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91.
Abstract

A study was made of the relationship of physique and developmental level, determined by use of the Wetzel Grid, to performance of junior high boys on four fitness tests: pull-ups, 50-yd. dash, standing broad jump, and softball throw. Subjects of different physique groups (heavy, medium, and thin) who were alike developmentally (accelerated, normal, and retarded) differed more markedly in performance than did subjects of different developmental levels who were alike with regard to physique. Subjects who were medium in physique and normal in development were the best performers. Subjects of heavy physique (many overweight) were the poorest performers. This would seem to indicate the need for a restudy of classification methods, particularly when norms are to be used for evaluating performance.  相似文献   
92.
Background:Active videogames or exergames have been used as an innovative way to promote physical activity(PA)among various populations.A player’s interest in active videogames is associated with the fun and entertaining nature of the games and may trigger situational interest,thus increasing engagement.The goal of this study was to examine the impact of situational interest dimensions on college students’PA when playing the design-based bike exergame Greedy Rabbit(Vescape,Berlin,Germany).Methods:Sixty undergraduate students(age:20.8±1.3 years,mean±SD,18-25 years old;51.7%males)were recruited from the kinesiology department of a university located in the southern region of Belgium.The participants were assigned to an experimental group(n=41)or a control group(n=19)based on an incremental cycling test.Students in the experimental group engaged in 1 session of Greedy Rabbit(Vescape)while students in the control group engaged in 1 session of a placebo version of Greedy Rabbit(Vescape).The length of the sessions ranged from 24 min to 31 min.Results:Results for the control group indicated that the players’PA metrics(cadence:F(19,360)=1.43,p=0.11;heart rate:F(19.360)=1.16,p=0.29;oxygen consumption:F(19,360)=0.83,p=0.67)were stable during the exergame.Results for the experimental group demonstrated the effects of time on the players’PA metrics and revealed significant associations between the change in the players’situational interest dimensions and PA metrics(cadence:F(19,800)=26.30,p<0.01;heart rate:F(19,800)=19.77,p<0.01;oxygen consumption:F(19,800)=10.04,p<0.01).Conclusion:An approach using a design-based exergame may be a relevant strategy for promoting levels of PA that yields positive health-related outcomes among college students.  相似文献   
93.
94.
The aim of the present study was to examine the relationship between the performance heart rate during an ultra-endurance triathlon and the heart rate corresponding to several demarcation points measured during laboratory-based progressive cycle ergometry and treadmill running. Less than one month before an ultra-endurance triathlon, 21 well-trained ultra-endurance triathletes (mean +/- s: age 35 +/- 6 years, height 1.77 +/- 0.05 m, mass 74.0 +/- 6.9 kg, = 4.75 +/- 0.42 l x min(-1)) performed progressive exercise tests of cycle ergometry and treadmill running for the determination of peak oxygen uptake (VO2peak), heart rate corresponding to the first and second ventilatory thresholds, as well as the heart rate deflection point. Portable telemetry units recorded heart rate at 60 s increments throughout the ultra-endurance triathlon. Heart rate during the cycle and run phases of the ultra-endurance triathlon (148 +/- 9 and 143 +/- 13 beats x min(-1) respectively) were significantly (P < 0.05) less than the second ventilatory thresholds (160 +/- 13 and 165 +/- 14 beats x min(-1) respectively) and heart rate deflection points (170 +/- 13 and 179 +/- 9 beats x min(-1) respectively). However, mean heart rate during the cycle and run phases of the ultra-endurance triathlon were significantly related to (r = 0.76 and 0.66; P < 0.01), and not significantly different from, the first ventilatory thresholds (146 +/- 12 and 148 +/- 15 beats x min(-1) respectively). Furthermore, the difference between heart rate during the cycle phase of the ultra-endurance triathlon and heart rate at the first ventilatory threshold was related to marathon run time (r = 0.61; P < 0.01) and overall ultra-endurance triathlon time (r = 0.45; P < 0.05). The results suggest that triathletes perform the cycle and run phases of the ultra-endurance triathlon at an exercise intensity near their first ventilatory threshold.  相似文献   
95.
In this study, we examined the effects of a prior run-up on intermittent maximal vertical jump performance. Seven regionally ranked male volleyball players volunteered to participate in the study. They performed three randomized tests: (1) six repeated intermittent maximal jumps (jump condition), (2) six repeated intermittent run-ups (run-up condition), and (3) six repeated run-ups followed by maximal jumps (run-up plus jump condition). All performances were assessed and blood lactate concentration and heart rate were measured before and after each of the tests. Mean ( +/- ) jump performance (64.7 +/- 2.3 cm) increased significantly (P = 0.02) over the course of the jump condition and was significantly higher (P < 0.001) than for the run-up plus jump condition (58.0 +/- 3.2 cm), which tended to decrease with repetition. Blood lactate concentration was significantly higher in the run-up plus jump condition (3.73 +/- 0.24 mmol . l(-1)) than in the jump (2.61 +/- 0.26 mmol . l(-1), P = 0.02) and run-up (2.86 +/- 0.18 mmol . l(-1), P = 0.03) conditions. The increase in heart rate was significantly higher both in the run-up plus jump condition (33 +/- 6 beats . min(-1), P = 0.05) and run-up condition (33 +/- 4 beats . min(-1), P = 0.02) than in the jump condition (21 +/- 3 beats . min(-1)). The results indicate that the addition of run-ups probably impeded performance in the repetition of vertical jumps.  相似文献   
96.
Two mechanisms have been suggested to explain stretching-induced maximum force depression: a mechanical alteration in the stretched muscle and an impairment of neural activation. Electrical stimulation allows standardization of the level of muscle activation without being limited by neural control. The aim of this study was to evaluate the stretching-induced changes in the electrical and mechanical properties of muscle during electrically elicited contractions. Twelve participants (age 22 +/- 1 years; body mass 75 +/- 2 kg; stature 1.79 +/- 0.02 m; mean +/- standard error) underwent six electrical stimulations of the medial gastrocnemius muscle before and after stretching. During the contractions, surface electromyogram (EMG) and mechanomyogram (MMG) were recorded simultaneously together with force. After stretching we found: (i) no differences in EMG parameters; (ii) MMG amplitude decreased by 4 +/- 1% (P < 0.05); and (iii) the peak force, the peak rate of force development, and the acceleration peak of force development decreased by 12 +/- 3%, 14 +/- 1%, and 24 +/- 5%, respectively (P < 0.05). In conclusion, acute passive stretching did not change EMG properties but altered the mechanical characteristics of the contracting muscle. Indeed, muscle force-generating capacity and stiffness of the muscle-tendon unit were significantly impaired.  相似文献   
97.
Since Hugh Montgomery discovered the first of what are now nearly 200 "fitness genes", together with rapid advances in human gene therapy, there is now a real prospect of the use of genes, genetic elements, and/or cells that have the capacity to enhance athletic performance (to paraphrase the World Anti-Doping Agency's definition of gene doping). This overview covers the main areas of interface between genetics and sport, attempts to provide a context against which gene doping may be viewed, and suggests a futuristic legitimate use of genomic (and possibly epigenetic) information in sport.  相似文献   
98.
The influence of anxiety on visual attention in climbing   总被引:2,自引:0,他引:2  
The object of the current study was to investigate anxiety-induced changes in movement and gaze behavior in novices on a climbing wall. Identical traverses were situated at high and low levels on a climbing wall to manipulate anxiety. In line with earlier studies, climbing times and movement times increased under anxiety. These changes were accompanied by similar changes in total and average fixation duration and the number of fixations, which were primarily aimed at the holds used for climbing. In combination with these findings, a decrease in search rate provided evidence for a decrease in processing efficiency as anxiety increased.  相似文献   
99.
Few studies have identified individual differences in vocational knowledge or its association with career aspirations or expectations of children. We investigated whether individual differences in grade, gender, academic achievement, and SES predict levels of vocational knowledge, and further examined the relationship between vocational knowledge and career aspirations and expectations. Children in the fourth through seventh grades (N = 132) from two rural school districts were administered measures of vocational knowledge, expectations, and aspirations. The results of this study suggest no differences in vocational knowledge in groups differing in grade, gender, and SES; however, academic achievement was a significant predictor of vocational knowledge. Moreover, results of regression analysis demonstrated that vocational knowledge adds significantly to the prediction of career aspirations and expectations. These results contribute to the emerging literature exploring mechanisms involved in the career development of rural children.  相似文献   
100.
This article studies the relationship between students’ perceptions of teaching and learning in a multidisciplinary honours programme and their impact on graduate attributes acquisition. The study, conducted among 73 honours students in a Dutch research university, evaluates perceived improvement in graduate attributes through annually collected survey data pertaining to student motivation, perception of the teaching and learning environment, engagement in the programme and registered course marks. The evaluation study reveals that to the extent of the perceived development of graduate attributes, three factors play crucial roles: students’ performance motivation, the amount of teacher support in creative and critical thinking, and students’ inclination to approach the honours track as a learning community.  相似文献   
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