No abstract

The purpose of this study was to examine the relationships between the decline ofrunning speed during a marathon race and the changes in running economy ， running mechanics and muscu − lar strength and power expended in the race ． Thirteen healthy males were measured fbr oxygen con − sumption (VO2) ， respiratory exchange ratio (RER)and running kinematics(stride frequency ， stride length ， support time and non − support time)during treadmill running (200 m ／ min ， 3min) ， maximal force and rate of force development (RFD) of isometric knee extension (ISO) ， and jumping height (JH) of counter − movement jump (CMJ)and 5 − rebound jump (5RJ)before and after a marathon race (42 ． 195km) ． 1)In all of the subjects ▽02 during treadmill running tended to increase ． RER was sig − nificantly decreased ， and non − support time was significantly shorter after the race ． Maximal force and RFD of ISO and JH of CMJ and 5RJ were significantly lower after the race ． Contact time of 5RJ was also significantly longer． 2)There were no relationships among the changes in running econo − my ， running mechanics and muscular strength and power ． 3)When the suhjects were divided into two groups according to relative change in running speed due to the race ， the KEEP group (n ＝ 6 ， ％ change ：0 ． 44 ＋f − 2． 6％)showed a significantly different RER ， non − support time ， maximal fbrce and RFD of ISO and contact time of 5RJ ， whereas the DOWN group (n ＝ 7 ， ％ change ： − 21 ， 8 ＋ 1 − 16 ． 8％) showed a significant increase in VO2 during treadmil1 running ， and significantly different RER ， and muscular strength and power measurements ． These results suggest that the decreases in running

Recendy we developed a usef 皿 12 ・ min submaXimal mn test at an intensity regulated by ratings of perceived exertion ill order to 血 directly assess an 血 dividuars cardiorespiratory fit 皿 ess ． The pur ・ pose of the present study was to evaluate the validity and reliability of the 12 ・ min subma ) dmal run test as a convellient measure of maximal oxygen uptake ( VO2max )and anaerobic threshold ( VO2AT)， The subjects were 103 men aged 22． 0± 2． 6 years ． All were asked to run for 12 mill at an intensity cor ・ responding to 130n the

This study aimed to clarify the effects of physical activity on the body type, physical fitness and motor ability in elementary school students living in Aomori prefecture. Subjects were 448 elementary school students（226 boys, 222 girls）living in Aomori Prefecture. As morphometry, we measured height and weight, and calculated the obesity index as an indicator of body type. Physical fitness and motor ability tests were grip strength, 20 m dash, side steps, standing long jump and the speed of the tennis ball throw. Physical activity was evaluated by pedometer, worn around the waist for 7 days. We examined the relationship between physical activity and body type. As a result, there was no significant correlation between physical activity and obesity index. In order to remove the influence of development of physical fitness and motor ability, T score of physical fitness and motor ability were calculated based on the age at the time of measurement by polynomial. Correlation analysis between physical activity and T score of physical fitness and motor ability showed a positive correlation between physical activity on weekdays and standing long jump in boys. A positive correlation was shown for the relationship between physical activity in weekdays and side steps and tennis ball-throwing velocity, physical activity in weekends and 20 m dash, side steps and tennis ball-throwing velocity, respectively, in girls. These results suggest that physical activity does not influence on body type in elementary school students who live in cold district. In addition, it is shown a weak correlation between physical activity and physical fitness and motor ability.

Purpose: The purpose of this study was to investigate the kinematic diŠerence in the skiing motion of the diagonal technique between diŠerent slopes during classical style cross-country 10 km o‹cial race. Methods: Data were collected from two o‹cial men 10 km cross-country races of classical technique on the same 5 km circuit course. Skiers passing in the uphill sections of the course were videotaped with a VTR camera (60 Hz) positioned at 0.4 km point (3.8 degree slope) in one race, and at 1 km point (12.4 degree slope) in another race. To reconstruct the two dimensional coordinates of the motion of subjects, a two dimensional direct linear transformation technique was used. Seven skiers including national class junior and collegiate skiers of Japan were selected as subjects on each race. Results: The time from the instant of the heel contact on the ski to the instant of the ski detaching the snow on the moderate slope was almost same as that on the steep slope. However, the gliding length after heel contact on the ski on the moderate slope was larger than that on the steep slope. The length of ski gliding resulted in the large skiing speed on the moderate slope.