Abstract：
PURPOSE:We asked whether submaximal exercise with chest wall restriction (CWR), as a model of restrictive pulmonary disease, would result in fatigue of the diaphragm in healthy humans. METHODS:To address this question, we used cervical magnetic stimulation of the phrenic nerves along with measures of transdiaphragmatic pressure. Seven healthy young men (30 ± 7 yr) completed pulmonary function tests and a maximal cycle exercise test. On a separate day, baseline measures of diaphragm contractility were obtained followed by cycle exercise at 45% of maximum intensity for 10 min with no restriction (NCWR). Diaphragm contractility was assessed again at 10 and 30 min after exercise. One hour later, inelastic straps were applied to reduce forced vital capacity by 40% followed by exercise at the same intensity. Diaphragm contractility was reassessed at 10 and 30 min after exercise. During exercise, the work of breathing, respiratory pressures, ventilatory parameters, and perceptions of respiratory and leg discomfort were recorded. RESULTS:The work of breathing and dyspnea ratings were greater during CWR exercise compared with NCWR (P < 0.05). The CWR condition had reductions in diaphragm contractility 10 min after exercise using nonpotentiated (-20.2% ± 15.3%) or potentiated twitches (-23.3% ± 12.4%, P < 0.05). There were no differences after exercise for NCWR (P > 0.05). The reduction in diaphragm contractility was correlated with the inspiratory elastic work of breathing (r2 = 0.74, P < 0.05). CONCLUSIONS:We conclude that fatigue of the diaphragm occurs under restricted conditions and likely contributes to poor exercise tolerance in patients with restrictive disease.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
Tomczak SE,Guenette JA,Reid WD,McKenzie DC,Sheel AWdoi
10.1249/MSS.0b013e3181ef5e67subject
Has Abstractpub_date
2011-03-01 00:00:00pages
416-24issue
3eissn
0195-9131issn
1530-0315journal_volume
43pub_type
杂志文章abstract：:This article provides an overview of the history behind the physiological concepts defining the role of the arterial baroreflexes and their regulation of arterial blood pressure during dynamic exercise. Initially, the case is made as to "why the arterial baroreflexes must be involved with blood pressure regulation dur...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章,评审
doi：10.1249/MSS.0b013e318180bc41
更新日期：2008-12-01 00:00:00
abstract：PURPOSE:To continuously measure core temperature (T(c)) and heart rate(HR), and quantify fluid balance during a 21-km mass-participation road racein warm, humid environmental conditions. METHODS:Eighteen heat-acclimatized male soldiers ingested a telemetric Tc sensor on the evening prior to the race and wore an ambula...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/01.mss.0000218134.74238.6a
更新日期：2006-05-01 00:00:00
abstract：:We provide an updated version of the Compendium of Physical Activities, a coding scheme that classifies specific physical activity (PA) by rate of energy expenditure. It was developed to enhance the comparability of results across studies using self-reports of PA. The Compendium coding scheme links a five-digit code t...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1097/00005768-200009001-00009
更新日期：2000-09-01 00:00:00
abstract：:Previous studies have suggested that, for the same power output, arm exercise requires higher oxygen uptake (VO2), carbon dioxide output (VCO2), and ventilation (VE) than leg exercise and that response kinetics are slower. To evaluate these differences, four healthy subjects performed a total of 95 arm cranking tests....
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1992-12-01 00:00:00
abstract：PURPOSE:This study compared the effect of an initial exercise consisting of either low-intensity eccentric or maximal isometric contractions (ISOs) on protective effect against maximal eccentric contraction (MaxECC)-induced muscle damage. METHODS:Untrained young men were placed into one of five groups (n = 13 per grou...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0b013e31825f69f3
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journal_title：Medicine and science in sports and exercise
pub_type： 临床试验,杂志文章
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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.0b0138059aec4
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abstract：:The assumption that lower extremity function is bilaterally symmetrical is prevalent throughout the biomechanics literature. The unilateral development of many overuse and acute injuries may suggest that this assumption is inaccurate. Analyses of bilateral function report conflicting results and may be partially attri...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1994-09-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1983-01-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000001495
更新日期：2018-04-01 00:00:00
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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
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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.0b013e3182687e5c
更新日期：2012-12-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章,随机对照试验
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更新日期：2017-11-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1097/00005768-200007000-00011
更新日期：2000-07-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/01.mss.0000178103.72988.cd
更新日期：2005-12-01 00:00:00
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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
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/00005768-199307000-00006
更新日期：1993-07-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章,评审
doi：10.1097/00005768-199608000-00010
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1984-06-01 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.0b013e318290c28a
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000001276
更新日期：2017-08-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1097/00005768-199701000-00002
更新日期：1997-01-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000001227
更新日期：2017-07-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1991-06-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/00005768-199406000-00008
更新日期：1994-06-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1097/00005768-200104000-00008
更新日期：2001-04-01 00:00:00
abstract：:Magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) are new and powerful tools to study tissue biochemistry, and to provide precise anatomical visualization of soft tissue structures. This review focuses on the use of these techniques to study exercise-induced muscle injury. MRS measurements sho...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章,评审
doi：
更新日期：1992-05-01 00:00:00
abstract：:Endocrine effects of self-administration of high doses of anabolic steroids and testosterone were investigated in five power athletes during 26 wk of training, and for the following 12-16 wk after drug withdrawal. After 26 wk of anabolic steroid and testosterone administration, serum testosterone concentrations had in...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1985-06-01 00:00:00
abstract：:Psychophysical scaling of symptoms or discomfort during exercise testing has evolved as an important adjunct to the study of therapeutic interventions in heart disease. One of the major shortcomings of clinical exercise testing, however, has been the assessment of chest pain. Although the presence and characteristics ...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章,评审
doi：
更新日期：1994-09-01 00:00:00
abstract：PURPOSE:The development of valid measures of built environments relevant for physical activity is an important step toward controlling the global epidemic of physical inactivity-related noncommunicable diseases and deaths. This study assessed the construct validity of a self-report neighborhood environment walkability ...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000001131
更新日期：2017-03-01 00:00:00
