Alterations in Strength and Maximal Oxygen Uptake Consequent to Nautilus Circuit Weight Training

Abstract

The purpose of this study was to determine the effects of a Nautilus circuit weight training program on muscular strength and maximal oxygen uptake ([Vdot]O ₂ max) by comparing these effects to those produced by adhering to either a free weight (FW) strength training program or a running (R) program. Male college students who voluntarily enrolled in either a FW training class (n = 11), a Nautilus (N) circuit weight training class (n= 12), or a R conditioning class (n= 13) were subjects for this investigation. All groups participated in their respective programs 3 days per week for 10 weeks. Strength was assessed using a Cybex II isokinetic dynamometer set at an angular velocity of 60° · s ^?1 and a damping of 2. The FW group served as the control group for the assessment of [Vdot]O ₂ max changes, while the R group served as controls for the assessment of strength differences. ANCOVA revealed that the N and R groups experienced significant (p < .01) increases in [Vdot]O ₂ max expressed in L · min ^?1 (10.9 and 11.4%), ml · kg ^?1 · min ^?1 (10.8 and 11.7%), and ml · kgLBW ^?1 · min ^?1 (7.1 and 7.5%) when compared to the FW group. There were no significant differences between the N and R groups. There were no significant differences among groups in final peak torque values (after covariance), and torque at the beginning and end of the range of motion for the knee extensors, knee flexors, elbow extensors, and elbow flexors. In general, isokinetic strength values elicited by the N group compared favorably to those generated by the FW group. It was concluded that for a training period of short duration, Nautilus circuit weight training appears to be an equally effective alternative to standard free weight (strength) and aerobic (endurance) training programs for untrained individuals.     

Validity of Palpation Recovery Pulse Rate to Estimate Exercise Heart Rate Following Four Intensities of Bench Step Exercise

Abstract

Previous investigations regarding activity during the post-knowledge of results (KR) interval have considered the performance of interference groups over KR-supplied acquisition trials as indicative of effects upon learning. The absence of transfer tests in these studies, however, preclude such an assumption. Indeed, the use of a retention test in the present investigation (no-KR trials following an interpolated phase) provided evidence suggesting that, while activity during the post-KR interval is detrimental to performance, no such assumption can be made regarding this effect upon learning. These findings are discussed relative to recent arguments that some of the commonly accepted “Laws of KR” may be contradictory when applied simultaneously to motor learning and performance.     

Physical Performance Tests in Job Selection a Model for Empirical Validation

Abstract

The aim of this study was to establish the net energy cost of dribbling a soccer ball. Eight male footballers ran for 5 min on a treadmill at speeds of 9, 10.5, 12 and 13.5km ·h ^–1 while dribbling a football against a rebound box; running at each of these speeds without the ball constituted controls. Oxygen uptake ([Vdot]O ₂ ), perceived exertion (RPE) and blood lactate levels were measured and compared between the two conditions. The energy expended increased linearly with speed for both exercise modes, the mean increment of 1.24 kcal·min ^–1 caused by dribbling being independent of the speed of motion. Individual differences in efficiency of dribbling could not be explained by considering different patterns of stride characteristics. Similarly, RPE showed a constant elevation for dribbling over running at each speed, and a linear increase with speed of motion for both modes. Blood lactate increased disproportionately with speed for dribbling, onset of metabolic acidosis being attained at a lower speed for the experimental task. It was concluded that dribbling a ball does significantly increase the energy cost and perceived exertion of motion, as well as inducing disproportionate rises in blood lactate when performed at high speeds.     

Specificity of a Maximal Step Exercise Test

To adhere to the principle of “exercise specificity” exercise testing should be completed using the same physical activity that is performed during exercise training. The present study was designed to assess whether aerobic step exercisers have a greater maximal oxygen consumption (max VO₂) when tested using an activity specific, maximal step exercise test (SET; arms and legs) versus a maximal running test (legs only). Female aerobic step exercisers (N=18; 20.7 ± 1.5 years) performed three maximal graded exercise tests (GXTs): 2 SETs; 1 treadmill test (TMT). The SET consisted of six 3-min progressive stages of alternate lead, basic step, basic step with biceps curls, knee raise with pull-down, repeater knee with pull-down, lateral lunge with pull-down, and side squat with shoulder presses. Stepping rate was 32 steps· min^?1 on an 8-in (20.32 cm) step for stages 1–3, and a 10-in (25.4 cm) step for stages 4–6. Submaximal and maximal heart rate (HR) and oxygen consumption (VO₂) were recorded at the end of each stage. Test–retest reliability for the first five stages of the SET ranged from .91 to .97 for HR, and from .84 to .96 for VO₂. Maximal HR was significantly greater (p =.0001) for the SET (200 ± 6.2 beats·min^?1) as compared to the TMT (193 ± 7.9 beats·min^?1). No significant difference was found for max VO₂ (42.9 ± 8.5, 41.2 ± 5.9 ml·kg^?1·min^?1, p =.14). The SET was a valid and reliable protocol for assessing responses of these aerobic step exercisers; however, max VO₂ from a TMT did not differ significantly from the SET. Conversely, max HR obtained from the criterion TMT was 7 beats·min^?1 lower than from the SET. If a training HR for step exercise (arms and legs exercise) is prescribed based on the max HR from treadmill exercise (legs only), then the training HR should be calculated from a TMT max HR that has been increased by 7 beats·min^?1 to obtain an intensity of step exercise comparable to that of running.     

雾湿天气条件对运动能力影响的研究

为了解雾湿天气对机件各种功能活动的影响，本文在晴朗和雾湿二种天气条件下，对机体最大吸氧量以及完成相同递增负荷直至最大工作能力时机体的体力状况进行研究。结果发现，雾湿天气使最大摄氧量和握力显著下降；进行轻量负荷后，心率和RPE与晴朗天气无异，但进行亚极量以上强度运动后，心率和RPE显著增大；在最大负荷工作时，雾显天气使运动至力竭时间显著缩短，而最大心率和最高血乳酸均显著增大。因此认为，雾湿天气对运动能力有不良的影响，并提示在雾温天气下进行体育教学和训练时要适当降低运动负荷。     

人体有氧能力的研究

本文概述了国内外有关儿童少年最大吸氧量的自然增长规律及其性别差异；并着重阐述了人体有氧能力与耐力运动项目成绩的关系。并根据研究数据和国内外学者的同类研究的数据，进行非线性回归模型的最小二乘拟合，建立了予测13～岁男性最大摄氧量的公式。本文还首次提出了最大摄氧量平台（VO2maxPD）的概念，进而深入的讨论了VO2max、VO2maxPD和VO2AT三者的关系。     

负载获取最大功率分析及计算

分析了不同电路中负载获取最大功率的条件 ,给出了线性二端网络负载获取最大功率的计算方法及实例。     

汉族、土家族男大学生最大有氧能力的比较研究

中国汉族和土家族男大学生的生长发育和心肺功能水平。以PWC_(170)值推算VO_(2max)发现,汉族男大学生身高、体重均显著高于同年龄段的土家族男大学生(P<0.01),但体脂%和去脂体重无显著差异(P>0.05);PWC_(170)值两民族间有显著性差异(P<0.05),PWC_(170)推算VO_(2max),绝对值汉族男大学生显著高于土家族男大学生(P<0.01),但相对值两民族间不存在显著性差异(P>0.05)。     

福建大豆主栽品种的组织培养研究

利用福建大豆主栽品种的子叶节为外植体,进行组织培养再生研究,探讨不同品种、不同激素和除草剂不同浓度的诱导效果。结果表明不同大豆品种诱导分化能力差别较大,供试品种中“莆豆8008”的诱导能力较强,丛生芽诱导率和平均丛生芽数分别为94.2%和2.69。不同激素种类和浓度对大豆子叶节丛生芽诱导,表明6-BA较适合于丛生芽的诱导,适宜浓度为1.67mg/L。大豆子叶节不定芽分化和伸长的除草剂Glufosinate梯度实验表明除草剂Glufosinate5mg/L可作为不定芽分化和伸长的选择压力,生根培养基上不宜加除草剂Glufosinate。     

最大摄氧量间接测定方法PWC170法与两步台阶实验法比较研究

采用文献资料法、对比法和数据统计法,对最大摄氧量及其间接测定方法进行了研究分析,初步总结出最大摄氧量受遗传、性别、年龄、环境、营养饮食状况、生活习惯和训练等因素的影响.运动时对心肺功能的测定是科学训练的一个重要方面.而评价心肺功能的最佳指标是最大摄氧量,最大摄氧量是反映有氧工作能力的有效指标之一.通过对最大摄氧量间接测定方法PWC170法与两步台阶实验法比较研究,有利于从测试的精确度、测试的简易性、测试的效率、测试费用及训练评价效果方面提供更好的理论依据.