Relative Acceleration and Maximum Velocity in Rugby Players According to Age Category and Playing Position.

ABSTRACT: Zabaloy, S, Freitas, TT, Alcaraz, PE, Gálvez-González, J, Pereira, LA, Comyns, T, Loturco, I, and Healy, R. Relative acceleration and maximum velocity in rugby players according to age category and playing position. J Strength Cond Res XX(X): 000-000, 2024-This study aimed to: (a) assess the intrasession reliability of the acceleration time constant (i.e., τ) and τ-derived measures; (b) analyze the influence of τ and maximum velocity (Vmax) on 40-m sprint performance and to compare various sprint-related outcomes among rugby players from different playing positions and age categories; and (c) explore the associations between τ and several sprint performance metrics. A total of 300 male rugby players volunteered to participate in this study and were divided into age categories (i.e., under-14 [U14]: n = 91, age: 12.6 ± 0.5 years; under-16 [U16]: n = 85, age: 14.8 ± 0.5 years; under-18 [U18]: n = 75, age: 16.6 ± 0.5 years; and Seniors: n = 49, age: 24.2 ± 4.1 years). The results demonstrated good to excellent reliability for all measured parameters (intraclass correlation coefficient >0.75 and coefficient of variation <9.0%). Younger players (i.e., U14 and U16) displayed lower τ values (effect size: moderate to large; p < 0.02) compared with their older peers (i.e., U18 and Seniors), regardless of their playing position. Moreover, τ was associated with sprint performance metrics at varying levels of correlations (Rho: small to almost perfect; p < 0.001). In conclusion, younger players exhibited lower τ values than their older counterparts, irrespective of their playing positions. The model employed in this study demonstrated its accuracy in assessing several key sprint performance metrics, offering insights that can enhance sprint training programs for rugby players, which can be based on the associations observed among these different variables.

Effects of Two Different Low-Volume Resistance Training Programs Applied During the Off-Season Period on the Speed-Power Performance of Elite Youth Soccer Players.

ABSTRACT: Loturco, I, Nunes, RFH, Lampert, RR, Silva, RLP, Hespanhol, JE, Novack, LF, Conde, JHS, Pereira, LA, and McGuigan, MR. Effects of two different low-volume resistance training programs applied during the off-season period on the speed-power performance of elite youth soccer players. . J Strength Cond Res 38(3): 571-576, 2024-The aim of this study was to analyze the changes in the speed-power performance of elite youth soccer players submitted to 2 different low-volume resistance training programs during the off-season period. Twenty under-17 players were randomly allocated to "traditional nonballistic" or "ballistic training" groups. Countermovement jump (CMJ), 20-m sprinting speed, and half-squat (HS) power tests were performed after the final match of the season (pretesting session) and at the beginning of the subsequent season (post-testing session), after 4 weeks of detraining. Between-group differences were assessed using a 2-way ANOVA with repeated measures followed by the Tukey's post hoc test. Performance variations were individually analyzed with the use of the "true changes" calculation. At post-tests, CMJ height and HS power remained unchanged ( p > 0.05) but similar and significant improvements in sprint speed were observed in both groups ( p < 0.05). However, notably, a larger number of players in the ballistic group exhibited "true changes" in HS power (i.e., 55 vs. 33%, compared with the traditional group, respectively). In conclusion, either low-volume ballistic or traditional resistance training schemes were able to increase sprint speed and maintain power output during a short interseason break in youth soccer players. Despite this apparent similarity, at the individual level, ballistic movements were more efficient at improving lower-body power. Practitioners can use the strategies described here to improve the sprint and power performance of soccer players during short periods of soccer-specific training cessation.

Variations in strength-speed-power performance across the season: do true changes occur in elite rugby players?

This study aimed to determine, through the use of a highly sensitive statistical tool, whether real changes in performance were present; and compare the rates of meaningful variations in strength, speed, and power parameters at different time-points during the competitive season in national team rugby players. Thirty-two players were assessed 5 times across the season using the following tests: squat jump and countermovement jump tests; 30-m sprint velocity; and one-repetition maximum (1RM) in the half-squat and bench-press exercises. A repeated-measures analysis of variance was conducted to test for differences between successive time-points. Individual coefficients of variation values were used to set target scores for post-measurements and examine whether changes in performance parameters were greater than the natural test variance, thus providing an indication of whether "true changes" occurred. No significant changes were detected in the vertical jump height, 1RM measures, and sprint velocity and momentum throughout the 11-month period (P > 0.05). True changes occurred much more frequently for strength-power measures than for sprint velocity and momentum. Elite rugby union players did not exhibit significant variations in neuromuscular performance across the competitive period, when a group-based analysis was conducted. However, at the individual level, "true changes" in strength-power-(but not in speed-) related qualities were consistently observed over the competitive season.

Mixed Training Programs Applied to Young Soccer Players: Effects on Speed-Power Abilities.

We compared the effects of two 4-week strength-power-speed training protocols on physical performance of young soccer players. Twenty-three highly trained under-20 soccer players were randomly allocated to two mixed-training groups: 1) "traditional" (TRAD: n=11), comprising vertically oriented strength-power exercises and linear sprints; or 2) "multidirectional" (MULTI: n=12), combining vertically and horizontally oriented strength-power exercises, linear sprints, and change-of-direction (COD) drills. Squat jump (SJ) and countermovement jump, 2) linear sprint, COD speed, and 3) jump-squat (JS) and hip-thrust (HT) power tests were performed pre- and post-training. Differences were determined using a two-way ANOVA with repeated measures and "target scores" were used to detect real changes in performance. No group-time interactions were found for any of the variables (p>0.05). Significant increases (p<0.05) in 20-m sprint velocity, JS- and HT-power were found in both groups, and in SJ in TRAD. Individual analyses revealed a greater number of meaningful changes in zig-zag velocity in MULTI while most players in TRAD displayed meaningful increases in SJ height. In conclusion, both training protocols resulted in similar adaptations but, at the individual level, it appears that MULTI protocol is superior to improve COD ability while TRAD should be preferred to maximize vertical jumping capabilities during short soccer pre-seasons.

Variations in Physical and Competitive Performance of Highly Trained Sprinters Across an Annual Training Season.

ABSTRACT: Loturco, I, Fernandes, V, Bishop, C, Mercer, VP, Siqueira, F, Nakaya, K, Pereira, LA, and Haugen, T. Variations in physical and competitive performance of highly trained sprinters across an annual training season. J Strength Cond Res 37(5): 1104-1110, 2023-We assessed the changes in sprint, jump, and power parameters across the annual training cycle and tested the longitudinal correlations among these variables in top-level sprinters. Thirteen sprinters training with 4 different Olympic sprint coaches were sequentially assessed over 14 months, from January 2019 to March 2020, within 4 consecutive training camps. Performance tests were conducted as follows: standing long jump, squat and countermovement jumps, 10-m and 60-m sprint time, and maximum power output in the half-squat, jump-squat, and hip-thrust exercises. The competitive results of the sprinters throughout the study period were also recorded and analyzed. A repeated measures analysis of variance was used to compare the physical measurements between different testing sessions. A Pearson product-moment correlation was applied to examine the longitudinal relationships between changes in speed-related and power-related parameters. Percentage change was computed and compared with coefficient of variation values to determine whether changes in performance metrics were higher than the test variance, thus providing an indication of whether true changes occurred on an individual basis. Overall, sprinters did not exhibit significant changes in sprint speed, jumping ability, and power output. In addition, variations in competitive times (i.e., 100 m races) followed a similar pattern, within an average range of ±1.36%, for both male and female sprinters. As expected, top-level sprinters presented only small variations in physical and competitive performance over time. Nevertheless, the use of an individual statistical technique (i.e., true changes calculation) revealed that these nonsignificant increases or decreases may represent meaningful changes in their competitive potential.

Interrelationships Between Multiple Speed Tests in Youth Soccer: Are Players Equally Efficient at Performing Different Sprint and Change of Direction Tasks?

ABSTRACT: Freitas, TT, Pereira, LA, Alcaraz, PE, Cadore, EL, Grazioli, R, Azevedo, PHSM, Jeffreys, I, and Loturco, I. Interrelationships between multiple speed tests in youth soccer: Are players equally efficient at performing different sprint and COD tasks? J Strength Cond Res 37(4): 848-853, 2023-We investigated the relationships between linear and multidirectional sprint tests in elite young soccer players, using different speed measurements and their associated deficits. Twenty-three under-17 and 17 under-16 soccer players performed, on the same day, 17-m linear sprint (with 10-m split times), curve sprints for "good" and "weak" sides (CSGS and CSWS, respectively), and zigzag and 505 change of direction (COD) tests. The Pearson's product moment test was used to determine the relationships among the tested variables. Significance level was set at p < 0.05. Large and very large significant correlations were observed between CSGS and CSWS and 10-m ( r = 0.73 and r = 0.53, respectively; p < 0.0001) and 17-m sprint velocity ( r = 0.84 and r = 0.74, respectively; p < 0.0001). Moderate and significant associations were identified between zigzag and 17-m sprint performances ( r = 0.40; p = 0.02). No significant relationships were found between 505 performance and 17-m sprint velocity and between the different COD tasks ( p > 0.05). Significant correlations were observed between sprint performance at 10- and 17-m and both CS and COD deficits ( r values ranging from 0.37 to 0.54; p < 0.05). In general, higher linear sprinting velocities were associated with superior performances in smoother multidirectional tasks (i.e., CS and zigzag tests) but not in more aggressive COD maneuvers (i.e., 505). Faster athletes in linear actions presented greater CS and COD deficits. No associations were detected between the different COD measurements, supporting the notion that the technical and mechanical demands of COD actions are angle and velocity dependent. From a practical perspective, comprehensive speed testing batteries (i.e., incorporating linear sprints, CS, and different COD assessments) should be administered to young soccer players, to better understand their ability to change direction and sprint over multiple trajectories.

Sprint and Jump Training on Sand vs. Grass Surfaces: Effects on the Physical Performance of Young Soccer Players.

ABSTRACT: Pereira, LA, Freitas, TT, Zabaloy, S, Ferreira, RCA, Silva, ML, Azevedo, PHSM, and Loturco, I. Sprint and jump training on sand versus grass surfaces: effects on the physical performance of young soccer players. J Strength Cond Res 37(9): 1828-1833, 2023-The aims of this study were to (a) examine the effects of a 6-week sand training program including both sprint and jump exercises on the speed-related and vertical jump performance of elite young soccer players and (b) compare the changes induced by a sand training scheme with those induced by a similar training program (in volume, intensity, and exercise types) performed on grass. Twenty-four under-20 soccer players were randomly allocated to 2 training groups, as follows: "sand" ( n = 12) or "grass" ( n = 12) groups. Athletes performed squat and countermovement jumps, linear sprints, and Zigzag change-of-direction speed tests at pre-, mid- (after 6 training sessions), and postintervention (after 12 training sessions). Both groups exhibited similar increases in the vertical jump and Zigzag performance after the 6-week training period ( p values ranging from 0.0001 to 0.025; effect size ranging from 1.05 to 3.78, for main effect of time). No significant changes were detected for the linear sprint velocity for both the groups ( p values ranging from 0.079 to 1.00; effect size ranging from 0.07 to 0.65, for main effect of time). In summary, training on sand or grass surfaces resulted in similar improvements in the physical performance of elite young soccer players. This study confirms the current evidence on the effectiveness of both soft and harder training surfaces in improving the sprint and jump performance of team-sport athletes.

Half-Squat and Jump Squat Exercises Performed Across a Range of Loads: Differences in Mechanical Outputs and Strength Deficits.

ABSTRACT: Loturco, I, McGuigan, MR, Freitas, TT, Bishop, C, Zabaloy, S, Mercer, VP, Moura, TBMA, Arruda, AFS, Ramos, MS, Pereira, LA, and Pareja-Blanco, F. Half-squat and jump squat exercises performed across a range of loads: differences in mechanical outputs and strength deficits. J Strength Cond Res 37(5): 1052-1056, 2023-The aim of this study was to compare the peak force (PF), peak power (PP), and peak velocity (PV) outputs produced during half-squat (HS) and jump squat (JS) exercises executed at 20, 40, 60, and 80% of 1 repetition maximum (1RM) in the HS (HS 1RM) and to compute and compare the strength deficit (SDef) achieved in these exercises across these loads. Twenty-four national rugby union players (age: 25.7 ± 3.6 years) performed HS 1RM and a progressive loading test in the HS and JS exercises. The PF, PP, and PV values were obtained in all loads for both exercises, and the SDef was calculated as the percentage difference between the PF at distinct relative intensities and the PF at HS 1RM. The differences in HS and JS variables were determined using an analysis of variance with repeated measures. Higher PF, PP, and PV outputs were generated in the JS in comparison with the HS exercise ( p < 0.05); moreover, the SDef magnitudes were significantly lower in the JS ( p < 0.01), for all loading conditions. Importantly, the differences in SDef, and as a consequence, PF, PP, and PV decreased progressively with increasing load. Overall, the loaded JS exhibited increased levels of PF, PP, and PV and reduced levels of SDef when compared to the traditional HS performed across a range of loads. The JS is indicated to reduce the SDef and improve the athletes' ability to apply force at higher velocities. Nevertheless, with heavier loads (i.e., ≥80% HS 1RM), its potential advantages and effectiveness may be seriously compromised.

Effects of a Short-Term Detraining Period on the Strength Deficit and Functional Performance of Highly Trained Soccer Players.

ABSTRACT: Loturco, I, Grazioli, R, Veeck, F, Nakamura, FY, Inácio, M, Schons, P, Preissler, A, Pinto, RS, Pereira, LA, McGuigan, MR, and Cadore, EL. Effects of a short-term detraining period on the strength deficit and functional performance of highly trained soccer players. J Strength Cond Res 37(10): 2058-2063, 2023-The aim of this study was to examine the effects of a 4-week detraining period on the neuromuscular performance of highly trained soccer players. Pre and post detraining, 18 adult soccer players (age: 27 ± 4.9 years; height: 180.2 ± 7.1 cm; body mass [BM]: 78.9 ± 7.6 kg) performed vertical jumps, 20-m linear sprints, curve sprint and change of direction speed tests, and a progressive loading test in the half-squat exercise with loads corresponding to 50, 100, and 150% of the players' BM to assess the peak-force (PF), mean power (MP), and strength-deficit (SDef). Pre and post differences in the variables of interest were analyzed using paired t -tests and effect sizes (ES). No significant changes were detected for vertical jumping height and sprint times. Higher PF at 50 and 100% BM and lower SDef were shown when comparing pre- and postassessments (ES = 0.66, 0.68, 0.55; p = 0.018, 0.016, and 0.046, respectively). The MP at 50 and 100% BM increased significantly after the detraining phase (ES = 0.56, 0.82; p = 0.049 and 0.007, respectively). The results indicate that these athletes were able to maintain and achieve satisfactory levels of performance after a short period of training cessation. Interestingly, some strength- and power-derived parameters improved significantly after short-term detraining, which may have important implications for training programs aimed at maximizing speed and power performance. It is recommended that coaches test their players not only at the beginning but also at the end of the season, to better evaluate variations in performance and thus create more efficient and tailored training strategies.

The load-velocity relationship in the jump squat exercise.

The purpose of this study was to test the load-velocity relationship in the jump squat (JS) exercise using three different velocity parameters (mean velocity [MV], mean propulsive velocity [MPV], and peak velocity [PV]). Twenty-six male rugby union players (24.3 ± 3.9 years; 1.81 ± 0.09 m; 101.3 ± 15.4 kg) performed a progressive loading test in the JS with loads corresponding to 20, 40, 60, and 80% of the half-squat 1RM (equivalent to 24, 46, 70, and 94% of the estimated JS-1RM). MV, MPV, and PV were continuously recorded during all attempts using a linear velocity transducer. Linear regression models were used to determine the relationships between JS loads and MV, MPV, and PV. Bar-velocity outputs demonstrated high levels of consistency and reliability (coefficient of variation ≤ 5% and intraclass correlation coefficient ≥ 0.90). The predictive power of MV, MPV, and PV were ≥ 91%, for all tested variables (P < 0.0001). The equations and bar-velocity values provided in this study can be used by coaches to precisely determine and prescribe JS training loads, from verylight to heavy loading conditions (i.e., ~20-100% JS 1RM).

Sand and grass surfaces are equally effective in promoting positive adaptations in the sprint performance of elite young soccer players.

This study compared the effects of two sprint-jump training programmes, performed on either sand or grass surfaces, on the sprint and jump performance of elite young soccer players over an 8-week training period. Fifteen under-20 soccer players were randomly allocated to the sand (n = 7) or grass (n = 8) group. Athletes performed 12 training sessions, comprising vertical and horizontal jump exercises, and linear and change-of-direction (COD) sprint drills. Pre- and post-measurements were completed in the following order: vertical jump, sprint speed at 10 m and 17 m, curve sprint (CS), and modified Zigzag COD tests. Between-group differences were determined using a two-way ANOVA with repeated measures and effect sizes (ES). No improvements in jump performance were found in either group. Significant increases were observed in the sand group for acceleration in 0-10 m and for 10- and 17-m linear sprint velocity (ES = 1.15, 1.16, and 1.81, respectively; P < 0.05). In contrast, no significant differences were detected for acceleration and linear sprint velocity in the grass group, comparing pre- and post-tests (ES ranging from 0.01 to 0.47; P > 0.05). Both sand and grass groups revealed similar increases in the CS and COD velocities after the training period (ES ranging from 0.98 to 1.93; P < 0.05). In conclusion, sprint-jump training programmes performed on both grass and sand surfaces elicited significant improvements in CS and COD performances, whereas acceleration and linear sprint velocity increased only in the sand group, after a short-term training period. The sand training surface was proven to be a practical strategy to improve sprint performance in all its forms in soccer players, which is of great interest and importance for coaches and sport scientists working in elite soccer.

Relationship Between Distinct Physical Capacities in Young Welsh Rugby Players.

ABSTRACT: Loturco, I, Ashcroft, P, Evans, N, Tombs, C, Pereira, LA, and Jeffreys, I. Relationship between distinct physical capacities in young Welsh rugby players. J Strength Cond Res 36(2): 441-447, 2022-We examined the correlations between aerobic fitness (assessed by the 30-15 intermittent fitness test [IFT]), maximum isometric strength, vertical jump, and speed performance of 37 under-16 (U16) Welsh regional rugby players. The physical assessments used in this research are part of a regional development program under the auspices of the players' development pathway created by the Welsh Rugby Union. The tests were performed in the following order: vertical jumps, isometric midthigh pull, 40-m sprint velocity, and 30-15 IFT. A Pearson's product moment correlation coefficient was used to estimate the magnitude of the relationships between the different physical variables. Overall, we found significant associations between jump height, sprint velocity, maximum isometric strength, and 30-15 IFT performance (r ranging from 0.44 to 0.70). Moreover, strong positive interrelationships were observed between strength, speed, and jump qualities (r ranging from 0.51 to 0.80). Although these findings remain to be established in prospective studies, it seems that U16 athletes are capable of simultaneously improving their aerobic fitness and neuromuscular performance. This can be confirmed by the close correlations between the 30-15 IFT and every neuromechanical parameter reported here. Therefore, practitioners are recommended to use multifaceted training schemes with their young rugby players, including different components of endurance, speed, strength, and power training.

Strength Deficit in Elite Young Rugby Players: Differences Between Playing Positions and Associations With Sprint and Jump Performance.

ABSTRACT: Zabaloy, S, Giráldez, J, Fink, B, Alcaraz, PE, Pereira, LA, Freitas, TT, and Loturco, I. Strength deficit in elite young rugby players: Differences between playing positions and associations with sprint and jump performance. J Strength Cond Res 36(4): 920-926, 2022-The aims of this study were twofold: to compare the strength-related performance between young forwards and backs rugby players and to examine the correlations between strength deficit (SDef), strength parameters, and sprint and jump performance. Fifty-seven male rugby players (mean ± SD: age, 17.4 ± 1.3 years) performed anthropometric and body composition assessments, vertical jumps, 30-m sprint, and squat (SQ) and bench press (BP) 1-repetition maximum tests (1RM SQ and BP). The differences in the tested variables between positions were analyzed through an independent t-test. A Pearson's correlation coefficient was used to assess the relationships among the variables. Significant differences were observed for anthropometric and body composition measures and jump and sprint performance between positions (p < 0.05; effect size [ES]: 0.60-1.34), except for 5-m velocity (p = 0.080; ES: 0.57). Backs demonstrated higher relative 1RM than forwards in both exercises (p = 0.009 and p = 0.008; ES = 0.88 and 0.91, for SQ and BP, respectively). In addition, backs demonstrated lower SDef from 70 to 90% 1RM (p < 0.048) but small-to-moderate nonsignificant lower SDef against lighter loads compared with forwards (50-60% 1RM). Overall, SDef across all loads (r: -0.378 to -0.529) and 1RM SQ (r: 0.504 to -0.590) were significantly related to sprint performance. Therefore, young rugby players who present lower magnitudes of SDef and superior 1RM SQ performance tend to be faster in linear sprints.

A Novel Strategy to Determine the 1-Repetition Maximum in the Jump Squat Exercise.

ABSTRACT: Loturco, I, McGuigan, MR, Rodríguez-Rosell, D, Pereira, LA, and Pareja-Blanco, F. A novel strategy to determine the 1-repetition maximum in the jump squat exercise. J Strength Cond Res 36(8): 2330-2334, 2022-This study aimed to determine the maximum relative load of the half-squat (HS; i.e., % HS 1-repetition maximum [1RM]) that can be used in its ballistic variation, namely, the jump squat (JS) exercise, and to examine whether this reference value varies in subjects with different strength levels. In total, 186 elite athletes from 10 distinct sport disciplines participated in this study. A progressive loading test up to HS 1RM was performed during the competitive phase of the season for all athletes. Mean propulsive velocity and propulsive phase duration were also assessed during the 1RM test. Athletes were divided into 3 distinct subgroups: "low," "middle," and "high" strength levels, based on their relative HS 1RM values (kg·kg -1 ). A 1-way analysis of variance was used to compare the variables assessed between the groups. Significance level was set at p < 0.05. The high group demonstrated the highest relative HS 1RM values, followed by the middle and low groups (all p < 0.05). No significant differences were observed between the groups for the remaining variables ( p > 0.05). It was observed that at 86.0 ± 5.4% 1RM, the full concentric action can already be considered as entirely propulsive in the HS exercise for all subjects, independent of their strength levels. Therefore, this relative strength value may be used as a reference for the 1RM in the JS exercise.

Traditional Free-Weight Vs. Variable Resistance Training Applied to Elite Young Soccer Players During a Short Preseason: Effects on Strength, Speed, and Power Performance.

ABSTRACT: Loturco, I, Pereira, LA, Reis, VP, Zanetti, V, Bishop, C, and Mcguigan, MR. Traditional free-weight vs. variable resistance training applied to elite young soccer players during a short preseason: Effects on strength, speed, and power performance. J Strength Cond Res 36(12): 3432-3439, 2022-Maximizing the neuromuscular capacities of players is a critical challenge during short soccer preseasons. This study compared the effects of 2 strength-power training regimes, on the strength, speed, and power performance of elite young soccer players during a 4-week preseason. Twenty-five under-20 players from the same club were pair matched in 2 training groups as follows: traditional training group (TTG) ( n = 13), athletes performed half-squat (HS) and jump-squat (JS) exercises as traditionally prescribed, and elastic band (EB) group (EBG) ( n = 12), athletes performed HS and JS with EB attached to the barbell. Vertical jump height, 20-m sprint velocity, change of direction (COD) speed, HS and JS power, and 1 repetition maximum (1RM) in the HS were assessed before, after 2-week, and after 4-week of training. A two-way analysis of variance with repeated measures was used to assess the effects of both training protocols over the experimental period. Both strategies were effective for significantly improving HS and JS power (effect sizes [ESs] = 1.00-1.77), HS 1RM (ES = 1.68 and 1.51 for TTG and EBG, respectively), vertical jumping ability (ES = 0.37-0.65), and COD speed (ES = 0.81 and 0.39 for TTG and EBG, respectively), when comparing premeasures and postmeasures. By contrast, both TTG and EBG failed to increase 20-m sprint velocity (ES ranging between -0.54 and 0.23). In conclusion, both training schemes were able to improve the strength and power performance but not the sprint capacity of young soccer players. To accelerate strength gains over very-short time periods (i.e., 2 weeks), variable resistance training may be advantageous. Conversely, to optimize power adaptations in ballistic exercises across a similar time period, traditional free-weight training may be preferred.

Percentage-Based Change of Direction Deficit: A New Approach to Standardize Time- and Velocity-Derived Calculations.

ABSTRACT: Freitas, TT, Pereira, LA, Alcaraz, PE, Azevedo, PHSM, Bishop, C, and Loturco, I. Percentage-based change of direction deficit: a new approach to standardize time- and velocity-derived calculations. J Strength Cond Res 36(12): 3521-3526, 2022-Change of direction (COD) efforts are crucial in team sports, and an extensive body of research has been devoted to investigating this complex and multifaceted skill. Most studies have assessed players' ability to change direction by reporting completion time or average velocity in different COD tasks. However, it has been argued that these variables may not accurately portray an athlete's true capability to quickly change direction. In this context, new metrics such as the COD Deficit (CODD) have been proposed to provide complementary information on the efficiency to change direction. The current literature presents 2 different CODD computations: time-derived and velocity-derived calculations. Despite both being consistent and representing the same phenomenon, the decision of using one or the other may produce different outcomes, thus influencing coaches' decisions and training strategies. To overcome this issue, we propose a new approach to the computation of the CODD, based on the difference in percentage between linear sprint and COD abilities, in an attempt to standardize the estimation of this variable and simplify the evaluation of COD performance.

Change of Direction Performance in Elite Players From Different Team Sports.

ABSTRACT: Loturco, I, Pereira, LA, Reis, VP, Abad, CCC, Freitas, TT, Azevedo, PHSM and Nimphius, S. Change of direction performance in elite players from different team sports. J Strength Cond Res 36(3): 862-866, 2022-The primary aim of this study was to examine the differences in change of direction (COD) deficit between elite futsal, soccer, handball, and rugby players. A secondary aim was to compare the performance in both COD and linear speed tests among these athletes. One-hundred sixty-one elite male players from 4 team sports performed a 20-m linear sprint speed and a Zigzag COD speed test. The COD deficit was calculated as the difference between linear and Zigzag test velocities. Differences in COD speed, COD deficit, and sprint velocity were assessed via 1-way analysis of variance. The significance level was set at p < 0.05. Soccer players displayed significantly lower performance than the remaining team sports, and rugby players performed better than all the other groups in the Zigzag COD test. Moreover, the COD deficit was significantly higher in soccer players in comparison with the other disciplines (p < 0.05). No differences were observed in the COD deficit among rugby, futsal, and handball players (p > 0.05). In summary, soccer players were slower than futsal, handball, and rugby players to change direction and presented the greatest COD deficit magnitude. By contrast, the fastest athletes in the COD speed test (rugby players) were not more effective than futsal and handball players at changing direction (as they exhibited similar levels of COD deficit). Coaches should be aware of this evidence, which reinforces previous findings, indicating that very specialized training strategies might be required to improve COD performance in professional athletes.

Change-of-Direction Ability, Linear Sprint Speed, and Sprint Momentum in Elite Female Athletes: Differences Between Three Different Team Sports.

ABSTRACT: Freitas, TT, Pereira, LA, Alcaraz, PE, Comyns, TM, Azevedo, PHSM, and Loturco, I. Change-of-direction ability, linear sprint speed, and sprint momentum in elite female athletes: differences between three different team sports. J Strength Cond Res 36(1): 262-267, 2022-The aim of this study was to compare the performance of elite female players from 3 different sports in linear sprint and change-of-direction (COD) tests and examine their efficiency for changing direction through the calculation of the COD deficit (i.e., the difference in velocity between a linear sprint and a COD task of equal distance). One hundred fifty-four elite players (rugby, n = 40, national team members; soccer, n = 57 and handball n = 57, first division players from the respective Brazilian National Championships) were assessed in the 20-m linear sprint and Zigzag COD tests. A one-way analysis of variance with a Tukey post hoc was used to detect between-sport differences. Female rugby sevens players achieved faster sprint velocities than handball (20-m: 6.21 ± 0.24 m·s-1; 6.07 ± 0.27 m·s-1, respectively; p < 0.05) and soccer players (5-m: 4.71 ± 0.26 m·s-1 vs. 4.51 ± 0.20 m·s-1; and 20-m: 6.08 ± 0.19 m·s-1; p < 0.05) and exhibited the greatest COD deficits (2.95 ± 0.25 m·s-1; 2.69 ± 0.19 m·s-1; 2.82 ± 0.17 m·s-1, for rugby, handball, and soccer, respectively; p < 0.05). Handball players outperformed all other athletes in the Zigzag test (3.38 ± 0.15 m·s-1; 3.26 ± 0.10 m·s-1; 3.26 ± 0.10 m·s-1, for handball, rugby, and soccer, respectively; p < 0.05) but presented the lowest COD deficits (p < 0.05). Furthermore, soccer players displayed inferior sprint momentum when compared with the other sports (p < 0.05). Linear sprint and COD ability differ significantly among elite female athletes from different team sports, with handball players exhibiting a greater COD speed and efficiency to change direction, with respect to their maximum sprint velocity. The between-sport differences observed suggests that specific training and game demands may affect both sprint and COD performance.

Change of Direction Performance in Young Tennis Players: A Comparative Study Between Sexes and Age Categories.

ABSTRACT: Fernandez-Fernandez, J, Loturco, I, Pereira, LA, Del Coso, J, Areces, F, Gallo-Salazar, C, and Sanz-Rivas, D. Change of direction performance in young tennis players: a comparative study between sexes and age-categories. J Strength Cond Res 36(5): 1426-1430, 2022-The aim of this study was to examine the differences in linear sprint, change of direction (COD) performance, and COD deficit in a large sample of under-13 (U13) and under-15 (U15) male and female tennis players. One hundred and twenty-eight junior tennis players grouped into 2 age-groups (U13 years [32 boys and 28 girls] and U15 [36 boys and 32 girls]) participated in this study. Tests included anthropometric measurements, sprints (5-, 10- and 20-m), and a modified version of the 505 COD test. The differences in performance between age-categories and sex were assessed via an independent t-test. The differences in the physical tests between U13 and U15 players were tested using a univariate analysis, with age and anthropometric variables as covariates. Effect sizes (ESs) were calculated for pairwise comparisons. Results showed that boys presented lower 20-m sprint times than girls in the U13 (ES: 0.54; p < 0.05), and lower linear sprint (5-20-m) and COD times than girls in the U15 category (ES varying from 0.67 to 1.60; p < 0.05). Comparing age-groups, U15 girls demonstrated a higher COD deficit than the U13 (p < 0.05), whereas no differences were found in the other variables. In boys, no significant differences were observed in any variable when comparing both categories. These results could be of great interest for coaches and researchers involved in the development and training of elite tennis players, suggesting the need to include strategies able to improve sprint and COD performance throughout the players' specialization process.

Do Faster, Stronger, and More Powerful Athletes Perform Better in Resisted Sprints?

ABSTRACT: Lizana, JA, Bachero-Mena, B, Calvo-Lluch, A, Sánchez-Moreno, M, Pereira, LA, Loturco, I, and Pareja-Blanco, F. Do faster, stronger, and more powerful athletes perform better in resisted sprints? J Strength Cond Res 36(7): 1826-1832, 2022-This study aimed to analyze the relationships between different strength, power, and speed abilities and resisted sprint performance across a wide range of sled loads (10, 30, and 50% body mass [BM]). Seventy-nine young physically active male sport science students (age: 22.8 ± 3.4 years, BM: 74.2 ± 9.1 kg, and height: 175.4 ± 8.5 cm) performed 2 testing sessions. Session 1 consisted of a 20 m sprint without any additional load and with 10, 30, and 50% BM. Session 2 consisted of countermovement jump and full squat (SQ) tests. The CMJ was performed without any additional load and with loads of 30 and 50% BM, and the SQ was performed with loads corresponding to 30, 50, 70, and 90% BM. Resisted sprint times were moderate to large correlated with unloaded sprint times (r = 0.79 to 0.89), unloaded and loaded jump height (r = -0.62 to -0.71), and SQ performance (r = -0.56 to -0.71). Negative relationships were observed between velocity loss induced by each sled load and jump and SQ performance. The magnitude of these relationships increased with increasing sled loads. In conclusion, differences in speed, strength, and power abilities may explain, at least partially, the individual response of each athlete during sprinting towing a sled, especially with heavier sled loads. Thus, faster, stronger, and more powerful athletes require heavier sled loads (relative to %BM) to experience similar exercise intensities.