Abstract:
:We suggest a mechanism by which blood volume changes might explain the hypotension that, after space flight, often accompanies the return to normal gravity. Upon entering microgravity, peripheral veins may collapse and, because of volume redistribution, raise the pressure in the central venous compartment. After some time in space, homeostatic mechanisms may cause volume excretion and reduce the pressure in the central venous compartment to normal values. Upon return to normal gravity, peripheral veins may re-expand and distribute a reduced blood volume into an enlarged space, thus lowering pressure in the central venous compartment. This would reduce cardiac preload, output, and arterial pressure. To prevent this sequence of events, leg cuffs might be inflated before the end of the space flight to allow homeostatic mechanisms to increase blood volume to normal levels.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
Tyberg JV,Hamilton DRdoi
10.1097/00005768-199610000-00029subject
Has Abstractpub_date
1996-10-01 00:00:00pages
S29-31issue
10 Suppleissn
0195-9131issn
1530-0315journal_volume
28pub_type
杂志文章abstract:PURPOSE:The prevalences of diabetes, hypertension, and high cholesterol all decrease with increased levels of physical activity and cardiorespiratory fitness. Whether these reductions extend beyond contemporary guideline activity levels and whether fitness affects medication use independent of activity, remains unclear...
journal_title:Medicine and science in sports and exercise
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doi:10.1249/mss.0b013e318145b337
更新日期:2007-11-01 00:00:00
abstract:INTRODUCTION:At the present there are limited tools available to measure muscle function in young children. Ground reaction force plates measure lower-body function and postural control in older children and adults. The purpose of this study was threefold: 1) develop normative data for evaluating global muscle developm...
journal_title:Medicine and science in sports and exercise
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pub_type: 临床试验,杂志文章
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更新日期:2003-08-01 00:00:00
abstract::Although estradiol (E2) is considered primarily for its role in reproduction, it can exert numerous physiological actions on a variety of tissues. However, there are several difficulties in isolating these actions and determining its impact for in vivo situations. Despite the limitations, it does appear that E2 can al...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,评审
doi:
更新日期:1990-06-01 00:00:00
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journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000002407
更新日期:2020-12-01 00:00:00
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journal_title:Medicine and science in sports and exercise
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journal_title:Medicine and science in sports and exercise
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doi:10.1249/00005768-198410000-00002
更新日期:1984-10-01 00:00:00
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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:1988-12-01 00:00:00
abstract:PURPOSE:The objectives of the present study were to examine gender differences and between-day variability of isometric hamstring muscle peak torque and perceived exertion. METHODS:Subjects included 20 healthy, college-aged male (N = 10) and female (N = 10) volunteers. Each subject completed five maximal voluntary iso...
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:10.1249/01.MSS.0000089246.90005.47
更新日期:2003-10-01 00:00:00
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journal_title:Medicine and science in sports and exercise
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doi:10.1249/01.mss.0000227318.39094.b6
更新日期:2006-07-01 00:00:00
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journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000002586
更新日期:2020-12-29 00:00:00
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journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e31824f5be4
更新日期:2012-08-01 00:00:00
abstract::A decrease in hepatic lactate dehydrogenase (LDH) activity following endurance training has been a consistent observation. In the present study, we sought to determine whether the training-induced decrease in hepatic LDH activity (pyruvate = substrate) was associated with a shift in the isoenzyme profile and/or altera...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1995-04-01 00:00:00
abstract:OBJECTIVE:The accurate determination of limitations in physical activity is important in evaluating patients with heart failure and in assessing the efficacy of treatment. However, the conventional measures used to evaluate hemodynamics, functional class, and exercise capacity all have limitations. Our objective was to...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199901000-00010
更新日期:1999-01-01 00:00:00
abstract:PURPOSE:Accurate and reliable measurement of physical activity plays an important role in assessing effective lifestyle interventions for obesity. This study examined reliability of accelerometer-based estimates of physical activity levels of overweight and obese adults before and after a lifestyle weight loss program....
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3181846cd8
更新日期:2009-01-01 00:00:00
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journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-200205000-00004
更新日期:2002-05-01 00:00:00
abstract:UNLABELLED:The cumulative effect of the female athlete triad (Triad) risk factors on the likelihood of low bone mineral density (BMD) in exercising women is unclear. PURPOSE:This study aimed to determine the risk of low BMD in exercising women with multiple Triad risk factors. METHODS:We retrospectively examined cros...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3182a03b8b
更新日期:2014-01-01 00:00:00
abstract:UNLABELLED:Accurate assessment of physical activity (PA) is necessary to identify the sedentary older individual who is in need of activity intervention. Activity monitors are quite popular, although it has been suggested that they are less accurate at slow gait speeds. PURPOSE:To examine the accuracy of the three act...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/mss.0b013e318158b504
更新日期:2008-01-01 00:00:00
abstract::We examined whether the relation between of ratings of perceived exertion (RPE) and exercise intensities associated with the lactate threshold (LT) and blood lactate concentrations (BLC) of 2.5 and 4.0 mM, established with an incremental protocol, held during 30-min treadmill run at constant velocity (V). RPE (11.6, 1...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/00005768-199406000-00021
更新日期:1994-06-01 00:00:00
abstract:PURPOSE:This study aimed to examine the longitudinal associations of person-related factors with physical activity (PA) behavior in young adults. METHODS:We analyzed longitudinal self-reported time spent in moderate-intensity PA (MPA; 4-7 METs) and vigorous-intensity PA (VPA; >7 METs) from 499 young adults (49% male) ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000000126
更新日期:2014-03-01 00:00:00
abstract:PURPOSE:This study was conducted to determine if fifth-grade students who walked or bicycled to school on a regular basis were more physically active than those that did not. METHODS:The sample consists of 219 fifth-grade students (10.3 +/- 0.6 yr, 44% male, 58% minority) from eight randomly selected urban and suburba...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000179102.17183.6b
更新日期:2005-12-01 00:00:00
abstract:PURPOSE:The purpose of this study was twofold: (a) to measure the effects of temporal parameters on both ball velocity and upper limb joint kinetics to identify pathomechanical factors during the tennis serve and (b) to validate these pathomechanical factors by comparing injured and noninjured players. METHODS:The ser...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e318299ae3b
更新日期:2013-11-01 00:00:00
abstract:PURPOSE:To assess reliability and validity of the 7-d physical activity recall (PAR) in 60- to 80-yr-old men from urban and rural homes in the southeastern United States. METHODS:Two hundred twenty 60- to 80-yr-old men (29% minority ethnicity) from Veterans Affairs primary care clinics completed two PAR interviews at ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000139893.65189.f2
更新日期:2004-09-01 00:00:00
abstract:PURPOSE:In this study, we examined the effects of body position (from deep to high position) in slide boarding by well-trained cross-country skiers. The main hypothesis was that a deeper, more "crouched" position would lead to reduced air resistance and enhanced power production during explosive extension of the lower ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000227536.13175.52
更新日期:2006-08-01 00:00:00
abstract::Muscle fatigue has been studied with a variety approaches, tools and technologies. The foci of these studies have ranged tremendously, from molecules to the entire organism. Single cell and animal models have been used to gain mechanistic insight into the fatigue process. The theme of this review is the concept that t...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,评审
doi:10.1249/MSS.0000000000001052
更新日期:2016-11-01 00:00:00
abstract:PURPOSE:To describe the influence of caffeine on physiological responses to exercise in young children and determine whether sex differences in these responses exist. METHODS:Twenty-six healthy 7- to 9-yr-old boys and 26 healthy 7- to 9-yr-old girls volunteered to participate in a double-blind, randomized, double cros...
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.0000191189.40436.73
更新日期:2006-03-01 00:00:00
abstract::The kinetics of gas exchange at the on-transient of exercise are appreciably slowed in older individuals. Eight older men (72 yr) completed 6 months of aerobic cycle training. Ventilation and gas exchange kinetics were determined at the onset of a below threshold (ventilatory threshold, V(E)T) square wave exercise fun...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1994-04-01 00:00:00
abstract:INTRODUCTION:Regular exercise can reduce the risk of developing cardiovascular disease through risk factor modification, with high-intensity exercise and more recently small muscle mass training providing alternatives to moderate-intensity exercise. METHODS:This study randomly assigned 53 healthy middle-age adults (ag...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1249/MSS.0000000000002053
更新日期:2019-11-01 00:00:00
abstract:INTRODUCTION:Loud sounds can decrease reaction time (RT) and increase force generated during voluntary contractions. Accordingly, we hypothesized that the loud starter's pistol at the Olympic Games allows runners closer to the starter to react sooner and stronger than runners farther away. METHODS:RT for the 100/110 m...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e31816770e1
更新日期:2008-06-01 00:00:00
abstract:PURPOSE:Cardiac aldosterone might be involved in the deleterious effects of nandrolone decanoate (ND) on the heart. Therefore, we investigated the involvement of cardiac aldosterone, by the pharmacological block of AT1 or mineralocorticoid receptors, on cardiac hypertrophy and fibrosis. METHODS:Male Wistar rats were r...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e318217e8b6
更新日期:2011-10-01 00:00:00