Physiological Effects of Deep Water Running following a Land-Based Training Program

Abstract

The purpose of this study was to examine differences in knowledge representation and problem solutions in expert and novice youth baseball players. Ninety-four players in two age divisions, 7–8 years of age and 9–10 years of age, were assigned to three levels of expertise: high; average; and low skilled. Each subject participated in an interview session to elicit knowledge representation and solutions to five different defensive game situations. Interviews were transcribed and analyzed for content, solution to the problem, errors in problem solution, and qualitative trends. The frequency of advanced solutions to each of the five situations were analyzed in separate chi-square tests for age and expertise. Differences among the levels of expertise were found for the accuracy of solutions to three complex situations. Age was significant for only one situation. Patterns of knowledge content accessed during advanced and less advanced responses indicated both experts and novices were in a beginning stage of developing baseball knowledge structures. Errors in problem solutions indicated children had difficulty monitoring critical conditions and making correct inferences. Players' and teammates' ability to execute baseball skills seemed to influence the content and structure of tactical knowledge accessed during problem solution.     

Selected Physiological Responses of Normal Young Men following Dehydration and Rehydration

Abstract

This study was designed to compare man's normal working physiological performance to that during rapid dehydration and rehydration. Seven trained men participated in submaximal exercise trials at three conditions (normal, dehydrated, and rehydrated). During each test measurements were recorded on the subject's rectal temperature change during exercise and recovery, exercise and recovery minute heart rates, minute volume, oxygen consumption, respiratory quotient, ventilatory efficiency, and oxygen pulse. Analysis of the data, employing analysis of variance and Duncan's Multiple Range Test, indicated significant differences in mean exercise and second minute recovery heart rates, with an elevation during the dehydration test, and a return to normalcy for the rehydration test. Oxygen pulse decreased notably with dehydration, returning to normal with rehydration. Mean rectal temperature change, first minute recovery heart rate, oxygen consumption, ventilatory efficiency, minute volume, and respiratory quotient did not exhibit significant change.     

Attitudes,Beliefs, Behavioral Intentions,and Behaviors of Women and Men toward Regular Jogging

Abstract

Fishbein's Behavioral Intention Model was examined in a study of the beliefs, attitudes, and behavioral intentions of women and men toward regular jogging. Data were collected from 296 female and male joggers and nonexercisers who were 30 years of age and older using a mail questionnaire which was constructed according to Fishbein's specifications. Significant and meaningful differences were found between joggers' and nonexercisers' beliefs. Nonexercisers thought jogging would require too much discipline, take too much time, and make them too tired. Joggers were more likely than nonexercisers to believe that regular jogging would have positive effects, and joggers evaluated being in good physical and mental condition more positively than nonexercisers. Nonexercisers indicated it was unlikely their referents (particularly physicians) thought they should jog regularly. The results supported the theory upon which the model was based: the relationship between the intention to jog and jogging behavior was high (r = .82) and behavioral intention was predicted from an attitudinal and a normative component alone (R = .742). The results of the study suggest that educators can develop behavior change strategies by focusing on change of beliefs and attitudes identifiable through the model.     

Changes in Self-Concepts during a Physical Development Program

Abstract

Three measures of self-concept were administered to children referred to a physical developmental clinic both before and after the six-week clinic program. The 74 children studied were referred primarily because of emotional disturbances, brain damage, and mental retardation. A comparison of preclinic and postclinic scores indicated the following significant changes: (a) decrease in self—self-ideal discrepancy on height, (b) increase in willingness to be with larger groups of children, (c) increase in willingness to be near the clinician, and (d) increase in desire (self-ideal) to be near the father. No significant changes occurred with respect to weight, arm length, leg length, or activity orientation.     

The Validity of the Sit-and-Reach Test and the Modified Sit-and-Reach Test in Middle-Aged to Older Men and Women

Abstract

A growing concern for the establishment of a national system of education was clearly evident in France during the last decades of the eighteenth century. Physical education was afforded an important role in the educational projections of the period. Beginning with La Chalotais' Essai d'éducation nationale (1763) authors began to express more and more support for the inclusion of a comprehensive program of physical education. Gabriel Coyer's De l'éducation publique (1770), Louis Philipon de la Madelaine's Vues patriotiques sur l'education du peuple (1783) and De l'éducation des collèges (1784), and Jean Ver dier's Maison d'éducation physique et morale (1772) and Cours d'éducation à l'usage des eleves (1777) all contributed significantly to the concept that physical education must constitute an important and integral part of any comprehensive and viable plan for national education. Among the most important deliberations of the various French revolutionary assemblies between 1789 and 1795 were those dealing with education as a concern of the state. Legislators tried valiantly to establish a sound national plan for education. The educational reports and projects presented to the various revolutionary assemblies by Talleyrand, Condorcet, Lepelitier, Lakanal, Romme, and Daunou are usually considered by educational historians to be the most significant. Each of these specified that due attention must be devoted to physical education for children and youth. The proposals, the decrees and the debates which they precipitated did much to attract attention to the importance of the subject. It seems most likely that the period from 1763 to 1795 in France witnessed the establishment of a precedent in modem times for the concept of state concern and support for physical education.     

Blood Plasma Cholesterol Changes during a Physical Training Program

Abstract

Blood plasma cholesterol levels were followed in six experimental and six control subjects during a five-week training program (two-mile run for time, five days per week) and an eight-week detraining period. Plasma cholesterol levels were determined by the Duboff-Stevenson ultramicro method.

Plasma cholesterol levels were significantly reduced during the course of intensive training. A temporary rise in plasma cholesterol occurred during exercise, probably indicative of fat mobilization and ultimate utilization during physical exercise. Plasma cholesterol levels returned to pretraining levels within four weeks after training was stopped. The diurnal and weekly blood cholesterol variations were rather small, 2 percent and 2.7 percent, respectively.

The pathways by which exercise assists in the lowering of plasma cholesterol levels are discussed.     

The Impact of Previous Athleticism on Exercise Habits,Physical Fitness,and Coronary Heart Disease Risk Factors in Middle-Aged Men

Abstract

A longitudinal study was performed to determine differences in physiologic variables, health behaviors, risk factors, or clinical status between former athletes (FA) (N = 345) and nonathletes (NA) (N = 75). The subjects, 420 self-referred white males aged 25-60 years old, were examined for prior athleticism and health. Athleticism was determined through self-reported high school or college athletic history. Baseline physiologic and health behavior characteristics were not different between the two groups. Of those study participants (N = 203 FA, 48 NA) who were sedentary at baseline, 208 (N = 167 FA, 41 NA) voluntarily began an exercise program during the followup period (average followup = 56 months). These numbers correspond to exercise adoption rates of 82 and 85 % for FA and NA respectively, and were not statistically different (95% CI FA = 0.76, 0.88, NA = 0.73, 0.97). Repeated measures analysis of covariance was performed to determine if physiologic responses to adoption were different between FA and NA. No statistically significant difference was found between the two groups, time effects were similar in the two, and no significant interaction of time by group was observed. We conclude that prior athleticism has little apparent impact on health and health behaviors, thus suggesting that contemporaneous exercise has more impact on clinical variables.     

Changes in running economy following downhill running

In this study, we examined the time course of changes in running economy following a 30-min downhill (-15%) run at 70% peak aerobic power (VO2peak). Ten young men performed level running at 65, 75, and 85% VO2peak (5 min for each intensity) before, immediately after, and 1 - 5 days after the downhill run, at which times oxygen consumption (VO2), minute ventilation, the respiratory exchange ratio (RER), heart rate, ratings of perceived exertion (RPE), and blood lactate concentration were measured. Stride length, stride frequency, and range of motion of the ankle, knee, and hip joints during the level runs were analysed using high-speed (120-Hz) video images. Downhill running induced reductions (7 - 21%, P < 0.05) in maximal isometric strength of the knee extensors, three- to six-fold increases in plasma creatine kinase activity and myoglobin concentration, and muscle soreness for 4 days after the downhill run. Oxygen consumption increased (4 - 7%, P < 0.05) immediately to 3 days after downhill running. There were also increases (P < 0.05) in heart rate, minute ventilation, RER, RPE, blood lactate concentration, and stride frequency, as well as reductions in stride length and range of motion of the ankle and knee. The results suggest that changes in running form and compromised muscle function due to muscle damage contribute to the reduction in running economy for 3 days after downhill running.     

Physiological Alterations in 7- to 9-Year-Old Boys following a Season of Competitive Wrestling

Abstract

Muscular and aerobic capacity changes resulting from three months of wrestling training were examined in a group of normally active 7- to 9-year-old boys (N = 23) who competed in an intramural league tournament. A nontraining group of twenty-two boys of similar age, height, and weight served as control subjects, and were studied during the same period of time. The subjects were measured for body dimensions and skinfolds, and were given measures of back lift, leg press, and arm endurance (dips and chins). They were also measured for [Vdot]E max, [Vdot]O ₂ max, and HR max employing a progressive treadmill protocol. Results of ANCOVA analyses indicated that (1) the mean improvements in [Vdot]E max (2.93 1·min ^?1 ) and in [Vdot]O ₂ max (+ 6.6 ml·kg ^?1 ·min ^?1 ) were not significantly greater than control (p > .05), nor was HR max; (2) arm endurance improved significantly over control (p < .05), as did the leg press, but the back lift was not improved significantly (p > .05); (3) no significant change occurred in height, weight, or in some of skinfolds (p > .05), but the wrestlers were less endomorphic and more ectomorphic than their control counterparts, and were judged essentially equivalent in mesomorphy. It is concluded that wrestling training in young boys improves strength, but does not improve aerobic capacity more than one would expect to see in normal children of similar age and size.     

运动性与病理性心肌肥大左室肌球蛋白α和β重链变化比较

对大鼠运动心肌肥大和病理心肌肥大模型心室肌球蛋白α和β重链的变化进行比较研究,结果发现大鼠经10周游泳训练后引起心肌肥大,心室肌球蛋白α重链百分比和肌原纤维ATPase活性升高,β重链百分比降低(p<0.05)。与此变化相反,自发性高血压大鼠和由异丙肾上腺素诱导的心肌肥大大鼠心室肌球蛋α重链百分比和肌纤维ATPase活性降低,β重链百分比升高(P<0.05)。说明运动心脏的重塑过程不同于病理性心脏,前者重塑后使心肌收缩性提高,后者重塑后心脏功能降低。     

Relative Endurance and Physiological Responses: A Study of Individual Differences in Prepubescent Boys and Adult Men

Abstract

The reliability of individual differences in relative endurance performance and physiological response was studied in prepubescent boys (N = 21) and adult men (N = 21). Subjects were tested twice (test and retest) on a relative endurance test consisting of pedalling a bicycle ergometer for 8 minutes duration at a high initial work-rate. The work-rate averaged 103% ± 1.0% VO₂ max (mean ± S.E.) for the children and 105% ± 1.1% VO₂ max for the adults, p > .05. Except for minute 3, children and adults had similar patterns for consistency of relative endurance performance (RPM). However, in comparison to adults, children had smaller individual difference variation for both VO₂ and HR (p > .05). On the average, children had a greater proportion of total variability in VO₂ (34% vs. 17%) and HR (49% vs. 13%) due to intra-individual variability in comparison to true individual differences. Children-adult differences were attributed to maturity differences.     

肥胖对男青年在中等强度有氧运动中生理代谢反应的影响

对无系统运动训练史的健康青年男性(肥胖组8人,对照组9人)进行65%VO2max负荷强度的功率自行车有氧运动,监测运动过程中受试者心率、血压、RPE及RQ等生理指标和血糖、血清TG、FFA及GH等生化指标的变化,分析有氧运动过程中肥胖者与常人是否存在生理代谢上的差异.研究发现,肥胖组安静时和运动中的心率和血压水平显著高于对照组,易出现运动疲劳;运动中RQ和血糖浓度显著高于对照组,而血清TG和FFA浓度增长幅度低于对照组;GH对运动的反应较为迟钝.结果提示肥胖者体能下降,脂肪氧化供能能力降低.     

Changes in jump performance and muscle activity following soccer-specific exercise

The jump performance of ten youth soccer players (mean age 15.8 years, s= 0.4) was assessed before and after 42 min of soccer-specific exercise performed on a non-motorized treadmill. A squat, countermovement, and drop jump were performed on a force platform and simultaneously surface EMG activity of four lower limb muscles was collected. Jump height deteriorated across all conditions with mean reductions of - 1.4 cm (s = 1.6; P < 0.05), - 3.0 cm (s = 2.9; P < 0.05), and -2.3 cm (s = 1.7; P < 0.01) in the squat, countermovement, and drop jump respectively. The impact force in the drop jump was the only force variable to show a significant change with fatigue (P < 0.05). Following the prolonged exercise, reductions in total muscle activity were non-significant for the squat jump, approached significance for the counter-ovement jump (P = 0.07), and achieved significance for the drop jump (P < 0.05). The results showed that completing soccer-specific exercise reduced performance in all jump tasks. Reductions in muscle activity were greatest for the drop jump, suggesting an influence of muscle stretch and loading on reduced muscle activity when fatigued.     

Changes in respiratory muscle and lung function following marathon running in man

Respiratory muscle fatigue has been reported following short bouts of high-intensity exercise, and prolonged, moderate-intensity exercise, as evidenced by decrements in inspiratory and expiratory mouth pressures. However, links to functionally relevant outcomes such as breathing effort have been lacking. The present study examined dyspnoea and leg fatigue during a treadmill marathon in nine experienced runners. Maximal inspiratory and expiratory pressure, peak inspiratory and expiratory flow, forced vital capacity, and forced expiratory volume in one second were assessed before, immediately after, and four and 24 hours after a marathon. During the run, leg effort was rated higher than respiratory effort from 18 through 42 km (P < 0.05). Immediately after the marathon, there were significant decreases in maximal inspiratory pressure and peak inspiratory flow (from 118 +/- 20 cm H(2)O and 6.3 +/- 1.4 litres x s(-1) to 100 +/- 22 cm H(2)O and 4.9 +/- 1.5 litres x s(-1) respectively; P < 0.01), while expiratory function remained unchanged. Leg maximum voluntary contraction force was significantly lower post-marathon. Breathing effort correlated significantly with leg fatigue (r = 0.69), but not inspiratory muscle fatigue. Our results confirm that prolonged moderate-intensity exercise induces inspiratory muscle fatigue. Furthermore, they suggest that the relative intensity of inspiratory muscle work during exercise makes some contribution to leg fatigue.     

Changes in respiratory muscle and lung function following marathon running in man

Abstract

Respiratory muscle fatigue has been reported following short bouts of high-intensity exercise, and prolonged, moderate-intensity exercise, as evidenced by decrements in inspiratory and expiratory mouth pressures. However, links to functionally relevant outcomes such as breathing effort have been lacking. The present study examined dyspnoea and leg fatigue during a treadmill marathon in nine experienced runners. Maximal inspiratory and expiratory pressure, peak inspiratory and expiratory flow, forced vital capacity, and forced expiratory volume in one second were assessed before, immediately after, and four and 24 hours after a marathon. During the run, leg effort was rated higher than respiratory effort from 18 through 42 km (P < 0.05). Immediately after the marathon, there were significant decreases in maximal inspiratory pressure and peak inspiratory flow (from 118 ± 20 cm H₂O and 6.3 ± 1.4 litres · s^?1 to 100 ± 22 cm H₂O and 4.9 ± 1.5 litres · s^?1 respectively; P < 0.01), while expiratory function remained unchanged. Leg maximum voluntary contraction force was significantly lower post-marathon. Breathing effort correlated significantly with leg fatigue (r = 0.69), but not inspiratory muscle fatigue. Our results confirm that prolonged moderate-intensity exercise induces inspiratory muscle fatigue. Furthermore, they suggest that the relative intensity of inspiratory muscle work during exercise makes some contribution to leg fatigue.     

Changes in selected cardiorespiratory responses to exercise and in body composition following a 12-week aerobic dance programme

Cardiorespiratory and body composition changes were evaluated in 25 sedentary females, aged 18 to 30 years, following 12 weeks of aerobic dance training (3 days a week, 45 min a session). Fifteen subjects, from the same population, comprised a control group: they maintained their normal activity and dietary habits over the course of the study. Analysis of variance of the values for selected cardiorespiratory responses revealed that the aerobic dance programme produced training effects in the experimental group. These training effects were indicated by significant improvements in O2 pulse, VE, heart rate and perceived exertion during submaximal exercise. Significant improvements were also noted in VO2 max, maximal O2 pulse, VE max, maximal heart rate and maximal running time on the treadmill. Additionally, increases in lean body mass and body density, together with decreases in percentage body fat and the sum of four skinfold thicknesses were found to be significant for the experimental group. No significant improvements in any of these variables were found for the control group. It was concluded that this 12-week aerobic dance programme was successful in promoting beneficial changes in cardiorespiratory fitness and body composition.     

山东省城市中年人群体育健康状况调查分析

运用献资料、问卷调查、专家访谈和数理统计方法，对山东省八城市三类主要人员中的35-55岁的579名（男332，女247人）中年人群参加体育健身运动状况、中年人的常见疾病和体育的作用于中年人身体健康方面的效果，从社会学的角度进行了前瞻性思考。城市中年人通过体育促进身体健康的认识端正，但角色冲突严重制约中年人的体育健身行为，精神障碍和身体肥胖是影响城市中年健康的主要症结，适宜的运动强度有益于提高中年人的身体健康水平。     

优秀男子铁饼运动员掷铁饼最后用力阶段非投掷臂速度变化的运动学分析

运用文献资料法、数理统计法等,对优秀男子铁饼运动员的数据进行分析。结果显示：优秀男子铁饼运动员掷铁饼最后用力阶段非投掷臂制动时机开始应在左脚着地后0.03 s左右或非投掷臂处于方位角180&#176;到220&#176;范围内。优秀男子铁饼运动员非投掷臂转动速度与左肩和右肩转动速度具有高度的相关性,通过相关分析发现非投掷臂与左肩转动速度保持一致,二者基本处于相对静止。部分优秀男子铁饼运动员的非投掷臂摆动方式存在着随着身体转动的一种被动式摆动的错误动作,非投掷臂的摆动是一种主动式的摆动。     

激流回旋运动员不同负荷训练后生理心理指标的比较研究

激流回旋属奥运会项目,如何用生理、心理指标对其进行监测,尚属空白.本文多次测试了激流回旋运动员安静和不同训练量、负荷强度后6项生理、心理指标,找出了具有实用价值且能客观反映激流回旋运动员疲劳状况的指标.主要结论为随训练强度增加,训练后心率增加,主观感觉级别增加,尿异常率增加,而手动稳定性下降;尿八项中敏感的指标是尿潜血和尿蛋白;反应时和临界闪烁融合频率变化不明显.     

Changes in running endurance performance following intermittent altitude exposure simulated with tents

Abstract

The effect of intermittent hypoxia on sea-level endurance performance was assessed by using hypoxic tents to simulate the live high-train low approach to altitude training. Eleven male sub-elite competitive runners and triathletes participated in a crossover study of usual training (control) and usual training with altitude exposure (altitude). Altitude treatment consisted of 25±3?d (mean±SD) of sleeping in tents for 8.1±0.6?h.d^?1, progressing from a simulated altitude of 2500?m to 3500?m above sea level. Washout period between control and altitude treatments was 4?wk. Three treadmill runs to exhaustion lasting ～2, ～4 and ～8?min were completed 7 and 12?d after control and altitude treatments. Times for standard competition distances (800, 1500 and 3000?m), were predicted using a log-log model, improved by 1.0% (90% confidence limits, ±1.3%), 1.4% (±1.2%) and 1.9% (±1.5%), respectively. Improvements were greater in the six athletes with an I allele for angiotensin converting enzyme (ACE): 2.3% (±1.5%), 2.2% (±1.5%), and 2.1%, (±2.1%), respectively. Effects of simulated altitude on hemoglobin concentration were unclear. Altitude exposure simulated with hypoxic tents is likely to enhance performance substantially in middle-distance endurance running events, especially for individuals with an I allele of the ACE gene.