The purpose of this study was to investigate the relationship between lean soft tissue mass (LSTM) and resting energy expenditure (REE) in whole body and several body regions, and find an appropriate way for estimation of REE for Throwers, Sprinters and Distance runners in track and field athletes. The subjects were 59 male college athletes (20 throwers, TR; 20 sprinters, SP; and 19 distance runners, DR). The body composition was measured using with Dual energy x-ray absorptiometry (DXA). The body regions subjected for head, trunk, arms, legs and whole body. Measurement of REE was made with respiratory gas analysis. The %Fat of TR was shown significantly higher than those of other groups (p<0.05). Significant differences were observed between groups for both regional and whole body LSTM: TR showed a significantly larger value than in the other groups and DR showed the lowest value among groups (p<0.05). The REE per body weight was significantly smaller in TR than in the other groups (p<0.05). On thSe other hand, REE per LSTM was almost constant at about 30 kcal/day/kg among groups. In addition, the whole body REE was closely correlated with LSTM in all subjects (r=0.805, p<0.05). From these results, it was suggested that REE is influenced by LSTM more strongly than by specific training mode in the track and field athletes.

View full abstract

The purpose of this study was to investigate the influence of the ratio of muscle thickness of rectus femoris to that of vastus intermedius on the running movement during a long-distance race. Twelve long-distance runners participated in this study. The muscle thickness of rectus femoris and vastus intermedius was measured by ultrasonography. The subjects were divided into two groups based on the ratio of muscle thickness. The RF group was comprised of the runners whose ratio of the muscle thickness of rectus femoris was 50% or more. The VI group was for those under 50%. Moreover, the running movement of subjects was filmed with a high-speed video camera during a 5000m race. The angle and angular velocity of knee and hip joints were calculated. Furthermore, the comparison of running movements between the RF group and VI group was done to classify them into contact, extension and flexion phases. As a result, the angle and angular velocity of hip and knee joints of the RF group were significantly smaller than those of the VI group. In particular, differences of angle and angular velocity between RF and VI at the knee joint were found in the contact and flexion phases. In addition, differences of angle and angular velocity between RF and VI at the hip joint were found in the extension and flexion phases. These results suggested the ratio of muscle thickness of rectus femoris to that of vastus intermedius have an influence on the movement of the long-distance runner.

View full abstract

The present study examined the effects of body cooling by spraying water on physiological and psychological responses during bicycle exercise in a hot environment. Eight college-aged cyclists performed bicycle exercise using a road racer at 40 km/h for 90 min in an environmental simulation room maintained at 35 ℃ and 80% relative humidity. The exercise experiments were repeated twice, with or without spraying of water on whole body after 60 min of exercise, presented in random order. As the results, spraying water attenuated body temperature elevation and decreased heart rate, oxygen uptake, and score of thermal sensation during the last 30 min of exercise. These results suggest that spraying water on the body decreased physiological and mental stress during bicycle exercise in a hot environment. Thus, spraying water may be a beneficial way of body cooling, which prevents the heat stroke and maintains the exercise performance during outdoor practice in heat.

View full abstract

The purpose of the study was to evaluate functional importance of two hip flexor growth, rectus femoris (RF) and psoas major (PM), on sprinters by investigating relation between each muscle size and the joint torque and angular velocity. Subjects were 24 female and 25 male sprinters and 64 age matched volleyball players and 20 untrained students participated in the study for comparative purpose. Maximal hip flexion torque (HF) was measured by an isokinetic dynamometer (Biodex System 3) at an angular velocity of 3.14 rad/s and an index of maximal hip flexion angular velocity (HAV) was calculated by dividing knee pull-up speed (COMBI Ballistic Master) by femur length. The muscle cross-sectional area (CSA) was obtained by using magnetic resonance imaging. In sprinters, the PM size (CSA x height) showed week but significant correlation with HF (r=0.48 and 0.34 for females and males respectively) although there was no significant relation between the RF size and HF, suggesting either muscle size of the two hip flexors was not a strong determinant of HF or HAV in sprinters. When all the data were included, muscle size of the two flexors was correlated significantly with HF irrespective of gender. In addition, the PM size was still correlated significantly with HAV. There was no significant difference in the RF CSA between sprinters and volleyball players although sprinters showed significantly larger PM CSA than volleyball players whether the data were expressed in absolute or body-size relative values. HF was significantly higher in volleyball players than in sprinters, while HAV was significantly higher in sprinters than in volleyball players. The present results suggested that predominant PM growth observed in sprinters was preferable to hip angular velocity and assumed to be an adaptation in favor for sprinting performance.

View full abstract

The present study focused on the effects of corrected visual acuity in game performance during water polo play.
Five male water polo players (age: 18.0 ± 3.4 yrs) participated in the study. The participants played games in two conditions; in the first game the players were using contact lenses and in the second game they were not. Their corrected visual acuity with contact lenses was 0.9 ± 0.17. The uncorrected visual acuity of players was 0.04 ± 0.04. The indicators of game performance were (1) the rate of errors; (2) the rate of contributed play; and (3) the rate of ball contacts. The indicators of errors and contributed plays followed the results reported by Enomoto et al. (2001). The participants completed self-evaluations regarding their play.
The results showed the significant difference in the rate of errors committed by players with corrected visual acuity using contact lenses and those with uncorrected visual acuity. According to their responses of questionnaire, there was a significant difference in aspects of the game related to vision between players with corrected visual acuity and those with uncorrected visual acuity.
These findings showed that corrected visual acuity using contact lenses led to a decrease in errors committed, clear vision during games led to significant improvements in game performance. In conclusion, this study suggested the corrected visual acuity is an important factor in scoring and winning in water polo.

View full abstract

The present study investigated the impact of limited visual information on the cognition of gymnastic movements among expert gymnasts. Participants, comprising 10 expert gymnasts and 10 novices, were asked to identify gymnastic elements after observing gymnastic movements displayed using the point-light method. The number of visible points was reduced during the experiment from 10 to 4 and then 2 points. Under all conditions, experts correctly identified more gymnastics elements than novices. In addition, experts based their answers on the power-related aspects of the movements, whereas novices based their answers primarily on visual and spatial representations of the movements.
These results suggest that expert gymnasts possess superior visuomotor skills with regard to gymnastic elements, which enables them to perform their own movements precisely.

View full abstract

Standing and seated position are used in Cycling. On level surface, seated position is selected and as the angle of inclination gradually increased, cyclists select standing position. However, when a constant inclination continues, two positions are often alternately switched. The aim of this study was to examine the influence of the posture selection (seated, standing and switching two postures) on uphill cycling. Trained cyclists participated in eight randomized sub maximal 4-min cycling bout on mortar-driven treadmill. Surface incline of treadmill were 5 and 7%. Additionally, they pedaled four posture condition, seated (SEA), standing (STA), and switched positions high frequency (10-sec: HF) and low frequency (30-sec: LF). Oxygen consumption during 4-min cycling and blood lactate concentration immediately after each bout were measured. Cycling on 5% incline, oxygen consumptions during STA, HF and LF were significantly higher than SEA. But, blood lactate concentration of HF was lowest, significantly difference was observed between SEA and STA. Our results suggest that the switching posture lower blood lactate concentration during uphill cycling.

View full abstract