Research suggests that psychological stress due to competing against opponents of different skill levels affects exercise intensity during kendo gokaku-geiko. However, few studies have clarified the relationship between psychological stress measured using objective indices and exercise intensity. In this study, we measured psychological stress, exercise intensity, and physical activity in players during kendo gokaku-geiko with opponents of different skill levels using objective, non-invasive, simple measures.
Six male members of the university kendo team participated in this study. They performed kendo gokaku-geiko for 3 minutes with highly skilled, equivalently skilled, and non-highly skilled opponents. We measured psychological stress indices (salivary amylase activity and autonomic balance [LF/HF]), exercise intensity indices (heart rate [HR], peripheral oxygen saturation [SpO2], rate of perceived exertion [RPE]), and physical activity indices (number of steps and strikes) during keiko.
We observed an increasing tendency of salivary amylase activity, HR, RPE, and physical activity indices during keiko with highly, but not with non-highly, skilled opponents. On the other hand, we detected an increasing tendency of LF/HF with both types of opponents.
These results suggest that in keiko with highly skilled opponents, the participants experienced tension (i.e. a “fight-or-flight response”) caused by strong pressure and attacks from their opponents; thus, they increased their physical activity and exercise intensity and were likely to experience high stress. On the other hand, in keiko with non-highly skilled opponents, the participants experienced low stress due to a lack of exercise intensity and low physical activity.
The Shosho-ryu Yawara during the Edo period is said to have been passed down as a secret jujutsu martial art only within Morioka domain. Today, however, many aspects of the names and classifications of the various techniques that make up the Shosho-ryu Yawara remain unknown, as do the details of each technique. The primary source used as research material until now-scrolls belonging to the Takahashi Family, a Shosho-ryu sect-is not enough to clarify the names and details of all the Shosho-ryu Yawara techniques. This is because a special feature of the Shosho-ryu Yawara is that when the master teaches his disciple a technique, he does not teach it fully. Hence, it is difficult to encompass all the Shosho-ryu Yawara techniques using only the scrolls handed down to a single sect.
The authors of this paper felt it essential to identify new primary sources. Our investigations resulted in the discovery of 13 scrolls at the Hanamaki Nitobe Memorial Hall in Hanamaki City, Iwate Prefecture, which had been kept as a record of the Shosho-ryu Yawara techniques and licenses handed down within the Eiichi Nitobe family. We annotated and reprinted all 13 of these scrolls so that the names and details of all the Shosho-ryu Yawara techniques can be organized and classified into a highly valuable source material. It turned out that the Nitobe family scrolls contained not only the list of techniques (names), but also included how to initiate these moves and their underlying knowledge. This is expected to greatly advance the academic understanding of the Shosho-ryu Yawara techniques.