bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neuromuscular Performance Changes in Elite Futsal Players Over a Competitive Season
Authors: Spyrou Konstantinos , Alcaraz Pedro E. , Marín-Cascales Elena , Herrero-Carrasco Rubén , Cohen Daniel D. , Freitas Tomás T. 
Published: February 2023

Abstract
Spyrou, K, Alcaraz, PE, Marín-Cascales, E, Herrero-Carrasco, R, Cohen, DD, and Freitas, TT. Neuromuscular performance changes in elite futsal players over a competitive season. J Strength Cond Res 37(5): 1111–1116, 2023—A professional futsal season imposes a great amount of physiological and mechanical stress on players. The main aim of this study was to examine the changes in neuromuscular performance qualities across the season. Ten professional male players performed a 10-m sprint, standing long jumps (SLJs), and countermovement jumps (CMJs) during the competitive season (i.e., every ∼5 weeks from September to January). A one-way repeated measures ANOVA with post hoc pairwise comparisons and effect sizes (ESs) were used to analyze potential differences among these assessments. A significant and large decline was found in concentric peak power (p = 0.040; ES = 1.24). A nonsignificant and moderate decrease was observed in sprint ability (p = 0.155; ES = 1.03), CMJ height (p = 0.175; ES = 1.00), and SLJ distance (p = 0.164; ES = 1.03). Regarding other CMJ kinetic variables, nonsignificant and moderate changes were found. In summary, considering the neuromuscular performance tests and variables assessed, only concentric peak power in CMJ decreased significantly across the season; however, nonsignificant decrements were observed in sprinting time, SLJ, CMJ height, and other kinetic metrics. CMJ variables during the jump-land cycle should be incorporated alongside more traditional measures (e.g., jump height) to monitor performance during the season.
Effect of High-Volume Cluster Sets vs. Lower-Volume Traditional Sets on Accuracy of Estimated Repetitions to Failure
Authors: Davies Timothy B. , Li Jiuzhang , Hackett Daniel A. 
Published: February 2023

Abstract
Davies, TB, Li, J, and Hackett, DA. Effect of high-volume cluster sets vs. lower-volume traditional sets on accuracy of estimated repetitions to failure. J Strength Cond Res 37(6): 1191–1198, 2023—This study investigated the effects of resistance training using cluster (CLUS) vs. traditional (TRAD) set structures on the accuracy of estimated repetitions to failure (ERF). Nineteen healthy male resistance trainers (age 21.0 ± 4.4 years) were randomized into 1 of the 2 bench press training routines performed for 6 weeks. Cluster (n = 10) performed 6 sets of 5 repetitions at 85% of 1 repetition maximum (1RM) with 30-second interrepetition rest and 3 minutes of interset rest. Traditional (n = 9) performed 3 sets of 5 repetitions at 85% 1RM with 5 minutes of interset rest. Maximum repetitions at 85% 1RM was performed before and after intervention to assess error in ERF and mean concentric velocity (MCV). The ERF, rating of perceived exertion, and maintenance of MCV were assessed throughout the intervention. Rating of perceived exertion was lower for sets 1–3 in CLUS compared with TRAD from weeks 1 to 4 (effect size [ES] = 0.8–2.4, p ≤ 0.04). The ERF was greater for sets 1–3 in CLUS than in TRAD during all intervention weeks (ES = 1.0–5.1, p ≤ 0.04). Maintenance of MCV was greater in CLUS compared with TRAD for all sets at week 1 (ES = 0.76, p = 0.002) and sets 4–6 at week 6 (ES = 0.77, p = 0.006). After the intervention, error in ERF did not change, and no differences were found between the groups. Findings indicate that accuracy of ERF does not improve after resistance training using set structures that induce different transient fatigue-related effects when using high loads in experienced resistance trainers.
Two-point Method Applied in Field Conditions: A Feasible Approach to Assess the Load-Velocity Relationship Variables During the Bench Pull Exercise
Authors: Miras-Moreno Sergio , García-Ramos Amador , Jukic Ivan , Pérez-Castilla Alejandro 
Published: February 2023

Abstract
Miras-Moreno, S, García-Ramos, A, Jukic, I, and Pérez-Castilla, A. Two-point method applied in field conditions: a feasible approach to assess the load-velocity relationship variables during the bench pull exercise. J Strength Cond Res XX(X): 000–000, 2022—This study explored the between-session reliability and concurrent validity of the load-velocity (L-V) relationship variables obtained from different methods during the Smith machine bench pull exercise. In a counterbalanced order, 23 resistance-trained male subjects performed 2 sessions against 6 different loads in one week and 2 sessions against the lightest and heaviest loads in another week. The L-V relationship variables (load-axis intercept [L
0], velocity-axis intercept [v
0], and area under the L-V relationship line [A
line]) were obtained using the mean and peak velocity by the standard multiple-point (all 6 loads were used for the L-V modeling), modified multiple-point (the data point that most reduced the coefficient of determination was omitted from the L-V modeling), and 2-point (only 2 loads were used for the L-V modeling) methods. The reliability of the L-V relationship variables was acceptable for all methods (within-subjects coefficient of variation [CV] = 2.09–9.21%). The standard multiple-point and 2-point methods provided greater reliability for all L-V relationship variables compared with the modified multiple-point method (CVratio ≥ 1.27), while the 2-point method provided similar (CVratio = 1.04 for A
line) or greater (CVratio = 1.50 for L
0 and 1.62 for v
0) reliability than the standard multiple-point method. The concurrent validity of the modified multiple-point and 2-point methods was acceptable for the L-V relationship variables (effect size ≤ 0.62; r ≥ 0.76). These results suggest that the 2-point method is not only a valid procedure but also more reliable, simpler, faster, and less prone to fatigue than multiple-point methods for assessing maximal neuromuscular capacities through the L-V relationship.
Astaxanthin Supplementation Does Not Affect Markers of Muscle Damage or Inflammation After an Exercise-Induced Muscle Damage Protocol in Resistance-Trained Males
Authors: Waldman Hunter S. , Bryant Andrea R. , Parten Alyssa L. , Grozier Corey D. , McAllister Matthew J. 
Published: February 2023

Abstract
Waldman, HS, Bryant, AR, Parten, AL, Grozier, CD, and McAllister, MJ. Astaxanthin supplementation does not affect markers of muscle damage or inflammation after an exercise-induced muscle damage protocol in resistance-trained males. J Strength Cond Res 37(7): e413–e421, 2023—It is well documented that exercise-induced muscle damage (EIMD) decreases exercise performance by elevated inflammation and subjective discomfort. Due to its potent antioxidative properties, astaxanthin (AX) may serve as a potential dietary supplement strategy for mitigating delayed-onset muscle soreness (DOMS) and enhancing recovery and performance. This study aimed to investigate the effects of AX on markers of muscle damage, inflammation, DOMS, and anaerobic performance and substrate metabolism. Thirteen resistance-trained men (mean ± SD, age, 23.4 ± 2.1 years) completed a double-blind, counterbalanced, and crossover design with a 1-week washout period between 2, 4-week supplementation periods at 12 mg·d−1 of AX or placebo. After each supplementation period, subjects completed 2 trials, with trial 1 including a graded exercise test (GXT) and a 30-second Wingate and trial 2 including an EIMD protocol followed by the collection of fasting blood samples (pre-post) to measure creatine kinase, advanced oxidative protein products, C-reactive protein, interleukin-6, insulin, and cortisol. Astaxanthin supplementation had no statistical effects on markers of substrate metabolism during the GXT, Wingate variables, or markers of muscle damage, inflammation, or DOMS when compared with placebo (all p > 0.05). However, 4 weeks of AX supplementation did significantly lower oxygen consumption during the final stage of the GXT (12%, p = 0.02), as well as lowered systolic blood pressure (∼7%, p = 0.04), and significantly lowered baseline insulin values (∼24%, p = 0.05) when compared with placebo. Collectively, these data suggest that 4 weeks of AX supplementation at 12 mg·d−1 did not affect markers of muscle damage, inflammation, or DOMS after an EIMD protocol in a resistance-trained male cohort.
Common High-Speed Running Thresholds Likely Do Not Correspond to High-Speed Running in Field Sports
Authors: Freeman Brock W. , Talpey Scott W. , James Lachlan P. , Opar David A. , Young Warren B. 
Published: February 2023

Abstract
Freeman, BW, Talpey, SW, James, LP, Opar, DA, and Young, WB. Common high-speed running thresholds likely do not correspond to high-speed running in field sports. J Strength Cond Res 37(7): 1411–1418, 2023—The purpose of this study was to clarify what percentage of maximum speed is associated with various running gaits. Fifteen amateur field sport athletes (age = 23 ± 3.6 years) participated in a series of 55-meter running trials. The speed of each trial was determined by instructions relating to 5 previously identified gait patterns (jog, run, stride, near maximum sprint, and sprint). Each trial was filmed in slow motion (240 fps), whereas running speed was obtained using Global Positioning Systems. Contact time, stride angle, and midstance free-leg knee angle were determined from video footage. Running gaits corresponded with the following running speeds, jogging = 4.51 m·s−1, 56%Vmax, running = 5.41 m·s−1, 66%Vmax, striding = 6.37 m·s−1, 78%Vmax, near maximum sprinting = 7.08 m·s−1, 87%Vmax, and sprinting = 8.15 m·s−1, 100%Vmax. Significant (p < 0.05) increases in stride angle were observed as running speed increased. Significant (p < 0.05) decreases were observed in contact time and midstance free-leg knee angle as running speed increased. These findings suggest currently used thresholds for high-speed running (HSR) and sprinting most likely correspond with jogging and striding, which likely underestimates the true HSR demands. Therefore, a higher relative speed could be used to describe HSR and sprinting more accurately in field sports.
Concurrent Validity and Reliability of Different Technologies for Sprint-Derived Horizontal Force-Velocity-Power Profiling
Authors: Cormier Patrick , Tsai Ming-Chang , Meylan César , Agar-Newman Dana , Epp-Stobbe Amarah , Kalthoff Zach , Klimstra Marc 
Published: February 2023

Abstract
Cormier, P, Tsai, M-C, Meylan, C, Agar-Newman, D, Epp-Stobbe, A, Kalthoff, Z, and Klimstra, M. Concurrent validity and reliability of different technologies for sprint-derived horizontal force-velocity-power profiling. J Strength Cond Res 37(6): 1298–1305, 2023—This study evaluated the validity and reliability of common systems to assess sprint-derived horizontal force-velocity-power (FVP

H
) profile metrics. Two double constellation athlete monitoring systems (STATSports Apex, Catapult Vector S7) and one timing gate system were compared with a radar gun for the computation of FVP

H
metrics. Intersystem validity was assessed using intraclass correlation coefficients (ICC), Pearson's correlation coefficients (R

2
), and Bland-Altman plots with absolute and percent agreement. Intrasystem reliability was assessed with agreement bias and ICC. STATSports demonstrated moderate agreement for F
0, P
max, τ, and D
rf (8.62, 6.46, -9.81, and 9.96%, respectively) and good agreement for V
0 and MSS (−2.18 and −1.62%). Catapult displayed good agreement across all metrics (F
0, V
0, P
max, MSS, τ, and D
rf: −0.96, −0.89, −1.85, −0.84, 0.38, and −0.27%, respectively). Timing gates demonstrated good agreement with V
0 and MSS (−2.62 and −1.71%) and poor agreement with F
0, P
max, τ, and D
rf (19.17, 16.64, −20.49, and 20.18%, respectively). Intrasystem reliability demonstrated good agreement (<2% bias) with very large to near-perfect ICC (0.84–0.99) for Catapult and STATSports systems. Overall, GPS/GNSS 10 Hz technology is reliable across devices and can provide moderate-to-good accuracy of FVP

H
metrics in single maximal effort sprints. However, Catapult provided better agreement for more FVP

H
metrics than STATSports, which may be related to differences in proprietary algorithms. Also, modeling timing gate data using current FVP

H
profiling techniques results in poor bias that requires greater investigation. GPS/GNSS data can be used for FVP

H
profiling, which could inform performance and rehabilitation processes.
Changes in Muscle Deoxygenation During Squat Exercise After 6-Week Resistance Training With Different Percentages of Velocity Loss
Authors: Costilla Manual , Casals Cristina , Marín-Galindo Alberto , Sánchez-Sixto Alberto , Muñoz-López Alejandro , Sañudo Borja , Corral-Pérez Juan , Ponce-González Jesús Gustavo 
Published: February 2023

Abstract
Costilla, M, Casals, C, Marín-Galindo, A, Sánchez-Sixto, A, Muñoz-López, A, Sañudo, B, Corral-Pérez, J, and Ponce-González, JG. Changes in muscle deoxygenation during squat exercise after 6-week resistance training with different percentages of velocity loss. J Strength Cond Res 37(8): 1573–1580, 2023—The present study compared, for the first time, the effects of 6 weeks of 20% (20VL) vs. 40% (40VL) velocity loss (VL) resistance training (RT) programs on muscle oxygen dynamics during the squat exercise. Twenty-three young men (21.4 ± 2.4 years) were randomly allocated into the 20VL group (n = 8), 40VL group (n = 7), or control group (CG; n = 8). The RT program consisted of 3 sets of Smith machine back squat exercise at 20VL or 40VL with a 3-minute rest between sets, twice per week for 6 weeks. Tissue oxygenation index (TOI) was measured using near-infrared spectroscopy in the vastus medialis and vastus lateralis during a squat test (8-repetition 1 m·s−1 load test), and the maximum (maxTOI) and minimum (minTOI) TOIs were measured during a 3-min recovery period. After the 6-week RT program, TOI increased significantly at the beginning of the test in both muscles (during the first 4 repetitions in the vastus lateralis and 5 repetitions in the vastus medialis) in the 20VL group (p < 0.05), with nonsignificant changes in the 40VL group and CG. The maxTOI was significantly increased in the vastus medialis (+3.76%) and vastus lateralis (+3.97%) after the training only in the 20VL group (p < 0.05). The minTOI in the vastus medialis reached during the test remained unchanged postintervention for both training groups, with the CG showing significantly higher values compared with the 20VL group (+14.1%; p < 0.05). In conclusion, depending on the VL reached during a squat RT program, different changes in muscle oxygen dynamics can be expected. Training at 20% of VL improves metabolic efficiency and the reoxygenation peak after the set.
Association Between Foundation Strength and Weightlifting Exercises in Highly Trained Weightlifters: Support for a General Strength Component
Authors: Zecchin Arthur , Puggina Enrico F. , Hortobágyi Tibor , Granacher Urs 
Published: February 2023

Abstract
Zecchin, A, Puggina, EF, Hortobágyi, T, and Granacher, U. Association between foundation strength and weightlifting exercises in highly trained weightlifters: support for a general strength component. J Strength Cond Res XX(X): 000–000, 2022—In addition to specific weightlifting exercises (i.e., clean and jerk and snatch), foundation strength exercises (i.e., overhead press, front squat, and deadlift) constitute an integral part of the weightlifters' training regime. The unexamined concept behind this training plan is that foundation strength exercises are associated with clean and jerk and snatch performance, implying the existence of a general strength component. We thus determined the relationship between performance in foundation strength exercises (overhead press, front squat, and deadlift) and weightlifting exercises (clean and jerk and snatch) in weightlifters. Well-trained weightlifters (N = 19, age: 26.8 ± 4.4 years; body mass index: 27.6 ± 2.3 kg·m−2; and training history: 4.6 ± 0.8 years) performed 1 repetition maximum tests (1RM) in foundation strength and weightlifting exercises, over 14 days, in a randomized order. We observed significant correlations in 1RM performance between the overhead press and snatch (r = 0.69), front squat and snatch (r = 0.73), overhead press and clean and jerk (r = 0.67), and front squat and clean and jerk (r = 0.72, all r values: p < 0.01). No significant correlations were found for 1RM performance between the snatch and deadlift or between the clean and jerk and deadlift (r-range: 0.20–0.58; p > 0.05). Stepwise linear regression revealed that 1RM performance in the overhead press and front squat explained 62% of the variance in snatch 1RM performance (F = 5.51; p < 0.04). Overhead press and front squat 1RM performance explained 59% of the variance in the clean and jerk 1RM performance (F = 5.14; p < 0.04). Our results demonstrate the existence of a general strength component between selected foundation strength exercises and weightlifting performance. However, the use of the front squat and overhead press to increase 1RM performance in weightlifting exercises needs to be determined in future research using a different methodological approach (i.e., longitudinal protocols), given that the observed correlations do not necessarily imply causation.
Validity and Reliability of an Isometric Row in Quantifying Maximal Force Production in Collegiate Rowers
Authors: Pineda Diana , Hudak Jonathan , Bingham Garett E. , Taber Christopher B. 
Published: February 2023

Abstract
Pineda, D, Hudak, J, Bingham, GE, and Taber, CB. Validity and reliability of an isometric row in quantifying maximal force production in collegiate rowers. J Strength Cond Res 37(8): e462–e465, 2023—The objective of this study was to examine the relationship between a maximal isometric strength test with a maximal dynamic strength test. The main outcome was to evaluate the isometric test to determine if it was a valid and reliable measurement tool for testing and monitoring of rowing athletes. Collegiate Division 1 rowers were tested on measures of maximal dynamic and isometric strength on 2 occasions separated by 14 days. Thirty-two female athletes (age: 19.9 11.0 years; height: 168.2 ± 7.6 cm; body mass: 71.3 as13.2 kg) participated in this study. Although the isometric test had greater reliability, both tests displayed good-to-excellent reliability (intraclass correlation coefficient = 0.79–0.92). Strong correlations were present for the relationship between isometric and dynamic strength tests (r = 0.76–0.82, p = <0.001). The data indicate that the isometric row test is valid and reliable compared with dynamic testing and may be used in conjunction with dynamic testing in the evaluation of collegiate rowers.
Acute Effects of Varied Back Squat Activation Protocols on Muscle-Tendon Stiffness and Jumping Performance
Authors: Krzysztofik Michał , Wilk Michał , Pisz Anna , Kolinger Dominik , Tsoukos Athanasios , Zając Adam , Stastny Petr , Bogdanis Gregory C. 
Published: February 2023

Abstract
Krzysztofik, M, Wilk, M, Pisz, A, Kolinger, D, Tsoukos, A, Zając, A, Stastny, P, and Bogdanis, GC. Acute effects of varied back squat activation protocols on muscle-tendon stiffness and jumping performance. J Strength Cond Res 37(7): 1419–1427, 2023—Intensity, movement velocity, and volume are the principal factors to successfully use postactivation performance enhancement. Therefore, 15 resistance-trained volleyball players completed 3 different back squat configurations as a conditioning activity (CA) in randomized order: (a) 3 sets of 3 repetitions at 85% 1RM (HL); (b) a single set of back squats at 60% 1RM until 10% mean velocity loss (VB); (c) and 2 sets of back squats at 60% 1RM until 10% mean velocity loss (2VB) on subsequent countermovement jump performance, Achilles tendon, and vastus lateralis stiffness with concomitant front thigh skin surface temperature assessment. The measurements were performed 5 minutes before the CA and at 2, 4, 6, 8, and 10 minutes. The jump height was significantly increased in the second minute and at peak, post-CA compared with baseline for all conditions (p = 0.049; ES = 0.23 and p < 0.001; ES = 0.37). Skin surface temperature was significantly increased for all post-CA time points compared with baseline in the 2VB condition (p from <0.001–0.023; ES = 0.39–1.04) and in the fourth minute and at peak post-CA in HL condition (p = 0.023; ES = 0.69 and p = 0.04; ES = 0.46), whereas for the VB condition, a significant decrease in peak post-CA was found (p = 0.004; ES = −0.54). Achilles tendon stiffness was significantly decreased for second, fourth, eighth, 10th, and peak post-CA in comparison to baseline for all conditions (p from p = 0.004–0.038; ES = −0.47 to −0.69). Vastus lateralis stiffness was significantly decreased for peak post-CA compared with baseline for all conditions (p = 0.017; ES = −0.42). We recommend using a single set of barbell squats with a 10% velocity loss as a mechanism of fatigue control to acutely improve jump height performance and avoid unnecessary increases in training volume.
Comparison in Repetitions to Failure Between Concentric-Only and Eccentric-Only Dumbbell Arm Curl Exercise at Four Different Relative Intensities
Authors: Shibata Keisuke , Yamaguchi Taichi , Takizawa Kazuki , Nosaka Kazunori 
Published: February 2023

Abstract
Shibata, K, Yamaguchi, T, Takizawa, K, and Nosaka, K. Comparison in repetitions to failure between concentric-only and eccentric-only dumbbell arm curl exercise at four different relative intensities. J Strength Cond Res XX(X): 000–000, 2022—The repetitions to failure (RF) were compared between concentric-only (CON) and eccentric-only (ECC) arm curl exercise for different intensities based on CON and ECC 1 repetition maximum (1RM), respectively, with 2 different inter-repetition rests. Sixteen healthy male, university students (19–22 years) participated in 6 sessions. In sessions 1 and 2, CON and ECC 1RM strength were determined. In sessions 3 to 6, CON and ECC dumbbell arm curl exercises were performed until momentary failure at the intensity of either 70, 80, 90 or 95% of CON and ECC 1RM, respectively, with the inter-repetition rest of 3 seconds (R3) for one arm and 6 seconds (R6) for the other arm in a pseudo-randomized order. A significant (p < 0.01) muscle contraction type × intensity interaction effect was evident for both R3 and R6 conditions. RF was greater (p < 0.01) in ECC than in CON at 70% (34.2 ± 13.3 vs 20.9 ± 5.4), 80% (22.0 ± 6.7 vs 11.6 ± 2.7), 90% (10.1 ± 3.1 vs 5.2 ± 1.3), and 95% (6.8 ± 2.1 vs 2.7 ± 0.8) for R3. RF was also greater (p < 0.01) for ECC than for CON at 80% (24.5 ± 8.1 vs 15.6 ± 3.6), 90% (10.8 ± 2.8 vs 7.2 ± 1.8) and 95% (6.7 ± 2.4 vs 3.9 ± 1.5) for R6, with greater (p < 0.05) RF for R6 than R3. Significant (p < 0.01) correlations in RF were evident between CON and ECC for R3 (r = 0.86) and R6 (r = 0.76). Equations to estimate 1RM were derived for CON and ECC at R3 and R6 (e.g., ECC 1RM = Load × 110.0/[110.5-RF] for R3). These results suggest that fatigue is less in ECC than in CON performed at the same relative intensity.