Journal of High Performance Sport
Online ISSN : 2434-7302
Print ISSN : 2434-7299
Volume 11
Displaying 1-12 of 12 articles from this issue
  • Yui Kawano, Toshiharu Yokozawa, Yasuyuki Kubo
    2023 Volume 11 Pages 1-11
    Published: 2023
    Released on J-STAGE: July 01, 2023
    JOURNAL OPEN ACCESS
    Judged sports, where judges' scores for the performance affect the results, have a great diversity of scoring formats, which is the scoring method for each sport. This study aimed to classify multiple events based on the characteristics of scoring formats in order to present a framework for understanding the diversity of judged sports. The scoring format for the 36 events of the 15 sports in the Olympic and Paralympic Games was organized based on the competition and judging regulations from the following seven perspectives: "Grading several people at a time," "Including a relative evaluation," "Including an overall evaluation," "Including an evaluation of the environment and tools," "Including a scale-based judging system," "Elements other than the judges' score affecting the results," and "Judging criteria including quantity descriptions." These events were classified via hierarchical cluster analysis using Ward's method to create a dendrogram. As a result, the judged sports covered in this study were divided into three types based on differences in the characteristics of their scoring formats: the "qualitative relative evaluation" type, in which the entire performance is evaluated comprehensively and relatively using qualitative judging criteria; the "deduction for physical movement" type, in which only physical movements are scored using a point deduction method and an absolute evaluation based on quantitative judging criteria; and the "mixed evaluation" type, which includes either an evaluation of the environment and tools or an overall evaluation of the entire performance, in addition to a quantitative judging criteria and an absolute evaluation. The classification into three types by this study will serve as a basis when considering training, coaching, scientific support and research methods in the future and will also allow the application of the findings for a particular sport to other sports classified in the same type.
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  • Satoshi Shibata, Rei Tahara, Masahiro Hagiwara, Koichi Watanabe, Norih ...
    2023 Volume 11 Pages 12-24
    Published: 2023
    Released on J-STAGE: July 01, 2023
    JOURNAL OPEN ACCESS
    In this report, we performed a retrospective analysis of the relationship between salivary secretory immunoglobulin A (SIgA) and daily subjective conditions and changes in physical condition during the expedition period in sailing competitions. We performed continuous salivary SIgA measurements on one elite female windsurfing athlete over about 1.5 months, which included participation in two international competitions. The two international competitions and their preparatory periods were divided into phase 1 and 2, respectively. The salivary SIgA concentration was calculated using “SIgA simple detection kit” developed by us. We calculated salivary SIgA secretion by multiplying it with saliva secretion per minute. The subjective condition indicator and physical symptoms were input into the measurement iPod application. In phase 2, subjective complaints of URTI (Upper Respiratory Tract Infection) symptoms were observed for a total of 4 days. When salivary SIgA secretion was compared within phase 2 according to the presence or absence of URTI symptoms. Looking at the variation of salivary SIgA secretion, a decrease in salivary SIgA secretion was observed before complaining of subjective URTI symptoms. There was no clear association between subjective conditioning indicator and the salivary SIgA secretion. However, there were cases in which recovery of salivary SIgA occurred with a delay, and subjective complaints of URTI symptoms were subsequently observed, even though the sense of fatigue was improved by adjusting the exercise intensity. The windsurfing competitions are held in a natural environment where the climates are highly variables, and the travel time for games and training camps, and expedition periods are long, so maintaining the condition during the expedition has been an issue. From the results of this report, it is thought that the measurement of salivary SIgA over time as an objective indicator to monitor the state of fatigue is useful for maintaining good condition.
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  • Focusing on the relationship between micro-surface shape changes and aerodynamics of grooved knit fabrics
    Koshi Suzuki, Kaoru Yamanobe, Akira Maeda
    2023 Volume 11 Pages 25-37
    Published: 2023
    Released on J-STAGE: July 01, 2023
    JOURNAL OPEN ACCESS
    Aerodynamic drag in speed skating is also reduced by equipment. Among them, many studies have been reported on the reduction of aerodynamic drag by suits. However, the relationship between the aerodynamic properties of grooved knit fabrics and the change in their micro-surface shape has not been clarified. Therefore, this study conducted the circular cylinder model wind tunnel experiments on two types of grooved knit fabrics (Type A and Aerodynamic drag in speed skating is also reduced by equipment. Among them, many studies have been reported on the reduction of aerodynamic drag by suits. However, the relationship between the aerodynamic properties of grooved knit fabrics and the change in their micro-surface shape has not been clarified. Therefore, this study conducted the circular cylinder model wind tunnel experiments on two types of grooved knit fabrics (Type A and Type B) with different micro-surface shapes. In addition, a full-scale model of a skater wind tunnel experiments were conducted on two types of one-piece suits (Suit A and Suit B) with different grooved knit fabrics used near the thighs. In the circular cylinder model experiment, the onset of criticality for Type A was in the lower speed range than for Type B. In a full-scale model of a skater experiment, the onset of criticality was slower in Suit A than in Suit B. Groove depth (Type A>Type B) may have affected the criticality. In addition, it is necessary to consider the environment of the competition venue, the physique of the athlete, and the speed of the skater when choosing between grooved knit fabrics. Suit A and Suit B use for 0.45 m (height 1.58 m)≦L≦0.53 m (height 1.84 m) at Heerenveen (elevation 0 m) was as follows. The Male 500 m was Suit B at any L, the Male 1000 m to 1500 m and Female 500 m to 1000 m events required the use of Suit A and Suit B depending on L, and the Male 5000 m and above and Female 1500 m and above were Suit A at any L.
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  • A case study in the badminton world championships
    Hiroki Ogata, Taro Iizuka, Ryosuke Ando, Daichi Yamashita, Hiroki Ozak ...
    2023 Volume 11 Pages 38-51
    Published: 2023
    Released on J-STAGE: August 08, 2023
    JOURNAL OPEN ACCESS
    In this case report, we examined the performance changes during tapering in two badminton athletes (one male and one female) who advanced to the finals at the World Championships (WC). Furthermore, the significance of a resistance priming session implemented during tapering was discussed. Both athletes participated in a pre-competition training camp in Japan before the WC. A resistance priming session was scheduled one and two days before the WC for the male and female athletes, respectively. Non-countermovement jump (NCMJ) and countermovement jump (CMJ) were measured using a linear position transducer to monitor performance responses from the camp to the WC final. The baseline of the jump performance was given from 15 days (male) and 151 days (female) prior to the WC final. In the male athlete, the mean power of NCMJ decreased 7 days before the finals. This result may be attributed to accumulated fatigue caused by high volume training in the training camp and the short taper period as well as long travel to the host city. In the female athlete, the mean velocity and power of CMJ were the same as baseline before the semi-final. That is, the quarter-final match, where she competed for 85 minutes-the longest game time among the previous matches, may have affected her fatigue. Regardless of these findings, both athletes showed higher jump performance than at baseline just before the final because the matches likely played a role in tapering. In addition, both athletes recorded their personal best jump height just before the final. These findings may indicate that jump performance can be an indicator of tapering and peaking. The findings of this report also demonstrate that athletes may maintain resistance training adaptations by taking advantage of resistance priming for peaking and tapering.
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  • Takehito Hirakawa, Norimasa Yamada
    2023 Volume 11 Pages 52-67
    Published: 2023
    Released on J-STAGE: November 23, 2023
    JOURNAL OPEN ACCESS

    This study aimed to assess pacing profiles of racewalkers who won medals for 50-km racewalking at the summer Olympic Games and World Championship by the International Association of Athletics Federation (IAAF). The pacing profiles were consequently used to determine the finish times associated with high probabilities of winning gold medals, design general mathematical models based on pacing profiles, and examine the extent of fit of these models with the best records for both the events. We fit polynomial approximation as well as exponential and logarithmic functions to split time for every 5 km, obtained earlier from the results of both the events. We subsequently calculated the posteriori probability of winning a gold medal with the Bayes theorem and designed general mathematical models using the most suitable pacing profiles. Finally, these models were fit to the best record for both the events. The following results were obtained: 1) the quadratic function was the highest value of the fit, 2) the posteriori probability of the causal relationship between the finish time of the best rank and the gold medalist was the highest, 3) all the general mathematical models designed using the three hypotheses were significant, and 4) the race pace estimated by this general mathematical model also fit well with the world record. The design method utilized in this study for the general mathematical model and its applications are expected to be useful in racewalking and other events where the race pace design and relevant methods are essential for winning.

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  • Takuya Yanaka, Takanori Kono, Takahiro Kubo, Yoshitaka Usui, Yusuke Ya ...
    2023 Volume 11 Pages 68-78
    Published: 2023
    Released on J-STAGE: December 23, 2023
    JOURNAL OPEN ACCESS

    In Nordic Combined competition, overall rank is decided by ski jumping and cross-country skiing performance. The aim of this study was to investigate whether the overall rank can be predicted from ski jumping and cross-country skiing in World Cup, Continental Cup and National Competition and whether the contribution of the two disciplines was different among each competition category. T-scores of overall (TTotal), ski jumping (TSJ) and cross-country skiing (TCC) were calculated from the time difference at the cross-country ski finish, ski jump point and cross-country ski time in each competition. The annual average T-scores were calculated in 2019─20 season and 2020─21 season. For each competition category, step-wise multiple regression analysis was conducted to predict TTotal from TSJ and TCC in both seasons. The results showed that TTotal variances were accounted for by the TSJ and TCC more than 99 %. In World Cup competition, the standardized partial regression coefficient of TSJ was higher than that of TCC in both seasons. On the other hand, the standardized partial regression coefficient of TCC was higher than that of TSJ in Continental Cup and National competition in both seasons. These results indicated that contribution to overall rank was different in competition categories. It is suggested that ski jumping performance is important for World cup athletes and cross-country skiing performance is important for Continental Cup and National athletes.

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  • Masahiro Hagiwara, Naokazu Miyamoto, Jiei Michishita
    2023 Volume 11 Pages 79-89
    Published: 2023
    Released on J-STAGE: January 13, 2024
    JOURNAL OPEN ACCESS

    It remains unclear whether and how the sailing order during the first upwind leg is related to the finishing place of the race in high-level sailing competitions such as the Olympic Games. The purpose of the present study was to clarify the associations in all ten classes in the sailing event of the Tokyo 2020 Olympic Games. All data were collected from publicly available online GPS sources. The sailing orders during the first upwind leg were calculated for every 10% phase from the start to the arrival at the first windward mark. Then, for each phase in each class, the percentage of the number of races in which the correlation coefficient between the sailing order at each phase during the first upwind leg and the finishing place was greater than 0.7 was calculated. The percentage of the number of races with a high correlation tended to increase from 10% to 100% phase of the first upwind leg. In several races, the sailing order just after the start (i.e., at 10% phase) correlated with the finishing place of the race. These findings suggest that a superior sailing position during the first upwind leg plays a crucial role in finishing well in the race.

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  • Kohei Hikawa, Mika Hangai, Sayaka Motojima, Moe Nakazawa, Koji Natori, ...
    2023 Volume 11 Pages 90-95
    Published: 2023
    Released on J-STAGE: December 23, 2023
    JOURNAL OPEN ACCESS

    Athletic rehabilitation aims for a safe and successful return to sport. In high-performance athlete, there are few reports on return to sport process, for reasons such as withholding of information disclosure. In this study, we describe an athletic rehabilitation program implemented by a multicenter and multiprofessional team for a Japanese national team artistic swimmer who underwent partial medial meniscectomy. Following this intervention, her physical function was better than preoperatively, and she performed well at the World Championships in which she participated approximately 20 weeks postoperatively. The rehabilitation program led to a significant change in her mindset, and enabled her to compete at a higher level. Rehabilitation for highperformance athletes requires a specialized approach; however, no specific equipment or technique were used in this case. Therefore, multicenter and multiprofessional athletic rehabilitation is considered applicable not only to high-performance athletes, but also to athletes in other categories. Rehabilitation for high-performance athletes requires a specialized approach; however, we did not use any specific technique in this case. Therefore, we think that multicenter and multiprofessional athletic rehabilitation can be applied not only to high-performance athletes, but also to athletes in other categories.

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  • Masako Hoshikawa
    2023 Volume 11 Pages 96-105
    Published: 2023
    Released on J-STAGE: January 16, 2024
    JOURNAL OPEN ACCESS

    The purpose of this report was to clarify sleep habits among elite Japanese athletes. Nocturnal sleep data recorded with wrist actigraphy from 111 Japanese athletes were analyzed. Time in bed, sleep latency, total sleep time and sleep efficiency were normally distributed, and were not different between male and female. Mean values and standard deviation of sleep parameters were 7 : 21±0 : 40 for time in bed, 11.4±7.5 min for sleep latency, 6 : 25±0 : 45 for total sleep time, and 87.1±5.2% for sleep efficiency. Four (3.6%) of 111 athletes showed sleep latencies equal to or longer than 30 min. Thirty-three (29.7%) showed total sleep duration less than 6 h. Thirty-four (30.6%) showed sleep efficiency lower than 85%. Overall, sleep latency and total sleep duration tended to be shorter, and sleep efficiency was a little bit higher than the values from foreign athletes in the previous report. To understand characteristics of individual sleep, the supplemental table with 5 divisions was created on each sleep parameter. However, it must be remembered that these tables are based on the sleep characteristics of Japanese athletes mentioned above.

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  • Taisuke Kinugasa, Toshiharu Yokozawa, Tomoya Nakanishi, Noriko Hakamad ...
    2023 Volume 11 Pages 106-116
    Published: 2023
    Released on J-STAGE: February 02, 2024
    JOURNAL OPEN ACCESS

    The practical questions of “What key factors contribute to competitive performance of the sport?” and “How to train those factors to enhance performance?” are daily challenges faced by coaches and sports scientists. The aim of the study was to conduct a literature review on sports performance structure models, and to propose an effective procedure to develop the models. During the screening phase of the literature review, only the title and abstract were evaluated. In addition, an attempt was made to develop a model which may lead to an effective sport science support, using speed skating as an example. As a result, we found that the definition of the sports performance structure model was not clear in the literature. Furthermore, the procedure for creating the structure model that can be used in sport science support was discussed, and the following procedure was proposed: firstly, to decide the primal outcome, which is generally the result of the competitive performance; secondly, to create a model using the logic via the literature review and/ or videos etc. with the competition rules; thirdly, to modify the model by collecting insights from coaches. By adopting the deterministic model approach, we were able to view the sports performance structure model as a modeling procedure to identify the relationship between sports performance and its biomechanical factors. Coaches and sports scientists will play an important role in model development which requires not only the latest theoretical knowledge about high-performance sport, but also a wealth of empirical insights through practices of the sports science support.

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  • Kaoru Yamanobe, Koshi Suzuki, Shunsuke Takenaka, Yuya Kimura, Hidenobu ...
    2024 Volume 11 Pages 117-133
    Published: 2024
    Released on J-STAGE: February 10, 2024
    JOURNAL OPEN ACCESS

    The purpose of this study was to determine the effects of the distance between the following skaters and their posture on the aerodynamic drag of a leading skater in the team pursuit event of speed skating by conducting wind tunnel experiments. Three full-scale human models were placed in a tandem arrangement, with four different distances (0.8, 0.9, 1.0 and 1.2 m) between the models. For the first model, the upper torso angle of attack α was always set to 0°. For the two following models, α was set to three different values (0, 20 and 40°) . Four combinations of posture conditions (A-D) were used for the three models. For each posture, A: two following skaters had α of 0°; B: the second and the third had α of 20°; C: the α of the following skaters the second and the third were 20° and 40° respectively; D: two following skaters had α of 40°. These combinations were planned so that the total projection area of the following skaters was larger in the order A<B<C<D. The results indicated that the distance between the three athletes, if within 1.2 m, in the team pursuit formation can reduce the drag of the leading skater. Furthermore, the largest reduction in drag was observed at 0.8 m, which is the smallest distance between the three skaters in this study, indicating that the smaller the distance between the skaters, the greater the reduction in drag. It was also clear that the posture of the following skaters (large upper torso angle of attack) can also reduce the drag of the leading skater. In addition, it was suggested that even changes in the posture of the third skater as well as the second skater could affect the aerodynamic drag of the leading skater.

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