体力科学
Online ISSN : 1881-4751
Print ISSN : 0039-906X
ISSN-L : 0039-906X
71 巻, 6 号
選択された号の論文の6件中1~6を表示しています
原著
  • 中山 貴文, 坂本 将基, 井福 裕俊
    原稿種別: 原著
    2022 年 71 巻 6 号 p. 479-492
    発行日: 2022/12/01
    公開日: 2022/11/19
    ジャーナル オープンアクセス

    Lower-extremity antigravity muscle contraction (the static muscle pump and muscle mechanoreflex) and the baroreflex are involved in regulating blood pressure (BP) during upright standing. We hypothesized that in females with orthostatic hypotension (showing a decrease > 20/10 mmHg within 3 min upon standing from supine), the muscle pump and mechanoreflex of the antigravity muscles is small during upright standing in those who have not undergone exercise training. To test this hypothesis, we compared the cardiovascular responses to head-up tilt, head-up suspension, head-up tilt + venous occlusion (which stops venous return from the lower extremities by static muscle pump), and head-up suspension + venous occlusion of 14 young females with orthostatic hypotension, of which seven had undergone exercise training (tOH) and seven had not (uOH), with those of eight females with orthostatic normotension (control) who had not undergone exercise training. Changes in BP, heart rate (HR), and stroke volume (SV) during both head-up tilt and suspension were measured. Although the increase in HR was larger and the decrease in SV tended to be smaller during head-up tilt than during suspension in the tOH, the response patterns of both were the same in the uOH. In occlusion trials, the increase in HR was larger during head-up tilt than during suspension in the tOH, whereas the increases in HR in both scenarios were the same in the uOH. These findings suggest a small muscle mechanoreflex of the antigravity muscles during upright standing in females with orthostatic hypotension who have not undergone exercise training.

  • 小山 浩司, 古島 弘三, 菅野 好規, 新津 あずさ, 小太刀 友夏, 新納 宗輔, 上野 真由美, 高橋 英司, 足立 和隆
    専門分野: 原著
    2022 年 71 巻 6 号 p. 493-503
    発行日: 2022/12/01
    公開日: 2022/11/19
    ジャーナル オープンアクセス

    Poor posture (thoracic hyperkyphosis) in children is reportedly caused by changes in their living environment. A previous study (conducted 30 years ago) reported that the position of the center of pressure (COP) in a child with an upright posture was approximately 40% from the heel. The present study aimed to determine the position and characteristics of the COP while standing in children aged 6–12 years. This study enrolled 83 elementary school students. A Win-Pod (Medicapteurs) platform was used to measure the COP. The COP position was expressed as a percentage from the heel as a relative ratio with a foot length of 100%. Spinal Mouse® was used to measure thoracic kyphosis, lumbar lordosis, sacral anteversion, and trunk inclination angles in the standing position. The COP position was 30.3±8.9% from the heel. We found positive correlations between the COP position, height, and weight. Further, the COP position was significantly more anterior in 28 upper elementary grade children (35.1 ± 9.2%) than in 25 middle (29.5 ± 8.6%) and 30 lower grade children (26.5 ± 6.7%). Regarding sex differences, the COP position was significantly more anterior in 46 boys (32.3 ± 9.8%) than in 37 girls (27.9 ± 6.9%). There was a weak positive correlation between the COP position and trunk inclination angle (r=0.251, p<0.05). Thus, we found that the COP position in modern children aged 6–12 years while standing was 30.3 ± 8.9% from the heel, indicating a shift toward the heel (backward) compared to that reported in previous studies.

  • 益尾 洋児, 玉木 彰
    原稿種別: 原著
    2022 年 71 巻 6 号 p. 505-514
    発行日: 2022/12/01
    公開日: 2022/11/19
    ジャーナル オープンアクセス

    National Institute of Occupational Safety and Health, Japan Step Test (JST) is a valid approach for cardiorespiratory fitness assessment among subjects aged 30-60 years. It estimates maximal oxygen uptake (VO2max) based on the heart rate (HR) index, a combination of HRs during and after exercise. This study assessed the cross-validity of the VO2max estimation using the JST among adolescent university students. A total of 20 healthy male university students were included in this study. Measurements were taken over three days, with cardiopulmonary exercise testing, JST, and the Chester step test (CST) measured on each day. Pearson’s product-rate correlation coefficient or Spearman’s rank-sum correlation coefficient was used for examining the association between measured VO2max and estimated VO2max and between measured VO2max and variables in the JST equation. Bland-Altman analysis was also used to examine the presence and extent of systematic errors between measured and estimated VO2max. Estimated VO2max by the JST showed a stronger correlation with measured VO2max than estimated VO2max by the CST. Moreover, the HR index showed the strongest correlation with measured VO2max in variables of the JST equation. However, estimated VO2max by the JST showed fixed and proportional errors when compared to measured VO2max. It was suggested that the HR index, a combination of HRs during and after exercise, was useful for estimating VO2max among adolescent university students. Estimated VO2max using the JST showed a strong correlation with measured VO2max, however, some estimation accuracy problems such as systematic errors.

  • 青葉 貴明, 中村 芙美子, 生田目 颯, 塚本 教貴, 膳法 亜沙子, 大槻 毅
    原稿種別: 原著
    2022 年 71 巻 6 号 p. 515-522
    発行日: 2022/12/01
    公開日: 2022/11/19
    ジャーナル オープンアクセス

    Water exercise has various health benefits. However, effects of low-intensity water exercise program, frequently conducted as a health promotion activity, on high frequency component of heart rate variability (HF, an index of cardiovagal activity and a predictor of future cardiovascular disease) has been unexplored. To investigate acute effects of a low-intensity water exercise program on cardiovagal activity, 35 young healthy men participated in this study as a part of the water exercise group (15 min of walking, 10 min of jogging, and 10 min of supine floating) or the control group (35 min of sitting at rest on land). Heart rate during walking, jogging, and floating in water were 88±13, 104±19, and 73±14 bpm, respectively. Ratings of perceived exertion (Borg’s 6—20 scale) were 9±2, 10±2, and 7±2, respectively. Before the low-intensity water exercise program or 35-min sitting rest, there were no intergroup differences in natural logarithm of HF (lnHF), the ratio of low to high frequency component of heart rate variability (LF/HF), heart rate, blood pressure, sublingual temperature, and salivary amylase activity. An interaction between time and group was found in lnHF (P = 0.01); lnHF was greater 15 min and 30 min after versus before the program in the water exercise group, whereas there were no differences in the control group. There were no interactions in LF/HF, heart rate, blood pressure, sublingual temperature, and salivary amylase activity. These results suggest that the low-intensity water exercise program consists of walking, jogging, and supine floating acutely enhances cardiovagal activity.

  • 平田 昂大, 中島 徹哉, 岩本 紗由美, 小熊 祐子, 神武 直彦
    原稿種別: 原著
    2022 年 71 巻 6 号 p. 523-530
    発行日: 2022/12/01
    公開日: 2022/11/19
    ジャーナル オープンアクセス

    The purpose of this study was to compare the characteristics of starters and non-starters with respect to the anthropometric and physical fitness in a Japanese university rugby team. Our sample pool consisted of 54 players of the K University rugby team, who were registered for the official games (all 7 games/year) in 2018 and 2019. The starter group (26 players) comprised of players with more than 3 games/year while the non-starter group (28 players) comprised of players that registered for official games but played less than 3 games. Anthropometric parameters, such as height, body mass, skinfold (8 items), girth (5 items), body composition, muscular strength, intermittent endurance, and sprint time, were assessed. We found that the starter group for forwards had lower skinfold (Biceps, Iliac crest, Supraspinale, Abdominal, Front thigh, and Medial calf) and percentage body fat than in the non-starter group. The starter group for backs had muscle strength of narrow chinning is higher than in the non-starter group. Finally, our study helped to clarify the physical factors that influence the difference in athletic performance between starters and non-starters in university rugby team. The forward starters had lower percentage body fat and better body composition and backs starters had better narrow chinning. The findings provide information to university rugby players who want to become starters, as well as help the coaching staff understand the factors that need to be strengthened in the players.

  • 田中 千晶, 武長 理栄
    原稿種別: 原著
    2022 年 71 巻 6 号 p. 531-539
    発行日: 2022/12/01
    公開日: 2022/11/19
    ジャーナル オープンアクセス

    The purpose of this cross-sectional study was to examine associations between self-rated health (SRH) and frequency of overall daily moderate-to-vigorous physical activity (MVPA), compliance with sedentary behaviour (SB), and sleep, sports participation, and active transportation to school among junior high school and high school students, using data of a random sampling survey in Japan. Participants were Japanese junior high school and high school students (437 boys and 398 girls). We analyzed data from the 2019 SSF National Sports-Life Survey of Children and Young People, which used the frequency of MVPA, screen time, sleep duration, organized sports participation and active transportation to school. The highest MVPA frequency and participation of sports were associated with better SRH adjusted age and annual family income (odds ratio (OR) 3.01; 95% CI, 1.30–6.93; OR=5.80; 3.08-10.93 for boys; OR=4.93; 2.22-10.96; OR=2.75; 1.59-4.75 for girls). The association with highest MVPA frequency was slightly increased after adjusting for meeting the SB for girls (OR=5.26; 2.23-12.43). Meeting SB was associated with better SRH after adjusting for meeting the frequency of MVPA among girls (OR=2.91; 1.49–5.69). These findings show that frequency of MVPA is important to better SRH in junior high school and high school students, independent of SB. In addition, SB is also important for girls, independent of MVPA. Thus, gender should be taken into account in order to better SRH in Japanese junior high school and high school students, as the factors associated with subjective health differ between boys and girls.

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