Abstract:
PURPOSE:To better understand the mechanical behavior of healing skeletal muscle; specifically the tissue's response after acute eccentric stretch injury. METHODS:Rabbit tibialis anterior (TA) muscle tendon units were subjected to an in vivo single stretch (eccentric) injury and mechanically evaluated (constant rate elongation to failure) at 1, 3, and 7 d postinjury. In addition to a traditional linear analysis (linear stiffness and failure load), an existing nonlinear rheological model was modified to interpret the experimental load-to-failure data. The models' performance were evaluated and discussed. RESULTS:No significant injury effect was observed, either within or between groups, across the 7-d healing interval, using the linear analysis. However, interpretation of the data using our nonlinear phenomenological model identified significant changes in mechanical behavior that went undetected by linear analyses. Percent differences, between injured and contralateral control limbs, of model parameter estimates were analyzed. Nonparametric statistical analysis illustrated significant changes in the first-order stiffness (k1) throughout the 7-d healing interval. Model simulations using mean values of each parameter revealed increased low-load tissue compliance after injury, with a decrease in linear slope that recovered steadily toward control values by day 7. At 7 d postinjury, virtually no differences were observed between injured and sham control tissues. CONCLUSIONS:Our findings suggest that acute eccentric injury increases the muscle's compliance 24 h after injury, with a steady recovery to uninjured values by the 7th day, yet these changes went undetected by linear analysis. Therefore, nonlinear analysis is necessary to recognize valuable information contained in the low-load region and to quantify important biomechanical phenomena of stretch-injured healing skeletal muscle.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
Corr DT,Leverson GE,Vanderby R Jr,Best TMdoi
10.1249/01.MSS.0000084423.39529.C5subject
Has Abstractpub_date
2003-09-01 00:00:00pages
1581-8issue
9eissn
0195-9131issn
1530-0315journal_volume
35pub_type
杂志文章abstract::The use of 14C as tracer to measure lactate turnover and oxidation and its role in gluconeogenesis are discussed. Lactate is formed as well as utilized in many cells, and most of it in the body is present within cells so that interpretation of 14C data from labelled lactate is more complex and more difficult than that...
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
abstract:PURPOSE:Previous studies have suggested that extreme endurance exercise may induce cardiac microdamage that could lead to subsequent myocardial fibrosis. Soluble suppression of tumorigenicity 2 (sST2) is a cardiac biomarker for assessment of myocardial fibrosis, inflammation, and strain. We evaluated baseline and exerc...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000001806
更新日期:2019-03-01 00:00:00
abstract:PURPOSE:The purpose of the present study was to examine the effect of increased protein intake on short-term decrements in endurance performance during a block of high-intensity training. METHODS:Trained male cyclists (VO(2max) = 64.2 ± 6.5 mL·kg(-1)·min(-1)) completed two 3-wk trials both divided equally into normal ...
journal_title:Medicine and science in sports and exercise
pub_type: 临床试验,杂志文章
doi:10.1249/MSS.0b013e3181f684c9
更新日期:2011-04-01 00:00:00
abstract:PURPOSE:Hyperventilation increases the clearance of carbon monoxide (CO) from blood; thus, we hypothesized that CO elimination would be enhanced with exercise. Accordingly, this study examined the effect of exercise on the half-life of carboxyhemolobin elimination. METHODS:Six healthy subjects (three males and three f...
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.0b013e3182602a00
更新日期:2012-11-01 00:00:00
abstract:PURPOSE:Light-intensity physical activity (LIPA) accounts for much of adults' waking hours (≈40%) and substantially contributes to overall daily energy expenditure. Encompassing activity behaviors of low intensity (standing with little movement) to those of higher intensity (slow walking), LIPA is ubiquitous, yet littl...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000000631
更新日期:2015-10-01 00:00:00
abstract:PURPOSE:To develop a protocol for isolating changes in aerodynamic and rolling resistances from field-based measures of power and velocity during level bicycling. METHODS:We assessed the effect of body position (hands on brake hoods vs drops) and tire pressure changes (414 vs 828 kPa) on aerodynamic and rolling resist...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3181fcb140
更新日期:2011-05-01 00:00:00
abstract::Older adults have low rates meeting the physical activity (PA) guidelines and high sedentary time. Low PA and excessive sedentary time have been linked to adverse health outcomes. Less is known about whether exercise training influences sedentary time and PA in various intensities. PURPOSE:This study aimed to examine...
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
abstract:PURPOSE:Apnea divers hyperinflate the lung by taking a deep breath followed by glossopharyngeal insufflation. The maneuver can lead to symptomatic arterial hypotension. We tested the hypotheses that glossopharyngeal insufflation interferes with cardiac function further reducing cardiac output (CO) using cardiac magneti...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e31821ff294
更新日期:2011-11-01 00:00:00
abstract::Throughout a beat swinging motion prior to a kip the gymnast changes the relative orientation of his legs and head-torso with respect to his arms. It was observed that if these changes occurred in a correct order he could rapidly increase his swing with his limited strength. If changes in orientation of the body parts...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1980-04-01 00:00:00
abstract:UNLABELLED:Two recently identified glucose transporters, GLUT8 and GLUT12, are expressed in human skeletal muscle and may be involved in insulin-mediated sugar transport. PURPOSE:The purpose of this study was to measure GLUT8 and GLUT12 mRNA levels in endurance-trained versus sedentary individuals in an effort to dete...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000222837.74015.f1
更新日期:2006-06-01 00:00:00
abstract:PURPOSE:This study aimed to examine the acute effect of caffeine on exercise capacity, exercise-related fatigue, and functional performance in prostate cancer survivors. METHODS:In this randomized, placebo-controlled, double-blind crossover study, 30 prostate cancer survivors (age, 70.3 ± 7.7 yr; body mass, 80.5 ± 13....
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.0000000000000429
更新日期:2015-03-01 00:00:00
abstract::Running technique and economy (VO2submax) were examined before and after a 6-wk period of running training. Fifteen males were filmed and performed 10-min economy runs at 3.36 m.s-1 on a treadmill. An incremental treadmill test was used to record running performance and maximal oxygen consumption (VO2max). Subjects we...
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:10.1097/00005768-199607000-00013
更新日期:1996-07-01 00:00:00
abstract:PURPOSE:This study examined the effect of exercise training on prepubertal children's (ET, N = 28) lipid-lipoprotein profile, relative to a maturity matched control group (CON, N = 20). METHODS:Training for ET involved stationary cycling for 30 min, 3 times.wk-1 for 12 wk, at 79.3 +/- 1.2% (mean +/- SD) peak heart rat...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199812000-00005
更新日期:1998-12-01 00:00:00
abstract:PURPOSE:Considering the different loading and training characteristics of the sports practiced during growth, it is important to specify and categorize the bone and soft tissue adaptations in adolescent athletes. This study aimed to categorize 10 different loading sports and a nonsport group and identify the difference...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000002420
更新日期:2020-12-01 00:00:00
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::Habitual physical activity reduces coronary heart disease events, but vigorous activity can also acutely and transiently increase the risk of sudden cardiac death and acute myocardial infarction in susceptible persons. This scientific statement discusses the potential cardiovascular complications of exercise, their pa...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,评审
doi:10.1249/mss.0b013e3180574e0e
更新日期:2007-05-01 00:00:00
abstract:PURPOSE:Previous studies have suggested that higher levels of physical activity may lower lung cancer risk; however, few prospective studies have evaluated lung cancer mortality in relation to cardiorespiratory fitness (CRF), an objective marker of recent physical activity habits. METHODS:Thirty-eight thousand men, ag...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3181c47b65
更新日期:2010-05-01 00:00:00
abstract:PURPOSE:This study aimed to test whether environmental hypoxia could potentiate the effects of exercise training on glucose metabolism and insulin sensitivity. METHODS:Fourteen adolescents with obesity were assigned to 6 wk of exercise training either in normoxic or in hypoxic conditions (FiO2 15%). Adolescents traine...
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.0000000000001694
更新日期:2018-11-01 00:00:00
abstract::Twelve male swimmers were studied psychologically before, during, and after 10 d of increased training. Daily training distance was increased from 4,000 to 9,000 m.d-1, and intensity was maintained at 94% of VO2max. Three of the swimmers were unable to tolerate the increased training load, and they did the same distan...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/00005768-198808000-00014
更新日期:1988-08-01 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::Twelve 9- to 12-year-old children (6 boys, 6 girls) performed four exercise-in-heat (35 degrees C, 45% RH) trials which differed in the composition of the fluids they drank. In each trial, subjects cycled for one 20-min and two 15-min bouts at 50% peak VO2 with 10-min rest periods in between. In a fourth bout, they cy...
journal_title:Medicine and science in sports and exercise
pub_type: 临床试验,杂志文章
doi:
更新日期:1995-06-01 00:00:00
abstract:PURPOSE:This study aimed to quantify the frequency, magnitude, and location of head impacts sustained by male and female collegiate ice hockey players during two seasons of play. METHODS:During two seasons, 88 collegiate athletes (51 females, 37 males) on two female and male National Collegiate Athletic Association va...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e31822b0ab4
更新日期:2012-02-01 00:00:00
abstract::The downswing phase in golf was represented as a double pendulum pivoted at the shoulder joint and hinged at the wrist. The motion of such a pendulum was used to derive a series of equations which were used to describe the instantaneous values of several of the component features of the downswing. Results of this anal...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/00005768-198201000-00012
更新日期:1982-01-01 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::Thirty-eight athletes with unilateral patellar tendinopathy (17 with a tendinopathy of the main body of the tendon, and 21 with an insertional tendinopathy) underwent ultrasound-guided multiple percutaneous longitudinal tenotomy under local anaesthetic infiltration after failure of conservative management. Thirty-four...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199911000-00003
更新日期:1999-11-01 00:00:00
abstract::The effect of glucose polymer (GP) ingestion upon endurance performance during walking exercise at 45% VO2max was examined. Also, performance on a battery of psychomotor tests was assessed to determine if exhaustion from endurance exercise was related to central nervous system dysfunction. Ten trained male subjects in...
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
abstract:PURPOSE:To test the hypothesis that the initial O2 uptake kinetics during exercise where the rise in blood flow (and, by implication, O2 delivery) to the working muscles during an abrupt increase in exercise intensity is reduced (i.e., arm exercise performed above the level of the heart) would be faster when preceded b...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000159013.20244.f8
更新日期:2005-04-01 00:00:00
abstract:PURPOSE:The objective of this study is to determine the effect of body mass index (BMI) on level of agreement between six previously established prediction equations for three commonly used accelerometers to predict summary measures of energy expenditure (EE) in youth. METHODS:One hundred and thirty-one youth between ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e318267b8f1
更新日期:2012-12-01 00:00:00
abstract::Ten eumenorrheic nonathletic women, aged 21-25, were studied on the 8th day following the LH peak in three consecutive cycles. Plasma level and metabolic clearance rate (MCR) of estradiol (E2) and progesterone (P) were measured before and during a 2-h continuous treadmill test at a speed corresponding to 70% of their ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1992-07-01 00:00:00
abstract:PURPOSE:Physiological and perceptual measures during interval exercise are not well understood. The current study therefore examined the correspondence between RPE, HR, and blood lactate concentration ([La]) during interval cycling. METHODS:VO2peak and the 4.0 mmol x L(-1) lactate threshold were determined. In session...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000180359.98241.a2
更新日期:2006-01-01 00:00:00