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Purpose: To evaluate the interference effects of various resistance-training (RT) protocols on rowing ergometer performance. Methods: Fourteen semiprofessional male rowers randomly completed 5 protocols in separate sessions: (1) control—no RT session was performed, (2) upper-body high-fatigue—4 sets to failure during the bench pull exercise, (3) upper-body low-fatigue—4 sets of 6 repetitions during the bench pull exercise, (4) lower-body high-fatigue—4 sets to failure during the leg-press exercise, and (5) lower-body low-fatigue—4 sets of 6 repetitions during the leg-press exercise. All sets were performed against the 12-repetition-maximum load with 2 minutes of interset rest. Following the completion of the protocols, subjects performed an all-out 1000-m rowing ergometer test. Results: Compared with the control condition, rowing ergometer performance was not significantly affected after the low-fatigue RT protocols (upper body: P ≥.487; Δ = 0.0%–0.2%; lower body: P ≥.200; Δ = −0.2%–0.5%), while it significantly declined following high-fatigue RT protocols (upper body: P ≤.001; Δ = 1.0%–2.0%; lower body: P ≤.002; Δ = 2.1%–2.5%). The average heart rate was significantly lower for the control condition compared with all RT protocols (P ≤.043; Δ = 1.0%–1.5%). Conclusions: To minimize interference on rowing performance, coaches should prioritize the level of effort in RT protocols over specific exercises, specifically avoiding high-fatigue protocols that lead to failure before rowing practice. [ABSTRACT FROM AUTHOR]

This study investigated how equipment and sex affect the prediction accuracy of the maximum number of repetitions performed to failure (RTF) using the fastest mean velocity of the set (MVfastest). Sixteen men and twelve women completed four sessions (two using free-weight equipment and two sessions using the Smith machine). Each session involved three sets of repetitions to failure against the 65%, 75%, and 85% of the one-repetition maximum, interspersed by 10-min of rest. The goodness-of-fit of the individualized RTF-MVfastest relationships was comparable between both equipment types and sexes (P ≥0.510). Moreover, there were not significant differences in the MVfastest associated with RTF between equipment types (P ≥0.258). However, the MVfastest associated with RTF was higher for men than for women in repetitions 6 to 15 (P ≤0.043; ES≥0.69). In addition, the absolute errors when predicting RTF showed no significant differences between equipment types and loads (P <0.444). Specifically, these RTF estimates were within an acceptable range for men (<2 repetitions), but not for women (≥2 repetitions) (main effect of sex: P ≤0.018; ES≥0.58). These findings suggest that individualized RTF-MVfastest equations estimate the RTF with an acceptable precision in men during bench press exercises in both equipment types but exhibit lower precision for women. [ABSTRACT FROM AUTHOR]

Background: Physical testing is crucial for athlete monitoring, talent identification, optimizing training, and tailoring programs to enhance game-performance in elite competitions. Hypothesis: Load-velocity (L-V) relationship variables discriminate between elite and junior volleyball players, correlate with volleyball-specific performance, and are generalizable across lower- and upper-body exercises. Study Design: Cross-sectional study. Level of Evidence: Level 3. Methods: A total of 9 elite and 11 junior volleyball players were assessed for the L-V relationship (load-axis intercept [ L 0], velocity-axis intercept [ v 0], and area under the L-V relationship line [ A line]) during the countermovement jump (CMJ) and bench press throw (BPT) exercises. Block and spike jump height, as well as standing and jumping spike speed were assessed 24 hours later. Results: Elite players presented greater magnitude in the L-V variables (P ≤ 0.03; effect size [ES] ≥ 1.06) and higher volleyball-specific performance (P ≤ 0.03; ES ≥ 1.09) than juniors (except for CMJ v 0 and A line). The L-V relationship variables were significantly associated with the block and spike jump height and jumping spike speed only in elite players (r ≥ 0.703 and P ≤ 0.04 in 11 out of 18 correlations). No significant associations were observed between CMJ and BPT for any L-V relationship variable (r ≤ 581; P ≥ 0.08, except for A line in junior players). Conclusion: The L-V relationship is a practical procedure to assess volleyball players' maximal mechanical capacities, which are associated with volleyball-specific performance in elite players. However, these data should not be used interchangeably between playing standards or exercises. Clinical Relevance: This information might help strength and conditioning coaches to prescribe more effective training programs that focus on developing the specific physical capacities necessary for players to potentially advance to elite status. [ABSTRACT FROM AUTHOR]

Background: The development and influence of physical capabilities and game action performance over the course of the season are a big challenge for coaches and players. Purpose: The aims of the present study were to examine (1) the seasonal changes in the physical capabilities (mechanical and kinematic) and game-performance indicators in top-level men volleyball players and (2) the relationship between these physical capabilities and game-performance indicators in official matches. Methods: Eleven top-level players participated. Players were physically tested 3 times during the season. Before each test, players' match performance (11 sets) was analyzed according to the level of opposition and match location. The percentage of change, statistical differences over the season (Friedman and Wilcoxon tests), and associations between variables (Spearman r) were calculated (P <.05) among mechanical (force–velocity profile during vertical jump and bench press), kinematic (jump height and spike ball speed), and game action performance features (coefficient, efficacy, and percentage of errors in serve, attack, and block). Results: The theoretical maximal force and velocity during vertical jump and bench press, respectively; the peak spike ball speed; and the serve efficacy significantly increased over the season. Moreover, there was a significant reduction in serve errors as the jump height increased (r = −.44; P =.026), as well as a significant increase in serve errors as the peak spike ball speed increased (r = −.62; P =.001). Conclusion: These findings reveal how the physical and game action performance variables evolve and interact during the season. This may help coaches and trainers to monitor and analyze the most relevant volleyball performance factors. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to (1) evaluate the acute effects of different interrepetition rest full-squat protocols on countermovement jump (CMJ) height, velocity loss (VL), and skin temperature (Tsk) and (2) determine whether the VL, the changes in Tsk, or the individual strength level is associated with the change in CMJ height. Methods: Sixteen resistance-trained men randomly performed 3 squat protocols at maximal intended velocity with 60% of the 1-repetition maximum (sets × repetitions [interrepetition rest]): traditional (2 × 6 [0 s]), cluster 2 (2 × 6 [30 s every 2 repetitions]), and cluster 1 (1 × 12; [36 s every repetition]), plus a control session. CMJ height was assessed before and 2, 4, and 8 minutes after the protocols. Results: There was a significant main effect of protocol for the VL (F = 20.54, P <.001) and loss in mean power (F = 12.85, P <.001; traditional > cluster 2 > cluster 1). However, we found a comparable reduction of CMJ height after 8 minutes: traditional (−3.4% [4.2%]), cluster 2 (−5.3% [4.9%]), cluster 1 (−5.4% [2.9%]), and control (−4.2% [3.6%]). Overall, mean Tsk acutely decreased after all the protocols. Higher individual strength level (but not VL or the changes in Tsk) was associated with lower CMJ-height loss (P <.05). Conclusions: Although different interrepetition rest full-squat protocols may alter the loss in velocity and power, they result in a similar decrease in Tsk and CMJ height, which could be more influenced by individual strength level than VL or changes in Tsk. [ABSTRACT FROM AUTHOR]

The aims of this study were to assess (i) the load–velocity relationship during the box squat exercise in women survivors of breast cancer, (ii) which velocity variable (mean velocity [MV], mean propulsive velocity [MPV], or peak velocity [PV]) shows stronger relationship with the relative load (%1RM), and (iii) which regression model (linear [LA] or polynomic [PA]) provides a greater fit for predicting the velocities associated with each %1RM. Nineteen women survivors of breast cancer (age: 53.2 ± 6.9 years, weight: 70.9 ± 13.1 kg, and height: 163.5 ± 7.4 cm) completed an incremental load test up to one‐repetition maximum in the box squat exercise. The MV, MPV, and the PV were measured during the concentric phase of each repetition with a linear velocity transducer. These measurements were analyzed by regression models using LA and PA. Strong correlations of MV with %1RM (R2 = 0.903/0.904; the standard error of the estimate (SEE) = 0.05 m.s−1 by LA/PA) and MPV (R2 = 0.900; SEE = 0.06 m.s−1 by LA and PA) were observed. In contrast, PV showed a weaker association with %1RM (R2 = 0.704; SEE = 0.15 m.s−1 by LA and PA). The MV and MPV of 1RM was 0.22 ± 0.04 m·s−1, whereas the PV at 1RM was 0.63 ± 0.18 m.s−1. These findings suggest that the use of MV to prescribe relative loads during resistance training, as well as LA and PA regression models, accurately predicted velocities for each %1RM. Assessing and prescribing resistance exercises during breast cancer rehabilitation can be facilitated through the monitoring of movement velocity. Highlights: Movement velocity allows to precisely determine the relative load during the box squat exercise without submitting the patient to excessive mechanical and metabolic stress.From a practical perspective, we suggest using the mean velocity and a linear adjustment.This approach could provide an advantage over traditional assessment methods, enabling the efficient evaluation and prescription of resistance training intensity in exercise rehabilitation programs for women survivors of breast cancer. [ABSTRACT FROM AUTHOR]

This study examined the impact of different inter-repetition rest (IRR) configurations (zero seconds [IRR0], three seconds [IRR3], and self-selected less than five seconds [SSIRR]) on estimating the number of repetitions (Nrep) and the percentage of completed repetitions relative to the maximum number of repetitions possible to failure (%rep) after reaching 10%, 20%, and 30% velocity loss thresholds (VLT). Eighteen men completed three sessions, each with a different IRR configuration, separated by 48–72 hours. Single sets of repetitions to momentary muscular failure were performed against 65%, 75%, and 85% of the one-repetition maximum during free-weight back squat and bench press exercises. No significant differences were reported between IRR configurations for the Nrep (P ≥0.089) and %rep (P ≥0.061), except for %rep after reaching the 20–30%VLT against 65%1RM and the 10–20%VLT against 75%1RM in the bench press exercise (P ≤0.048). Additionally, both Nrep and %rep exhibited high interindividual variability (between-subject CV=14–79%) across the different IRR configurations. The individual %rep-%VLT relationships were slightly stronger than the general %rep-%VLT relationships (median R2 =0.914–0.971 vs. 0.698–0.900). Overall, regardless of the IRR configuration, this novel velocity-based approach does not guarantee the same effort levels across subjects in the free-weight back squat and bench press sets. [ABSTRACT FROM AUTHOR]

This study aimed to examine the load-velocity (L-V) relationship in the bench-press (BP) and leg-press (LP) exercises performed unilaterally, and compared this unilateral L-V relationship with the bilateral variants. Nineteen men (age=23.5±2.1 years) completed two incremental tests in BP and LP, performed bilaterally and unilaterally, across two sessions with a 48-hour rest period. We found a close relationship between medium propulsive velocity (MPV) and %1RM in unilateral BP (R2 =0.97, SEE=0.06 m·s-1) and LP (R2 =0.96, SEE=0.06 m·s-1). No significant differences were observed between the preferred and non-preferred sides in the L-V relationship for either exercise. Additionally, higher velocities were achieved in unilateral exercises compared to bilateral exercises, particularly with light and moderate loads (30–70%1RM) in BP (p<0.05) and with light loads (30–45%1RM) in LP (p<0.05). Close L-V relationships were observed in unilateral exercises, without differences in the L-V relationships between preferred and non-preferred sides despite the interlimb asymmetries in the absolute strength values. Interestingly, lower velocities were observed at light loads (~30–45% 1RM) for bilateral compared to unilateral exercises, which could be explained by different strength deficits for these exercises. [ABSTRACT FROM AUTHOR]

This study (a) evaluated the reliability of a curvilinear sprint (CS) test to assess kinetic and kinematic outcomes in basketball players, (b) compared the kinetic and kinematic outcomes derived from curvilinear vs. linear sprints (LS), and (c) examined the association of both the CS and LS with change of direction (COD) performance. Thirty young basketball players (17 men and 13 women) competing at the national level (i.e., Spanish Basketball National League) performed a novel CS test around the 3-point line (the 3-point line CS test) to the right and left sides. The maximum and average values of acceleration (ACC), velocity (VEL), and centripetal force (CentF) were measured using Local Positioning System technology (WIMU PRO, Realtrack Systems S.L., Almería, Spain). All outcomes showed a high relative (intraclass correlations coefficient ≥ 0.90) and absolute (coefficient of variation [CV] < 5%) reliability, except the maximal CentF to the right (CV = 5.41 %) and left sides (CV = 7.72%). Linear sprints displayed higher ACC and VEL outputs compared with the 3-point line CS test (all p < 0.001). Both sprinting tests were very large to nearly perfect associated with COD performance (LS r range from -0.71 to -0.86; CS r range from -0.68 to -0.94; p < 0.001), and the curvilinear ACCmax was the kinematic outcome most strongly associated with COD performance (r range from -0.73 to -0.94). In conclusion, the 3-point line CS test is reliable to measure CS performance in basketball and presents different kinetic and kinematic features than LS. [ABSTRACT FROM AUTHOR]

This study examined which mechanical variables derived from a vertical jump (i.e. concentric peak force [ConcPF] and eccentric peak force [EccPF], flight time [FT]: contraction time [CT], eccentric deceleration rate of force development [EccDecRFD]) and linear sprint (i.e. theoretical maximal force [F0] and velocity [V0], maximal power output [Pmax], the peak ratio of the effective horizontal component [RFpeak], and the index of force application technique [DRF]) determined the change of direction (COD) performance to a greater extent. Sixteen male soccer players (age: 21.8 ± 2.9 years; height: 175.94 ± 6.88 cm; weight: 73.23 ± 9.59 kg) were assessed for a countermovement jump, the horizontal force velocity (FV) profile, and the COD ZigZag test. The horizontal FV profile parameters were significantly associated with COD performance, while jump mechanical variables did not show any significant association (r = 0.08–0.19; p > 0.05). Specifically, F0 (r = −0.56), Pmax (r = −0.68), and RFpeak (r = −0.54) were strongly associated with COD performance. Moreover, a 1 N·kg−1 increase in F0 was associated with −0.11 s to complete the ZigZag test, whereas 1 W·kg−1 and 1% increase in Pmax and RFpeak were associated with −0.05 and −0.03 s, respectively, to complete the COD test. Horizontal force production during sprinting might play a key role in COD performance. Assessing the horizontal FV profile might help coaches to prescribe a specific training programme to maximize sprint acceleration, which might improve COD performance. [ABSTRACT FROM AUTHOR]

The aims of this study were: (i) to analyse the load-velocity relationship in the bilateral leg-press exercise in female breast cancer survivors, (ii) to assess whether mean velocity (MV) or peak velocity (PV) show stronger relationship with the relative load, and (iii) to examine whether linear (LA) or polynomic (PA) adjustment predict the velocities associated with each %1RM with greater precision. Twenty-two female breast cancer survivors (age: 50.2 ± 10.8 years, weight: 69.6 ± 15.2 kg, height: 160.51 ± 5.25 cm) completed an incremental load test until 1RM in the bilateral leg-press exercise. The MV and the PV of the concentric phase were measured in each repetition using a linear velocity transducer, and were analysed by regression models using LA and PA. A very close relationship of MV (R2 = 0.924; p < 0.0001; SEE = 0.08m.s−1 by LA, and R² = 0.952; p < 0.0001; SEE = 0.063 m.s−1 by PA) and PV (R² = 0.928; p < 0.0001; SEE = 0.119 m.s−1 by LA and R² = 0.941; p < 0.0001; SEE = 0.108 m.s−1 by PA) with %1RM were observed. The MV of 1RM was 0.24 ± 0.03 m·s−1, whereas the PV at 1RM was 0.60 ± 0.10 m.s−1. A comprehensive analysis of the bilateral leg-press load-velocity relationship in breast cancer survivors is presented. The results suggest that MV is the most recommendable velocity variable to prescribe the relative load during resistance training, and that the PA presents better accuracy to predict velocities associated with each %1RM, although LA is sufficiently valid to use this model as an alternative to the quadratic model. The implications for resistance training in breast cancer are discussed. Highlights The load-velocity relationship in the bilateral leg-press exercise was described in female breast cancer survivors. The mean velocity is the most recommendable velocity variable to prescribe the relative load during resistance training in this population. The polynomial adjustment presents a better accuracy to predict velocities associated with each %1RM, although the linear adjustment is sufficiently valid as an alternative. This study will likely contribute to improving exercise prescription and monitoring in breast cancer survivors. [ABSTRACT FROM AUTHOR]

Baena-Raya, A, Jiménez-Reyes, P, Romea, ES, Soriano-Maldonado, A, and Rodríguez-Pérez, MA. Gender-specific association of the sprint mechanical properties with change of direction performance in basketball. J Strength Cond Res 36(10): 2868–2874, 2022—We evaluated the gender-specific associations between the mechanical variables derived from the horizontal force-velocity (FV) profile (i.e., theoretical maximal force [ F 0], velocity [ V 0], maximal power output [ P max ], peak ratio of the effective horizontal component [ RF peak ], and the force application technique index [ D RF ]) and the change of direction (COD) performance for basketball players. Seventy-one players (23 women and 48 men) were assessed for the horizontal FV profile and COD using the modified 505 and V-cut tests. The FV profile parameters were significantly higher for the men than those for the women. The F 0 , RF peak , and P max were strongly associated with performance in the 505 test (women r range = −0.72 to −0.82; men: r range = −0.67 to −0.75; p < 0.001) and the V-cut test (women r range = −0.68 to −0.76; men r range = −0.45 to −0.50; p < 0.001), as well as with a lower COD deficit (women r range = 0.58 to 0.75 (p < 0.01); men r range = 0.49 to 0.54; all p < 0.001). For the women, a 1 N·kg−1 increase of the F 0 was associated with −0.20 seconds and −0.56 seconds in the 505 and V-cut tests, respectively, and 0.16 seconds for the COD deficit. In the men, it was associated with −0.13 seconds and −0.37 seconds in the 505 and V-cut tests, respectively, and 0.10 seconds for the COD deficit. F 0 , RF peak , and P max are the most determinant sprint mechanical properties to successfully COD and reduce the COD deficit. The horizontal FV profile assessment is recommended for diagnosing and prescribing a training program for basketball players. [ABSTRACT FROM AUTHOR]

The aims of this systematic review were to synthetize the current evidence about (i) the force-velocity (FV) profile parameters (maximal values of force [F0], velocity (V0), and power [Pmax]) obtained from the Samozino's method in different sports; (ii) the association of the FV profile parameters with sport performance outcomes; and (iii) the effects of specific training programmes on the FV profile parameters. PubMed, SportDiscus, Web of Science, and Medline databases were searched for articles published between October 2008 (conception of the Samozino's method) and October 2020. Twenty-one studies (10 descriptive, 6 correlational, and 5 longitudinal) met the inclusion criteria. The main findings revealed greater F0, Pmax, and V0 values and better jump/sprint performance for high-level athletes compared to their low-level counterparts. The vertical Pmax showed the highest correlation with jump height. The horizontal F0, Pmax, and V0 were nearly perfectly correlated with 5/10-m, 10/20-m and 30/40-m sprint times, respectively. Training programmes using heavy- or light-loads specifically enhanced F0 and V0, respectively. These results suggest that the FV profile parameters discriminate between athletes of different sport disciplines and levels of practice, present significant correlations with a number of sport performance outcomes, and can be modified after short-term training programmes. [ABSTRACT FROM AUTHOR]

Abstract: Baena-Raya, A, Robles-Ruiz, J, Pérez-Castilla, A, Pareja-Blanco, F, and Rodríguez-Pérez, MA. Effects of light versus very heavy resisted sprint training on multidirectional speed in semi-professional soccer players. J Strength Cond Res XX(X): 000-000, 2024-The purpose of this study was to evaluate the effects of an 8-week resisted linear sprint training (RST) program with 2 loading conditions (light vs. very heavy) on linear sprint (LS), curve sprint (CS), and change of direction (COD) performance in young soccer players. Thirty-eight male under-19 soccer players were assessed for 30-m LS, CS, and modified 505 COD tests. Players were randomly allocated into 3 groups: control (n = 18), light (n = 10), and very heavy RST (n = 10). Light and very heavy RST groups performed RST with external loads resulting in a 25 and 75% velocity loss from the player's maximal LS velocity, respectively. The control group did not perform any sprint training. Significant group × time interactions were observed for LS, CS, and COD performances (p < 0.05). The control group showed no performance improvement. Both RST groups showed significant improvements in LS at 10-, 20-, and 30-m (p ≤ 0.03; effect size [ES] ≥ 0.62), whereas no significant changes were observed for the split times (p > 0.05). CS performance was significantly increased by the 2 RST groups (p ≤ 0.03; ES ≥ 0.60), except for light RST on CS right side at 17-m (p = 0.09; ES = 0.46). Change of direction performance was only significantly enhanced by the very heavy RST group (p ≤ 0.001; ES ≥ 0.80). No significant changes between RST groups were observed. In conclusion, using both light and very heavy RST can enhance LS and CS performance, whereas very heavy RST is recommended to optimize COD performance in young soccer players., (Copyright © 2024 National Strength and Conditioning Association.)

Background: Estimating repetitions in reserve (RIR) has been established as a valid and practical method for monitoring set configuration concerning proximity to failure in resistance training. However, factors such as sex and exercise equipment could interfere with the estimation process. Therefore, this study aimed to determine the influence of sex (female vs male) and exercise equipment (free-weight vs Smith machine) on the RIR estimation at different relative loads during the bench press exercise., Hypothesis: Men would be more accurate than women in the RIR estimation, and participants would better perceive their actual effort at the Smith machine compared with the free-weight bench press exercise., Study Design: Repeated measures design., Level of Evidence: Level 3., Methods: In a counterbalanced order, recreationally trained participants (12 female, 14 male) performed 2 identical sessions with the free-weight bench press exercise in 1 week and 2 identical sessions with the Smith machine bench press exercise in another week (first session for familiarization and second session for validity analysis). In each session, participants performed single sets of repetitions to failure against 3 relative loads (65%, 75%, and 85% of the 1-repetition maximum [1RM])., Results: Results revealed a significant interaction between RIR and sex at 65% 1RM ( P < 0.01; women: -1.2 [-1.7 to -0.6] repetitions; men: -0.1 [-0.6 to 0.3] repetitions), and between RIR and exercise equipment at 65% 1RM ( P < 0.01; free-weight: -1.1 [-1.5 to -0.6] repetitions; Smith machine: -0.2 [-0.6 to 0.2] repetitions), but not at 75% and 85% 1RM., Conclusions: RIR estimation is a valid method for monitoring set configuration. However, this method tends to underestimate RIR at 65%1RM with female athletes and in the free-weight exercise for both sexes., Clinical Relevance: Strength and conditioning coaches should help their athletes understand effort awareness in the aforementioned context., Competing Interests: The authors report no potential conflicts of interest in the development and publication of this article.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Ministerio de Universidades award no. FPU19/00542.