Medicine and science in sports最新文献_第7页

Control of sweating rate while exercising in the heat. 控制在高温下运动时的排汗率。

Medicine and science in sports Pub Date : 1979-01-01

E R Nadel

引用次数: 0

Metabolic effects of anabolic steroid on skeletal muscle. 合成代谢类固醇对骨骼肌代谢的影响。

Medicine and science in sports Pub Date : 1979-01-01

V Rogozkin

引用次数: 0

Low exercise ventilation in endurance athletes. 耐力运动员的低运动通气。

Medicine and science in sports Pub Date : 1979-01-01

B J Martin, K E Sparks, C W Zwillich, J V Weil

{"title":"Low exercise ventilation in endurance athletes.","authors":"B J Martin, K E Sparks, C W Zwillich, J V Weil","doi":"","DOIUrl":"","url":null,"abstract":"Previous studies have shown that endurance athletes are endowed with low ventilatory responses to chemical stimuli. The implications of this association have never been clear. Although recent evidence shows that exercise ventilation (VE) correlates with ventilatory chemoresponsiveness in a group of athletes, the extent to which non-athletes may differ from athletes in this regard is unknown. We have examined the relationship between ventilatory chemoresponsiveness and exercise VE in a group of 7 non-athletes, and contrasted these findings with those obtained previously from 8 endurance and 8 non-endurance athletes. Correlation lines of exercise VE with chemical responses were similar in slope and intercept for both athletes and non-athletes. However, we found that non-athletes had greater exercise VE per unit metabolic rate (VO2 or VCO2), and greater ventilatory responses to O2 and CO2, when compared with endurance athletes at equal relative work loads (P less than 0.05). The lower exercise VE/VCO2 of endurance athletes as compared with non-athletes persisted in hyperoxia, indicating that factors other than differences in hypoxic sensitivity explain the lower exercise VE of endurance athletes. Low exercise VE may be the link between low ventilatory chemosensitivity and outstanding endurance athletic performance.","PeriodicalId":18528,"journal":{"name":"Medicine and science in sports","volume":"11 2","pages":"181-5"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11696965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Neural and humoral signals for pulmonary ventilation arising in exercising muscle. 运动肌肉产生的肺通气的神经和体液信号。

Medicine and science in sports Pub Date : 1979-01-01

M Mahler

{"title":"Neural and humoral signals for pulmonary ventilation arising in exercising muscle.","authors":"M Mahler","doi":"","DOIUrl":"","url":null,"abstract":"This review analyzes attempts to isolate and quantify the neurally and humorally mediated portions of the ventilatory response to moderate exercise. 1. Dejours' \"neuro-humoral theory\" postulates that, following a change from rest to moderate, constant-load exercise in man, the abrupt initial increase in VE is neurally mediated, and the subsequent gradual rise in VE is humorally mediated. However, no compelling evidence exists to support either of these hypotheses. Moreover, there is a plausible alternative method of partitioning VE into fast and slow components: the steady-state value of VE may be entirely due to the slow component. 2. The similarity between the kinetics of VE and VCO2 during exercise suggests that the ventilatory response may be primarily triggered by a signal that has its origin in the CO2 flux to the lung. Intravenous CO2 loading in resting animals produces such a flux, unaccompanied by possible neural signals arising from contracting muscles. However, experiments of this type have produced drastically conflicting results. 3. With cross-circulation techniques, the ventilatory response to neural signals from exercising limbs can be isolated, by sending the blood leaving these limbs directly into the venous system of another animal. Experiments of this type with anesthetized dogs led Kao and co-workers to conclude that the increase in VE during steady-state exercise is entirely due to neural signals originating in the exercising limbs. 4. In skeletal muscle, the kinetics of VO2 closely follow those of the concentrations of creatine phosphate and free creatine: a sensor of either of these concentrations could thus theoretically serve as a useful \"metaboreceptor\". The extracellular concentration of K+ in contracting muscles also changes rapidly enough to lead cardio-ventilatory adjustments, and thus might possibly trigger a neural signal involved in their control.","PeriodicalId":18528,"journal":{"name":"Medicine and science in sports","volume":"11 2","pages":"191-7"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11696968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Medicine and science in sports Pub Date : 1979-01-01

G M Andrew, J O Parker

引用次数: 0

Age at menarche, family size, and birth order in athletes at the Montreal Olympic Games, 1976. 1976年蒙特利尔奥运会上运动员的初潮年龄、家庭规模和出生顺序。

Medicine and science in sports Pub Date : 1979-01-01

R M Malina, C Bouchard, R F Shoup, A Demirjian, G Lariviere

引用次数: 0

Age at menarche, family size, and birth order in athletes at the Montreal Olympic Games, 1976. 1976年蒙特利尔奥运会上运动员的初潮年龄、家庭规模和出生顺序。

Medicine and science in sports Pub Date : 1979-01-01 DOI: 10.1249/00005768-197901140-00009

R. Malina, C. Bouchard, R. Shoup, A. Demirjian, G. Larivière

引用次数: 56

Basketball: the mechanics of hanging in the air. 篮球:悬挂在空中的力学。

Medicine and science in sports Pub Date : 1979-01-01 DOI: 10.1249/00005768-197901130-00010

R. Bishop, J. Hay

{"title":"Basketball: the mechanics of hanging in the air.","authors":"R. Bishop, J. Hay","doi":"10.1249/00005768-197901130-00010","DOIUrl":"https://doi.org/10.1249/00005768-197901130-00010","url":null,"abstract":"A theoretical technique to permit basketball players to \"hang in the air\" prior to the release of a shot is presented. The purposes of this study were (a) to determine whether skilled players used such a technique when delaying the release of their shot and (b) to determine whether such players could be readily taught to \"hang in the air\" using this technique. Six current members of the Iowa basketball team were filmed, executing jump-shots. During each trial the players \"faked\" or \"pumped\" to delay the release of the shot. Qualitative analysis of the film revealed that none of the players demonstrated the coordinated limb movement involved in the theoretical technique. Prior to a second filming session, two former Iowa varsity players practiced a predetermined sequence of body movements. Each player performed eight trials and the results were analyzed quantitatively. The vertical displacements and the vertical velocities of the center of gravity, vertex of the head and mid-point of the hips were plotted against time. Results clearly indicated that the players were able to maintain the same vertical position of the head and hips (and thus, the trunk) for about 0.2 sec at or near the peak of the jump. It was concluded that a skilled player could be taught, in a relatively short period of time, to \"hang in the air\" using the techniques presented.","PeriodicalId":18528,"journal":{"name":"Medicine and science in sports","volume":"7 1","pages":"274-7"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91077232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Reduced heart rate response to exercise in ischemic heart disease: the fallacy of the target heart rate in exercise testing. 缺血性心脏病运动降低心率反应:运动试验中目标心率的谬误。

Medicine and science in sports Pub Date : 1979-01-01 DOI: 10.1249/00005768-197901130-00001

A. Powles, J. Sutton, J. Wicks, N. Oldridge, N. Jones

{"title":"Reduced heart rate response to exercise in ischemic heart disease: the fallacy of the target heart rate in exercise testing.","authors":"A. Powles, J. Sutton, J. Wicks, N. Oldridge, N. Jones","doi":"10.1249/00005768-197901130-00001","DOIUrl":"https://doi.org/10.1249/00005768-197901130-00001","url":null,"abstract":"When exercise testing 159 patients with prior myocardial infarction, we identified 39 who were limited by fatigue. This group was all in sinus rhythm; none were taking drugs likely to impair the chronotropic response of the heart; none experienced chest pain or developed ischemic ECG changes. In 18 of this group, maximal heart rate achieved with exercise was 2SD or more below the age predicted value, and their heart rate response to exercise was reduced compared to that of the other 21 whose maximal exercise heart rates were within 2SD of age predicted values. A subgroup of 8 subjects with reduced exercise heart rates was studied before and after vagal blockade. In the 4 subjects whose infarction was inferior, the reduction in heart rate response was more profound and persisted after vagal blockade, suggesting either reduced pacemaker responsivness, due to ischemia or infarction, or autonomic imbalance as possible mechanisms. All 8 showed alinear increases in ventilation at higher power outputs and mean blood lactate postexercise was 7.5 mM/I without vagal blockade. Our findings suggest that a reduced heart rate response to exercise, already shown to imply added coronary risk, may be subdivided aetiologically and possibly prognostically. The use of a \"Target Heart Rate\" in such patients offers no safety margin, and maximal exercise capacity will be grossly over-estimated if extrapolated from the submaximal heart rate response. A cardiovascular limitation to exercise may be detected by an alinear increase in ventilation.","PeriodicalId":18528,"journal":{"name":"Medicine and science in sports","volume":"17 1","pages":"227-33"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91256135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Performance evaluation of Olympic weightlifters. 奥运会举重运动员的成绩评价。

Medicine and science in sports Pub Date : 1979-01-01 DOI: 10.1249/00005768-197901130-00012

J. Garhammer

引用次数: 45