Physiological and biomechanical responses to walking underwater on a non-motorised treadmill: effects of different exercise intensities and depths in middle-aged healthy women     

Piero Benelli  Franca Colasanti  Massimiliano Ditroilo  Antonio Cuesta-Vargas  Giorgio Gatta  Francesco Giacomini 《Journal of sports sciences》2013,31(3):268-277

Abstract

Non-motorised underwater treadmills are commonly used in fitness activities. However, no studies have examined physiological and biomechanical responses of walking on non-motorised treadmills at different intensities and depths. Fifteen middle-aged healthy women underwent two underwater walking tests at two different depths, immersed either up to the xiphoid process (deep water) or the iliac crest (shallow water), at 100, 110, 120, 130 step-per-minute (spm). Oxygen consumption (VO₂), heart rate (HR), blood lactate concentration, perceived exertion and step length were determined. Compared to deep water, walking in shallow water exhibited, at all intensities, significantly higher VO₂ (+13.5%, on average) and HR (+8.1%, on average) responses. Water depth did not influence lactate concentration, whereas perceived exertion was higher in shallow compared to deep water, solely at 120 (+40%) and 130 (+39.4%) spm. Average step length was reduced as the intensity increased (from 100 to 130 spm), irrespective of water depth. Expressed as a percentage of maximum, average VO₂ and HR were: 64–76% of peak VO₂ and 71–90% of maximum HR, respectively at both water depths. Accordingly, this form of exercise can be included in the “vigorous” range of exercise intensity, at any of the step frequencies used in this study.  相似文献   

Matching of Male and Female Subjects Using VO2 max     

Kirk J. Cureton 《Research quarterly for exercise and sport》2013,84(2):264-268

Abstract

We compared cardiorespiratory responses to exercise on an underwater treadmill (UTM) and land treadmill (LTM) and derived an equation to estimate oxygen consumption (VO₂) during UTM exercise. Fifty-five men and women completed one LTM and five UTM exercise sessions on separate days. The UTM sessions consisted of chest-deep immersion, with 0, 25, 50, 75, and 100% water-jet resistance. All session treadmill velocities increased every 3 min from 53.6 to 187.8 m·min^-1. Cardiorespiratory responses were similar between LTM and UTM when jet resistance for UTM was ≥ 50%. Using multiple regression analysis, weight-relative VO₂ could be estimated as: VO₂ (mLO₂·kg^-1·min^-1) = 0.19248 · height (cm) + 0.17422 · jet resistance (% max) + 0.14092 · velocity (m·min^-1) - 0.12794 · weight (kg) - 27.82849, R²= .82. Our data indicate that similar LTM and UTM cardiorespiratory responses are achievable, and we provide a reasonable estimate of UTM VO₂.  相似文献   

The Effect of Adding External Weight on the Aerobic Requirement of Bench Stepping     

Philip R. Stanforth  Dixie Stanforth 《Research quarterly for exercise and sport》2013,84(4):469-472

Purpose

As there is little research that investigates the experiences of minority boys participating in youth development programs (Fashola, 2003), the current research focused on a sport-based youth development program for early adolescent Black and Latino boys in Hartford, CT. Specifically, the present study explored (a) what attracted minority boys to participate in youth development programs, (b) what kept them involved, and (c) whether their involvement translated into positive developmental outcomes.

Method

The study used semistructured individual interviews to collect data from 8 participants and their parents. The research team deductively coded interviews in accordance with the a-priori framework of the Five Cs and Sixth C of youth development (i.e., competence, character, caring, confidence, connection, and contribution; Roth &; Brooks-Gunn, 2003). In addition, interviews were deductively coded to investigate why participants became involved in the program and why they continued participation.

Results

Findings from the study indicated that participants became involved with the Sport Hartford Boys (SHB) program mainly due to its emphasis on sport-related activities. Moreover, findings related to the youths' continued involvement revealed their value for the SHB program as a safe place that kept them out of trouble and provided experiences that led to positive personal development. Furthermore, results indicated that participation in the program facilitated the development of each “C” of youth development.

Conclusion

By promoting positive relationships and providing opportunities for self-exploration in a safe and trusting environment, afterschool programs can cultivate positive youth development in minority boys, at least in the short term.  相似文献   

Physiological Responses to Maximal Treadmill and Handweighted Exercise     

David Shaun Bryant  Fredric L. Goss PhD  Robert J. Robertson  Kenneth F. Metz  David S. Feingold 《Research quarterly for exercise and sport》2013,84(3):300-304

Abstract

The purpose of this investigation was to compare the peak physiological responses among four protocols that employed different amounts of handweighted exercise in 16 males (aged 26.3 ± 4.1 years). The four protocols were (a) uphill treadmill running (UR; 3.36 m-s¹, 2.5% grade increase-3 min¹); (b) uphill treadmill walking while pumping 1.36kg handweights (HW) (UWHW; 1.79ms¹, 5.0% grade increase-3 min¹; (c) treadmill walking while pumping .91-kg HW (WHW; 1.79 m-s¹, 0% grade, .91kg HW increase-3 min¹); and (d) standing in place and pumping HW (SHW; arm work as described in WHW). It was hypothesized that the peak responses would be inversely proportional to the estimated muscle mass activated (i.e., UR = UWHW > WHW > SHW). Dependent variables included peak oxygen uptake (VO₂ peak), peak heart rate (HRpeak), peak ventilation (V_epeak), and peak respiratory exchange ratio (RERpeak). No differences were noted between UR and UWHW with respect to any of the dependent variables. All variables (except RERpeak) were greater (p < .01) in UR and UWHW than either WHW or SHW. RERpeak was greater (p < .01) in UR and UWHW than in WHW. VO₂peak and HRpeak were greater (p < .01) in WHW when compared to SHW. Mean VO₂peak was 97.5, 69.7, and 60% of UR for UWHW, WHW, and SHW, respectively. Therefore, walking and pumping handweights provides a maximal stimulus to the oxygen transport system.  相似文献   

The Hit & Turn Tennis Test: An acoustically controlled endurance test for tennis players     

Alexander Ferrauti  Vanessa Kinner  Jaime Fernandez-Fernandez 《Journal of sports sciences》2013,31(5):485-494

Abstract

This study was conducted to validate and evaluate the “Hit & Turn Tennis Test”, an acoustically progressive on-court endurance test for tennis players. Ninety-eight competitive tennis players (53 males, 45 females) of different age groups participated in the study. For validation, the adult male players completed three Hit & Turn tests, one on a clay court and two on a carpet surface, a tennis-specific ball machine test and an incremental treadmill run in a randomized order. A stronger correlation between maximal performance (r = 0.81, P < 0.01) and maximal oxygen uptake (r = 0.96, P < 0.01) was observed between the Hit & Turn test and the ball machine test, than between the Hit & Turn test and the treadmill test. For test–retest, we found a significant correlation between maximal performance on the same (r = 0.83, P < 0.01) and on different surfaces (r = 0.74, P < 0.01). During test evaluation, maximal performance was higher in males than in females (P < 0.01) and increased by consecutive age group in boys (P < 0.01) but not in girls (P = 0.97). In conclusion, Hit & Turn maximum test performance can be recommended as a valid and reliable indicator for tennis-specific endurance.  相似文献   

Enhanced expectancies improve movement efficiency in runners     

Isabelle Stoate  Rebecca Lewthwaite 《Journal of sports sciences》2013,31(8):815-823

Abstract

We followed up on recent findings demonstrating that enhancing performers' expectancies can improve their performance. Specifically, we examined whether providing experienced runners with positive feedback regarding their movement efficiency would increase running efficiency. Two groups of experienced runners ran on a treadmill at 75% of their maximum oxygen consumption ([Vdot]O_2max) for 10 min. One group (enhanced expectancy) was provided with (fabricated) feedback about the efficiency of their running style every 2 min. A control group was not given feedback. Oxygen consumption decreased in the enhanced expectancy group across measurement times (every 2 min for 10 min), but remained the same in the control group. In addition, performance perceptions changed only in the enhanced expectancy group, indicating a perception of greater ease of running and reduced fatigue when assessed after compared with before running. Finally, positive affect increased from a pre- to a post-test in the enhanced expectancy group, in contrast to the control group. Our findings show that enhanced expectancies can have a positive effect on movement efficiency and running experience. They add to the accumulating evidence for the social-cognitive-affective-motor nature of motor performance.  相似文献   

Muscularity,Heavy Athletics and Urban Leisure in Ethiopia, 1950s–1970s     

Katrin Bromber 《国际体育史杂志》2013,30(16):1915-1928

This article focuses on the development of heavy athletics in urban Ethiopia during Haile Selassie's reign. In an attempt to modernise the country, educational institutions and missionary movements such as the Young Men's Christian Association were used to create healthy citizen bodies. By focusing on weightlifting, bodybuilding and wrestling, the article shows different trajectories of institutionalisation due to specific ideas about modernity and global sports. As a way of showcasing self-improvement, and by lucrative bodybuilding performances, urban leisure arguably paved the way in Ethiopia for the muscular male body as an ‘acceptable' aesthetic form.  相似文献   

The Changing Role of Sports in Urban Development: A Case Study of Debrecen (Hungary)     

Gábor Kozma  Károly Teperics  Zsolt Radics 《国际体育史杂志》2013,30(9):1118-1132

In the last few decades, researchers are paying more and more attention to study the connections between sports and urban development. The main purpose of this study is to examine the changing role of sports in urban development through the example of Debrecen and to present the differences between the various historical periods. As a result, it can be concluded that on the one hand, in the inter-war years and in the period after 2000, the broader influence of sports was recognised, and local government made special efforts to use sports for the development of local economy, as well as for the improvement of the image of the city. By contrast, in the period between 1945 and 1990, the main approach used was from the side of mass sports, with satisfying the needs of workers and the general population deemed as the most important. On the other hand, from the early 1930s, i.e. from the beginning of urban planning (with the exception of the period during World War II and the 1950s), the leaders of the city paid special attention to ensure that sports facilities be included in the local development plans of Debrecen.  相似文献   

不同强度自行车运动对普通男大学生锻炼者能量消耗的影响研究     

王世涛 《体育科技》2013,(5):60-61,66

目的：探讨不同强度自行车运动对普通男大学生锻炼者能量消耗的影响.方法：利用CORTEX3B便携式心肺功能仪依次测出32名男大学生在4级不同负荷阶段的能量消耗相关指标,并加以统计分析.结论：从能量消耗角度看,18km/-77r/min负荷强度下的能量消耗最为平均,从长时间自行车运动供能角度来说对男大学生健身有积极作用.  相似文献   

休闲体育消费的若干理论问题     

陈华 《湖北体育科技》2013,32(3):189-191,220

采用文献资料、逻辑推理等研究方法,以休闲消费和精神消费理论为基础,对休闲体育消费的内涵、分类、特征、性质、功能、影响因素和发展策略进行初步的探讨。  相似文献