To investigate a relationship between gender differences in recovery from skeletal muscle fatigue and muscle oxygenation, we examined whether there is a difference in oxygen supply and consumption of the working muscles after intermittent handgrip exercise between young males and females using near-infrared spectroscopy (NIRS). Healthy young subjects (25.8±3.9 years ; males, n=10 ; females, n=10) repeated static maximal voluntary contractions (MVC) with a handgrip for 5 seconds followed by 5 seconds rest for a period of 4 minutes in Study 1. The MVC force was measured before, each minute during the handgrip exercise, and 2, 5, and 10 minutes following the exercise. In Study 2, the selected 10 subjects (males, n=5 ; females, n=5) performed the same exercise and their total- and deoxy- hemoglobin/myoglobin level was measured using the venous occlusion NIRS method; and O₂ supply index (OSI) and O₂ consumption index (OCI) calculated before and after the exercise. In Study 1, females exhibited higher %MVC force at the end of the exercise and during the recovery period than males (p<0.05). In Study 2, the %OSI was significantly lower in females than in males at 5 and 10 minutes in the recovery period (p<0.05), but no significant differences were detected in %OCI. Furthermore, %MVC of the recovery period correlated with %OCI of the recovery period in females (r=0.724, p=0.015), but not in males. These findings suggest that female working muscles can convert consumed oxygen more effectively after an intermittent handgrip exercise, and therefore, be able to recover muscle force faster.

Skeletal muscle is comprised of multiple fiber types. Slow-twitch oxidative muscle fibers have greater capillary density compared with fast-twitch glycolytic fibers of skeletal muscle. To gain insight into the molecular mechanism underlying the difference of capillary density, we investigated whether the basal gene expression of vascular endothelial growth factor (VEGF), a major angiogenesis-related factor, and its transcriptional factors (hypoxia-inducible factor-1α, transforming growth factor-β1, c-jun, and c-fos) differs between these two fiber types of rat skeletal muscle. The mRNA expression of VEGF and its transcriptional factors was significantly higher in slow type fiber of muscle (soleus muscle) compared with fast type fiber of muscle (plantaris and tibialis anterior muscles). These results suggest that the difference of basal gene expression of VEGF and its transcriptional factors between slow and fast fiber types of skeletal muscle may partly contribute to the difference in capillary density between these two fiber types.

Anthropometrical measurement were obtained on 178 male nonathletic university students and 168 male athletic university students (Swimming, Handball, Soccer, Rugby, Running, Thrower, Judo and Gymnastics) aged 18-22 years.
The results obtained were as follows
The mean values of height and body weight for nonathletes were 170.2cm and 59.7kg respectively. The mean values of height and body weight for athletes except gymnastics and long distance runner were larger than those for nonathletes. Athletes showed larger mean values of girth of chest than nonathletes (86.1cm) . The mean values of girth of upper arm and girth of thigh for nonathletes were 26.9cm and 50.6cm respectively. The mean values of girth of upper arm for athletes except basketball, long distance runner and jumper were considerably larger than that for nonathletes. Athletes except long distance runner, jumper and gymnastics showed larger mean values of thigh than nonathletes. The mean values of skinfold thickness for athletes except heavy weight class of judo were thinner than that for nonathletes and the percentage of body fat calculated by using the prediction formura from mean skinfold thickness, body surface area and body weight for athletes was smaller than that for nonathletes
Plotting of body weight and body fat content in standard measure against height in standard measure with family of iso-deviation line was used to compare the body composition and body shape of athletes with those of nonathletes. In this plotting, physical characteristics could be expressed as the difference (R) between the points representing the mean value of athletes on the origin, (the mean values of nonathletes) and ratio of deviation (r) from standard line representing correlation of body weight or body fat content to height for nonathletes. Plotting R against r with family of lines of the same height was proposed to differentiate physical characteristics of athletes participating in different kinds of sports and to evaluate the effect of training on physical characteristics. Plotting of girth of upper arm and girth of thigh in standard measure against girth of chest was used for the evaluation of difference in body shape of athletes.

Arterial compliance progressively decreases with aging. This aging-induced reduction of arterial compliance causes an increase of systolic blood pressure (SBP), whereas regular exercise increases arterial compliance. We hypothesized that an increase in daily physical activity (DPA) produces a beneficial effect on systemic arterial compliance (SAC ; an index of central arterial compliance) and this phenomenon could decrease SBP in the elderly. We investigated the relationship among DPA, SAC, SBP, diastolic blood pressure (DBP), and some other risk factors for cardiovascular and/or cerebrovascular events (total cholesterol, HDL-cholesterol, and HOMA-R) cross-sectionally in 127 elderly persons (42 male, 85 female : aged 74±4 years) . The DPA was estimated by expended calories using an accelerometer. The SAC was calculated from a finger pulse pressure waveform recorded by using PORTAPRES ; and stroke volume obtained from the same pressure waveform based on the volume-clump method. The analyses demonstrated that SBP was directly and decreasingly affected by SAC, and that DPA had an increasing effect on SAC. Furthermore, SBP was directly and increasingly affected by DBP, and DBP was directly and decreasingly affected by both SAC and DPA. Therefore, it is considered that DPA may have suppressive effects on the rise of SBP through the indirect effects of changing SAC and DBP. These findings suggest that an increase in DPA could improve the age-induced reduction of arterial compliance and rise of SBP in elderly humans.

High-sensitivity C-reactive protein (CRP) is a novel risk factor for coronary artery disease. It is well known that body weight loss is effective in reducing serum CRP concentration ; however, the effect of exercise training on serum CRP concentration has not been fully elucidated. The purpose of this study was to examine the effect of a 24-week exercise training program on serum CRP concentration in 169 healthy middle-aged and elderly subjects (65.9±6.4 years). Each subject underwent baseline testing (peak oxygen uptake, daily physical activity, body weight, and serum CRP levels), and repeated these tests on completion of the training program. The subjects were classified into 2 groups based on initial CRP levels : normal<1.0 mg/L, n=139, and high≥1.0mg/L, n=30. On completion of the program, both daily physical activity and peak oxygen uptake increased significantly (+33.9±72.4%, p<0.0001, +5.4±14.7%, p=0.014, respectively). However, body weight did not change significantly. In addition, CRP levels of the entire group did not change significantly. However, CRP levels significantly decreased among the high baseline CRP group (from 1.82±0.81 mg/L to 0.98±0.59 mg/L, p<0.0001). It was concluded that serum CRP levels are reduced without body weight loss in response to exercise training in healthy middle-aged and elderly subjects with high initial CRP levels.

Habitual aerobic exercise decreases arterial stiffness, a risk factor for cardiovascular disease, and increases aerobic exercise capacity. Exercise habits can be difficult to maintain over time. We sought to determine if the prospect of participating in a sports tourism event (mountain climbing) helped older adults maintain increased aerobic exercise capacity and decreased arterial stiffness after a supervised training program. Forty community-dwelling middle-aged and older individuals were divided into training (n=20) and control (n=20) groups. The training group participated in six weeks of face-to-face exercise intervention (walking, 60%–75% of age-predicted maximal heart rate, 35–50 min/day, 1 day/week) and was additionally offered home-based walking (45 min/day, 2–4 days/week). During the same period, the control group was asked not to change their lifestyle. In the last session of the exercise program, we announced a mountain climbing event planned for six months in the future. The participants were encouraged to maintain their exercise habits leading up to the event. Arterial stiffness (brachial-ankle pulse wave velocity) and maximal oxygen uptake were measured before and after the six-week intervention and two weeks before the mountain climbing event. In the training group, arterial stiffness decreased, and maximal oxygen uptake increased after the intervention; these improvements were successfully maintained until the mountain climbing event. These parameters did not change significantly in the control group. Sports tourism may motivate older adults to maintain their exercise habits after a supervised training program.

Flexibility is an important factor of physical fitness to prevent sports injuries. However, the best timing to improve flexibility during the growth and development period in children has been unclear. To compare the acute effects of static stretching on flexibility between school-grade children in the growth and development period, we measured the hip joint flexion range of motion (RoM) by using straight leg raising (SLR) before and after static stretching (6 exercises, 15 seconds, 2 sets) in 50 young male children aged 7 to 13 years (the second grade of elementary school to the first grade of junior high school). The RoM in SLR significantly increased after stretching versus that before stretching in all subjects. This positive improvement of RoM was statistically significant among all grade levels. Notably, the change rate in RoM after stretching was significantly greater in the fourth grade of elementary school than in the other grades. The rate of height increase during the past year was lower in students from the fourth grade than in students from the second grade of elementary and the first grade of junior high school. These results suggest that flexibility training is more effective during the slow-down period of growth and development in young male children.

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.

In Japan, where the population is aging, it is important to train exercise instructors who promote health in older adults. Previous studies demonstrated that an intergenerational program that was not focused on exercise improved university students’ perceptions of older adults, but the effects of an intergenerational exercise-related program have not been explored. This study investigated whether obtaining experience in providing exercise instruction to older adults improved university students’ attitudes toward these adults and their willingness to acquire exercise instruction-related qualifications. Second-year university students majoring in sport and health sciences were divided into intervention (n = 29) or control (n = 33) groups. Students in the intervention group participated in a 5-session program that involved choreographing exercise with music and giving exercise instructions to community-dwelling older adults. In the final session, the students and older adults performed the exercise together, and this session was videotaped. Explicit attitudes toward older adults improved from before to after the program in the intervention group. The percentage of students in the intervention group who were willing to acquire exercise instruction-related qualifications was greater after the program than before it. In the control group, there were no detectable differences in these measures before and after the study period. Students’ feelings (i.e., vitality, stability, pleasure, and arousal) acutely improved after each session in the intervention group. These results may imply that after experiencing the provision of exercise instruction to older adults, university students’ explicit attitudes toward these adults and their willingness to obtain exercise instruction-related qualifications were increased.