Abstract:
:A rapid, transient, rise in cytoplasmic free calcium ion concentration ([Ca2+]i-transient) couples electrical excitation to contraction in muscle. Such [Ca2+]i-transients in muscle are actually subcellular spatio-temporal events that are determined dynamically by i) diffusional fluxes of Ca2+, ii) by the binding or unbinding of Ca2+ to ligands such as troponin c and calmodulin, and iii) by the various cellular processes, such as release of Ca2+ from sarcoplasmic reticulum, that produce fluxes of Ca2+ across the membranes bounding organelles or the cell. In heart muscle, a particularly large number of cellular processes contribute to the cytoplasmic [Ca2+]i-transient, compared with skeletal muscle. In addition, the actual change in cytoplasmic free [Ca2+]i is now known to be a small fraction of the total [Ca] transient (free plus bound) because most (98 to 99%) of the Ca2+ that enters the cytoplasm binds to ligands. In this article it is shown that under most physiological conditions the SR is the major determinant of the [Ca2+]i-transient in heart, that release of Ca2+ from the SR is induced by Ca2+ entering via L-type Ca(2+)-channels, and that the Na/Ca exchanger is the major route by which Ca2+ leaves the cell. The precise quantitative contribution of all these processes to the [Ca2+]i-transient still remains to be determined, however.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
Wier WGsubject
Has Abstractpub_date
1991-10-01 00:00:00pages
1149-56issue
10eissn
0195-9131issn
1530-0315journal_volume
23pub_type
杂志文章,评审abstract:PURPOSE:This study aimed to examine the effects of footwear and neuromuscular fatigue induced by short distance trail running (TR) on running economy (RE) and biomechanics in well-trained and traditionally shod runners. METHODS:RE, vertical and leg stiffness (Kvert and Kleg), as well as foot strike angle were measured...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000000981
更新日期:2016-10-01 00:00:00
abstract:OBJECTIVE:To evaluate the effect of chronic moderate-intensity exercise upon the alterations of immune system cell function induced by energy restriction. METHODS:Forty male Wistar rats were randomly assigned to the following groups: sedentary animals fed ad libitum (SF, N = 10) or submitted to energy restriction (SER...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000147626.32295.38
更新日期:2004-12-01 00:00:00
abstract::To test whether strenuous exercise with and without caloric restriction alters LH secretion, and whether these changes are apparent in the immediate post-exercise period, LH pulse parameters were studied in four moderately trained eumenorrheic women over three successive menstrual cycles. Blood samples were obtained 5...
journal_title:Medicine and science in sports and exercise
pub_type: 临床试验,杂志文章,随机对照试验
doi:
更新日期:1995-10-01 00:00:00
abstract:INTRODUCTION:This study examined the influence of a supplement matrix on the excretion pattern of nandrolone metabolites in response to ingestion of a trace amount of 19-norandrostenedione. METHODS:Ten male and nine female volunteers (mean ± SD: age = 26 ± 3 yr, height = 1.71 ± 0.09 m, body mass = 70.9 ± 13.2 kg) were...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,随机对照试验
doi:10.1249/MSS.0b013e3181bf94d6
更新日期:2010-04-01 00:00:00
abstract::Our understanding of the responses of men and women to cold stress is extremely limited. Various scientists have suggested that there could be gender differences in thermoregulatory responses due to sexual dimorphism in body fatness and its distribution, in body surface area, and in mass. In addition, there are also s...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,评审
doi:10.1249/00005768-198810001-00017
更新日期:1988-10-01 00:00:00
abstract:PURPOSE:To provide evidence that lower-extremity muscle activity during running is tuned in response to the loading rate of the impact forces at heel-strike. METHODS:Six runners ran two 30-min trials per week for 4 wk. The trials tested two shoes which differed only in the material hardness of the midsole. The shoes w...
journal_title:Medicine and science in sports and exercise
pub_type: 临床试验,杂志文章
doi:10.1097/00005768-200209000-00021
更新日期:2002-09-01 00:00:00
abstract::The knee joints of 81 veteran soccer players between ages 40 and 74 were examined. An analysis of and relationships between soccer practice at a top level, osteoarthritis, meniscectomy, and leg axes were evaluated. One-hundred and sixty-two knees were assessed through clinical examination and X-ray examination using a...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/00005768-198508000-00005
更新日期:1985-08-01 00:00:00
abstract:PURPOSE:Studies have shown that the classical sit-and-reach (CSR) test, the modified sit-and-reach (MSR), and the newly developed back-saver sit-and-reach (BS) test have poor criterion-related validity in estimating low-back flexibility but yielded moderate criterion-related validity in hamstring flexibility. The V sit...
journal_title:Medicine and science in sports and exercise
pub_type: 临床试验,杂志文章
doi:10.1097/00005768-200009000-00021
更新日期:2000-09-01 00:00:00
abstract:PURPOSE:To examine whether normalized quadriceps and hamstring strength would predict quadriceps and hamstring muscle activation amplitudes and whether these neuromuscular factors would predict knee kinematics and kinetics during a drop jump task. METHODS:Thirty-nine females and 39 males were measured for isometric qu...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3181e3b3f
更新日期:2009-04-01 00:00:00
abstract::Vertical loading rates are typically found to be lower in forefoot compared to rearfoot strikers, promoting the idea that forefoot striking is desirable and may reduce running injury risk. However, prior work using linear models has shown that foot inclination angle (FIA) at initial contact is a poor predictor of vert...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000002023
更新日期:2019-10-01 00:00:00
abstract::We examined illness patterns in a cohort of 530 male and female runners who completed a monthly log for 12 months. The average number of upper respiratory tract infections (URTIs) per person per year for the cohort was 1.2. An upper respiratory tract infection was indicated by the report of any of the following sympto...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1991-02-01 00:00:00
abstract::This study assessed body density (BD) in an ethnically diverse sample of women (African American, Caucasian, Mexican American and Native American) (N = 139) who were between 20 and 30 or 40 and 50 yr of age and of normal weight for their height. BD was assessed using three methods: hydrostatically determined density (...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199701000-00013
更新日期:1997-01-01 00:00:00
abstract:PURPOSE:Above a given exercise intensity, rapid muscle fatigue will occur. We explored the possibility of assessing torque threshold for peripheral fatigue during single-legged repetitive isometric knee extensor exercise. We hypothesized this fatigue threshold to be related to the general aerobic fitness level and the ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e318249d701
更新日期:2012-07-01 00:00:00
abstract::The relationships between individual performance and lactate exchange and removal abilities were studies in 12 male rowers all subjected to three measurements on a rowing ergometer. An incremental exercise carried out to determine the maximal oxygen uptake (VO2max) and the corresponding maximal aerobic power (Pamax), ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199703000-00016
更新日期:1997-03-01 00:00:00
abstract::The 1-mile run/walk test is the field test of choice for evaluating maximal aerobic power (VO2max) in school-aged children. The objective of this study was to determine the relative importance of selected metabolic determinants of mile run/walk performance in children 6-14 yr of age. Mile run/walk time (MRWT), VO2max,...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1991-05-01 00:00:00
abstract::Red blood cells obtained from well-trained athletes consumed glucose at a higher rate than those from sedentary subjects when incubated in vitro in a glucose containing medium at 37 degrees C. Similar results were obtained when fructose was substituted for glucose, but not when galactose was the monosaccharide. The ut...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1981-01-01 00:00:00
abstract:PURPOSE:This study aimed 1) to define the principal components of physical function assessed by 10 common lower extremity physical performance tests and 2) to derive a reduced-item set of physical performance tests that efficiently and accurately measures raw performance and limb symmetry on each underlying component i...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000002422
更新日期:2020-12-01 00:00:00
abstract:UNLABELLED:Cell-derived procoagulant microparticles (MP) might be able to contribute to exercise-induced changes in blood hemostasis. PURPOSES:This study aimed to examine (i) the concentration and procoagulant activity of cell-derived MP after a moderate endurance exercise and (ii) the differences in the release, clea...
journal_title:Medicine and science in sports and exercise
pub_type: 临床试验,杂志文章
doi:10.1249/MSS.0b013e3182068645
更新日期:2011-07-01 00:00:00
abstract:PURPOSE:To examine the relationship between variable lower-limb coordination and shoulder joint kinetics and kinematics in the high-performance flat first serve in tennis. METHODS:Three-dimensional data describing three flat serve (FS) techniques, each executed with varying lower-limb involvement: foot-up (FU), foot-b...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/mss.0b013e31815c6d61
更新日期:2008-02-01 00:00:00
abstract:INTRODUCTION:Inhaled beta2-agonists are important therapeutic agents for the treatment of exercise-induced asthma in athletes but are restricted by international antidoping regulations. PURPOSE:To investigate whether 18 mug of inhaled formoterol affects endurance performance during running at high altitudes until exha...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,随机对照试验
doi:10.1249/01.mss.0000233801.46906.9b
更新日期:2006-12-01 00:00:00
abstract:PURPOSE:Existing studies have failed to provide evidence of a positive effect on exercise performance by wearing compression short tights covering only both thighs. This could be due to an inadequate pressure intensity that otherwise has a significant effect if applied on the crucial point in the thigh. This study aime...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000000330
更新日期:2014-11-01 00:00:00
abstract:INTRODUCTION:Unilateral elbow pain results in sensorimotor dysfunction that is frequently bilateral, affects local and remote upper limb muscles, and persists beyond resolution of local tendon symptoms. These characteristics suggest supraspinal involvement. Here, we investigated 1) the excitability and organization of ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000000469
更新日期:2015-04-01 00:00:00
abstract:PURPOSE:To determine whether quantitative methods could separate golfers with a possible dystonic cause of the "yips" from those that appear to be nondystonic. METHODS:Twenty-seven golfers completed 10 two-handed and 10 right hand-only putts. Surface EMG assessed forearm muscle co-contraction and motion detectors moni...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000001687
更新日期:2018-11-01 00:00:00
abstract::This paper introduces the terminology and application of parameter estimation techniques for clarifying models of pulmonary gas-exchange control dynamics. Results are given of modeled first-order systems, and the extension of such models to higher orders is discussed with examples. It is emphasized that justification ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1990-02-01 00:00:00
abstract::Nine subjects participated in an exercise program for 40 min/day, 6 days/wk. The training work rates were kept constant for the first 4 wk. The work rates were then increased to a higher level and kept constant for an additional 5 wk. During both training periods, maximum oxygen uptake (VO2max) increased for the first...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1981-01-01 00:00:00
abstract:PURPOSE:Deceptive manipulations of performance intensity have previously been investigated in cycling time trials (TT) but used different magnitudes, methods, and task durations. This study examines previously used magnitudes of deception during 16.1-km TT and explores yet unexamined psychological responses. METHODS:T...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000000694
更新日期:2015-11-01 00:00:00
abstract:PURPOSE:The best sprint performances are usually reached between the ages of 20 and 30 yr; however, even in well-trained individuals, performance continues to decrease with age. Although this inevitable decrease in performance has been related to reductions in muscular force, velocity, and power capabilities, these mea...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000001039
更新日期:2016-12-01 00:00:00
abstract:PURPOSE:Walking is likely to contribute substantially to nonexercise activity thermogenesis. The Tracmor triaxial accelerometer system (Maastricht, The Netherlands) is the most widely validated system for detecting body movement in free-living subjects. The aim of this study was to validate the Tracmor triaxial acceler...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-200109000-00024
更新日期:2001-09-01 00:00:00
abstract::Studies using wearable sensors to measure posture, physical activity (PA), and sedentary behavior typically use a single sensor worn on the ankle, thigh, wrist, or hip. Although the use of single sensors may be convenient, using multiple sensors is becoming more practical as sensors miniaturize. PURPOSE:We evaluated ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000002306
更新日期:2020-08-01 00:00:00
abstract:PURPOSE:Cross-sectional studies suggest that training can increase muscle carnosine (MCarn), although longitudinal studies have failed to confirm this. A lack of control for dietary β-alanine intake or muscle fiber type shifting may have hampered their conclusions. The purpose of the present study was to investigate th...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,随机对照试验
doi:10.1249/MSS.0000000000001697
更新日期:2018-11-01 00:00:00