This study clarified what kind of training environment empowers female ball sport athletes to assert their own opinions, and examined the relationship between training environment, competition level, and life skills acquisition level in the developmental age category. We surveyed 838 female athletes from age 18 to 36 belonging to the Japan Top League Alliance, made up of 373 athletes with national team experience and 456 without, and confirmed the following two major points.

　First, female athletes' life skills were classified into four clusters (overall high group, overall low group, communication-active group, communication-passive group). In the developmental years category, it was evident that the overall high group was in an environment in which it was easy to obtain direct support from the coach, whereas the overall low group and communication-passive group had weak relationships with the coach.

　Second, when directly encouraged by coaches, those with national team experience displayed high levels of social norm skills and problem-solving skills, although this was limited to communication regarding the competition. In contrast, those without national team experience scored higher on all four life skills when coaches took an indirect approach to atmosphere creation. Furthermore, in order to enhance athletic performance, it is thought that instructors aim to create a training environment that encourages activities outside the realm of sports such as academic and volunteer activities, as well as those within their sport. Thus, there were differences in the training environment during the developmental years depending on the level of competition, and there were also differences in the life skills acquired.

　The results suggest that communication between instructors and athletes is an important factor in the training environment and life skills of female athletes.

　To determine whether loss aversion, an important concept in prospect theory, is influential in Japanese baseball, this study conducted a case study of a baseball head coach. The purpose of this study was to elucidate (1) whether or not loss aversion influences decision-making among Japanese baseball head coaches, and (2) if loss aversion does influence decision-making, to determine how these practices were implemented. The following findings were obtained.

　1) One of the head baseball coaches for a Japanese college team consistently exhibited loss aversion. This type of decision-making was referred to as “loss-averse decision-making” in this study.

　2) The loss-averse decision-making was the result of a process in which the head coach of a college baseball team felt tension and lack of power, and placed an excessive emphasis on short-term outcomes.

　3) The college baseball head coach overcame loss-averse decision-making in this case study by using a league championship as a reference point. The change in reference point occurred when the coach perceived a change in the external environment, including suggestions from the mentor.

　4) Loss-averse decision-making was overcome when the head coach of the college baseball team reflected on his coaching by observing the head coach of the opposing team, thereby increasing his pitching options.

　Building upon Igarashi et al.'s (2017) research, this study clarified the subjective and objective structure of blocks against four-person attacks in volleyball by top center players. We adopted a quantitative approach to investigate the relationship between the split step (SS) and block performance (BP), including committed blocks. Additionally, we examined the relationship between the quality and quantity (SS and BP) of “Kyanseru” (canceling) and “Kaijo” (releasing) by top center players during blocks against four-person attacks using inductive reasoning (a comprehensive approach). This study derived the following results: The cognitive element of anticipating the opponent's attack may lead to unconsciousness of the physical action (SS), which can be considered a technical element. This suggests that the participants' subjective and objective aspects of the “Kyanseru” and “Kaijo” may differ. Kitagawa's (a leading center player in Japan) “Kyanseru” is subjectively “always done from a committed block position.” However, “Kyanseru” can be considered to be similar to a lead block (SS with double-footed landing). Tomimatsu's (another leading center player in Japan) “Kaijo” occurs at a low rate when he is not split-stepping. “Kaijo” occurs during a right attack on double-footed SS.

　These findings, which holistically analyze blocks against four-person attacks by top center players, offer novel scientific insights that can be applied by players and coaches in the field. They also exemplify how knowledge acquisition can contribute to practical application by clarifying the subjective and objective structure of blocks against such attacks.

　The purpose of this study was to clarify the relationship between the performance variables of each jump, the lower limb kinetics variables during in the rebound jump (RJ) take-off phase and men striking time, including with and without selection, by measuring various jumping abilities in 20 university male kendo players at different levels of competition. The results obtained are as follows.

　・In jumping ability, the upper group showed significantly better results in the left and right single leg standing broad jump and RJ-index.

　・The stiffness of each leg in the take-off phase of the RJ was significantly higher in the upper group than in the lower group.

　・There was a significant negative correlation between the stiffness of the left leg in the RJ take-off phase and the striking time of the men strike in Task 1.

　These results indicate that the upper group has a higher ability to exert horizontal force with single leg, and is superior in the RJ-index, which requires explosive force in a short period of time. In addition, the left leg of the RJ had high stiffness and a stiff spring during the stepping phase, suggesting high plantar flexion of the ankle joint. The results suggest that these factors influence the action of the men strike and contribute to the shortening of striking time.

　This is a case study on training in the off-season to improve the jumping performance of female ski jumper who got six times of victory. Testing included vertical jump without counter movement (SJ), vertical jump with counter movement (CMJ), and vertical jump with counter movement and swinging motion of arms (ACMJ). In the case, SJ was added to the weight training and jumping training program, and CMJ and ACMJ were instructed not to be performed.

　As a result, SJ showed significant improvement. (SJ: 10.2%, CMJ: 3.7%, ACMJ: 0.3%). The ratios of SJ to CMJ (SJ / CMJ) and SJ to ACMJ (SJ / ACMJ) were close to 100% after training.

　These results suggest that it was inferred that superior SJ jumping abilities is important for ski jumpers.