| This article adopts literature method,video analysis method,mathematical statistics method,comparative analysis method,case analysis method,etc.,taking the competition skills and tactics of the world’s outstanding women’s middle and long distance freestyle swimmers as the research object,and selects 4 world-class outstanding women’s middle and long distance freestyle.Athletes Ledecky,Titmus,Wang Jian Jiahe and Li Bingjie were the subjects of investigation.Using the video image analysis system software Swimming racesy to analyze the 400 m,800m,and 1500 m freestyle videos of 4 athletes participating in the 2016-2019 years,and analyze the technical and tactics of my country’s outstanding women’s long-distance freestyle swimmers and the world’s top swimmers through horizontal and vertical comparisons To find out the potential of skills and tactics and find out the existing problems,to provide support for the excellent women’s middle and long distance freestyle swimming events in my country.The research analysis draws the following conclusions:1.Through a horizontal comparative analysis of the various technical links of the world’s outstanding women’s middle and long distance freestyle swimmers:(1)The mid-swimming stage occupies more than 70% of the 400 m,800m,and 1500 m freestyle,which is the technical link that accounts for the largest proportion.Through one-way analysis of variance,it is concluded that the stroke frequency,stroke width,and speed of Wang Jian Jiahe and Li Bingjie during the mid-trip phase are extremely significantly different from those of Ledecky and Titmus(P<0.01),indicating the mid-trip phase This is the main reason for the gap between my country’s two young players and the world’s top players.Among them,Ledecky,Titmus,and Li Bingjie used the middle cross technique with fast stroke and short stroke in the competition,while Wang Jian Jiahe used the middle and front cross technique with slow stroke and long stroke.(2)The turning stage accounts for more than 26% of the 400 m,800m,and 1500 m freestyle,which is the second largest technical link except for the mid-swimming stage.Through one-way analysis of variance,Li Bingjie’s 400 m,800m,and 1500 m freestyle turns are significantly different from those of Ledecky,Titmus,and Wang Jian Jiahe(P<0.05),and they lag behind in the total turnaround time.It shows that the turning phase is another shortcoming of Li Bingjie.(3)The starting postures of the 4 athletes all adopt the squatting start,and the starting time of 15 m is not big,all between 6.65s-7s.Ledecky’s underwater butterfly legs are up to 6 times after the start,and the longest sliding distance is 12m;Titmus and Wang Jian Jiahe’s underwater butterfly legs are less than 4 times,and the sliding distance is 10m;Li Bingjie’s The number of underwater butterfly strokes is 6-8 times,and the sliding distance is also 10 m.It can be seen that although the start time of the four athletes is not much different,there is a gap between the two young players and Titmus in the sliding distance and the underwater butterfly leg technology of Ledecky.(4)The 5m sprint time of the four athletes is almost the same,all between 2.62s-2.90 s,and they will hold their breath in the last 5m sprint.Wang Jian Jiahe and Li Bingjie usually only enter the sprint stage at the last 50 m in the game,while Ledecky and Titmus start sprinting at the last100 m or even 150 m.In contrast,they enter the sprint stage much later.(5)Judging from the 400 m,800m,and 1500 m freestyle performances of the four athletes,the physical energy distribution pattern is roughly the same(P>0.05),and the overall characteristics are in line with the pattern of "fast in the front and fast in the middle,stable in the middle",that is,"uniform speed swimming" Tactics.Through the analysis of the speed reserve index,it is concluded that the competition tactics of "competing for power and winning bids" are adopted in the arrangement of the matches.Although Chinese teenagers can maintain a relatively high speed reserve index,their results are far behind the world’s top players in both the preliminaries and the finals.2.Through collecting the competition data of the world’s outstanding women’s middle and long distance freestyle swimmers and longitudinal comparative analysis,it is concluded that:(1)Ledecky is an all-rounder,and currently holds the world records for women’s 400 m,800m,and 1500 m freestyle.Through research,it was found that Ledecky performed stably in each link of the 400 m,800m,and 1500 m freestyle without major fluctuations.The main factor of the 2019 World Championships failure is that the stroke length becomes shorter while the normal stroke frequency is maintained,but the swimming speed remains the same;the winning factor for the 2016 Olympic Games is mainly the stroke frequency and the downstream speed increases when the stroke width remains unchanged,indicating the stroke water The effect is good,resulting in improved performance.(2)Titmus mainly focuses on the 200 m and 400 m freestyle events,while the 800 m and1500m freestyle events are rarely involved.Through research,it is found that Titmus is stable in all links of the 400 m freestyle.The main factor for the improvement of the 400 m freestyle performance in the 2019 World Championships is the turnaround time.The turnaround time for the 2017 World Championships was 60.72 s,and the 2019 World Championships was 58.94 s,an increase of 1.78 s.(3)Wang Jian Jiahe’s main development direction is in the 800 m and 1500 m freestyle.Through research,it is found that Wang Jian Jiahe’s performances in the 400 m,800m,and1500 m freestyle start and sprint phases show a downward trend,but the range is not large;the swim speed and turn phase performances are stable during the middle swim.Compared with its own technology,the 2018 Asian Games showed the characteristics of faster stroke frequency and shorter stroke length.(4)Li Bingjie is currently mainly moving closer to the 400 m freestyle event.When collecting data,she found that she participated less in the 800 m and 1500 m freestyle competitions.Through research,it is found that Li Bingjie’s response time in the 400 m,800m,and 1500 m freestyle starts getting faster and faster;the speed of the 400 m freestyle swim and the15 m turn time remain stable;the overall performance of the sprint stage shows a downward trend.Among them,Li Bingjie’s turning technique is relatively stable personally,but it lags far behind other elite athletes. |
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