Analysis Of The Key Factors That Affecting The Performance Of Track Start For Elite Swimmers

Research objective: starting is an important training content for short distance swimmers.As the main starting technique in swimming competition,the track start must be attached great importance to technical optimization.The purpose of this study is to screen the key indicators that affect the performance of the track start block,flight and water entry phase,conduct in-depth correlation analysis on the key indicators,optimize the key indicators,and finally achieve the goal of improving the 5-meter time.In addition,the starting performance characteristics of male and female short-distance athletes are compared to provide a practical reference standard for daily starting training.Research methods: Kistler Performance Analysis System for Swimming was used to test the track start of 51 athletes of the Chinese swimming team.Through mathematical statistics,the indexes provided in the analysis system were screened to find out the key indexes affecting the track start of athletes.And then,Thirty-four short-distance athletes were selected from a total of 51 athletes to analyze the correlation between the key indicators of track start and other indicators,optimize the key indicators,and compare the performance characteristics of male and female athletes.Research results:(1)After screening the key indicators through statistical methods,the remaining indicators are: time on-block,take-off horizontal velocity,entry distance,and the peak horizontal force on rear plate;(2)The peak horizontal force on rear plate would not affect the time on the block(p>0.05).For male athletes with short distances,the time on the block is 0.70±0.04 s.The movement indexes that affect the time on the block include the time of the first movement on the rear force plate,the time of the first movement on the grab and the average acceleration(p<0.05);For female athletes,the time on the block is 0.75±0.06 s.The movement indexes that affect the time on the block include the first movement,the first movement on the rear force plate,the time when the back foot leaves the rear force plate and the average acceleration(p<0.05);(3)For male athletes,the peak horizontal force of the backboard was 1.00±0.12 BW.For female athletes,the action index affecting the peak horizontal force of the backboard was the angle of the front knee joint(p<0.05),and the peak horizontal force of the backboard was 0.79±0.11BW;(4)Take-off horizontal velocity was not affected by the time on the block(p>0.05).The greater the horizontal force peak of the rear kick plate,the greater the take-off horizontal velocity(p<0.05).However,there was no linear relationship between the peak horizontal force on rear plate and the take-off horizontal velocity after the short distance athletes were grouped by gender(p>0.05).In addition,the higher the peak power,the higher the take-off horizontal velocity(p<0.01).The take-off horizontal velocity of short distance male athletes was 4.88±0.60m/s,and there was no linear relationship between the take-off horizontal velocity and the indicators of the take-off phase(p>0.05),while for female athletes,the take-off horizontal velocity was4.17±0.25m/s,which is correlated with the body inclination(p<0.05).The take-off horizontal velocity determines the athletes’ entry velocity(p<0.01),and the increase of the take-off horizontal velocity usually leads to the decrease of the athletes’ entry angle(p<0.01);(5)There was no linear relationship between time on the block and entry distance(p>0.05).The greater the horizontal force peak of the rear kick plate,the greater the entry distance(p<0.01).However,For short distance athletes,there was no linear relationship between the horizontal force peak of the rear kick plate and the entry distance(p>0.05).In addition,for female athletes,the peak power and the takeoff angle also has a certain effect on the entry distance(p<0.05).The entry distance of male athletes was 3.15±0.13 m,and that of female athletes was 2.75±0.75 m.Research conclusion:(1)The key indicators obtained after screening by statistical methods are time on-block,take-off horizontal velocity,entry distance,and the peak horizontal force on rear plate.(2)For short distance male athletes,the time indicators that affect time on-block include the initial movement time of the backboard,the initial movement time of the handle;In addition,the higher the peak power is,the higher takeoff horizontal velocity is.(3)For short distance female athletes,the time indicators that affect time on-block are the initial movement time,the initial movement time of the back kick board,the time of the back foot off the stage;The motion index that affects the peak horizontal force on rear plate is the front knee joint angle.The higher the peak power,take-off horizontal velocity.The peak power will also affect the water entry distance to some extent.(4)Performance of block will be decided directly and enter the water phase: on the block of preparing gestures and movements will affect the time on-block and peak horizontal force on rear plate,time on-block and peak horizontal force on rear plate together determines the take-off horizontal velocity,which affect water entry angle and enter the water.