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The aim of this study was to assess the effectiveness of two resistance training (RT) programs (free weight [FW] and elastic band [EB]) on velocity variables (handball throwing velocity [HTV] and maximal theoretical velocity [V0]) using load-velocity (L-V) relationship modelling. Both programs lasted 6 weeks and consisted of performing bench press and overarm dumbbell pull-over using free weights (FW group) or elastic bands (EB group). Nineteen male sports science students were randomly assigned to EB (n=10) or FW group (n=9). Both RT programs increased HTV and V0, although the increment was greater in the FW (>2 m·s-1) compared to the EB group (·s-1). RT programs had selective effects on the strength variables being FW more effective in increasing 1-repetition maximum, while EB in increasing maximal isometric force. Very large correlations were observed between two-point (L-V relationship modelled through two pairs of L and V data) and multiple-point methods (L-V relationship modelled through six pairs of L and V data) (V0: r=0.96; HTV: r=0.93). All coefficients of variation showed high validity both for V0 and HTV (≤6.2%). Altogether, FW training should be used for increasing the velocity of the throwing performance, while the two-point method for following training-induced changes.

This study aimed to determine the influence of physical fitness level and sex on intraocular pressure (IOP) during the low-intensity aerobic exercise. Forty-four participants (twenty-two men) cycled 30 minutes at low intensity (10% of the maximal power). Maximal power was determined by asking participants to perform maximal sprints of 6 seconds against 3-4 different resistances separated by 3 minutes of rest. The IOP was measured on 9 occasions (1) prior to the warm-up, (2) after the warm-up, (3-7) every 6 minutes during the low-intensity cycling task, and (8-9) 5 and 10 minutes after the cycling task. Low-intensity aerobic exercise had a lowering effect on IOP, being the beneficial effect more accentuated and prolonged in the High-fit group (IOP reduction compared to baseline lasted 30 minutes) than in the Low-fit group (IOP was only reduced at 6 minutes of exercise compared to baseline). Participants´ sex had no effect on the IOP behaviour at any time point (p = 0.453). These findings indicate that individuals who need to reduce IOP levels (i.e., glaucoma patients or those at risk) should increase or maintain a high fitness level to benefit more from the IOP lowering effect during low-intensity aerobic exercises.

The present study aimed to explore the possibility of comprehensively assessing whole-body muscle strength by testing as few muscle groups as possible, using a single testing method (isometric or isokinetic dynamometry) and a single variable (maximal force or rate of force development). Knee, hip, shoulder and elbow extensors and flexors were evaluated in males with high (n = 26) and low strength levels (n = 32). The principal component analysis revealed three factors that explained 62.5% of the total variance, while the main factors were loaded by the different testing methods and strength variables for the muscles acting on the knee (first component), hip (second component) and arm joints (third component). These results were confirmed by a three-way ANOVA which revealed a significant factor of group (P 0.001) and the interaction test type × group (P = 0.002), but not of test type (P = 0.644), muscle group (P = 0.999), or their interactions (P 0.205). The correlations of strength outcomes across the muscles ranged from trivial to very large (

Reliability and sensitivity of reaction time (RT) during quasi-realistic soccer situations was explored in 10 professional soccer players (skilled; age = 20.9 ± 3.6 years) and 10 males without soccer experience (nonskilled; age = 23.4 ± 0.5 years). The participants were instructed to react as fast as possible to a stimulus presented via the video-based method while standing on force platforms. RT was computed as the difference between the instant when the rate of force development of any leg reaches 5% of its maximal value and the instant of stimulus presentation. The results revealed acceptable to high reliability of RT (intraclass correlation coefficient median = .90; coefficient of variation ≤ 5.83%), and shorter RT for skilled compared with nonskilled participants in three out of eight comparisons (effect size range = 1.00–1.41). The video-based methods can be confidently used to assess the RT in soccer players.

Background: The possibility to selectively assess the force exerted by each leg during bilateral jumps has allowed sport scientists to explore inter-leg asymmetries, this metric being a rich source of research due to its potential applications to improve sports performance and reduce the risk of injury. The purpose of this study was to explore the reliability and agreement of single-leg mechanical performance and inter-leg asymmetry variables obtained by two procedures of analysis (Synchronous [simultaneous jump detection for both legs] and Asynchronous [specific jump detection for each leg]) during bilateral countermovement jumps (CMJs). Method: During a single testing session, 74 participants performed 5 maximal height bilateral CMJs on dual force platforms (Kistler, model 9260AA6, Winterthur, Switzerland), and the 2 trials that differed the least in terms of squat depth and jump height were considered for statistical analyses. The following mechanical variables were calculated separately for each leg using the Synchronous and Asynchronous procedures: mean force, peak force, and propulsive impulse. Results: The procedures showed comparable reliability, except for mean force and propulsive impulse of the left leg (higher for the Asynchronous procedure). The agreement between the procedures was very high, while the most reliable mechanical variable was mean force (CV≈2.9%, ICC≈0.98), followed by peak force (CV≈4.4%, ICC≈0.96) and propulsive impulse (CV≈6.4%, ICC≈0.91). Reliability of inter-leg asymmetries was greater using mean and peak force (ICC range=0.74–0.82) than using propulsive impulse (ICC range = 0.65–0.66). Significance: Both Synchronous and Asynchronous procedures can be used to evaluate single-leg mechanical performance (mean force, peak force, and propulsive impulse) and asymmetries, whereas mean force should be used to evaluate single-leg mechanical performance and mean or peak force to assess asymmetries., Ministry of Education, Science & Technological Development, Serbia 451-03-68/2020-14/200015 451-03-68/2020-14/200021, Universidad de Granada/CBUA

This study aimed to determine the instruction that maximizes fencing attack performance and to explore the sensitivity of a novel efficiency index (EI) that considers reaction time, attack velocity, and absolute error to discriminate between beginners and experienced fencers. Instructions that directed attentional focus internally (react as fast as possible and perform the attack movement as fast as possible) or externally (be as accurate as possible) were provided prior to stimulus presentation. The EI did not differ between the instructions in any group (p > .05), the instructions “react as fast as possible” and “be as accurate as possible” promoted in beginners the highest and the lowest EI, and the EI was higher for fencers. Our findings suggest that the EI could be recommended as a general index of fencing attack efficiency.

We would like to thank all the subjects who selflessly participated in the study. This study was funded by the Spanish Ministry of Science and Innovation (PID2019-110074GB-I00/SRA (State Research Agency)/10.13039/501100011033) and by the grants 451-03-68/2020-14/200015, 451-03-68/2020-14/200021 from the Ministry of education, science, and technological development of Republic of Serbia. The experiments comply with the current laws of the country in which they were performed. The authors have no conflict of interest to declare. The datasets generated during and/or analyzed during the current study are not publicly available, but are available from the corresponding author who was an organizer of the study., This study aimed to compare the between-session reliability of performance and asymmetry variables between unilateral and bilateral standing broad jumps (SBJ). Twenty-four amateur basketball players (12 males and females) completed two identical sessions which consisted of four unilateral SBJs (two with each leg) and two bilateral SBJs. Mean and peak values of force, velocity and power, and impulse were obtained separately for each leg using a dual force platform. Inter-limb asymmetries were computed using the standard percentage difference for the unilateral SBJ, and the bilateral asymmetry index-1 for the bilateral SBJ. All performance variables generally presented an acceptable absolute reliability for both SBJs (CV range = 3.65-9.81%) with some exceptions for mean force, mean power, and peak power obtained with both legs (CV range = 10.00-15.46%). Three out of 14 variables were obtained with higher reliability during the unilateral SBJ (CVratio >= 1.18), and 5 out of 14 during the bilateral SBJ (CVratio >= 1.27). Asymmetry variables always showed unacceptable reliability (ICCrange = -0.40 to 0.58), and slight to fair levels of agreement in their direction (Kappa range = -0.12 to 0.40) except for unilateral SBJ peak velocity [Kappa = 0.52] and bilateral SBJ peak power [Kappa = 0.51]) that showed moderate agreement for both SBJs. These results highlight that single-leg performance variables can be generally obtained with acceptable reliability regardless of the SBJ variant, but the reliability of the inter-limb asymmetries in the conditions examined in the present study is unacceptable to track individual changes in performance., Spanish Government PID2019-110074GB-I00/SRA, Ministry of education, science, and technological development of Republic of Serbia 451-03-68/2020-14/200015 451-03-68/2020-14/200021

A military-specific reaction time (RT) test was developed to explore its reliability and sensitivity to discriminate between military personnel and sport science students. Fifteen male professional Spanish soldiers and 16 male sport science students completed two RT test modalities: military-specific and nonspecific RT tests. For each RT test modality, both the Simple (i.e., one stimulus, one response) and the Go, No-Go RT (i.e., true, and false stimuli, one response) were tested. The military-specific RT test consisted of a video presented through virtual reality glasses of a forest environment in which soldiers would appear from behind different bushes (stimuli) and the response consisted of pressing the button of a gun-shaped mouse (when they saw a soldier pointing a rifle at them). Both Simple and Go, No-Go RT reached acceptable reliability in both populations (coefficient of variation ≤ 9.64%). Military personnel presented a lower RT than sport science students during the military-specific RT test (p ≤ .001), while no differences were obtained during the nonspecific RT test. RT values were not significantly correlated between the military-specific and nonspecific RT tests (r ≤ .02). These findings collectively suggest that the novel military-specific RT test is an ecologically valid alternative to evaluate the information processing abilities of military personnel.

This study aimed to determine whether the provision of jump height feedback (knowledge of result; KR) can increase the performance and the consistency of output variables. In a randomised order, sixteen participants performed six squat or countermovement jumps (three from a 90o knee angle and three from a self-preferred knee angle) with or without KR over four sessions. The provision of KR significantly increased peak force (p = 0.046, 1.83%), mean force (p = 0.037, 1.45%), peak velocity (p < 0.001, 3.71%), mean velocity (p = 0.004, 3.44%), peak power (p < 0.001, 4.22%) and mean power (p = 0.001, 4.69%). A high within-session reliability was observed for all variables (coefficient of variation [CV] ≤ 5.62%, intraclass correlation coefficient [ICC] ≥ 0.95). No systematic differences in reliability were detected between the jumps performed without KR (CV = 3.00 ± 1.38%, ICC = 0.97 ± 0.03) and with KR (CV = 3.04 ± 1.49%, ICC = 0.97 ± 0.04). These results suggest that the provision of jump height feedback during vertical jump testing is effective to enhance vertical jump performance but it does not reduce the variability between jumps.

This study aimed to evaluate the feasibility of a video-based technology for assessing the reaction time (RT) during karate kumite situations. The Simple RT (one stimulus and one response), 2-Choic...

Ocular physiology is sensitive to cognitively demanding tasks. However, it is unknown whether the intraocular pressure is also affected by the cognitive demands of military operations. The main objective was to determine the impact of a virtual reality shooting simulation with two levels of complexity on intraocular pressure levels in military personnel. Eighteen active-duty members of the Spanish Army and eighteen civilians performed two 4 min simulated shooting tasks with two levels of complexity using a virtual reality. In the “easy” task participants performed a simulated shoot when the stimulus (military with a rifle) appeared, while in the “difficult” task the stimulus randomly was a military with a rifle or with his hands on the air and participants were instructed to respond only when the military with a rifle appeared. Intraocular pressure was measured with a rebound tonometer before and immediately after each task. Complementarily, perceived levels of mental load and shooting performance (reaction time) were assessed. Intraocular pressure was greater after completing the more complex task in both military personnel (p-value < 0.01, Cohen´s d = 1.19) and civilians (p-value < 0.01, Cohen´s d = 1.16). Also, perceived levels of task load and reaction time were higher in the difficult compared to the easy shooting tasks (both p < 0.001). The rise in intraocular pressure is positively associated with the cognitive demands of simulated military operations. The potential application of this finding is the development of objective tools based on intraocular pressure for the evaluation of the mental state in real-world contexts, permitting to improve soldiers´safety and performance., CEMIX (Centro Mixto UGR-MADOC, Army of Spain) 5/4/20 TR-COMBATE

This study aimed to explore the relationship between the inter-limb differences in unilateral countermovement (CMJ) height and the inter-limb differences in bilateral CMJ force production, and to elucidate whether the self-reported preferred leg contributes more to force production than the non-preferred leg. Twenty-three senior basketball players performed in a single session eight unilateral CMJs (four with each leg) and four bilateral CMJs. Impulse, peak force, mean force were recorded during the bilateral CMJ, and jump height during the unilateral CMJ.

This study was funded by the Spanish Ministry of Science and Innovation (PID2019- 110074GB-I00 / SRA (State Research Agency) /10.13039/501100011033)., This study aimed to evaluate the between-session reliability of single-leg performance and asymmetry variables during unilateral and bilateral countermovement jumps (CMJ). Twenty-three basketball players completed two identical sessions which consisted of four unilateral CMJs (two with each leg) and two bilateral CMJs. Mean and peak values of force, velocity and power, impulse, and jump height were obtained separately for each leg using a dual force platform. All performance variables presented an acceptable reliability (CVrange = 4.05-9.98%) with the exceptions of jump height for the unilateral CMJs and mean power, peak velocity, peak power, and impulse for the left leg during the bilateral CMJ (CV >= 11.0%). Nine out of 14 variables were obtained with higher reliability during the unilateral CMJ (CVratio >= 1.16), and 4 out of 14 during the bilateral CMJ (CVratio >= 1.32). Asymmetry variables always showed an unacceptable reliability (ICCrange = 0.15-0.64) and poor/slight levels of agreement in direction (Kappa(range) = -0.10 to 0.15) for the unilateral CMJ, while an acceptable reliability (ICCrange = 0.74-0.77) and substantial levels of agreement in direction (Kappa(range) = 0.65 to 0.74) were generally obtained for the bilateral CMJ. These results suggest that single-leg performance can be obtained with higher reliability during the unilateral CMJ, while the bilateral CMJ provides more consistent measures of inter-limb asymmetries., Spanish Government PID2019110074GB-I00/SRA

This study aimed to compare the between-session reliability of different performance variables during 2 variants of the Smith machine back-squat exercise. Twenty-six male wrestlers performed 5 testing sessions (a 1-repetition maximum [1RM] session, and 4 experimental sessions [2 with the pause and 2 with the rebound technique]). Each experimental session consisted of performing 3 repetitions against 5 loads (45–55–65–75–85% of the 1RM). Mean velocity (MV), mean power (MP), peak velocity (PV), and peak power (PP) variables were recorded by a linear position transducer (GymAware PowerTool). The best and average scores of the 3 repetitions were considered for statistical analyses. The coefficient of variation (CV) ranged from 3.89% (best PV score at 55% 1 RM using the pause technique) to 10.29% (average PP score at 85% 1 RM using the rebound technique). PP showed a lower reliability than MV, MP, and PV (CVratio ≥ 1.26). The reliability was comparable between the exercise techniques (CVratio = 1.08) and between the best and average scores (CVratio = 1.04). These results discourage the use of PP to assess back-squat performance at submaximal loads. The remaining variables (MV, MP, or PV), exercise techniques (pause or rebound), and repetition criteria (best score or average score) can be indistinctly used due to their acceptable and comparable reliability.

This study aimed to explore the effect of the knee angle and loading condition on the magnitude and reliability of squat jump (SJ) performance variables. Thirteen male sport sciences students performed in a random order 4 SJ types (knee angle of 80o [SJ80], 90o [SJ90], 100o [SJ100], and self-preferred [SJ(pref)]) against 3 external loads. The push-off distance (HpO), jump height (Hmax), maximum force (Fmax) and maximum power (Pmax) were obtained from force platform recordings. The HpO during the SJ(pref) (43.4 +/- 6.4 cm) was always between SJ90 (44.3 +/- 4.8 cm) and SJ100 (40.5 +/- 4.2 cm). The magnitudes of Hmax, Fmax and Pmax were comparable or higher during the SJ(pref). The increase of the knee angle was associated with larger values of Fmax and Pmax, but no significant differences were observed for Hmax. An acceptable reliability was observed for HpO (coefficient of variation [CV] lt = 5.09% and intraclass correlation coefficient [ICC] gt = 0.78), Hmax (CV lt = 6.06% and ICC gt = 0.84), Fmax (CV lt = 3.25% and ICC gt = 0.96) and Pmax (CV lt = 2.93% and ICC gt = 0.96). Reliability did not systematically differ between the 4 SJ types. In conclusion, the higher magnitudes and comparable reliability of the performance variables obtained during the SJ(pref) support its use for testing lower-body ballistic performance against different loads.

This study explored the acute effects of strength-oriented resistance training sessions performed using three different set configurations on barbell velocity and the force–velocity (F–v) relationship of upper-body muscles in men and women. Thirteen men (age: 23.8 ± 2.5 years; 6-repetition maximum [6RM] load: 73.4 ± 15.6 kg) and 13 women (age: 21.5 ± 1.4 years; 6RM load: 32.8 ± 5.2 kg) performed 24 repetitions with a 6RM load during the bench press exercise using traditional (TR: 6 sets of 4 repetitions with 3 min of rest between sets), cluster (CL: 6 sets of 4 repetitions with 15 s of intra-set rest every two repetitions and 2 min and 45 s of rest between sets) and inter-repetition rest (IRR: 1 set of 24 repetitions with 39 s of rest between repetitions) set configurations. The F–v relationship parameters [maximum force (F0), maximum velocity (v0) and maximum power (Pmax)] were determined before and after each training session. The average training velocity did not differ between the three set configurations (p = 0.234), but the IRR set configuration generally provided higher velocities during the last repetition of each set. Significant decreases in F0 (p = 0.001) and Pmax (p = 0.024) but not in v0 (p = 0.669) were observed after the training sessions. Comparable velocity loss was observed for men and women (− 12.1% vs. − 11.3%; p = 0.699). The administration of very short intra-set rest periods does not allow for the attainment of higher velocities than traditional set configurations during strength-oriented resistance training sessions conducted with the bench press exercise when the work-to-rest ratio is equated.

The aims of this study were (1) to evaluate the shape of the load-velocity (L-V) and force-velocity (F-V) relationships obtained during the medicine ball throw (MBT) test, (2) to explore the reliability of their parameters (L-V parameters: maximal load ( L0), maximal velocity ( V0(L-V)), slope of the L-V relationship ( a(L-V)), and area under the L-V relationship line (Aline); F-V parameters: maximal force ( F0), maximal velocity ( V0(F-V)), slope of the F-V relationship ( a(F-V)), and maximal power ( Pmax)), (3) to explore the concurrent validity of the two-point with respect to the multiple-point method, and (4) to evaluate the external validity of L0 and F0 with respect to the maximal strength. Twelve males performed MBTs against four loads, a bench press 1-repetition maximum (1 RM), and maximal isometric medicine ball push. The L-V and F-V relationships were strongly linear (individual r ≥ 0.886). V0 was the only variable that always showed an acceptable reliability (CV ≤ 3.4%). L0 and F0 presented trivial to moderate correlations with the bench press 1RM and maximal isometric medicine ball push performance. Therefore, the MBT test can be implemented to reveal the maximal velocity capacity of upper-body muscles, but not maximal force or power capacities due to their low reliability and external validity.

Background: One-repetition maximum (1RM) tests are time-consuming, and they might not always be logistically possible or warranted due to increased risk of injury when performed incorrectly or by novice athletes. Repetitions-to-failure tests are a widespread method of predicting the 1RM, but its accuracy may be compromised by several factors such as the type of exercise, sex, training history, and the number of repetitions completed in the test. Hypothesis: The touch-and-go bench press would provide a higher 1RM than the concentric-only bench press for both genders regardless of whether the 1RM was obtained by the direct or repetitions-to-failure method and the error in the 1RM prediction would be positively correlated with the number of repetitions performed to failure and negatively correlated with the 1RM strength and resistance training experience. Study Design: Cross-sectional study. Level of Evidence: Level 3. Methods: A total of 113 adults (87 men and 26 women) were tested on 2 sessions during the concentric-only and touch-and-go bench press. Each session consisted of an incremental loading test until reaching the 1RM load, followed by a repetitions-to-failure test. Results: The 1RM was higher for the touch-and-go bench press using both the direct (men, 7.80%; women, 7.62%) and repetitions-to-failure method (men, 8.29%; women, 7.49%). A significant, although small, correlation was observed between the error in the estimation of the 1RM and the number of repetitions performed ( r = 0.222; P < 0.01), 1RM strength ( r = −0.169; P = 0.01), and resistance training experience ( r = −0.136; P = 0.05). Conclusion: The repetitions-to-failure test is a valid method of predicting the 1RM during the concentric-only and touch-and-go bench press variants. However, the accuracy of the prediction could be compromised with weaker and less experienced individuals and if more than 10 repetitions are completed during the repetitions-to-failure test. Clinical Relevance: The repetitions-to-failure test does not require any sophisticated equipment and enables a widespread use in different training environments.

Purpose The use of face mask is globally recommended as a preventive measure against COVID-19. However, the intraocular pressure (IOP) changes caused by face masks remain unknown. The objective of this study was to assess the impact of wearing surgical and FFP2/N95 face masks during a 400-m walking protocol on IOP in primary open-angle glaucoma (POAG) patients. Methods Thirteen subjects diagnosed of POAG (21 eyes) were enrolled in this study. IOP was measured at baseline, during the 400-m walking protocol and after 5 min of passive recovery while POAG patients wore a surgical mask, FFP2/N95 mask and no mask in randomized order. From the 21 POAG eyes, we analyzed the IOP changes caused by physical exercise with two face masks and without wearing any face mask. Results At rest (baseline and recovery measurements), the use of the different face masks did not affect IOP levels (mean differences ranging from 0.1 to 0.6 mmHg). During physical activity, wearing an FFP2/N95 mask caused a small (mean differences ranging from 1 to 2 mmHg), but statistically significant, IOP rise in comparison to both the surgical mask and control conditions (Cohen’s d = 0.63 and 0.83, respectively). Conclusion Face masks must be used to minimize the risk of SARS-CoV-2 transmission, and POAG patients can safely use FFP2/N95 and surgical masks at rest. However, due to the IOP rise observed while walking with the FFP2/N95 mask, when possible, POAG patients should prioritized the use of surgical masks during physical activity.

Purpose: To compare the accuracy of nine 1-repetition maximum (1RM) prediction methods during the paused and touch-and-go bench press exercises performed in a Smith machine. Method: A total of 86 men performed 2 identical sessions (incremental loading test until reaching the 1RM followed by a set to failure) in a randomized order during the paused and touch-and-go bench press exercises. Individualized load–velocity relationships were modeled by linear and polynomial regression models considering 4 loads (45%–60%–75%–90% of 1RM) (multiple-point methods) and considering only 2 loads (45%–90% of 1RM) by a linear regression (2-point method). Three minimal velocity thresholds were used: the general velocity of 0.17 m·s−1 (general velocity of the 1RM [V1RM]), the velocity obtained when lifting the 1RM load (individual V1RM), and the velocity obtained during the last repetition of a set to failure. Results: The 1RM prediction methods were generally valid (range: r = .96–.99, standard error of the estimate = 2.8–4.9 kg or 4.6%–8.0% of 1RM). The multiple-point linear method (2.79 [2.29] kg) was more precise than the multiple-point polynomial method (3.54 [3.31] kg; P = .013), but no significant differences were observed when compared with the 2-point method (3.09 [2.66] kg, P = .136). The velocity of the last repetition of a set to failure (3.47 [2.97] kg) was significantly less precise than the individual V1RM (2.91 [2.75] kg, P = .009) and general V1RM (3.00 [2.65] kg, P = .010). Conclusions: Linear regression models and a general minimal velocity threshold of 0.17 m·s−1 should be recommended to obtain a quick and precise estimation of the 1RM during the bench press exercise performed in a Smith machine.

Purpose: To test whether the force–velocity (F–V) relationship obtained during a specific single-stroke kayak test (SSKT) and during nonspecific traditional resistance-training exercises (bench press and prone bench pull) could discriminate between 200-m specialists and longer-distance (500- and 1000-m) specialists in canoe sprint. Methods: A total of 21 experienced male kayakers (seven 200-m specialists and 14 longer-distance specialists) participated in this study. After a familiarization session, kayakers came to the laboratory on 2 occasions separated by 48 to 96 hours. In a randomized order, kayakers performed the SSKT in one session and the bench press and bench pull tests in another session. Force and velocity outputs were recorded against 5 loads in each exercise to determine the F–V relationship and related parameters (maximum force, maximum velocity, F–V slope, and maximum power). Results: The individual F–V relationships were highly linear for the SSKT (r = .990 [.908, .998]), bench press (r = .993 [.974, .999]), and prone bench pull (r = .998 [.992, 1.000]). The F–V relationship parameters (maximum force, maximum velocity, and maximum power) were significantly higher for 200-m specialists compared with longer-distance specialists (all Ps ≤ .047) with large effect sizes (≥0.94) revealing important practical differences. However, no significant differences were observed between 200-m specialists and longer-distance specialists in the F–V slope (P ≥ .477). Conclusions: The F–V relationship assessed during both specific (SSKT) and nonspecific upper-body tasks (bench press and bench pull) may distinguish between kayakers specialized in different distances.

Purpose: The aim of this study was to explore the strength capacities of the injured and non-injured leg following a unilateral anterior cruciate ligament reconstruction. Methods: Eight elite soccer players (age = 25.5 ± 3.9 years; height = 1.83 ± 0.04 m; body mass = 78.9 ± 4.5 kg) volunteered to participate in this study. Nine months after the anterior cruciate ligament reconstruction and just before initiating the full training process, the maximal peak torque of the quadriceps and hamstring muscles were measured at 60 and 180 degrees/ second using isokinetic dynamometry. Obtained peak torques were used for calculating hamstring-to-quadriceps ratio, limb symmetry index, and to estimate maximal torque capacity using a two-velocity method (i.e., linear torque-velocity relationship modeled considering peak torque obtained at 60 and 180 degrees/second). Results: No differences were found between hamstring-to- -quadriceps ratios of the injured and non-injured leg (p = 0.165), nor between limb symmetry index of the quadriceps and hamstring muscles (p = 0.985), regardless of the angular velocity applied during tests. The two-point method revealed significant differences between quadriceps and hamstring muscle groups both in the injured and non-injured leg (p < 0.001; maximal estimated torque was higher for quadriceps compared to hamstring muscles), while the differences between same muscle groups of the different legs were not significant. Conclusions: Collectively, these findings indicate that 9 months were enough for reaching a certain strength level of the injured leg that permits a safe return to play.

This study aimed to compare the reliability and agreement of mean velocity (MV) and maximal velocity (Vmax) between the two velocity monitoring devices (GymAware vs T-Force) most commonly used in the scientific literature. Twenty resistance-trained males completed two testing sessions. The free-weight barbell back squat one-repetition maximum (1RM) was determined in the first session (125.0 ± 24.2 kg; mean ± standard deviation). The second session consisted of two blocks of 16 repetitions (six repetitions at 45% 1RM and 65% 1RM, and four repetitions at 85% 1RM). Half of the repetitions were performed with the GymAware on the left side of the barbell and the other half of the repetitions were performed on the right side of the barbell (opposite placement for the T-Force). MV and Vmax were recorded simultaneously with the GymAware and T-Force. The overall reliability, which was calculated pooling together the data of three loads, did not differ between the T-Force (coefficient of variation (CV) = 5.28 ± 1.79%) and GymAware (CV = 5.79 ± 2.26%) (CVratio = 1.10), but the reliability was higher for Vmax (CV = 5.08 ± 1.79%) compared to MV (CV = 5.98 ± 2.73%) (CVratio = 1.18). MV was significantly higher for the T-Force ( p max ( p = 0.455, Δ = 0.22%). These results support the use of both the GymAware and T-Force as gold-standards in studies designed to validate other velocity monitoring devices. However, systematic bias, albeit rather constant, exists for the magnitude of MV between the two devices.

Background This study aimed to compare the effect of two upper-body resistance training programs (strength-oriented vs. ballistic) on bench press (BP) performance and handball throwing velocity (HTV). Methods Thirty resistance-trained males were randomly assigned to a strength-oriented training group (STG) or a ballistic training group (BTG). The study consisted of 11 sessions: 2 pre-tests (week 1), 8 training sessions (weeks 2-5), and 1 post-test (week 6). The STG performed the BP at the 70-90% of the one-repetition maximum (1RM), and the BTG the BP throw at the 40% of 1RM. BP performance (BP 1RM and maximum velocity achieved against 20 kg [BP20]) and HTV were assessed before and after training. Results The STG enhanced BP 1RM (effect size [ES]=0.24) but not BP20 (ES=0.21) or HTV (ES=0.10). The BTG enhanced BP20 (ES=0.63) but not BP1RM (ES=0.27) or HTV (ES=0.02). HTV was not significantly correlated with the BP 1RM (r≤0.181) or BP20 (r≤0.220). Conclusions These results indicate that a short-term RT program based exclusively on the BP exercise performed against either heavy (strength-oriented) or light loads (ballistic) is not effective to increase HTV in resistance-trained men with little handball experience.

Purpose: To explore the effect of several methodological factors on the number of repetitions performed before and after reaching certain velocity loss thresholds (VLTs). Method: Fifteen resistance-trained men (bench press 1-repetition maximum = 1.25 [0.16] kg·kg−1) performed with maximum intent a total of 182 sets (77 short sets [≤12 repetitions] and 105 long sets [>12 repetitions]) leading to failure during the Smith machine bench press exercise. Fifteen percent, 30%, and 45% VLTs were calculated, considering 2 reference repetitions (first and fastest repetitions) and 2 velocity variables (mean velocity [MV] and peak velocity [PV]). Results: The number of repetitions performed before reaching all VLTs were affected by the reference repetition and velocity variable (P ≤ .001). The fastest MV and PV during the short sets (75.3%) and PV during the long sets (72.4%) were predominantly observed during the first repetition, while the fastest MV during long sets was almost equally distributed between the first (37.1%) and second repetition (40.0%). Failure occurred before reaching the VLTs more frequently using PV (4, 8, and 33 occasions for 15%, 30%, and 45% VLTs, respectively) than MV (only 1 occasion for the 45% VLT). The participants rarely produced a velocity output above a VLT once this threshold was exceeded for the first time (≈10% and 30% of occasions during the short and long sets, respectively). Conclusions: The reference repetition and velocity variable are important factors to consider when implementing VLTs during resistance training. The fastest repetition (instead of the first repetition) and MV (instead of PV) are recommended.

This study aimed to compare the magnitude of the force-velocity (F-V) relationship parameters (maximum force [F-0], maximum velocity [V-0], F-V slope, and maximum power [P-max]) between the squat jumps (SJ) performed from different knee angles. The F-V relationships of 12 men were assessed in 3 sessions during the SJ performed from a knee angle of 80 degrees (SJ80), 90 degrees (SJ90) and 100 degrees (SJ100). The SJ100 provided likely to very likely higher values of F-0 and P-max compared to SJ80 (86% and 98%, respectively) and SJ90 (73% and 94%, respectively), while unclear and trivial differences were observed for the remaining comparisons. The magnitude of the correlations between the 3 SJ types was very large to nearly perfect for P-max (r range = 0.864 to 0.940), moderate to very large for F-0 (r range = 0.438 to 0.778), and small to large for V-0 (r range = 0.361 to 0.642) and the F-V slope (r range = 0.178 to 0.645). These results suggest that the F-V relationship assessed during the SJ exercise is affected by the initial knee angle with the increase of the knee angle from 80 degrees to 100 degrees being associated with higher values of F-0 and P-max, while V-0 remains unchanged.

This study aimed to compare the reliability and magnitude of velocity variables between 3 variants of the bench press (BP) exercise in participants with and without BP training experience. Thirty males, 15 with and 15 without BP experience, randomly performed 3 variants of the BP on separate sessions: (I) concentric-only, (II) fast-eccentric and (III) controlled-eccentric. The mean velocity (MV) and maximum velocity (Vmax) of the concentric phase were collected against 3 loads (≈30%1RM, 50%1RM, and 75%1RM) with a linear velocity transducer. Reliability was high regardless of the variable, BP variant, and load (coefficient of variation [CV] ≤ 4.47%, intraclass correlation coefficient [ICC] ≥ 0.87). The comparison of the CVs suggested a higher reliability for the fast-eccentric BP (8 out of 12 comparisons), followed by the concentric-only BP (5 out of 12 comparisons), and finally the controlled-eccentric BP (never provided a higher reliability). No differences in reliability were observed between experienced (CV ≤ 4.71%; ICC ≥ 0.79) and non-experienced (CV ≤ 6.29%; ICC ≥ 0.76) participants. The fast-eccentric BP provided the highest MV (p < 0.05) and no differences were observed for Vmax. These results support the assessment of movement velocity during the fast-eccentric BP even in participants without experience. Sin financiación 3.337 JCR (2020) Q2, 30/88 Sport Sciences 1.208 SJR (2020) Q1, 47/288 Orthopedics and Sports Medicine No data IDR 2020 UEC

This study aimed to compare the effect of three interset rest intervals (1, 3, and 5 minutes) on (I) mean velocity during a resistance training session conducted in a Smith machine with the squat and bench press exercises, and (II) the pre- and post-exercise force-velocity relationship. Fifteen male university students completed three sessions (i.e., Rest 1', Rest 3', and Rest 5') consisting of three sets of five repetitions against the 10RM load during the squat and bench press exercises. The force-velocity relationship (maximal values of force [F0], velocity [v0], and power [Pmax]) was evaluated at the beginning and at the end of each session with the countermovement jump and bench press throw exercises. During training, mean velocity was slower in sets 2 and 3 of the Rest 1' protocol compared to Rest 3' and Rest 5', but no significant differences were present between Rest 3' and Rest 5'. After training, there was a significant decrease in F0 (p = 0.017) and Pmax (p = 0.010), but not in v0 (p = 0.259). These results support the Rest 3' as the most time-efficient protocol, among those analysed, for the maintenance of high mean velocities during training sessions not leading to failure. Sin financiación 2.832 JCR (2020) Q2, 42/88 Sport Sciences 0.752 SJR (2020) Q2, 104/288 Orthopedics and Sports Medicine No data IDR 2020 UEC

Background: Isokinetic testing has been routinely used to assess the capacities of individual muscle groups. In this study we aimed to evaluate the sensitivity of the force-point (F-v) relationship assessed through the two-point method to discriminate between antagonist muscle groups and males with di erent physical activity levels. Methods: The concentric force output of the knee, hip, elbow, and shoulder flexors and extensors of 27 active and 13 non-active men was recorded at 60 and 180 /s to determine the F-v relationship parameters (maximum force [F0], maximum velocity [v0], and maximum power [Pmax]). Results: F0 and Pmax were higher for knee extensors (e ect size [ES] = 1.97 and 0.57, respectively), hip extensors (ES = 2.52 and 0.77, respectively), and shoulder flexors (ES = 1.67 and 0.83, respectively) compared to their antagonist muscles, while v0 was higher for knee flexors compared to knee extensors (ES = 0.59). Active males revealed higher F0 for knee extensors (ES = 0.72) and knee flexors (ES = 0.83) and higher Pmax for knee flexors (ES = 0.70), elbow extensors (ES = 0.83) and shoulder extensors (ES = 0.36). Conclusions: The sensitivity of the two-point method for testing the maximal mechanical capacities was high for the knee, moderate for the hip and shoulder, and low for the elbow joint., Ministry of Education, Science, and Technological Development of the Republic of Serbia 451-03-68/2020-14/200015 451-03-68/2020-14/200021

Cuevas-Aburto, J, Jukic, I, Chirosa-Ríos, LJ, González-Hernández, JM, Janicijevic, D, Barboza-González, P, Guede-Rojas, F, and García-Ramos, A. Effect of traditional, cluster, and rest redistribution set configurations on neuromuscular and perceptual responses during strength-oriented resistance training. J Strength Cond Res 36(6): 1490-1497, 2022-This study aimed to compare the acute effect of traditional (TR), cluster (CL), and rest redistribution (RR) set configurations on neuromuscular and perceptual measures of fatigue. Thirty-one resistance-trained men randomly performed a Control session and 3 experimental sessions consisting of the squat (SQ) and bench press (BP) exercises performed against the 10 repetition maximum load using TR (3 sets of 6 repetitions; 3 minutes of interset rest), CL (3 sets of 6 repetitions; 30 seconds of intraset rest every 2 repetitions; 3 minutes of interset rest), and RR (9 sets of 2 repetitions; 45 seconds of interset rest) set configurations. A significant effect of "set configuration" (p = 0.002) was observed for barbell velocity. The average velocity of the training session was lower for TR compared with CL (% difference = 5.09% in SQ and 5.68% in BP) and RR (% difference = 5.92% in SQ and 2.71% in BP). The 3 set configurations induced comparable decrements in countermovement jump height (% difference from -6.0% to -8.1%) and throwing velocity (% difference from -0.6% to -1.2%). Ratings of perceived exertion (RPE-10) values collected after the sets were higher for TR (SQ: 6.9 ± 0.7 a.u.; BP: 6.8 ± 0.8 a.u.) compared with CL (SQ: 6.2 ± 0.8 a.u.; BP: 6.4 ± 0.7 a.u.) and RR (SQ: 6.2 ± 0.8 a.u.; BP: 6.6 ± 0.9 a.u.), while the session RPE did not differ between the set configurations (p = 0.595). CL and RR set configurations allow for higher velocities and lower RPE values during resistance training sessions not performed to failure in comparison with a TR set configuration.

This study aimed to compare the reliability and magnitude of the force-velocity (F-V) relationship parameters between the squat jumps performed from the 90 degrees (SJ90) and self-preferred knee angle (SJ(pref)). A secondary aim was to explore the effect of the analysis procedure (force platform [FP] and Samozino's [SAM] method) and the number of loads tested (three- and two-point methods) on the F-V relationships. Twelve men were tested in two sessions during the SJ90 and SJ(pref). Two identical blocks of jumps were performed in each session against three external loads. The F-V relationship parameters (maximum force, maximum velocity, F-V slope and maximum power) were determined at each block through the FP and SAM procedures using the data collected under three (three-point method) or only the two most distant loads (two-point method). The average coefficient of variation (CV) of the four F-V parameters revealed a higher reliability for the SJ90 compared to the SJ(pref) (5.86% vs. 7.55%; CVratio = 1.29) with more pronounced differences using the FP (CVratio = 1.43) than the SAM procedure (CVratio = 1.14), and higher reliability for the SAM compared to the FP (6.14% vs. 7.27%; CVratio = 1.18). The SJ(pref) and SAM procedures provided comparable or higher magnitude of the F-V relationship parameters than the SJ90 and FP, respectively. The three- and two-point methods revealed a comparable reliability and trivial differences in the magnitude of the F-V relationship parameters. The routine testing procedure of the F-V relationship could be simplified using the SJ(pref), the SAM procedure and the two-point method. This is the peer-reviewed version of the article: Janićijević, D.; Knežević, O.; Mirkov, D. M.; Perez-Castilla, A.; Petrović, M. R.; Samozino, P.; Garcia-Ramos, A. Assessment of the Force-Velocity Relationship during Vertical Jumps: Influence of the Starting Position, Analysis Procedures and Number of Loads. European Journal of Sport Science 2020, 20 (5), 614–623. [https://doi.org/10.1080/17461391.2019.1645886]

Purpose: To compare the effects of 2 upper-body strength-training programs differing in set configuration on bench press 1-repetition maximum (BP1RM), bench press throw peak velocity against 30 kg (BPT30), and handball throwing velocity. Methods: Thirty-five men were randomly assigned to a traditional group (TRG; n = 12), rest redistribution group (RRG; n = 13), or control group (n = 10). The training program was conducted with the bench press exercise and lasted 6 weeks (2 sessions per week): TRG—6 sets × 5 repetitions with 3 minutes of interset rest; RRG—1 set × 30 repetitions with 31 seconds of interrepetition rest. The total rest period (15 min) and load intensity (75% 1RM) were the same for both experimental groups. Subjects performed all repetitions at maximal intended velocity, and the load was adjusted on a daily basis from velocity recordings. Results: A significant time × group interaction was observed for both BP1RM and BPT30 (P Conclusions: Resistance-training programs based on not-to-failure traditional and rest redistribution set configurations induce similar changes in BP1RM, BPT30, and handball throwing velocity.