- 著者
- Yoshihisa Umemura
- 出版者
- 一般社団法人日本体力医学会
- 雑誌
- The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)
- 巻号頁・発行日
- vol.5, no.1, pp.7-12, 2016-03-25 (Released:2016-03-18)
- 参考文献数
- 37
- 被引用文献数
- 1 6
Mechanical loads on the skeleton imposed by exercise increase bone mass and strength. The sensor in the osteocyte that detects mechanical stress, the mechano-sensor, responds to bone strain caused by mechanical loading. Greater magnitude and rate of strain increases osteogenic response, making high-impact exercise, which imposes large and dynamic strain on the skeleton, an effective mode of exercise. However, the sensitivity of the mechano-sensor (mechano-sensitivity) drops after a large number of repetitions performed within an exercise session, which has diminishing returns. It takes several hours or several days to reestablish mechano-sensitivity after the last loading session. It is important to consider the time to recovery of mechano-sensitivity when determining optimal exercise frequency.
- 著者
- Jumpei Osakabe Masanobu Kajiki Ryosuke Inada Takaaki Matsumoto Yoshihisa Umemura
- 出版者
- The Japanese Society of Physical Fitness and Sports Medicine
- 雑誌
- The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)
- 巻号頁・発行日
- vol.11, no.1, pp.9-19, 2022-01-25 (Released:2022-01-14)
- 参考文献数
- 27
- 被引用文献数
- 1
Japanese collegiate and club lacrosse games are often held under environmental conditions of extreme heat in the summer. Lacrosse players are also required to wear protective equipment, which is a risk factor for heat-related illness. Nevertheless, the thermoregulatory responses of lacrosse players under such conditions are poorly understood. The present study compared the thermoregulatory responses in subjects wearing the mens’ lacrosse uniform or general athletic clothes during an exercise-simulated lacrosse match played in the heat (high temperatures). Eight men performed two experimental trials of 4 × 15-min intermittent cycling exercise in the heat (35°C, 50% relative humidity). All participants performed two trials wearing a lacrosse uniform (WEAR) or general athletic clothes (CON). The physiological strain index was significantly higher (p < 0.05) in the WEAR condition than in CON, and exceeded the high risk level for heat-related illness in WEAR during the 3rd quarter. Additionally, rectal temperature, skin temperature, heart rate, and ratings for perceived exertion, thermal sensation, and thermal comfort were significantly higher (p < 0.05) in the WEAR condition than in CON. Rectal temperature continued to increase during half-time in the WEAR condition, but not in CON (p < 0.05). These findings indicate that lacrosse players are at a higher risk of heat-related illness compared to other team sport athletes during a match because of the protective equipment worn, especially after half-time. Although further studies are required to confirm the thermoregulatory responses during an actual lacrosse match, our data will be useful in developing strategies to minimize the risk of heat-related illness.