This study examined running economy (RE) during a two-stage incremental protocol that was combined into an endurance training session 6 hours following a strength training session. In addition, this study investigated running performance which consisted of a two-stage RE protocol and time to exhaustion (TTE) the day after strength and endurance training sessions undertaken on the same day. Twelve trained and moderately trained male runners performed strength and endurance training sessions 6 hours apart with running performance tests conducted the following day. Cost of running (CR) and rate of perceived exertion (RPE) were collected during the endurance training session whereas CR, RPE and TTE were collected during the running performance test. Maximal voluntary contraction (MVC) tests were conducted prior to and following the strength and endurance training sessions and the running performance tests. The results showed that CR significantly increased during the second stage of the endurance training session (p<0.05). During the running performance test, significant increases were found for CR during the first and second stages and for RPE during the second and third stages (p<0.05). The MVC was significantly reduced immediately following the strength training sessions, pre-post the endurance training session, and running performance test (p<0.05). The findings in the current study show that RE is impaired 6 hours following a strength training session. Furthermore, combined strength and endurance training on the same day appears to cause an accumulation effect of fatigue which impairs running performance the following day.
The purpose of this study was to investigate the comparison and influence of soy-based foods and wheat-based foods on weight loss. Fifty healthy participants were randomly assigned to either the soy group (n=24) or the wheat group(n=26). The intervention program was performed for eight weeks. The nutritional supplement was taken before dinner every day, and aerobic exercise and weight training were performed twice a week. Body weight, waist circumference, lipids, glucose, and insulin were measured before and after the intervention. Thirty-eight subjects completed the study (soy group: n=17, wheat group: n=21). At the end of the eight-week intervention, the mean weight of the soy group decreased significantly from 73.4±9.4 kg to 69.0±9.8 kg, and the mean weight of the wheat group decreased significantly from 75.5±10.7 kg to 72.7±11.0 kg. There was a time and group interaction, and the relative decrease in weight from pre- to post-intervention was greater in the soy group than the wheat group. Our data suggested that each group significantly lost weight but that the weight loss was more significant in the soy group.
The aim of this study was to examine the influence of milk peptide intake on the recovery from muscle damage following high-intensity eccentric exercise. To clarify this issue, we designed a cross over comparison study between peptide intake and control after eccentric calf raise exercise. Six healthy male volunteers (ranging from 19 to 22 years) performed high-intensity eccentric calf raise exercise. The CK, MRI T2 value of the calf were measured at pre-, post-, and on, day 1, 2, 3, 5 and 8 following the exercise to evaluate muscle damage as well as muscle soreness using a visual analog scale (VAS). Statistical differences in all measurements between the peptide and control condition were analyzed using two-factorial ANOVA. The peak value of each measurement between two trials was analyzed using the T-test. A statistical significance of p<0.05 was adopted. The peak CK level (p<0.05), MRI T2 value (p<0.05), and VAS (p<0.01) in the peptide condition were significantly lower than those in control. Although the mechanism of recovery from muscle damage is unclear, our finding suggests that milk peptide intake may be effective for decreasing muscle damage after high-intensity eccentric exercise.
The purpose of the current study was to investigate the concurrent validity of the stages of exercise behavior change based on body composition by using dual energy x-ray absorptiometry (DXA). Numerous studies have investigated the validity of the stages of exercise behavior change. However, the evidence available regarding the validity of these stages based on body composition is inadequate. DXA can reliably estimate the body composition, and its use is minimally stressful for most individuals. Participants were 193 female Japanese university students in various stages of change regarding exercise; their body compositions were estimated. The participants classified as being in the action and maintenance stages exhibited the lowest percent body fat and the highest bone-free lean mass, as measured by DXA. These results offer additional partially support for the validity of the stages of exercise behavior change based on body composition by using DXA.
The present study sought to examine age-related differences in reaction time responses under simple- and dual-task conditions in active middle-aged males. Fifty healthy males aged 42 to 64 years who took part in public marathon events in 2010 or 2011, and who had participated in ski marathon events for more than 2 years were assessed, and whole body reaction times (WBRTs) were measured by under simple-task and dual-task conditions. In the dual-task condition, participants performed WBRTs measurements while they counted backwards aloud to 1, starting from 100. Although reaction times in the simple-task condition were not associated with age (r=0.21, p=0.14), a significant positive correlation was found between age and reaction times in a dual-task task condition involving concurrent cognitive tasks (r=0.45, p<0.01). One-way analysis of variance revealed that older subjects (60 years and older) responded more slowly than two younger groups (aged <50 and 50-59 years) in dual-task conditions (F=7.87, p<0.01). However these age-related differences were not found in simple-task reaction times (F=1.74, p=0.19). The present findings suggest that attentional capacity assessed by reaction time in dual-task conditions declined with age in active middle-aged males.
The present study focused on whether the movement correction capability during interceptive action can be improved by practice and investigated what practice method would enable the improvement. Two possible practice methods were conducted, i.e., practice with direct interception of an accelerating target (within-trial target velocity changes; WT practice), and practice with interception of 2 constant-velocity targets that are presented in uncertain order (inter-trial target velocity changes; IT practice). After practice, the rate of movement correction and movement kinematics of both groups were investigated at post- and transfer tests that included various novel target conditions. In the post-test, only the IT practice group showed improved rate of movement correction and movement velocity patterns with rapid acceleration for the accelerating targets despite having no direct experience with target velocity change during practice. In the transfer test, the WT practice group showed a relatively high rate of movement correction for the novel target velocity changes. These results indicate that movement correction capability during interception can be improved by practice. However, WT and IT practices lead to the development of different movement correction strategies.
Differences in skill performance associated with side preference are observed in sports codes where an equivalent level of performance by both limbs is desired. In Australian Rules Football, some players can achieve long, accurate kicks with either foot, but other players typically have significant discrepancies between kicking sides. To improve punt kicking for distance and accuracy, video self-model training was applied to kicks made with the non-preferred foot, using the feedforward method. To show players performing at a level they could not currently achieve with their non-preferred foot, video of self was made with preferred foot kicks mirror-reversed and watched by the participants. Kicks made for distance showed an improvement in relative side-to-side performance from pretest to post-test, that continued at the retention test.
The purpose of this study was to investigate the effects of fatigue on ground reaction forces and leg kinetics during all-out 600 m running. Eight male middle-distance runners were asked to perform two kinds of running, i.e. an all-out 600 m run and a non-fatigued 80 m run with the same velocity as at the 550 m mark of the 600 m run. Their running motion was videotaped and the ground reaction forces were measured at the 150 m and 550 m marks of the 600 m run and at the 50 m mark of the 80 m run. The step length, ground reaction forces, ankle plantar flexion torque, and knee extension torque of the support leg decreased due to fatigue. The hip joint torque of the recovery leg decreased due to the difference in running speed rather than fatigue. From these results, we suggest that in the final stage of 800 m race, a runner should not try to extend the step length by thrusting against the ground with the support leg but should maintain the step time as much as possible by moving the recovery leg quickly.
In this study, we focus on a discussion of whether collective responsibility in high school baseball is right or wrong, analyzing the point at issue from the viewpoint of communitarianism and aiming to provide a new viewpoint for the argument. We selected the obligation concept as a concrete perspective for our analysis and used it to examine the point at issue. The crucial issue was whether a person who is a member of a baseball club should take responsibility for the actions of other members of the same baseball club. First, we reviewed criticism of communitarianism to moral individualism. Second, we clarified the obligation concept as defined by Sandel, who is a representative of the communitarian viewpoint. Finally, we used that concept to frame the issue mentioned above. As a result, we propose that members of a baseball club have obligations of solidarity toward one another in terms of their communities, which in this case are both the baseball club and the school.
The purpose of this study was to examine the contextual interference effect modulated by skill level in the throwing of different ball types by pitchers. College and high school baseball pitchers were asked to throw straight balls and breaking balls to the outside half and lower half of the home plate. Twenty pitchers were divided into 4 groups, determined by a combination of practice order (random or blocked) and skill level (high or low). A pretest comprised 10 trials (5 straight balls and 5 breaking balls in random order); 40 trials in a practice session were divided into 4 blocks, 10 trials each; and a posttest and retention test (after one day) involved 10 trials, similar to the pretest. The main finding of interest was an interaction effect of skill level with practice order in the retention test. For the low level pitchers there was no difference of practice order groups. However, for the high level pitchers, those in the random practice order group showed better control than the blocked practice order group. The result suggests that the contextual interference effect is modulated by skill level of pitchers.
The purpose of this study is to examine the role played by the technological development of TV satellite transmissions on the rapid expansion of sport economy in the United States in the 1970s and 80s. The satellite transmission technology, especially the adoption of Ku-band frequencies, created ‘superstations’ and put an end to the exclusivity of the nationwide land-line networks by the ‘Big Three’ TV Networks. Thousands of isolated cable systems managed to receive programmes from other areas of the country via these superstations due to the creation of these satellite networks. Owing to the new networks, the number of the nationally televised sports games/matches drastically increased, most of which used to be only broadcast locally. Accordingly, the price of broadcast rights, the ad-boards, and merchandising increased. In conclusion, the rapid expansion of the sport economy in the US was caused by the technological innovation of satellite transmissions, and this process occurred between approximately 1978 and 1984.
The purpose of this study was to re-evaluate the concept of “experience” and ”education” presented by J. Dewey in order to better understand the concept of ”sport as experience”. Dewey's ideas of “interaction” and “continuance” are the representative concepts upon which his theory of “experience” is based. Such experience may arise from the interaction between an organism and its environment, and is linked to past, present and future experience. Through this concept, Dewey explains the process of experience and concludes that education proceeds through a stack of experience. The present study also considers the concept of “experience” as applied to “experience of sport” in terms of both process and substance, and subsequently the relationship between sport and the education process. ”Experience of sport” arises from constant interaction between a moving body and its environment, and the process has two stages: the “first experience” and the “secondary experience”. The former stage involves direct experience and the latter is a reflective stage. Substantially, “experience of sport” is a type of consciousness experienced by individuals when they interact. In other words, it cannot be understood by an observer, but only through individual experience. Individuals may acquire “experience of sport” from every other experience and gain an overall picture through self-reflection. This “an experience” proposed by Dewey. A significant stock of sport experience can be gained over time, and this experience is held over thereafter. Such a process of consecutively reconstituted experience, i.e. the process of development through experience, is the educational process envisaged by Dewey. Thus, “experience of sport” allows for the possibility of educational development, so that individuals may gain new experiences and undergo successive developmental processes. The concept of “an experience of sport” is crucial for appreciating the importance of sport education and for extending the avenues of human education.
The aim of this study was to compare and validate a kinematic-based event detection method for a foot strike and toe-off during an accelerated sprinting. Five male sprinters ran 10, 15, and 25 m with maximal effort while a motion capture system collecting the positional data before the foot strike and after the toe-off at the 2nd, 6th, and 10th step. The ground reaction force at these steps was also recorded simultaneously. The foot strike was determined using the peak vertical acceleration of the markers on the toe and the first and fifth metatarsal head. The toe off was detected using the peak vertical acceleration and the lowest point of the marker on the toe. As a result, the method using the peak vertical acceleration of the marker on the toe was sufficiently reliable and accurate for detecting the foot strike during the accelerated sprinting. For the toe-off, using the lowest point of the marker on the toe reliably and accurately detected event timing. In conclusion, the foot strike and toe-off events for serial steps during accelerated sprinting on a ground or a treadmill can be detected accurately using proposed kinematic-based methods.
The purposes of this study were to examine the relationship between the presence or absence of involvement in sports for people with disabilities and the demographic factors of athletes and to examine the relationship between the interest in sports for people with disabilities and the demographic factors of athletes not involved in such sports. The participants were students from 2-year or 4-year colleges. They were athletes who participated in competitive sports and belonged to an athletic club. The items surveyed were the participant's demographic factors, involvement in sports for people with disabilities, and stages of behavior change related to involvement in sports for people with disabilities. Results showed that athletes who participated in individual sports and athletes with more years of experience in competitive sports were more likely to have been involved in sports for people with disabilities. Moreover, the upperclassmen or older athletes, regular or semi-regular players, and athletes with more years of experience in competitive sports were more likely to have an interest in being involved in sports for people with disabilities. Detailed studies should be conducted on college athletes, and approaches for such students should be implemented based on the findings in this study.
In the present study, we aimed to investigate the joint moments applied to the cutting leg (CL) knee during the sidestep cut and during the final step before cutting (BC) at slow and fast speeds. Seven male university basketball players performed a sidestep cut 60° to the left, at fast (FAST, 80% of the maximum running speed) and slow (SLOW, 50% of the maximum running speed) speeds. The impulse of the mean anterior-posterior component of the ground reaction force and the peak external flexion moment of the BC knee during the FAST task were significantly larger than those during the SLOW task (0.54±0.27 Ns·kg−1 vs. 0.12±0.27 Ns·kg−1, P<0.05, and 3.16±0.64 Nm·kg−1 vs. 2.69±0.42 Nm·kg−1, P<0.05, respectively). The peak external valgus moment of the knee during the first half of the CL stance was also significantly larger during the FAST task than during the SLOW task (1.85±0.56 Nm·kg−1 vs. 0.95±0.57 Nm·kg−1, P<0.05). The peak external flexion moment of the CL knee joint did not significantly differ between the FAST and SLOW tasks. The external load applied to the knee joint could be decreased by avoiding the combination of an external valgus moment and an internal extension moment of the CL knee. Therefore, BC deceleration during a high-speed sidestep cut is an effective strategy for decreasing the external load on the CL knee joint.