The Effects of Vertical vs. Horizontal plyometric Training on Sprinting Kinetics in Post Peak Height Female Student Athletes

Plyometric training is a form of jump training that is a useful method to improve sprinting speed due to its propensity to improve neural efficiency, increase joint stiffness and contraction speed. While research has shown that plyometrics can improve jumping and sprinting performance, no studies have compared the effects of different types of plyometric training on sprinting speed in young females. Therefore, the aim of the study was to compare different forms of plyometric training (horizontal and vertical) on sprinting performance in young females. Thirty young females from a private girls college were randomly divided into two groups and trained for seven weeks, twice a week; vertical plyometric (n=11, age 13.50 ± 0.96, peak heigh velocity-PHV: 1.60 ± 1.14), horizontal plyometric training (n=10, 13.40 ± 0.92, PHV:1.60 ± 0.93), and a physical education class as a control (n=15, age, 15.60 ± 0.31, PHV: 2.90 ± 0.55). Participants were tested for sprinting kinetics i.e. force (Fo), maximum power (Pmax), theoretical velocity (Vo), maximal velocity (Vmax), 10, 20 and 30 m split times using a radar gun over 30 m, isometric strength, vertical jump height and horizontal jump distance before and after the intervention. Both the intervention groups significantly improved all performance variables (g= 0.32- 1.30; p<0.05). The vertical group improved all kinetic variables except Fo and Pmax whereas the horizontal group improved all kinetic variables with a greater effect size g= 0.40-1.30. In comparison to the control group, the vertical group significantly improved Vo, Vmax, vertical and broad jump scores whereas the horizontal group significantly improved broad jump and 20 m split time scores (p<0.05). The findings of this study suggest that horizontal plyometric training is more effective in improving sprinting kinetics.

Practice versus Game External Load Measures in Starters and Non-Starters of a Men’s Collegiate Soccer Team

Monitoring external loads may minimize injury risk and improve physical performance. The purpose was to describe the external loads of a men’s collegiate soccer team during practice and games at the start of in-season play. In the first 2 weeks of the competitive season, National Collegiate Athletic Association Division I soccer athletes (n=19; mean±SD, age: 20.3±0.9 yr; body mass: 77.9±6.8kg; body height: 178.87±7.18cm; body fat: 10.0±5.0%; VO2max: 65.39±7.61mL/kg/min) wore a global positional system device (GPS/GNSS) during practices (n=8) and games (n=3). Starters were classified as players who maintained a minimum playing time of 45 minutes per game (n=10); other players were considered non-starters (n=9). External load metrics collected were: total distance (TD), player load (PL), high-speed distance (HSD, >13 mph (5.8 m/s)), high inertial movement analysis (IMA, >3.5m/s2), and repeated high intensity efforts (RHIE). Multivariate and repeated measures analyses of variance assessed differences in external load measures for practices and games in starters and non-starters. Relative to game loads, practices were quantified as high (>1 SD above the mean), medium (1 SD below the mean), low (2 SD below the mean) and very low (3 SD below the mean). For starters and non-starters, TD, PL, HSD, IMA, and RHIEs were lower in practices compared to games (p<0.001). No practices were classified as high or medium for any external load measure, with the majority of practices (75-100%) being classified as very low. Therefore, practice did not simulate game volumes or intensities. An individualized approach to monitoring is recommended to ensure starters receive adequate recovery and non-starters receive exposure to game-load physical stress.

The effects of a sled push at different loads on 20 metre sprint time in well-trained soccer players

This study determined the effects of a single sled push at different loads on sprint performance in competitive male soccer players. Twenty male competitive outfield soccer players (age 19.6±1.3y, body mass 73.6±8.2kg) were split into experimental (n=10) and control groups. In the experimental group, 20m linear sprint time was measured immediately before and 5, 6 and 7minutes after the sled push with either 50 or 100% body mass. The control group performed the 20m sprints only. A repeated measures ANOVA comparing control and experimental groups revealed no effects of time, group or time by group interaction for either experimental condition (all P>0.05). The repeated measures ANOVA compared the experimental conditions revealed effects of time (P=0.034) and group (P=0.002), but not time by group (P>0.05). The effects sizes demonstrated within group effects on sprint time that were small to moderate (-0.26 to 0.71) and trivial to small (-0.31 to 0.09) for the 50% and 100% body mass condition, respectively. These findings demonstrate that a sled push has no significant effect on 20 m sprint time in competitive footballers. If coaches continue to prescribed a sled push before sprinting, a single 15 m push with 50% body mass could have positive benefits.

Exploring The Power Clean

The power clean and its variations are prescribed by strength and conditioning coaches as part of the ‘big three’ to develop “total body strength”. This article explores the application of the power clean and its variations to athletic performance and introduces strength and conditioning coaches to teaching progressions, with specific emphasis on developing the correct body positioning required for the power clean. Teaching components are addressed with special reference to taller athletes. It is recommended that strength and conditioning coaches teach the hang clean follow a progression model to decrease movement complexity when advancing athletes to the power clean.

Kinetics and kinematics of sprinting in mid and post peak height velocity female athletes

Sprinting speed is a crucial physical capacity and can change throughout an athlete’s growth. Previous research has shown that both kinetic and kinematic variables change across maturation in young males. However, due to the changes in growth and hormonal levels, the kinetic and kinematic factors associated with sprinting may vary in young females compared to their male counterparts. Therefore, determining kinetics (force, maximal power) and kinematics (step length, step frequency, contact time and flight time) associated with sprinting in young females can provide valuable insights into training for this cohort. Thirty-two young female athletes, 11 mid-peak height velocity (PHV) age (12.8±0.6) and 21 post PHV (13.5±0.93) performed two 15 and 30 m sprints each. Theoretical velocity, maximal velocity, step length, force and power max were significantly higher in post PHV girls (p<0.05). Univariate regression analysis reported that the best predictors of velocity (15 and 30 m) were contact time, power max, stride frequency, step length and leg length with contact time being the strongest predictor. The findings of this research provide insight into the natural development of sprinting in young females and will help practitioners specifically develop training programs that can effectively improve sprinting kinetics and kinematics in this cohort.

The anthropometric, physical, and relative age characteristics of an English Premiership rugby union academy

Long-term athlete development is a primary focus for the England Rugby Football Union (RFU). The purpose of this study was to explore the anthropometric, physical, and relative age characteristics of rugby union academy players based on age group and playing position. Seventy-eight participants were examined for height, body mass, 10 and 20 m sprint, countermovement jump, reactive strength index, aerobic capacity, isometric hip extension, dominant handgrip strength, and birth quartile (BQ) across three age categories (i.e., under-16, under-18, and under-21) and two positions (forwards and backs). ANOVA and Kruskall–Wallis analysis were used to examine differences across each age category and position. TukeyHSD and Dunn’s test with Bonferroni correction was used for further post-hoc analysis. BQ distributions were compared against national norms using chi-square analysis. Results revealed that both older forwards (P=0.005) and backs (P=0.002) had significantly greater body mass, maximal aerobic capacity, and power compared to younger players. However, older forwards had slower 10 m sprint times compared to younger forwards. Moreover, relatively older players were significantly overrepresented across all age groups when compared to relatively younger players. Findings suggest that: (a) players should aim to develop greater parameters of body mass and aerobic capacity; (b) forwards should aim to develop acceleration and strength; (c) backs should aim to develop power and quickness; (d) players need to develop anthropometric and physical qualities and differences are apparent by age and position; and, (e) coaches should consider relative age when recruiting and developing young players. Key words: Talent identification; Talent development; Expertise; Physical development; Physiological profile; Rugby football

The Value of Having an Expert Sports Performance and Medicine Staff in the National Football League

An expert strength and conditioning coach can be an important component of a sports performance and medicine staff that will train their athletes to help them become more resilient to injury. Previous research in a variety of sports has shown that teams with players that have fewer games missed due to injury have achieved greater success. The purpose of this study was to determine if a relationship exists between games missed due to injury by offensive and defensive starters on National Football League (NFL) rosters and a NFL team’s ability to win during the 2010-19 NFL seasons. A Spearman rank-order correlation analysis set at (p ≤ 0.01) level of significance indicated that fewer games missed by starters in the NFL is correlated with multiple variables associated with winning such as games won per season and playoff appearances. These results were obtained after analyzing all 32 NFL teams from the 2010-19 seasons. Descriptive statistics were also used to further analyze the data set and found that teams ranked in the top-five in terms of fewest injuries outperformed the remainder of the teams in the NFL according to multiple variables associated with winning. The data in this study supports that NFL organizations should look to reduce the games missed due to injury of their athletes, which may be accomplished through hiring expert sports performance and medicine staff members, such as a strength and conditioning. hire an expert strength and conditioning coach capable of reducing the risk of athletes getting injured in order to increase their team’s chances of winning.

The effects of an upper body conditioning stimulus on lower body post-activation performance enhancement (PAPE): a pilot study

Complex training where a high-load conditioning stimulus (CS) is performed prior to a biomechanically similar plyometric movement has been demonstrated to acutely enhance the performance of the plyometric movement in a phenomenon called post-activation performance enhancement (PAPE). Despite the positive influence PAPE can have on power production, the abundance of research has only investigated PAPE locally while comparing biomechanically similar movements. The purpose of this study was to determine if a heavy barbell bench press could elicit PAPE in a lower body plyometric movement. Eight (n = 8) resistance-trained males performed one set of countermovement jumps (CMJs) before (pre-CS) and three sets of CMJs after (post-CS) a heavy bench press set. Changes in muscle activation, jump height, work, power output, and rate of force development (RFD) during the early (E-RFD) and late (L-RFD) stages were compared between pre-CS and post-CS. The level of significance was set at p < .05. There were no significant differences in muscle activation, jump height, work, power output, or E-RFD (p > .05). There was a significant increase in L-RFD between pre-CS and the final set of jumps post-CS (p = .01). These results suggest that an upper body CS may not influence PAPE in the lower body. However, pairing a high-load upper body exercise with a lower body plyometric does not seem disadvantageous, and could be implemented as a strategy to maximize workout time efficiency with proper fatigue management incorporation.

The use of interval-training methods by coaches of well-trained middle- to long-distance runners

Limited research exists on how coaches of well-trained middle- to long-distance runners implement interval-training (IT) methods. IT interventions within research focus on physiological measures whereas coaches focus on performance, leading to a disconnect between the IT methods utilized in research and practice. This study aimed to identify how coaches of well-trained middle- to long-distance runners implement IT methods within the training regimen. A survey was developed that comprised 5 sections: participant demographics, the use of IT, the type and characteristics of IT, recovery from IT, and reasons for including IT. Thirty (29 male, 1 female) coaches completed the survey. All coaches prescribed short, medium and long work intervals into the training regimen using race paces of 800m, 3000m, and 10000m, respectively, to prescribe intensity. Active recovery modalities were prescribed by the majority of coaches between sets and repetitions of all types of work intervals. The majority of coaches periodized the type of work interval prescribed relative to the competition date, with 1-2 IT sessions prescribed per week, year-round. Most coaches reported learning about IT primarily from their own training and coaching books, however, the most valuable sources of education for IT were ranked as scientific literature, coaching courses and workshops.