There is increasing research evidence for the efficacy of resistance training programs for improving health and functional status in older adults. Resistance training has been shown to be an effective method to avoid age related losses in skeletal muscle tissue. Resistance training appears to be a potential solution for prevention purposes by inducing increases in strength, power and muscle cross sectional area, in addition to moderately improving endurance. There are also improvements in some aspects of functional status such as walking speed. Further research is required to determine the efficacy of resistance exercise for fall prevention. It does appear that muscular power and rate of force development are important indicators of health and functional status in older adults. Therefore resistance training programs should incorporate some of these aspects into the program design. Resistance training also provides an alternative method of rehabilitation for various disease states such as cardiovascular disease and type II diabetes. It now appears that resistance training is a critical component of exercise programs designed to improve health in older populations and should receive similar emphasis to aerobic activities such as walking.
This study examines the relationship between exercise and Health-related Quality of Life (HR-QOL). The HR-QOL was evaluated through a questionnaire survey, the SF-36, which is used world wide as a measure of HR-QOL. Normative data were gained from a lay away plan survey using a questionnaire containing the SF-36 and a stage of change for exercise (SCE). The questionnaire was sent to 1000 randomly selected subjects aged 20 or above with a response rate of 48.3% (n=483) at the baseline and 33.65% (n=257) at the 2-year follow-up stage. Findings suggest the SCE transition was associated with General Health and Vitality, while subjects who displayed a physically active lifestyle showed an increased tendency in Physical Functioning and Mental Health.
Behavior of fascicles and tendinous structures of the m. gastrocnemius medialis (MG) was quantitatively re-evaluated from the viewpoints of force-length and force-velocity relations during 4 types of human vertical jumping in vivo, based on our previous studies. Eight male subjects performed maximal-effort 1: ankle plantarflexion jumping (AJ) from the standing position, 2: squat jumping (SQJ) from the squat position, 3: counter movement jumping (CMJ) from the standing position, and 4: straight legged drop jumping (DJ) from a height of 0.20 m. Kinematic and kinetic data were obtained using a high-speed camera and a force platform system. Also, behavior of fascicles and tendinous structures were determined using ultrasonography. Vertical displacements of the body center of gravity from the standing position were 0.16m, 0.43m, 0.44m and 0.33m in AJ, SQJ, CMJ and DJ, respectively. During the take-off phase, there was no stretching of the fascicles of the MG in all jumping conditions. In AJ and SQJ, on the other hand, the fascicles of the MG shortened in the early take-off phase. As a result, 2.2J, 4.9J, 6.6J and 7.6J of elastic energy were stored in the tendinous structures of the MG in AJ, SQJ, CMJ and DJ, respectively. During the push-off phase, 2.1J (47% of total muscle-tendon complex work in the push-off phase), 4.4J (86%), 3.8J (79%) and 5.8J (75%) of the stored energy was reutilized in each of the conditions, respectively. The fascicles of the MG operated within the optimal range of the sarcomere force-length relationship during jumping. Also, the fascicles worked in the relatively low shortening velocity region of the instantaneous force-velocity relationship in all jumping conditions.
The purpose of the present study was to examine the change of walking pattern during conscious focus on the plantar arch. Four walking conditions were selected. Although the walking pattern was normal for each condition, the subject was asked to consciously focus on one of three regions of the plantar arch (Fore-foot Mid-foot and Rear-foot), or to walk without conscious focus on plantar pressure sensations (Normal). A well trained female subject performed five trials in each condition. Selected kinematic and kinetic parameters, including ground reaction force, joint angle and torque of the lower limb, and force generated by the agonist muscles, were analyzed using a 3D motion capture and force-plate system. Electromyograms of the agonist muscles were simultaneously measured. The normal walking motion was significantly different from the consciously focused conditions in the following ways: the Mid and Rear movement patterns were similar to Normal, but the recorded kinematic and kinetic values were greater. The walking pattern of Fore showed a similar pattern to running.
It is well known that warm-up (W-up) routines improve exercise performance and that the duration and intensity of W-up affects high intensity aerobic exercise performance. Previous studies have suggested that intensity and/or duration of W-up affect high intensity aerobic exercise performance, but the total workloads used in those studies were different. In this study, the effects of W-ups of different intensities upon the equal total workloads of high intensity aerobic exercise performance were investigated. Subjects performed three exercise tests under differing W-up conditions. These conditions were firstly W-up at lactate threshold (LT), secondly at 50%LT and thirdly, at the onset of blood lactate accumulation (OBLA). The total workload of each W-up was the equal as 15 minutes at LT. Following a 5-min rest period after completion of W-up, each subject performed a cycling exercise test at 100% VO2peak until experiencing exhaustion. The duration of the exercise test was used as an index of exercise performance. Vastus lateralis and rectal temperatures of each subject were measured. No significant differences were observed at vastus lateralis (50%LT; 36.8 +/- 0.4°C, LT; 37.2 +/- 0.5°C, OBLA; 37.4 +/- 0.3°C, p>0.05) or rectal (50%LT; 37.0 +/- 0.3°C, LT; 37.2 +/- 0.4°C, OBLA; 37.4 +/- 0.4°C, p>0.05) temperatures after performing W-up at any of the three different intensities. Similarly, significant differences were observed at exercise test duration between W-up conditions (50%LT; 214 +/- 84 sec, LT; 306 +/- 125 sec, OBLA; 274 +/- 118 sec, p>0.05). These results suggest that if total workloads are the equal and rises in body temperature are similar, W-ups of different intensities have the same effect on high intensity aerobic exercise performance.
This study examined if the adaptation in muscle strength and whole body and regional lean tissue mass (LM) differs in older men (M) and women (W) subsequent to a program of high-intensity resistance exercise. Ten men and six women aged 65-78 yr underwent 20 weeks of training, twice per week, for 3 sets of 8RM for 7 upper and lower body exercises. Dynamic muscle strength was determined by 1-RM and isometric knee extensor strength by dynamometry. Lean tissue mass was determined by dual energy X-ray absorptiometry. Following training, men and women exhibited significant (p<0.001) though similar increases in dynamic upper (women, 28.9±11.7%; men, 32.0±11.1%; mean±SD) and lower (W, 38.4±14.7%; M 30.3±11.7%) body strength, and isometric knee extensor strength. There was a significant time effect (p<0.001) for whole body LM (W, 0.85±0.83 kg; M, 0.70±0.70 kg), upper limb LM (W, 0.21±0.16 kg; M, 0.25±0.13 kg), lower limb LM (W, 0.38±0.42 kg; M, 0.27±0.41 kg) and trunk LM (W, 0.25±0.38 kg; M 0.18±0.34 kg), with no interaction (p=0.58-0.78). These results suggest that well-functioning older men and women show similar gains in muscle strength and whole body and regional lean tissue mass indicating comparable neuromuscular and anabolic responses accompanying resistance training.
The purpose of this study was to evaluate the conditioning of elite mogul skiers through the 2001-2002 Federation International de Ski season (that is, the World Cup freestyle competition and the Salt Lake City Winter Olympic Games) using a single-case study method. Four elite mogul skiers were observed independently and measured in parameters such as athletic condition. The results indicated that during the competition season there was no significant change in the conditioning of the world-class skiers of this group. However, the conditioning of the intermediate skiers did change. It was concluded that it is preferable to use the single-case study method when analyzing physical conditioning.
The purpose of this study was to re-examine importance of kick-off and 50m restart kick (KO) play in rugby football games with their changes in recent years to be considered. Twenty top-ranking, high level international matches in 2004-05 were analyzed, and data from an earlier study on thirteen matches at the same level in 1994-95 were utilized and supplemented with additional analysis. The main results were as follows: 1) The number of KO plays in 2004-05 was not significantly different from those in 1994-95. However, the ratio of KO plays in the total number of set plays increased significantly. 2) Short KO (S-KO) plays in which kicked ball falls between the 10m∼22m lines and long KO (L-KO) plays in which kicked ball goes beyond the 22m line were executed at an approximately even rate in 2004-05 although almost all KO plays were S-KO in 1994-95. 3) The average rate of ball acquisition by kicking sides in S-KO in 2004-05 was .32 even in total. The value was still low and was not significantly different from those in 1994-95. 4) Whether the ball could be gained in S-KO was significantly related to the time during which kicking sides occupied the opponent's territory beyond their 10m line continuously and the rate of scoring after KO in 2004-05 as well as in 1994-95. 5) Whether the ball could be recaptured by kicking sides while occupying the opponent's territory beyond their 10m line continuously after L-KO was significantly tied to the territory time and the scoring rate in 2004-05. It was confirmed from these results that KO play still played an important role in rugby football games in recent years.
This study examined whether subjective health complaints were associated with school-related stress and physical activity among Japanese 6th grade school children and determined the influence of physical activity on the relationship between school-related stress and health complaints. In addition, other health practices were examined as moderators of the association between stress and health complaints. A self-administered questionnaire was conducted for 1,978 pupils at 25 public elementary schools throughout Okinawa, Japan. As a result of two-way analysis of variance, school-related stress showed a significant main effect on health complaints among both boys and girls. However, physical activity did not show a main effect on health complaints among either boys or girls. There was also no observed interaction between school-related stress and physical activity on health complaints. Other health practices had significant main effects on health complaints in this age group. Pupils who slept for 7-8 hours, ate breakfast everyday, watched TV for less than 4 hours a day, or played video games for less than 4 hours a week were less likely to report health complaints. However, there was no observed interaction between school-related stress and each health practice on health complaints. This study suggests that physical activity in this age group has no direct or buffering effects on health outcomes.
To investigate universal principles of growth and development, the author examined the questions of when mathematical functions can be applied to growth curves, what type of functions can be used, and, from a consideration of the historical background, the context for application and validity of such mathematical functions. Examinations of this issue have developed along two main lines: the establishment of logistic models as sigmoid curves showing the proliferation process of living organisms, and the establishment of polynomial systems (spline functions) that describe smoothing of the growth curve and fluctuations in the process. The conceptual prescriptions of fitting functions for the former are structural models, and those for the latter are nonstructural models. The fundamental thinking is that, similar to proliferation of organisms, growth phenomena can be described and explained with the use of differential equations. However, changes in aspects of growth curves are produced with differences in measurement intervals: waves are seen in growth phenomena as measurement intervals become shorter. Thus, a mathematical function is needed that can describe the changes in growth phenomena using a scaling concept on the time axis. To do this it is necessary to separate growth phenomena from biology and develop mathematical functions derived from an independent conceptual framework. In this context, the author has proposed unique wavelets. Herein, the author discusses the historical and theoretical backgrounds of mathematical fitting functions and their validity. The author also examine the interface of these functions with growth study, and its theoretical background.
This study aimed to investigate the gender differences in yearly changes in the cross-sectional areas (CSAs) and dynamic torques of thigh muscles in high school volleyball players. The CSAs of the quadriceps femoris (QF) and hamstrings (HAM) and dynamic torques during knee extension (KE) and flexion (KF) at a pre-set velocity of 1.05 rad · s-1 were determined longitudinally with an interval of one year. Only the males showed significant increases in the CSAs of QF and HAM, without a significant change in the CSA ratio between the two muscle groups. The KF torque significantly increased in both genders, but KE torque did in the males only. Moreover, both genders showed significant increases in the ratio of KF torque to the product of HAM CSA and body height (T/CSA*ht). The relative gains in KF torque and its T/CSA*ht were significantly greater for the males than for the females. Additionally, only the males significantly increased the ratio of KF to KE in torque and T/CSA*ht. The present results indicated that, at least in high school volleyball players, males compared to females showed greater increases in thigh muscle CSA and knee flexion torque.
The purpose of this study was to examine the effective contents of a comprehensive health education curriculum for promoting QOL of obese children. In cooperation with S. town (Awa County, Chiba Prefecture), we considered effective contents of a comprehensive health education curriculum for promoting QOL. First, practical training was conducted by health specialists including school nurses and public health nurses for the purpose of forming a health education plan for promoting QOL on the PRECEDE Model. Second, in order to examine consistency of needs among the specialists, obese children and their parents, a questionnaire survey about QOL was conducted with elementary school children and their parents in 2002. As a result of this study, it was found that the contents of a comprehensive health education curriculum should include knowledge of the relation between obesity and lifestyle related disease as part of the cognitive domain, should promote self confidence as part of the affective domain, and should promote engaging in outdoor physical activities and participating in community events as part of the psychomotor domain.
The purpose of this study was to examine motivational factors affecting consumption behavior of K-league and J-league spectators, and their predictability to explain it. We found that 10 motivational factors significantly, but not sufficiently explained the current attendance frequency of the K-league spectators, whereas these factors well predicted their future consumption behavior. It was considered that there is great potential in the K-league spectator market. The results of the J-league spectators indicated that team identification and vicarious achievement were strong predictors to explain the variance in the game attendance frequency of the J-league spectators, and these results were consistent with the results of Mahony, et al., (2002). However, we found a new predictor (social interaction) to explain this variance. Also, we found that escape was a new positive predictor to explain the intention to attend future games of the K-league and J-league spectators, and escape, player, and team identification were related to the future merchandise consumption of both the K-league and J-league spectators.
This study examines the views of students (7-18 years) related to Physical Education (PE), based on a sample of 2,300 students in Japan (N=1266) and England (N=1034). The study gathered data related to feelings towards PE, self-perception of ability, views of its importance relative to other subjects, and understanding of the outcomes of participation. Reflecting earlier work, this study found most students enjoy and value PE; younger students of both countries are most likely to be positive about PE and more confident about their ability. Despite substantial agreement between the two groups, significant differences were found between responses relating to self-competence, and the importance attached to PE in relation to other subjects. Since PE is an integral feature of young people's introduction to life-long physical activity, evidence related to their views of the subject should be a matter of interest to policymakers and practitioners.
Analysis and recommendations of knowledge and needs for “Prevention and Management of Sports Injury” on high/vocational school students, will serve as a reference in teaching material selection and lecturing method for teachers in relating subject, so as to achieve effective teaching which also fulfills the needs of students. The purpose of this study was to investigate the current level of knowledge and needs for “Prevention and Management of Sports Injury” among 1,649 high/vocational school students. The main results from the analysis are: Knowledge for Prevention and Management of Sports Injury has statistically significant in gender, type of school, education system, grade and source of knowledge. Needs for Prevention and Management of Sports Injury has statistically significant in only gender and source of knowledge. The entire study population considered training for “Prevention and Management of Sports Injury” highly needed indicating students who were more acquainted with “Prevention and Management of Sports Injury” had higher needs for more knowledge.
The purpose of this study was to investigate the effects of different intensities of resistance exercise training on established bone loss in ovariectomized (ovx-ed) rats by densitometry and histomorphometry. Thirty Female Wistar rats were ovx-ed or sham-operated (SHM) at 3 months of age and maintained untreated for 5 months after surgery to establish osteopenia. When they reached 8 months, the ovx-ed rats were divided into four groups in accordance with varying weights applied to a squat-training device: The weight classifications were 1) kept sedentary (OVX); 2) lifted 0 g (LOW); 3) 750 g (MID); and 1500 g (HIGH). The rats in the three training groups performed weight-lifting of 10 reps, performing 2 sets per day, 3 days a week for a ten week period. The Femora and tibiae were removed from each rat and were used for analyses. Ovx induced a significant loss of total BMC in all the bones tested. The ovx-induced femoral BMC loss was observed at all locations tested on the bone (proximal, shaft, and distal), and exercise-intensity dependent restoration was found at the proximal and the distal sites, but not at the shaft. In the tibia, ovx-induced significant bone loss occurred only at the proximal metaphyseal site. The training increased the tibial BMC of all sites in an exercise-intensity dependently, irrespective of the degree of ovx effect. At the tibial shaft, the training increased the cortical bone mass significantly above sham level by the bone apposition at the periosteum. At the proximal tibial metaphysis, exercise had no effect on the cancellous bone volume after ovx-induced bone loss. This finding suggests that the exercise induced bone increase in the ovx-ed rats was from cortical bone, not from cancellous bone, at least in the proximal tibia. These findings indicate that the weight-lifting exercise in rats reversed the ovx-induced bone loss in an exercise-intensity dependent and site-specific manner, even in established osteopenic skeleton 5 mon after ovx.
The purpose of this study was to investigate the effects of long-term chicken breast extract (CBEX) supplementation, a rich source of carnosine and anserine, on relatively high intensity endurance performance. Sixteen healthy male subjects were divided into CBEX group (n=8) and placebo group (n=8). The CBEX group was orally administered 200 ml CBEX drink which contained 4g of carnosine and anserine per day for 30 days. The placebo group was orally administered 200ml the same taste CBEX drink which contained no carnosine and anserine. Before and after the ingestion period, the subjects performed three sessions of consecutive endurance exercise (first session: 30-min at 50%VO2max; second session: 15-min at 75%VO2max; third session: until exhaustion at 100%VO2max) to measure exercise duration time at 100%VO2max, blood lactate concentration and ratings of perceived exertion (RPE) during the three sessions of consecutive endurance exercise. The exercise duration time at 100%VO2max was significantly increased after supplementation in the CBEX group. Blood lactate concentration and RPE at 75%VO2max was significantly decreased after supplementation in the CBEX group. These results suggest that the long-term ingestion of carnosine and anserine could enhance muscle buffering capacity, and in turn improve relatively high intensity endurance performance such as the so-called “last spurt” resulting from attenuation of the muscle fatigue at submaximal exercise.
Myostatin, a potent negative regulator of skeletal muscle growth, plays an important role in the regulation of muscle size. However, the mechanisms by which muscle myostatin production is regulated have not been fully understood. We hypothesized that testosterone, a positive regulator of muscle growth, causes a reduction of muscular myostatin content. To test this, we measured the content of myostatin in skeletal muscle after injection of testosterone at varied doses. Male C57BL/6j mice (age, 11 wk; n=6 for each group) were subjected to subcutaneous injections of testosterone (0.3, 0.6, or 1.2mg/ day per 100g body weight) for 3 days. On the 4th day, the gastrocnemius/ plantaris complex (Gast/ Plant) and the soleus muscles were dissected and the content of myostatin protein was measured. Injection of testosterone tended to cause increases in body weight, Gast/ Plant and soleus muscle wet weight when compared to the control group. Myostatin content in the Gast/ Plant muscle decreased significantly after the injection at 1.2mg per 100g body weight when compared to both control and after the injection at 0.3mg per 100g body weight. In the soleus muscle, the myostatin content also decreased significantly after the injection at 0.3, 0.6 or 1.2mg per 100g body weight when compared to the control group. These results suggest that testosterone plays a part in the regulation of myostatin content in skeletal muscle.
Great public concern has arisen recently from the results of annual nationwide surveys carried out by the Ministry of Education, Culture, Sports, Science and Technology, which have shown that school children's motor ability have been declining. It is important to determine the age at which the decline of physical fitness and motor ability starts, so that we can find the cause and improve the situation. However, changes in preschool children's motor ability development has not been studied so far. Thus, this research intends to make clear chronological changes in preschool children's motor ability development by analyzing data from forty years of nationwide surveys made by the author, et al., in 1966, 1973, 1986, 1997 and 2002. The result of the analysis is as follows: the motor ability of preschool children improved from 1966 to 1973, stayed unchanged from 1973 to 1986 and declined significantly from 1986 to 1997. This result shows similarities to the results in the surveys of school-age children. The cause of the decline was considered from the point of view of physical activity experience and environmental factors. There are no significant differences in the constitution of preschool children from 1986 to 1997. Thus, constitution seems not to be the cause of the decline. Further research made clear that time spent playing outdoors had decreased sharply over almost the same period as the decline in motor ability. This suggests that the decrease in physical activity experience through outdoor play may be the cause of decline. To further support our theory, the same research also reports a decrease in the number of playmates and places for outdoor play, which are the essential environmental factors that determine how much a child plays outdoors.