Most of the research combining small-sided games (SSGs) with high-intensity interval training (HIIT) is using the short or long forms of HIIT. However, other types of HIIT as repeated sprint training (RST) could enhance different stimuli. The purpose of the current research was to analyze the within- and between-group variations of physical fitness and body composition of two combined training interventions: (i) SSGs combined with a short high intensity interval training (sHIIT); and (ii) SSGs combined with a RST. This study followed a randomized parallel study design. Twenty-eight youth soccer players (age: 17.3 ± 0.5) belong to the same team were assigned equally to two intervention groups: SSG + sHIIT versus SSG + RST. Training intervention lasted 4 weeks, with a 2-session/week frequency. The players were tested twice, once before and after the intervention with the following tests: skinfolds (fat mass); Sargent jump test (SJT); standing long jump; sprinting time at 10-, 20-, or 30-m; 5-0-5 for time and deficit; 30-15 intermittent fitness test (30-15IFT) based on the final velocity, and repeated sprint ability (RAST) for peak, minimum, average power, and fatigue index. A mixed analysis of variance was conducted to considering factor × time effect. Between-group analysis revealed no significant differences at baseline and post-intervention period for fat mass, sprinting time at 10-, 20-, and 30-m, change-of-direction (COD) time and deficit, SJT and standing long jump, final velocity at 30-15IFT and RAST peak, average power, and fatigue index ( p > 0.05). Within-group analysis revealed that both groups significantly reduced fat mass ( p ≤ 0.001), SJT ( p ≤ 0.001), standing long jump ( p ≤ 0.001), sprint time at 10- and 20-m ( p ≤ 0.001), 30-m ( p = 0.002), COD time ( p ≤ 0.001) and deficit ( p < 0.05), RAST average ( p < 0.05), and final velocity 30-15IFT ( p ≤ 0.001). Only SSG + RST had significant improvements on COD deficit and peak power ( p < 0.05). The result of the current research suggests that either SSG + sHIIT or SSG + RST are effective for improving physical fitness in youth soccer players, with a multiple beneficial effect on locomotor profile, speed and COD, jumping performance and repeated sprint ability.

Purpose This randomised controlled trial examined the effect of an 8-week volume-equated programme of Nordic hamstring exercise (NHE) training, executed at frequencies of 1- or 2-days per week, on fitness (10 m and 40 m sprint, ‘505’ change of direction [COD] and standing long jump [SLJ]) in male youth soccer players (mean age: 16.4 ± 0.81 years). Method Players were divided into an experimental group (n = 16) which was further subdivided into 1-day (n = 8) and 2-day (n = 8) per week training groups and a control group (n = 8). Results There were significant group-by-time interactions for 10-m sprint (p<0.001, η2 = 0.120, d = 2.05 [0.57 to 3.53]), 40-m sprint (p = 0.001, η2 = 0.041, d = 1.09 [-0.23 to 2.4]) and COD (p = 0.002, η2 = 0.063, d = 1.25 [-0.09 to 2.59). The experimental group demonstrated a ‘very large’ effect size (d = 3.02 [1.5 to 4.54]) in 10-m sprint, and ‘large’ effect sizes in 40-m sprint (d = 1.94 [0.98 to 2.90]) and COD (d = 1.84 [0.85 to 2.83). The control group showed no significant changes. There were no significant differences between the 1-day and 2-day training groups. In three of the four tests (40 m, COD, SLJ) the 2-day group demonstrated larger effect sizes. Ratings of perceived exertion (RPE) were significantly lower in the 2-day group (p<0.001, 3.46 [1.83 to 5.04). Conclusion The NHE increases fitness in youth soccer players and there may be advantages to spreading training over two days instead of one.

This study aimed to compare the effects of horizontal (HJ) and vertical (VJ)-based plyometric jump training on male semi-professional soccer player's performance (e.g., change-of-direction speed [5-0-5 test]; 10-m, 20-m, and 30-m linear sprint speed). A parallel-study design was conducted. Participants were organized into HJ (n = 10) or VJ (n = 9) during 12 weeks. Measures of athletic performance were obtained in four phases: (i) before and (ii) end of the pre-season, (iii) during (weeks 7th), and (iv) after the intervention. The within-group analysis revealed that both HJ and VJ improved change of direction ($${x}^{2}$$ x 2  = 27.783; p < 0.001 ($${x}^{2}$$ x 2  = 21.635; p < 0.001),), 10-m linear sprint time ($${x}^{2}$$ x 2  = 28.576; p < 0.001), 20-m linear sprint time ($${x}^{2}$$ x 2  = 28.969, p < 0.001), and 30-m linear sprint time ($${x}^{2}$$ x 2  = 26.143; p < 0.001). Similarly, the VJ-group also imposed significant changes on 5-0-5 time, 10-m linear sprint time ($${x}^{2}$$ x 2  = 25.787; p < 0.001), 20-m linear sprint time ($${x}^{2}$$ x 2  = 24.333, p < 0.001), and 30-m linear sprint time ($${x}^{2}$$ x 2  = 22.919; p < 0.001). Between-group analysis revealed no significant differences in any of the assessment moments. HJ and VJ plyometric jump training are effective for improving the change-of-direction and a linear sprint of semi-professional players with no difference between types of intervention.

Purpose The way coaching cues are worded can impact on the quality with which a subsequent motor skill is executed. However, there have been few investigations on the effect of coaching cues on basic motor skill performance in youths. Method Across several international locations, a series of experiments were undertaken to determine the effect of external coaching cues (EC), internal coaching cues (IC), analogies with a directional component (ADC) and neutral control cues on sprint time (20 m) and vertical jump height in youth performers. These data were combined using internal meta-analytical techniques to pool results across each test location. This approach was amalgamated with a repeated-measures analysis to determine if there were any differences between the ECs, ICs and ADCs within the different experiments. Results 173 participants took part. There were no differences between the neutral control and experimental cues in any of the internal meta-analyses except where the control was superior to the IC for vertical jump (d = -0.30, [-0.54, -0.05], p = 0.02). Just three of eleven repeated-measures analyses showed significant differences between the cues at each experimental location. Where significant differences were noted, the control cue was most effective with some limited evidence supporting the use of ADCs (d = 0.32 to 0.62). Conclusion These results suggest the type of cue or analogy provided to a youth performer has little subsequent effect on sprint or jump performance. Accordingly, coaches might take a more specific approach that is suited to the level or preferences of a particular individual.