Abstract：
INTRODUCTION:The vascular endothelium plays an important role in the maintenance of vascular health and the modulation of vascular tone and blood pressure. Recently, it has been demonstrated that blood pressure reactivity to physical activity is greater in the morning, and possibly, diurnal variation in vascular function may also be evident. The aim of this study was to assess vascular responses after exercise at different times of day. METHODS:After 45 min of supine rest, 12 male normotensives completed a 30-min bout of cycling at 70% peak oxygen uptake beginning on separate days at 0800 and 1600 h. Edge detection and wall tracking of high-resolution arterial B-mode ultrasound images combined with synchronized Doppler waveform analysis were used to measure brachial and femoral conduit artery diameter and to calculate blood flow and shear rate. Measurements were recorded before and 20 min after exercise. RESULTS:At 5 min after exercise, the mean +/- SE brachial shear rate was 72 +/- 21 arbitrary unit (AU) higher in the morning compared with the afternoon (P = 0.05), but this was not compensated for by enlargement of arterial diameter (P = 0.59). No diurnal variation was observed in the femoral artery measurements. CONCLUSION:Diurnal difference in conduit artery regulatory control manifests as an elevated intravascular shear stress after morning exercise. Potentially, higher postexercise shear rate in the morning in at-risk individuals could contribute to the elevated cardiovascular risk evident in the postwaking hours.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
Jones H,Green DJ,George KP,Black MA,Atkinson Gdoi
10.1249/MSS.0b013e318195109csubject
Has Abstractpub_date
2009-06-01 00:00:00pages
1188-93issue
6eissn
0195-9131issn
1530-0315journal_volume
41pub_type
杂志文章abstract：:Ski charging was measured using giant-slalom style skis as gliding capacitors. The voltage measured across the plates was proportional to the charge on the base. While resting on dry snow or suspended in the air, the voltage was slowly reduced by the data logger itself. On wet snow the decay was much faster. While sta...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1995-01-01 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
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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
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章,多中心研究
doi：10.1249/mss.0b013e318155a7fe
更新日期：2007-12-01 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.0b013e31802dd3cc
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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.0b013e3181e91d90
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000001227
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000000782
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journal_title：Medicine and science in sports and exercise
pub_type： 临床试验,杂志文章
doi：10.1249/01.mss.0000176302.99185.be
更新日期：2005-11-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/00005768-198606000-00018
更新日期：1986-06-01 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
doi：10.1097/00005768-199712000-00006
更新日期：1997-12-01 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：10.1097/00005768-200209000-00011
更新日期：2002-09-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0b013e3182390212
更新日期：2012-04-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/01.mss.0000117111.76228.bf
更新日期：2004-03-01 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：
更新日期：1993-04-01 00:00:00
abstract：PURPOSE:Strain magnitude is known to be a primary determinant of the osteogenic response to loading. However, whether bone adaptation to muscle loading is determined primarily by load magnitude is unclear. The purpose of this study was to determine the contribution of load magnitude from muscle action on the site-speci...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1097/00005768-199909000-00009
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1991-04-01 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
doi：10.1097/00005768-200206000-00017
更新日期：2002-06-01 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
pub_type： 杂志文章
doi：
更新日期：1995-09-01 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：1991-08-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1994-05-01 00:00:00
abstract：PURPOSE:High-intensity interval training (HIIT) represents a potent stimulus to the dynamic oxygen uptake (V˙O2) response in adults, but whether the same is evident in youth is unknown. HIIT has also been suggested to place a lower demand on the respiratory system, decreasing the likelihood of exacerbation in those wit...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000002270
更新日期：2020-06-01 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.0000000000000871
更新日期：2016-06-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/01.MSS.0000079073.20399.11
更新日期：2003-08-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：2005-06-01 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:Recent literature suggests that subconcussive impacts may influence cognitive functioning across the life span. These effects are suggested to manifest as functional and possibly structural changes. Head impact biomechanics during American football have been characterized from the high school to professional le...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0b013e3182798758
更新日期：2013-04-01 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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