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Both resisted and assisted training programs are key parts of the NASE 5-Step Training Model for the speed improvement of athletes in power sports. The study by Wibowo, on the Impact of Assisted Sprinting training (AS) and Resisted Sprinting Training (RS) in Repetition Method on Improving Sprint Acceleration compared both methods for their effectiveness in improving early and late acceleration.
The purpose of this research was to determine the impact of assisted sprinting training (AS) and resisted sprinting training (RS) in repetition method on improving sprint acceleration capabilities. This research used an experimental method in the pre-test and post-test design. The research sample were twelve male collegiates track sprinters, athletic division Indonesia University of Education, Bandung. Six male collegiates track sprinters for AS and six male collegiates track sprinters for RS. It used simple random sampling. The instrument used was 30 m sprint test. After training three times per week for six week, data were obtained from pre-test and post-test processed statistically by t-test. The AS group and RS group showed significant changes on improving sprint acceleration capabilities. No significant different between AS and RS on improving sprint acceleration capabilities. In AS the increase was better than RS at a distance of 10 m from a distance of 30 m. While, in RS the increase was better than AS at a distance of 10-20 m and 20-30 m from a distance of 30 m. Accordingly, to improve acceleration at a distance 10 m use AS, while to improve acceleration at a distance of 10-20 m and 20-30 m from a distance of 30 m use RS.
Coaching Application: Although both AS and RS training improved acceleration, AS was slightly more effective during early and RS during late acceleration. The use of “contrast training” combines both AS and RS to alter motor patterns by using programs that impose demands easier (sprint-assisted training) and harder (sprint-resisted training) than the normal sprinting action during the same workout session. This approach may trick the neuromuscular system into performing at a higher level by making the task of sprinting more difficult or a bit easier than normal.
For both approaches (harder and easier), the resistance load is performed first, following by assisted training that makes sprinting an easier task. The heavy load is thought to excite the nervous system and allow for greater recruitment of motor neurons (post-activation potentiation) in the set that follows. Resisted sprints immediately follow the general warm-up and dynamic warm-up sessions. Three repetitions of maximum resisted sprints are performed, using a 2-5 minute recovery period between each. The contrast training session ends with one set of three repetitions over the same distance with no resistance or assistance. It is also acceptable to complete one resisted sprint, followed by one assisted sprint, and ending with one normal sprint. Another formula for contrast training is to complete 2-3 sets of one resisted effort, and finally a normal sprint.
Wibowo, Ricky. 2017 The Impact of Assisted Sprinting Training (AS) and Resisted Sprinting Training (RS) in Repetition Method on Improving Sprint Acceleration Capabilities. Jurnal Pendidikan Jasmani dan Olahra ga Volume 9 Nomor 1.
Hang clean and hang snatches produce similar improvements in female collegiate athletes: The study by Ayers and colleagues described in the Abstract below focused on hang clean and hang snatches to determine the training effects on the power, strength, and speed of female collegiate athletes.
Olympic weightlifting movements and their variations are believed to be among the most effective ways to improve power, strength, and speed in athletes. This study investigated the effects of two Olympic weightlifting variations (hang cleans and hang snatches), on power (vertical jump height), strength (1RM back squat), and speed (40-yard sprint) in female collegiate athletes. Twenty-three NCAA Division I female athletes were randomly assigned to either a hang clean group or hang snatch group. Athletes participated in two workout sessions a week for six weeks, performing either hang cleans or hang snatches for five sets of three repetitions with a load of 80-85% 1RM, concurrent with their existing, season-specific, resistance training program. Vertical jump height, 1RM back squat, and 40-yard sprint all had a significant, positive improvement from pre-training to post-training in both groups (p≤0.01). However, when comparing the gain scores between groups, there was no significant difference between the hang clean and hang snatch groups for any of the three dependent variables (i.e., vertical jump height, p=0.46; 1RM back squat, p=0.20; and 40-yard sprint, p=0.46). Short-term training emphasizing hang cleans or hang snatches produced similar improvements in power, strength, and speed in female collegiate athletes. This provides strength and conditioning professionals with two viable programmatic options in athletic-based exercises to improve power, strength, and speed.
Coaching Application: To improve sprinting speed, strength training exercise choices should be selected that train the movement patterns involved in sprinting, rather than the involved muscle groups. These exercises should mimic the movements that produce hip extension and involve multi-joint rather than single movements. Squats, dead lifts, lunges, step-ups and numerous variations of these weight room exercises, the Olympic Lifts, and plyometrics (hopping, jumping, and bounding) are recommended for a complete strength training program designed to increase overall strength, core strength, ground reaction force, and mass specific force (ratio of body weight/ground reaction force).
JL Ayers, M DeBeliso, TG Sevene, and KJ Adams. 2018. Hang cleans and hang snatches produce similar improvements in female collegiate athletes. Biol Sport. September: 33(3): 252-56
Predictors of Sprint Performance in Professional Rugby Players: Relative strength and power are key factors that affect the speed of athletes during the start, acceleration, and maximum speed phase of a short sprint. The Abstract of a study by Cunningham and colleagues, described below, reinforces this concept.
The ability to accelerate and attain high speed is an essential component of success in team sports; however, the physical qualities that underpin these activities remain unclear. This study aimed to determine some of the key strength and power predictors of speed with professional rugby players.
Methods: Twenty professional players were tested for speed (0-10-meter sprint and a flying 10-meter sprint), strength (3 repetitions maximum squat), lower body power countermovement jumps (CMJ, and drop jumps (DJ), reactive strength and leg spring stiffness. The strength and power variables were expressed as absolute values and relative values for analysis.
Results: Both relative strength (r=.55, P<0.05) and relative power (-.082, P<0.01) were negatively correlated with 10-meter time. Leg spring stiffness and DJ contact time were also related to the flying 10-meter time (r=.046 and 0.47 respectively, P(<0.05) while relative strength index was negatively related to both the 10-meter and flying 10-meter Tims (r=0.60 and r=0.62, P<0.05). Acceleration was significantly related to relative strength, relative power and jump height from a 40 cm DJ. Maximum velocity sprinting was significantly related to relative power, contact time, height and leg stiffness. The study provides an insight into those physical attributes that underpin sprinting performance in professional rugby union players and specifically highlights the importance of relative strength and power in the expression and development of different speed components (e.g. acceleration, maximum velocity). Coaching Application: Findings on “relative strength” reinforce the importance of acquiring a favorable ratio of Ground Reaction Force/Body Weight. Acceleration and maximum speed improve when GRF increases and/or body weight decreases. Team sport athletes should strive to become as strong as possible with minimum body fat. In the above study, absolute strength was not related to 10-meter or flying 10-meter speed. When 1RM strength was expressed relative to body mass, significant relationships wwere identified with jump height and 10-meter speed. In addition, acceleration and maximum speed are separate entities and require different training approaches to improve.
Cunningham, D.J., West, D.J., Owen, N.J., Shearer, D.A., Finn, C.V., Bracken, R.M., Crewther, B.T., Scott, P., Cook, C.J., and Kilduff, L.P. 2013. Strength and Power Predictors of Sprinting Performance in Professional Rugby Players. The Journal of Sports Medicine and Physical Fitness. 53: 1-2
The NFL Combine and Performance on the Football Field: Do high scores on the NFL Combine physical tests predict success in the NFL? Several studies have been conducted to answer these and other questions. The investigation by Kuzmits and colleagues described in the abstract below is perhaps one of the most negative.
Kuzmits and Adams investigated the correlation between National Football League (NFL) combine test results and NFL success for players drafted at three different offensive positions (quarterback, running back, and wide receiver) during a 6-year period, 1999-2004. The combine consisted of series of drills, exercises, interviews, aptitude tests, and physical exams designed to assess the skills of promising college football players and to predict their performance in the NFL. Combine measures examined in this study included 10-, 20-, and 40-yard dashes, bench press, vertical jump, broad jump, 20- and 60-yard shuttles, three-cone drill, and the Wonderlic Personnel Test. Performance criteria include 10 variables: draft order; 3 years each of salary received and games played; and position-specific data. Using correlation analysis, we find no consistent statistical relationship between combine tests and professional football performance, with the notable exception of sprint tests for running backs. We put forth possible explanations for the general lack of statistical relations detected, and, consequently, we question the overall usefulness of the combine. We also offer suggestions for improving the prediction of success in the NFL, primarily the use of more rigorous psychological tests and the examination of collegiate performance as a job sample test. Finally, from a practical standpoint, the results of the study should encourage NFL team personnel to reevaluate the usefulness of the combine’s physical tests and exercises as predictors of player performance. This study should encourage team personnel to consider the weighting and importance of various combine measures and the potential benefits of overhauling the combine process, with the goal of creating a more valid system for predicting player success.
Another study by Sierer, et. al. compared the NFL Combine performance differences between drafted and non-drafted players. Findings were slightly more positive. Although drafted athletes were found to perform better than non-drafted athletes, the success of each athlete in the NFL was not used as a criterion measure and predictive validity was not established. Boulier and Stekler used a data base from NFL drafts between 1974 and 2005 and a range of measures to determine the success of players selected in the draft. The study examined the success of drafting quarterbacks and wide receivers and also found combine test scores to be only slightly helpful in predicting NFL success at these positions.
It is understandable why it is so difficult to statistically determine success from field tests since football is skill specific and physical tests cannot mimic the many key situations for each player position. Clearly, there is room for improvement even in the area of speed tests where researchers found some predictive value. Football is a game of quickness, starting, stopping, and acceleration. An analysis of game play would reveal that it is a rare occasion when players in most positions sprint a distance of 40 yards. The First 3-step test and the 10-yard dash are much more sport specific for interior linemen (blocking, pass and run rushing) than the 40-yard dash. If the 40-yard dash is deemed necessary, the test should be changed to include split times at 5, 10, and 20 yards. Also, a plant, cut, and 10-yard acceleration test is also more football-appropriate for linebackers, defensive backs, and linemen.
Although the 2018 NFL Combine was more comprehensive and controlled than during the period the three studies above were conducted, it is time for further investigation to determine the predictive value of individual tests and combined scores on game performance in this modern era.
Boulier, Bryan Leslie and H.O. Stekler. 2010. Evaluating National Football League Draft Choices: The Passing Game. International Journal of Forecasting Vol. 26, Issue 3, July 589-605
Kuzmits, F.E., and A.J. Adams. 2008. The NFL Combine: Does it Predict Performance in the National Football League. J Strength Cond Res. Nov;22(6):1721-7.)
Sierer, S.P., Battaglini, C.L., Mihalik, J.P., Shields, E.W., and NT Tomasini. 2006. The National Football League Combine: performance differences between drafted and non-drafted players entering the 2004 and 2005 drafts. Journal of Strength & Conditioning Research: January 2008 – Volume 22 – Issue 1 – pp 6-12.
Effectiveness of a wireless Sensor Insole in measuring vertically directed ground reaction force (GRF) during the sprinting action: The availability of a device to accurately measure the amount and direction of force applied to the ground with each step during the sprinting action would be major breakthrough. The specific training programs and exercises that increase GRF, decrease ground contact time (GCT), and improve speed in short sprints could then be accurately identified. The technology to develop these sensors is available and researchers are now experimenting with various devices and protocols. An abstract of a study by Nagahara and Morin (2018), who tested one type of shoe insole sensor, follows.
Temporal variables and vertical ground reaction force have been used as measures characterizing sprinting. A recently developed wireless pressure sensor insole (sensor insole) could be useful for monitoring sprinting in terms of temporal variables and vertical ground reaction force during training sessions. The purpose of this study was to examine the concurrent validity of the sensor insole for measuring temporal and vertical force variables during sprinting. One athlete performed five 50-m sprints, and the step-to-step vertical ground reaction force and plantar pressure were simultaneously measured by a long-force platform system (reference device) and the sensor insole, respectively. The temporal and vertical ground reaction force variables were calculated using signals from both devices, and a comparison was made between values obtained with both devices for 125 steps analyzed. The percentage bias, 95% limits of agreement, and Bland–Altman plots showed low agreement with the reference device for all variables except for step frequency. For the vertical ground reaction force variables, the sensor insole underestimated the values (−18.9 to −48.3%) compared to the force platform. While support time and time to maximal vertical force from the foot strike were overestimated by the sensor insole (54.6 ± 8.0% and 94.2 ± 23.2%), flight time was underestimated (−48.2 ± 15.0%). Moreover, t-test revealed the significant difference in all variables between the sensor insole and force platform, except for step frequency. The bias for step frequency (0.4 ± 7.5%) was small. However, there was heteroscedasticity for all variables. The results from this study demonstrate that a wireless pressure sensor insole is generally not valid to measure the temporal and vertical force variables during sprinting. Thus, using the examined sensor insole for monitoring sprinting characteristics is not recommended at this time.
Coaching Application. Although findings of the above study indicate that a wireless shoe sensor did not accurately measure temporal and vertical ground reaction forces, it is a first step toward the development of a low cost device that is as accurate or more accurate than the costly force plate technology currently available. Developing a low cost, accurate device is a challenge, however, the tremendous importance of finding ways to increase GRF and decrease GCT during the start, acceleration, and maximum speed phase of a short sprint, encourages researchers to continue their pursuit in this area of interest.
Reference: Ryu Nagahara and Jean-Benoit Morin. 2018. Sensor insole for measuring temporal variables and vertical force during sprinting. Proceedings of the Institution of Mechanical Engineers. Part P: Journal of Sports Engineering and Technology. First Published January 19, 2018.
Meta-analysis techniques have the advantage of combining the results from multiple studies to increase power, resolve uncertainty when studies disagree, and improve the accuracy of findings. Rumpf and colleagues (2016) used this technique to analyze the effects of various training programs on sprint performance. Findings reveal important information for team and individual sport coaches and athletes. An abstract of this study is provided below.
Linear sprinting speed is an essential physical quality for many athletes. There are a number of different training modalities that can be used to improve sprint performance. Strength and conditioning coaches must select the most appropriate modalities for their athletes, taking into consideration the sprint distances that typically occur during competition. The study purpose was to perform a brief review as to the effect of specific (free sprinting; resisted sprinting by sleds, bands, or incline running; assisted sprinting with a towing device or a downhill slope), nonspecific (resistance and plyometric training), and combined (a combination of specific and nonspecific) training methods on different sprint distances (0–10, 0–20, 0–30, and 31+ m). A total of 48 studies fulfilled the inclusion criteria, resulting in 1,485 subjects from a range of athletic backgrounds. The training effects associated with specific sprint training were classified as moderate (effect size [ES] = −1.00; %change = −3.23). Generally, the effect of specific sprint training tended to decrease with distance, although the largest training effects were observed for the 31+ m distance. The greatest training effects (ES = −0.43; %change = −1.65) of nonspecific training were observed for the 31+ m distance. The combined training revealed greatest effects (ES = −0.59; %change = −2.81) for the 0–10 m distance. After this review, specific sprint training methods seem the most beneficial over the investigated distances. However, the implementation of nonspecific training methods (e.g., strength and power training) could also benefit speed and athletic performance.
*Coaching Application: This analysis dealt primarily with the start and acceleration phase of a short sprint. Findings support the use of specific training (free sprinting: resisted and assisted), non-specific training (resistance and plyometrics), and a combination of each. Combined training was shown to be most effective for the 0-10 meter distance whereas non-specific training was more effective for distances in excess of 31 meters. Although specific training methods appeared to be more beneficial, the authors made it clear that nonspecific training (strength and power) also are important. This study did not examine the effects of each training program on ground reaction force (GRF) or rate of force development such as ground contact time (GCT) which remain as key aspects of all sprint training programs.
Rumph, Michael C., Lockie, Robert G.,Cronin, John B., Jalivand, Farzad. 2016. Effect of Different Sprint Training Methods on Sprint Performance Over Various Distances: A Brief Review. Journal of Strength and Conditioning Research, Vol. 30, Number 6, June, 1767-1785.
Complex Training with Male Rugby Players: Complex training involves the integration of strength training, plyometrics, and sport-specific movements. A single workout may involve intense strength exercises followed by a plyometric exercise to simultaneously train the nervous system and fast twitch muscle fibers. A slow, heavy strength exercise such as a squat, and a lighter fast, repetition of a sprint, plyometric jump or Olympic lift, can be combined. A heavy, slow movement is followed by a fast repetition. Alternating both plyometric and resistance training with other stretch-shortening activities in the same workout has been shown to be an effective technique.
A study by Comyns, et. al. examined the effect of various resistive loads on the biomechanics of performance of a fast stretch–shortening cycle activity to determine if an optimal resistive load exists for complex training. Twelve elite rugby players performed three drop jumps before and after three back squat resistive loads of 65%, 80%, and 93% of a single repetition maximum (1-RM) load. All drop jumps were performed on a specially constructed sledge and force platform apparatus. Flight time, ground contact time, peak ground reaction force, reactive strength index, and leg stiffness were the dependent variables. Repeated-measures analysis of variance found that all resistive loads reduced (P < 0.01) flight time, and that lifting at the 93% load resulted in an improvement (P < 0.05) in ground contact time and leg stiffness. From a training perspective, the results indicate that the heavy lifting will encourage the fast stretch–shortening cycle activity to be performed with a stiffer leg spring action, which in turn may benefit performance. However, it is unknown if these acute changes will produce any long-term adaptations to muscle function. *Coaching Application: Research suggests that complex training has an acute ergogenic effect on upper body power which also includes improved jumping performance. Improved performance may require 3-4 minute rest intervals between the weight training and plyometrics sets and the use of heavy weight training loads. Studies indicate that complex training is equally or more effective than strength training or plyometric training alone in increasing speed strength and maximum speed.
Comyns, Thomas M., Harrison, Andrew J., Hennessy, Liam, and Randal Jensen. 2007. Identifying the optimal resistive load for complex training in male rugby players. Sports Biomechanics, Vol. 6, Issue 1.
The importance of ground reaction force (GRF) and the speed with which force is applied during the pushing action away from the ground cannot be overemphasized.These two factors are major determinants of sprint performance for athletes in all sports during each phase of a short sprint.
A study by Nagahara and associates (2017) aimed to investigate the step-to-step spatiotemporal variables and ground reaction forces during the acceleration phase for characterizing intra-individual fastest sprinting within a single session. Step-to-step spatiotemporal variables and ground reaction forces produced by 15 male athletes were measured over a 50-m distance during repeated (three to five) 60-m sprints using a long force platform system. Differences in measured variables between the fastest and slowest trials were examined at each step until the 22nd step using a magnitude-based inferences approach. There were possibly–most likely higher running speed and step frequency (2nd to 22nd steps) and shorter support time (all steps) in the fastest trial than in the slowest trial. Moreover, for the fastest trial there were likely–very likely greater mean propulsive force during the initial four steps and possibly–very likely larger mean net anterior–posterior force until the 17th step. The current results demonstrate that better sprinting performance within a single session is probably achieved by 1) a high step frequency (except the initial step) with short support time at all steps, 2) exerting a greater mean propulsive force during initial acceleration, and 3) producing a greater mean net anterior–posterior force during initial and middle acceleration.
Coaching Application: The more force athletes can apply to the ground, and the faster this force is applied (ground contact time), the greater the start and acceleration speed. Training to increase GRF during early and late acceleration focuses on improving absolute strength (maximum) and speed-strength (applying force quickly each step). Improvement in these areas requires unique training approaches and exercises. *NASE members are referred to the following issues of Sports Speed Digest on the NASE website for specific training exercises and programs:
January: 2015, 2016, 2018, March: 2014, May: 2016, July: 2008, September: 2011, 2014, November: 2013.
Nagahara, Ryu, Mizutani, Akifumi, Matsuo, Hiroaki, Tetsuo Fukunaga. 2017. Step-to-step spatiotemporal variables and ground reaction forces of intra-individual fastest sprinting in a single session. Journal of Sports Sciences. Pages 1-10 | Accepted 29 Sep 2017, Published online: 07 Oct 2017
1/19/18 NASE Blog Post: Although expensive force plate technology has been around for decades in the labs of researchers, it is now beginning to find its way to university and professional sports teams. Researcher Weyand and colleagues, for example, have used a treadmill-mounted force plate to measure ground reaction force (GRF), rate of force production (RFP), and swing time between stance periods of the same foot for years in their innovative studies on sprinting. According to Carl Valle, “providers of force plate systems and services are growing in popularity—Sparta Science, P3, Andy Franklin Miller, and more. Accelerometer-based products like Bar Sensei and Push have made efforts to capture force production in the weight room.
The ability of the human body to generate maximal power is linked to a host of performance outcomes and sporting success. Power-force-velocity relationships characterize limits of the neuromuscular system to produce power, and their measurement has been a common topic in research for the past century. Unfortunately, the narrative of the available literature is complex, with development occurring across a variety of methods and technology. This review focuses on the different equipment and methods used to determine mechanical characteristics of maximal exertion human sprinting. Stationary cycle ergometers have been the most common mode of assessment to date, followed by specialized treadmills used to profile the mechanical outputs of the limbs during sprint running. The most recent methods use complex multiple-force plate lengths in-ground to create a composite profile of over-ground sprint running kinetics across repeated sprints, and macroscopic inverse dynamic approaches to model mechanical variables during over-ground sprinting from simple time-distance measures during a single sprint. This review outlines these approaches chronologically, with particular emphasis on the computational theory developed and how this has shaped subsequent methodological approaches. Furthermore, training applications are presented, with emphasis on the theory underlying the assessment of optimal loading conditions for power production during resisted sprinting. Future implications for research, based on past and present methodological limitations, are also presented. It is our aim that this review will assist in the understanding of the convoluted literature surrounding mechanical sprint profiling, and consequently improve the implementation of such methods in future research and practice.
Coaching Application: Force plate technology is still in its early stages of development and doesn’t do much more than measure the amount of force that an athlete transfers to the ground over time (GRF and ground contact time GCT) when integrated into a high speed treadmill as with the Weyand studies. Ground reaction force and GCT are two major determinants of speed during the start, acceleration, and maximum speed phase of a short sprint and the ability to measure these values each time the foot strikes the ground is invaluable. Pre- and post-testing following various training programs and exercises can identify the most effective means of increasing both vertically and horizontally-directed GRF, and identify force imbalances between the right and left limbs. However, until equipment costs are lowered and the accuracy and sophistication of force plate technology improves, coaches and athletes should continue to use the field tests described in various issues of Sports Speed Digest to provide estimates of absolute and relative ground reaction force.
References: Cross, Matt R., Brughelli, Matt, Samozino, Jean Benoit Morin. 2017. Methods of Power-Force-Velocity Profiling During Sprint Running: A Narrative Review. Sports Medicine, July, Vol. 47, Issue 7, 1255-1269.
Change of Direction (COD) requires high-speed stopping and starting, acceleration, faking, cutting and reaccelerating, and also contains both a physical and perceptual-cognitive component. Physical components include ground reaction force (GRF), proper form and technique, and sport-specific movements. Key cognitive components include visual scanning, reaction time and decision making based on an opponent’s action. Change of direction speed is considered a preplanned action, whereas agility includes both the physical aspects of directional change and the cognitive and decision making realm (reaction to a stimulus) needed to respond to an opponent’s action. The study described below involves only the physical components of COD.
Mechanical variables during change of directions (for example, braking and propulsive forces, impulses, and ground contact times (GCT), have been identified as determinants of faster change of direction speed (CODS) performance. The purpose of this study was to investigate the mechanical determinants of 180° CODS performance with mechanical characteristic comparisons between faster and slower performers; while exploring the role of the penultimate foot contact (PEN) during the change of direction. Forty multidirectional male athletes performed 6 modified 505 (mod505) trials (3 left and right), and ground reaction forces were collected across the PEN and final foot contact (FINAL) during the change of direction. Pearson’s correlation coefficients and coefficients of determination were used to explore the relationship between mechanical variables and mod505 completion time. Independent T-tests and Cohen’s d effect sizes (ES) were conducted between faster (n = 10) and slower (n = 10) mod505 performers to explore differences in mechanical variables. Faster CODS performance was associated (p≤ 0.05) with shorter GCTs (r = 0.701–0.757), greater horizontal propulsive forces (HPF) (r = −0.572 to −0.611), greater horizontal braking forces (HBF) in the PEN (r = −0.337), lower HBF ratios (r = −0.429), and lower FINAL vertical impact forces (VIF) (r = 0.449–0.559). Faster athletes demonstrated significantly (p ≤ 0.05, ES = 1.08–2.54) shorter FINAL GCTs, produced lower VIF, lower HBF ratios, and greater HPF in comparison to slower athletes. These findings suggest that different mechanical properties are required to produce faster CODS performance, with differences in mechanical properties observed between fast and slower performers. Furthermore, applying a greater proportion of braking force during the PEN relative to the FINAL may be advantageous for turning performance.
Coaching Application: Change of direction speed is largely determined by the amount of force (GRF-ground reaction force) one can apply to the ground with the plant foot and the speed (GCT-ground contact time) with which horizontally- and vertically-directed force is applied to to shorten the braking effect of the plant foot and the step prior to the plant (penultimate foot contact). Correct form and technique is also important in the proper execution of various fakes and cuts used in tam sports, and, in applying greater force application with the penultimate foot-ground contact.
Keep in mind that typical COD drills do not transfer well to specific team sports. It requires ingenuity on the part of coaches and players to develop drills that mimic game situations and the movements commonly encountered during competition. This approach is superior and offers the best opportunity for transfer to playing speed in a sport.
Dos’Santos, Thomas; Thomas, Christopher; Jones, Paul A.; Comfort, Paul. 2017. Mechanical Determinants of Faster Change of Direction Speed Performance in Male Athletes. Journal of Strength & Conditioning Research. March, Vol. 31, Issue 3, 696-705.