± 2.3 yrs) at RR2 and RR3 levels were monitored for 8 weeks, performing in their usual training sessions while wearing unobtrusive motion sensors. The motion sensors were attached to the waist and lower leg in all training sessions, each lasting between 80 and 90 min. Performance metrics data collected from the motion sensors included player loads, race loads, work/rest ratio and impact shock directions, along with training factors (duration, frequency, distance, race time and rest time). Results showed that weekly training loads (player and race loads) followed acceptable threshold levels, according to assessment criteria (smallest worthwhile change, acute/chronic work ratio). The relationship between race velocity (performance index) and race load was non-linear and statistically significant, which led to different performance efficiency groups. Wearable motion sensor metrics revealed small to moderate technical adaptations following repeated sprint attempts in temporal running performance, variability and consistency. In conclusion, using a wearable-based system is an effective feedback tool to monitor training quality, revealing important insights into adaptations to training volumes in disabled athletes. Full article

Background: In karate, the ability to execute high-velocity movements, particularly kicks and punches, is heavily dependent on the strength and power of the lower limb muscles, especially the knee extensors. As such, this study aimed to evaluate the effects of an 8-week eccentric training program utilizing the reverse Nordic exercise (RNE) integrated into karate training compared with regular karate training only on measures of physical fitness in youth karate athletes. Methods: Twenty-seven youth karatekas were recruited and allocated to either RNE group (n = 13; age = 15.35 ± 1.66 years; 7 males and 6 females) or an active control group ([CG]; n = 14; 7 males and 7 females; age = 15.30 ± 1.06 years). To track the changes in measures of physical fitness before and after training, tests to assess linear sprint speed (i.e., 10 m), change of direction (CoD) speed (i.e., modified 505 CoD), vertical jumping (i.e., countermovement jump [CMJ] height) and horizontal jumping distance (i.e., standing long jump [SLJ]), and lower-limb asymmetry score (i.e., the difference between SLJ-dominant and non-dominant legs) were carried out. Results: The results indicated significant group-by-time interactions in all measures of physical fitness (effect size [ES] = 1.03 to 2.89). Post-hoc analyses revealed significant changes in the RNE group across all performance measures (effect size [ES] = 0.33 to 1.63). Additionally, the asymmetry score exhibited a moderate decrease from pre to posttest (∆46.96%, ES = 0.64). In contrast, no significant changes were observed in the CG across all fitness measures. Moreover, the individual response analysis indicated that more karatekas from the RNE group consistently achieved improvements beyond the smallest worthwhile change threshold across all fitness measures. Conclusions: In summary, RNE training is an effective approach to enhance various physical fitness measures besides lower-limb asymmetry scores in youth karatekas and is easy to incorporate into regular karate training. Practitioners are therefore encouraged to consistently integrate RNE training to enhance essential physical fitness components in young karatekas. Full article

Intake of New Zealand blackcurrant (NZBC) extract for 7 days has been shown to improve high-intensity intermittent running (HIIR) performance. Objectives: We examined the repeat response of NZBC extract on HIIR performance. Methods: Sixteen active males (age: 23 ± 3 yrs, height: 179 ± 5 cm, mass: 79 ± 11 kg, $\dot{V}$O_2max: 55.3 ± 5 mL∙kg⁻¹∙min⁻¹, velocity at $\dot{V}$O_2max: 17.2 ± 0.8 km∙h⁻¹, mean ± SD) participated. Familiarized subjects completed the HIIR test at individualized exercise intensities with stages consisting of six 19 s high-intensity running bouts interspersed by 15 s of low-intensity running and 1 min of inter-stage rest. The test was repeated at increasing speeds until exhaustion, under four conditions; two with a daily dose of 600 mg of NZBC extract (CurraNZ™, providing 210 mg anthocyanins) and two with a placebo, each over 7 days. The study used a double-blind, randomized, cross-over design with a wash-out period of at least 14 days. Results: For the cohort, there were no differences between the placebo and NZBC conditions for mean heart rate (p = 0.071), mean oxygen uptake (p = 0.713), and mean lactate (p = 0.121) at exhaustion for the HIIR. The NZBC extract increased the mean total running distance and mean high-intensity running distance by 7.9% and 8.0% compared to the placebo. With NZBC extract, 8 of the 16 participants (50%) enhanced in both trials beyond the smallest worthwhile change for total running distance (≥173 m) and high-intensity running distance (≥111 m). For repeated responders, total running distance and high-intensity running distance was increased by 16.7% (95% CI [11.0, 22.4%] and 16.6% (95% CI [11.0, 22.2%]. Three participants had enhanced running performance in one trial beyond the SWC, and five participants were considered non-responders. Conclusions: This is the first study on the repeated response by an anthocyanin-rich supplement on high-intensity running performance. New Zealand blackcurrant extract can substantially enhance intermittent high-intensity running performance in consistent responders. Future work should examine dosing strategies of New Zealand blackcurrant, and whether a repeated response rate exceeding 50% can be attained. These findings suggest that NZBC extract could be beneficial for athletes participating in high-intensity team sports. Full article

Background/Objective: Soccer is a multifactorial sport, requiring physical, psychological, technical, and tactical skills to succeed. Monitoring and comparing physical characteristics over time is essential to assess players’ development, customize training, and prevent injury. The use of wearable sensors is essential to provide accurate and objective physical data. Methods: In this longitudinal study, 128 male adolescent soccer players (from Under 12 to Under 19) were evaluated at two time points (pre- and post-season). Participants completed the Euleria Lab test battery, including stability, countermovement and consecutive jumps, agility, and quick feet tests. A single Inertial Measurement Unit sensor provided quantitative data on fifteen performance metrics. Percentage changes were compared to the Smallest Worthwhile Changes to assess significant changes over time. Results: The results showed significant improvements in most variables, including a 19.7% increase in quick feet, 10.9% in stability, and 9.6% in countermovement jumps. In principal component analysis, we identified four principal components—strength-power, balance, speed-agility, and stiffness—that explained over 80% of the variance. Conclusions: These findings align with previous studies assessing seasonal changes in adolescent soccer players, showing that the proposed test battery seems to be adequate to highlight physical performance changes and provide coaches with meaningful data to customize training and reduce injury rates. Full article

Background/Objectives: Jump test assessment is commonly used for physical tests, with different type of devices used for its evaluation. The purpose of the present study was to examine the validity and reliability of a freely accessible mobile application (VertVision, version 2.0.5) for measuring jump performance. Methods: With that intent, thirty-eight college age recreationally active subjects underwent test assessment after a specific warm-up, performing countermovement jumps (CMJs) and squat jumps (SJs) on a contact platform while being recorded with a smartphone camera. Jump height was the criterion variable, with the same formula being used for both methods. Data analysis was performed by two experienced observers. Results: The results showed strong correlations with the contact platform (ICC > 0.9) for both jumps. Furthermore, between-observer reliability was also high (ICC > 0.9; CV ≤ 2.19), with lower values for smallest worthwhile change (≤0.23) and typical error of measurement (≤0.14). Estimation error varied when accounting for both observers, with the SJ accounting for bigger differences (4.1–6.03%), when compared to the CMJ (0.73–3.09%). Conclusions: The study suggests that VertVision is a suitable and handy method for evaluating jump performance. However, it presents a slight estimation error when compared to the contact platform. Full article

This study aimed to investigate the longitudinal evolution of vertical jump height in soccer players and its association with their genotypic profiles. The genotypes of 37 soccer players were characterized and the countermovement jump (CMJ) height, concentric mean power, force, and jump strategy were assessed at two time points: at the onset of the regular season (Pre) and at the conclusion of the first half (Mid). AMPD1 (rs17602729), ACE (rs4646994), ACTN3 (rs1815739), CKM (rs8111989), and MLCK (rs2849757 and rs2700352) polymorphisms were genotyped. No significant differences were found between Pre and Mid in concentric power (p = 0.068; d = 0.08) or force (p = 0.258; d = 0.04), while jump height displayed trivial increases (p = 0.046; d = 0.15). Individual analysis revealed that 38% of participants increased the vertical jump height and mean concentric power over the smallest worthwhile change (SWC), while 27% experienced an increased mean concentric force. The positive responders were characterized by a decreased frequency of the AA genotype and an increased frequency of the CA genotype for the c.37885C>A polymorphism of MLCK (p = 0.035), as well as a decreased frequency of the TT genotype of ACTN3 (p = 0.042) and the CC genotype of AMPD1 (p = 0.022). Our findings suggest that genetic analysis could explain some variability in neuromuscular adaptations during the in-season. Full article

The Q-LAC analyzer, a portable device employing near-infrared spectroscopy (NIRS), was designed to measure muscle oxygen saturation (SmO₂) during physical exercise. This study aimed to assess the reliability of the Q-LAC analyzer in determining SmO₂ levels during incremental cycling exercise. Thirteen physically active males (age 28.1 ± 5.3 y; height 181.2 ± 5.7 cm; body mass 79.9 ± 11.1 kg; BMI 24.2 ± 2.4 kg/m²) participated in this study. A submaximal incremental exercise test (SIET) on an electromagnetic cycle ergometer with a seven-day interval was performed twice. SmO₂ levels in the vastus lateralis (VL) muscle of the dominant leg were simultaneously recorded using the Q-LAC device during both tests. The study calculated the intraclass correlation coefficient (ICC), the coefficient of variation (CV), the standard error of measurement (SEM), the smallest worthwhile change (SWC), and mean detectable change (MDC). A within-within-subjects ANOVA revealed no statistically significant effects for session (F_1,12 = 0.97, p = 0.34, η² = 0.07) and the interaction between session and workload (F_4,48 = 0.19, p = 0.94, η² = 0.02). ICC values ranged from 0.72 to 0.91. Furthermore, the analysis of CV, SEM, and SWC indicated that SmO₂ measurements obtained with the Q-LAC device exhibit good reliability but marginal sensitivity. In conclusion, the portable Q-LAC analyzer provides consistent measurements of muscle oxygen saturation during low-to-moderate-intensity exercise on a cycle ergometer. Full article

The aim of this study was to analyze the match-to-match variation in high-intensity demands from one Portuguese professional football team according to playing positions. Twenty-three male outfield professional football players were observed during eighteen matches of the Portuguese Second League. Time–motion data were collected using Global Positioning System (GPS) technology. Match running performance was analyzed based on the following three playing positions: defenders (DF), midfielders (MF), and forwards (FW). Repeated measures ANOVA was utilized to compare match running performance within each position role, and seasonal running variation. Practical differences were assessed using the smallest worthwhile change (SWC), coefficient of variation (CV), and twice the coefficient of variation (2CV). Significant differences were found among playing positions in total distance covered (F = 15.45, p < 0.001, η² = 0.33), average speed (F = 12.79, p < 0.001, η² = 0.29), high-speed running (F = 16.93, p < 0.001, η² = 0.36), sprinting (F = 13.49, p < 0.001, η² = 0.31), accelerations (F = 4.69, p = 0.001, η² = 0.132), and decelerations (F = 12.21, p < 0.001, η² = 0.284). The match-to-match running performance encompassed TD (6.59%), AvS (8.67%), HSRr (37.83%), SPR (34.82%), ACC (26.92%), and DEC (27.85%). CV values for total distance covered ranged from 4.87–6.82%, with forwards and midfielders exhibiting the greatest and smallest variation, respectively. Midfielders demonstrated the highest match-to-match variation for all other analyzed variables (8.12–69.17%). All playing positions showed significant variation in high-demanding variables (26.94–37.83%). This study presents the initial analysis of match-to-match variation in high-intensity demands within a Portuguese professional football team. Thus, the position’s specificity and context can provide a helpful strategy for evaluating match-to-match running performance, and for recommending individualized training exercises based on the peak and high-intensity demands for each player’s role within the game. Full article

The Yo-Yo Intermittent Test is frequently used to monitor changes in athletes’ performance in response to different interventions. However, the question remains as to whether, and to what extent, retakes of this test would contribute to these changes. This case study sought to determine the magnitude of practice effects, involving test repetition, on performance in the Yo-Yo Intermittent Recovery Test. A recreational soccer player performed four attempts of the Yo-Yo Intermittent Recovery Test—Level 1 (YYIR1) with a week’s rest in between. The same participant repeated this test protocol (four attempts of the YYIR1) again after six months. Changes in distance covered, level achieved, maximal oxygen uptake, and heart rate between the first and last attempt were assessed. The smallest worthwhile change (SWC), the coefficient of variation (CV), and the 2CV were calculated to identify a trivial, a possibly meaningful, and a certainly meaningful change in YYIR1 performance. The distance covered in the first set of measurements increased from 1320 m to 1560 m (15.4%), which corresponds to a 4.6% increase in the level achieved (from 16.6 to 17.4). Similarly, the distance covered in the second set of measurements increased from 1280 m to 1560 m (17.9%), which corresponds to a 5.5% increase in the level achieved (from 16.5 to 17.4). The participant’s performance changes fell outside of the SWC and the CV, but not the 2CV during both sets of measurements. These improvements in YYIR1 performance may be ascribed to practice with repeated attempts of the test by improving running technique at the turning point and/or by simply increasing the linear speed. This fact should always be kept in mind when interpreting the effects of training. Practitioners should differentiate between practice effects associated with repeated test execution and adaptation induced by conducting sport-specific training. Full article