Tary maximal leg strength training on peak power output (Wpeak), vertical jump performance, and field performances in junior soccer players. Twenty-two male soccer players participated in this investigation and were divided into 2 groups: A resistance training group (RTG; age 17 ± 0.3 years) and a control group (CG; age 17 ± 0.5 years). Before and after the training sessions (twice a week for 2 months), Wpeak was determined by means of a cycling force-velocity test. Squat jump (SJ), countermovement jump (CMJ), and 5-jump test (5-JT) performances were assessed. Kinematics analyses were made using a video camera during a 40-m sprint running test and the following running velocities were calculated: The first step after the start (Vfirst step), the first 5 m (Vfirst 5 meters), and between the 35 m and 40 m (Vmax). Back half squat exercises were performed to determine 1-repetition maximum (1-RM). Leg and thigh muscle volume and mean thigh cross-sectional area (CSA) were assessed by anthropometry. The resistance training group showed improvement in Wpeak (p < 0.05), jump performances (SJ, p < 0.05 and 5-JT, p < 0.001), 1-RM (p < 0.001) and all sprint running calculated velocities (p < 0.05 for both Vfirst step and Vfirst 5 meters, p < 0.01 for Vmax). Both typical force-velocity relationships and mechanical parabolic curves between power and velocity increased after the strength training program. Leg and thigh muscle volume and CSA of RTG remained unchanged after strength training. Back half squat exercises, including adapted heavy loads and only 2 training sessions per week, improved athletic performance in junior soccer players. These specific dynamic constant external resistance exercises are highly recommended as part of an annual training program for junior soccer players....

Our hypothesis was that the addition of an 8-week lower limb plyometric training program (hurdle and depth jumping) to normal in-season conditioning would enhance measures of competitive potential (peak power output [PP], jump force, jump height, and lower limb muscle volume) in junior soccer players. The subjects (23 men, age 19 ± 0.7 years, body mass 70.5 ± 4.7 kg, height 1.75 ± 0.06 m, body fat 14.7 ± 2.6%) were randomly assigned to a control (normal training) group (Gc; n = 11) and an experimental group (Gex, n = 12) that also performed biweekly plyometric training. A force-velocity ergometer test determined PP. Characteristics of the squat jump (SJ) and the countermovement jump (CMJ) (jump height, maximal force and velocity before take-off, and average power) were determined by force platform. Video-camera kinematic analyses over a 40-m sprint yielded running velocities for the first step (VS), the first 5 m (V5m) and between 35 and 40 m (Vmax). Leg muscle volume was estimated using a standard anthropometric kit. Gex showed gains relative to controls in PP (p < 0.01); SJ (height p < 0.01; velocity p < 0.001), CMJ (height p < 0.001; velocity p < 0.001, average power p < 0.01) and all sprint velocities (p < 0.001 for V5m and Vmax, p < 0.01 for VS). There was also a significant increase (p < 0.05) in thigh muscle volume, but leg muscle volume and mean thigh cross-sectional area remain unchanged. We conclude that biweekly plyometric training of junior soccer players (including adapted hurdle and depth jumps) improved important components of athletic performance relative to standard in-season training. Accordingly, such exercises are highly recommended as part of an annual soccer training program.

We hypothesized that replacement of a part of the normal in-season regimen of top-level adolescent handball players by an 8-week biweekly course of lower and upper limb plyometric training would enhance characteristics important to competition, including peak power output (Wpeak), jump performance, muscle volume, and ball throwing velocity. Study participants (23 men, age: 17.4 ± 0.5 years, body mass: 79.9 ± 11.5 kg, height: 1.79 ± 6.19 m, body fat: 13.8 ± 2.1%) were randomly assigned between controls (C; n = 11) and an experimental group (E, n = 12). Measures preintervention and postintervention included force-velocity ergometer tests for upper (Wupper peak) and lower limbs (Wlower peak), force platform determinations of squat jump (SJ) and countermovement jump (CMJ) characteristics (jump height, maximal force, initial velocity, and average power), video filming of sprint velocities (first step [V1S], first 5 m [V5m], and 25-30 m [Vmax]), and anthropometric estimates of leg muscle volume. E showed gains relative to C in Wupper peak and Wlower peak (p < 0.01 and p < 0.001), SJ (height p < 0.01; force p ≤ 0.05), CMJ (height p < 0.01; force p < 0.01 and relative power p ≤ 0.05), and sprint velocities (p < 0.001 for V1S, V5m, and Vmax). E also showed increases in leg and thigh muscle volumes (p < 0.001), but arm muscle volumes did not differ from control. We conclude that introduction of biweekly plyometric training into the standard regimen improved components important to handball performance, particularly explosive actions, such as sprinting, jumping, and ball throwing velocity.

Pper limb (PPUL) and lower limb (PPLL) force-velocity tests, maximal upper limb force assessed by 1 repetition maximum bench press (1RMBP), and pullover (1RMPO) exercises, estimates of local muscle volume and 3-step running handball throwing velocity (T3-Steps). Fourteen male handball players volunteered for the investigation (age: 19.6 ± 0.6 years; body mass: 86.7 ± 12.9 kg; and height 1.87 ± 0.07 m). Lower and upper limb force-velocity tests were performed on appropriately modified forms of a Monark cycle ergometer, with measurement of PPUL and PPLL, and the corresponding respective maximal forces (F0UL and F0LL) and velocities (V0UL and V0LL). T3-Steps was assessed using a radar Stalker ATS system™. Muscle volumes of the upper and lower limbs were estimated with a standard anthropometric kit. T3-Steps was closely related to absolute PPUL and to F0UL (r = 0.69, p < 0.01 for both relationships). T3-Steps was also moderately related to 1RMBP and 1RMPO (r = 0.56, p < 0.05; r = 0.55, p < 0.05 respectively), and to PPLL and F0LL (r = 0.56, p < 0.05; r = 0.62, p < 0.05, respectively). When PPLL was expressed per unit of limb muscle volume, the relationship with T3-Steps disappeared. This suggests the importance of muscle volume to performance in throwing events. Force-velocity data may prove useful in regulating conditioning and rehabilitation programs for handball players. Our results also highlight the contribution of both the lower and the upper limbs to handball throwing velocity, suggesting the need for coaches to include upper and lower limb strength and power programs when improving the throwing velocity of handball players....

Hammami, M, Gaamouri, N, Shephard, RJ, and Chelly, MS. Effects of contrast strength vs. plyometric training on lower-limb explosive performance, ability to change direction and neuromuscular adaptation in soccer players. J Strength Cond Res 33(8): 2094–2103, 2019—The aim was to compare the effects of 2 differing 8-week in-season strength training programs (contrast strength training [CST] vs. plyometric training [PT]) on selected performance tests (5 and 40 m sprints, S 4 × 5 m change of direction test, squat jump [SJ] and countermovement jump [CMJ], leg peak power on a cycle-ergometer force-velocity test, 1 repetition maximal half-squat, and electromyographic [EMG] activity of the vastus lateralis, vastus medialis, and rectus femoris muscles during vertical jump tests). Forty male soccer players (age = 15.8 ± 0.4 years; body mass = 58.8 ± 6.3 kg; body height = 1.74 ± 0.06 m; body fat = 10.5 ± 1.9%) were divided between a contrast strength group (CSG, n = 14), plyometric group (PG, n = 14), and control group (CG, n = 12). Both training programs enhanced sprint performance (p < 0.001 in 5 m; p ≤ 0.05 in 40 m) and change of direction test scores (p < 0.001) relative to controls. The plyometric group and CSG increased SJ height relative to the CG, with a slightly greater response in CSG compared with PG (p ≤ 0.05). Most CMJ scores increased significantly in both CSG and PG relative to the CG, with no intergroup differences in training response. Most force-velocity scores increased significantly in the CSG relative to PG and CG. The EMG parameters also increased in the CSG relative to both PG and CG. In summary, most measures of athletic performance in male soccer players were enhanced after CST and PT. However, the improvement of physical performance was better with 8 weeks of CST than with PT. Thus, coaches should be encouraged to include CST as an element of in-season conditioning.

The aims of this study were to test the potential of in-season heavy upper and lower limb strength training to enhance peak power output (Wpeak), vertical jump, and handball related field performance in elite male handball players who were apparently already well trained, and to assess any adverse effects on sprint velocity. Twenty-four competitors were divided randomly between a heavy resistance (HR) group (age 20 ± 0.7 years) and a control group (C; age 20 ± 0.1 years). Resistance training sessions were performed twice a week for 8 weeks. Performance was assessed before and after conditioning. Peak power (W(peak)) was determined by cycle ergometer; vertical squat jump (SJ) and countermovement jump (CMJ); video analyses assessed velocities during the first step (V(1S)), the first 5 m (V(5m)), and between 25 and 30 m (V(peak)) of a 30-m sprint. Upper limb bench press and pull-over exercises and lower limb back half squats were performed to 1-repetition maximum (1RM). Upper limb, leg, and thigh muscle volumes and mean thigh cross-sectional area (CSA) were assessed by anthropometry. W(peak) (W) for both limbs (p < 0.001), vertical jump height (p < 0.01 for both SJ and CMJ), 1RM (p < 0.001 for both upper and lower limbs) and sprint velocities (p < 0.01 for V(1S) and V(5m); p < 0.001 for V(peak)) improved in the HR group. Upper body, leg, and thigh muscle volumes and thigh CSA also increased significantly after strength training. We conclude that in-season biweekly heavy back half-squat, pull-over, and bench-press exercises can be commended to elite male handball players as improving many measures of handball-related performance without adverse effects upon speed of movement.