This study investigated the relationship between punching impact and selected strength and power variables in 15 amateur boxers from the Brazilian National Team (9 men and 6 women). Punching impact was assessed in the following conditions: 3 jabs starting from the standardized position, 3 crosses starting from the standardized position, 3 jabs starting from a self-selected position, and 3 crosses starting from a self-selected position. For punching tests, a force platform (1.02 × 0.76 m) covered by a body shield was mounted on the wall at a height of 1 m, perpendicular to the floor. The selected strength and power variables were vertical jump height (in squat jump and countermovement jump), mean propulsive power in the jump squat, bench press (BP), and bench throw, maximum isometric force in squat and BP, and rate of force development in the squat and BP. Sex and position main effects were observed, with higher impact for males compared with females (p ≤ 0.05) and the self-selected distance resulting in higher impact in the jab technique compared with the fixed distance (p ≤ 0.05). Finally, the correlations between strength/power variables and punching impact indices ranged between 0.67 and 0.85. Because of the strong associations between punching impact and strength/power variables (e.g., lower limb muscle power), this study provides important information for coaches to specifically design better training strategies to improve punching impact.

Pereira, LA, Nimphius, S, Kobal, R, Kitamura, K, Turisco, LAL, Orsi, RC, Cal Abad, CC, and Loturco, I. Relationship between change of direction, speed, and power in male and female National Olympic Team handball athletes. J Strength Cond Res 32(10): 2987-2994, 2018-The aims of this study were to (a) assess the relationship between selected speed- and power-related abilities (determined by 20-m sprint, unloaded countermovement jump [CMJ] and squat jump [SJ], and loaded jump squat [JS]) and performance in 2 distinct change of direction (COD) protocols (Zigzag test and T-test) and (b) determine the magnitude of difference between female and male Brazilian National Olympic Team handball athletes. Fifteen male and 23 female elite handball athletes volunteered to perform the following assessments: SJ and CMJ; Zigzag test and T-test; 20-m sprint with 5-, 10-, and 20-m splits; and mean propulsive power in JS. Pearson's product-moment correlation (p ≤ 0.05) was performed to determine the relationship between the COD tests (Zigzag test and T-test) and speed-power measures (sprint, SJ, CMJ, and JS). The differences between male and female performances were determined using the magnitude-based inference. Moderate to very large significant correlations were observed between both COD tests and the speed-power abilities. Furthermore, male athletes demonstrated likely to almost certainly higher performances than female athletes in all assessed variables. The results of the current study suggest that different speed-power qualities are strongly correlated to the performance obtained in various COD assessments (r values varying from 0.38 to 0.84 and from 0.34 to 0.84 for correlations between speed and power tests with Zigzag test and T-test, respectively). However, the level of these associations can vary greatly, according to the mechanical demands of each respective COD task. Although COD tests may be difficult to implement during competitive seasons, because of the strong correlations presented herein, the regular use of vertical jump tests with these athletes seems to be an effective and applied alternative. Furthermore, it might be inferred that the proper development of loaded and unloaded jump abilities has potential for improving the physical qualities related to COD performance in handball athletes.

The aim of this study was to investigate the effects of adding vertical/horizontal plyometrics to the soccer training routine on jumping and sprinting performance in U-20 soccer players. The vertical jumping group (VJG) performed countermovement jumps (CMJ), while the horizontal jumping group (HJG) executed horizontal jumps (HJ). Training interventions comprised 11 sessions, with volume varying between 32 and 60 jumps per session. The analysis of covariance revealed that CMJ height and peak force improved only in the VJG, and that HJ distance and peak force improved in both groups. Velocity in 20 m (VEL 20 m) did not improve in either group; however, velocity in 10 m (VEL 10 m) presented a moderate positive effect size (ES = 0.66) in the HJG, while the ES was large (1.63) for improvement in the 10-20 m acceleration in the VJG, and it was largely negative (-1.09) in the HJG. The transference effect coefficients (calculated by the equation: TEC = result gain (ES) in untrained exercise/result gain (ES) in trained exercise) between CMJ and VEL 20 m and ACC 10-20 m were 1.31 and 2.75, respectively. The TEC between HJ and VEL 10 m, VEL 20 m and ACC 0-10 m were 0.44, 0.17 and 0.44, respectively. The results presented herein indicate that the plyometric training-axis is decisive in determining neuromechanical training responses in high-level soccer players.

The purpose of this study was to test which specific type of exercise (i.e., jump squat (JS) or half-squat (HS)) is more effective at maintaining speed and power abilities throughout a preseason in soccer players. Twenty-three male soccer players were randomly allocated into two groups: JS and HS. The mean propulsive power, vertical jumping ability, and sprinting performance were evaluated before and after 4 weeks of a preseason period. The optimum power loads for the JS and HS exercises were assessed and were used as load-references. The soccer players performed 10 power oriented training sessions in total. Both JS and HS maintained power in JS and speed abilities (P > 0.05, for main effects and interaction effect) as indicated by ANCOVA. Both groups demonstrated reduced power during HS (ES = -0.76 vs. -0.78, for JS and HS, respectively); both groups improved acceleration (ACC) from 5 to 10 m (ES = 0.52). JS was more effective at reducing the ACC decrements over 0-5 m (ES = -0.38 vs. -0.58, for JS and HS, respectively). The HS group increased squat jump height (ES = 0.76 vs. 0.11, for HS and JS, respectively). In summary, JS is more effective in reducing the ACC capacity over very short sprints while HS is more effective in improving squat jump performance. Both strategies improve ACC over longer distances. New training strategies should be implemented/developed to avoid concurrent training effects between power and endurance adaptations during professional soccer preseasons.

Fourteen male elite sprinters performed short-distance sprints and jump tests until 18 days before 100-m dash competitions in track and field to determine if these tests are associated with 100-m sprint times. Testing comprised of squat jumps (SJ), countermovement jumps (CMJ), horizontal jumps (HJ), maximum mean propulsive power relative to body mass in loaded jump squats, and a flying start 50-m sprint. Moderate associations were found between speed tests and competitive 100-m times (r = 0.54, r = 0.61, and r = 0.66 for 10-, 30-, and 50-m, respectively, p ≤ 0.05). In addition, the maximum mean propulsive power relative to body mass was very largely correlated with 100-m sprinting performance (r = 0.75, p < 0.01). The correlations of SJ, CMJ, and HJ with actual 100-m sprinting times amounted to -0.82, -0.85, and -0.81, respectively. Because of their practicality, safeness, and relationship with the actual times obtained by top-level athletes in 100-m dash events, it is highly recommended that SJ, CMJ, and HJ be regularly incorporated into elite sprint-testing routines.