Abstract:
:Mechanical efficiency of positive work (eta+) and elastic behavior of human skeletal muscles were investigated on a special sledge apparatus which allowed the use of the normal stretch-shortening cycle exercises. Twenty-five young men were investigated in a total of 92 exercise situations, in which the intensity of the prestretch (eccentric contraction) was different, but the shortening phase (concentric contraction) was kept constant in all conditions. The results demonstrated that eta+ was on the average 35.8% +/- 6.4% and correlated positively with the prestretch intensity (r = 0.413; P less than 0.001), reaching a highest individual value of 51.5%. Estimation performed on the elastic characteristics of the leg extensor muscles confirmed an earlier suggestion that the pure muscle elasticity plays an important role in potentiating performance in stretch-shortening cycle exercises. The analysis of the myoelectrical activity of the leg extensor muscles showed that the nervous system plays an essential role in regulating muscle stiffness and thus utilization of muscle elasticity in ballistic exercises.
journal_name
Int J Sports Medjournal_title
International journal of sports medicineauthors
Aura O,Komi PVdoi
10.1055/s-2008-1025751subject
Has Abstractpub_date
1986-06-01 00:00:00pages
137-43issue
3eissn
0172-4622issn
1439-3964journal_volume
7pub_type
杂志文章abstract::Leptin, the product of the ob-gene, is specifically released by adipocytes. In addition to its metabolic function it seems to affect the feedback-mechanisms of the hypothalamic-pituitary-gonadal-axis. We studied 13 female juvenile elite gymnasts with anorexia athletica (AA) and 9 female patients with anorexia nervosa ...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-1999-8834
更新日期:1999-10-01 00:00:00
abstract::As of 2017, the international football federation introduced the change of direction ability test (CODA) and the 5×30 m sprint test for assistant referees (ARs) and continued the 6×40 m sprint test for field referees (FRs) as mandatory tests. The aim of this study was to evaluate the association between performance in...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/a-0577-4073
更新日期:2018-07-01 00:00:00
abstract::During the period 1975-1981, 221 persons were treated conservatively at Tampere University Central Hospital for an acute knee ligament injury. A total of 194 patients (88%) were reexamined 8 +/- 3 years after the injury. In the clinical and radiological results, there were no significant differences between competitiv...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-2008-1025682
更新日期:1987-10-01 00:00:00
abstract::The purpose of the present study was to ascertain whether increase in step frequency at a given velocity during running reduces the lower extremity loading variables, which is associated with tibial stress fracture in runner. We hypothesized that the lower extremity loading variables at a given speed would be minimize...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-0031-1291232
更新日期:2012-04-01 00:00:00
abstract::This study investigated sex-specific effects of surface instability on kinetics and lower extremity kinematics during drop jumping and landing. Ground reaction forces as well as knee valgus and flexion angles were tested in 14 males (age: 23±2 years) and 14 females (age: 24±3 years) when jumping and landing on stable ...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-0034-1384549
更新日期:2015-01-01 00:00:00
abstract::Over 30 years ago hemodynamic studies on patients with high altitude pulmonary edema (HAPE) excluded the prior contention that the basic cause was left ventricular failure and correctly implicated the pulmonary circulation as the culprit. Physiological studies during the acute stage have revealed a normal pulmonary ar...
journal_title:International journal of sports medicine
pub_type: 杂志文章,评审
doi:10.1055/s-2007-972589
更新日期:1997-01-01 00:00:00
abstract::The reproducibility of performance in a laboratory test impacts on the statistical power of that test to detect changes of performance in experiments. The purpose of this study was to determine the reproducibility of performance of distance runners completing a 60 min time trial (TT) on a motor-driven treadmill. Eight...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-2007-971879
更新日期:1998-01-01 00:00:00
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journal_title:International journal of sports medicine
pub_type: 杂志文章,meta分析
doi:10.1055/s-0044-100280
更新日期:2018-04-01 00:00:00
abstract::Prolonged altitude exposure usually leads to considerable weight loss of which a large part is from muscle tissue. This loss reduces maximum alactic anaerobic muscle power. It was hypothesized that most of the weight loss may simply be the result of malnutrition due to lack of palatable food in an uncomfortable enviro...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-2007-1021171
更新日期:1993-07-01 00:00:00
abstract::T-lymphocytes were determined by rosette formation with sheep erythrocytes in the peripheral blood obtained from 30 healthy aged subjects who were practicing Taichiquan (88 style) exercise and 30 age-matched normal aged who served as a control group. At rest the total number of T-lymphocytes and the number of active T...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:
更新日期:1989-06-01 00:00:00
abstract::Male (n = 9) and female (n = 8) collegiate cross-country runners were studied during a training session to determine the amount of iron lost in the sweat. Sweat samples were collected from the arm using polyethylene bags. Total sweat loss was determined by weighing subjects before and after the runs. Average time of s...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-2007-1024978
更新日期:1988-02-01 00:00:00
abstract::An in vitro method has been developed of cultivating anatomically intact articular cartilage (humeral head of dog) while excluding both bone tissue and other connective tissues with a condom, which controls changes in hydration and minimizes loss of proteoglycans. Compressive loading experiments were carried out with ...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-2007-972661
更新日期:1997-08-01 00:00:00
abstract::Physical exercise activates blood coagulation and enhances fibrinolytic activity. To investigate whether these activations of blood coagulation and fibrinolysis are balanced post-exercise and during the period of recovery, 11 moderately active young men were examined immediately after a standardised cycle ergometer te...
journal_title:International journal of sports medicine
pub_type: 临床试验,杂志文章
doi:10.1055/s-2007-971109
更新日期:1999-04-01 00:00:00
abstract::We investigated the possible influence of an exhaustive physical exercise on mental stress biomarkers (serotonin, tryptophan, and beta-endorphin) along with dopamine, noradrenaline and free fatty acids in an ultramarathon race in which 45 km was run on the first day and 90 km on the second. We obtained serum samples a...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-2008-1038490
更新日期:2008-11-01 00:00:00
abstract:UNLABELLED:To define the respective roles of the periphery and central oxygen transport in the exercise limitation of heart transplanted patients (HTR), we compared 11 HTR (15.1 +/- 10.8 months after transplantation) to six age and weight matched normal controls (C), during an incremental exercise test (30 W/3 min step...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-2007-972847
更新日期:1996-05-01 00:00:00
abstract::Cross-sectional studies provide evidence of larger cardiac dimensions and mass in endurance trained than in untrained females. Much less is known regarding adaptations in cardiac function following training in untrained subjects. We aimed to study left ventricular (LV) adaptation to indoor cycling in previously untrai...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-0043-112341
更新日期:2017-09-01 00:00:00
abstract::The relationship between running intensity and the accumulation of hypoxanthine and uric acid in plasma was studied in four well-trained runners. The runners each performed several 800-m runs at different velocities, each run being performed on separate days. Venous blood samples were collected before and at regular i...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-2007-1024844
更新日期:1990-12-01 00:00:00
abstract::This study investigated the validity of determining the final work rates of cycling and walking ramp-incremented maximal cardiopulmonary exercise tests (CPETs) using a non-exercise model to predict maximal oxygen uptake VO2max and the American College of Sports Medicine ACSM's metabolic equations. The validity of usin...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-0034-1395590
更新日期:2015-10-01 00:00:00
abstract::The purpose of the present study was to correlate the acute and chronic decrease in blood pressure (BP) following resistance training (RT). 13 normotensive women (18-49 years) completed an acute whole body RT session with 3 sets of 10 repetitions at 60% 1RM and then 8 weeks of RT as follows: 3/week, 3 sets of 8-12 rep...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-0034-1382017
更新日期:2015-01-01 00:00:00
abstract::The purpose of this randomized cross-over study was to investigate the effects of a 4-min long, 2-mm vertically-vibrating vibration-exercise on muscle performance and body balance in healthy subjects. Sixteen volunteers (eight men and women aged 18-35 years) underwent both the 4-min vibration- and sham-interventions i...
journal_title:International journal of sports medicine
pub_type: 临床试验,杂志文章,随机对照试验
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更新日期:2002-07-01 00:00:00
abstract::This study aimed to investigate the impact of a 16-week dance-based aerobic exercise program on lymphocyte function in healthy and type 2 diabetes mellitus (T2DM) women. We enrolled 23 women: 11 with T2DM and 12 non-diabetic controls. Initially, we performed anthropometry and body composition measurements, afterwards,...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/a-1309-2037
更新日期:2020-12-15 00:00:00
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journal_title:International journal of sports medicine
pub_type: 杂志文章,随机对照试验
doi:10.1055/s-0032-1323829
更新日期:2013-05-01 00:00:00
abstract::This study compared 6 weeks of incline treadmill interval training (INC) performed on a 10% treadmill grade using either sprint-like efforts or slower, longer bouts. 24 individuals were randomly assigned between 2 groups that each completed 2 INC and one 30-min level-grade sessions∙wk-1. Training intensities, bout dur...
journal_title:International journal of sports medicine
pub_type: 杂志文章,随机对照试验
doi:10.1055/s-0042-109539
更新日期:2016-11-01 00:00:00
abstract::The aim of this study was to compare heart rate variability (HRV) recovery after two iso-volume (5 km) exercises performed at different intensities. 14 subjects volunteered (25.17±5.08 years; 74.7±6.28 kg; 175±0.05 cm; 59.56±5.15 mL·kg(-1)·min(-1)) and after determination of peak oxygen uptake (VO2Peak) and the speed ...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-0042-100292
更新日期:2016-06-01 00:00:00
abstract::The purpose of this study was to assess the agreement in body composition measurements of wheelchair athletes using skinfolds, bio-impedance analysis (BIA) and air displacement plethysmography (ADP) relative to dual-energy X-ray absorptiometry (DXA). A secondary objective was to develop new skinfold prediction equatio...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-0042-104061
更新日期:2016-09-01 00:00:00
abstract::Screening for cardiac health should involve relevant parameters or indices that are easy and inexpensive to obtain. Various cardiac adaptation mechanisms develop during regular exercise that are affected by many factors, and these are reflected on a surface electrocardiogram. QT dispersion has been considered a surrog...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-2003-45256
更新日期:2004-04-01 00:00:00
abstract::MR measurements can be accurately performed during 4486 km of running, opening a window into in vivo assessment of hindfoot articular cartilage under extreme ultra-endurance loading. This observational cross-sectional study included 22 randomized participants of TransEurope FootRace between Italy and the North Cape, w...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-0043-118008
更新日期:2018-01-01 00:00:00
abstract::Our purpose was to determine if an acute bout of heading soccer balls adversely affected postural control and self-reported symptoms of cerebral concussion. Thirty-one college-aged soccer players were randomly placed into either a kicking group or a heading group. Subjects either kicked or headed 18 soccer balls over ...
journal_title:International journal of sports medicine
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1055/s-2004-819941
更新日期:2004-07-01 00:00:00
abstract::Based on the importance of exercise and crucial role of liver in metabolism, the aim of this study was to determine whether the expression of peroxisome proliferator-activated receptor (PPAR)-α, γ and adiponectin receptor 2 in OLETF rat liver were altered in conjunction with improved metabolism with exercise training....
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-0031-1271755
更新日期:2011-08-01 00:00:00
abstract::This study aimed to investigate how the trunk muscularity is related to sprint running performance. In 23 youth soccer players, the cross-sectional images at the mid level of each of L1-L2, L2-L3, L3-L4, L4-L5, and L5-S1 were obtained using magnetic resonance imaging to determine the cross-sectional areas (CSAs) of re...
journal_title:International journal of sports medicine
pub_type: 杂志文章
doi:10.1055/s-0030-1268502
更新日期:2011-03-01 00:00:00