Abstract：
:Based on the assumption that the stretch-shortening cycle is a natural way of muscle function, the occurrence of such a cycle was investigated in a diagonal technique of cross-country skiing. Cinematographic, special force platform, and telemetered EMG techniques were employed. The four subjects studied were all elite international level cross-country skiers, and the measurements were taken either under world championship conditions (cinematography) or during special test situations outdoors (EMG, force platform, and cinematography). The skiing was performed on the fixed uphill course (competition) and on the variable uphill tracks (2.5 degrees-11 degrees). The latter condition allowed mounting of a special long force platform system under the track. The results indicated that the leg kick phase is preceded by a typical unweighting phase, which is followed by braking and propulsion phases. Angular velocity curves of the hip, knee, and ankle joints revealed indirectly the segmental occurrence of the stretch-shortening cycle. Similar phenomena could be identified for the elbow joint during the pole plant and thrust phases. On a steep uphill track, the muscle activation pattern and the ground reaction forces resembled in many instances those of slow level running. Based on the results, a model was suggested to describe how the preloading of the leg thrust phase takes place as a sequential flow from one joint to another.
journal_name
Int J Sports Medjournal_title
International journal of sports medicineauthors
Komi PV,Norman RWdoi
10.1055/s-2008-1025703subject
Has Abstractpub_date
1987-03-01 00:00:00pages
48-54eissn
0172-4622issn
1439-3964journal_volume
8 Suppl 1pub_type
杂志文章abstract：:This study examined the validity of 2 kinematic systems for estimating force and power during squat jumps. 12 weight-trained males each performed single repetition squat jumps with a 20-kg, 40-kg, 60-kg and 80-kg load on a Kistler portable force plate. A commercial linear position transducer (Gymaware [GYM]) and accel...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-0030-1270487
更新日期：2011-04-01 00:00:00
abstract：:The aim of the present study was to analyze the effects of age on cardiorespiratory fitness (CRF), muscle strength and heart rate (HR) response to exercise adaptation in women in response to a long-term twice-weekly combined aerobic and resistance exercise program. 85 sedentary women, divided into young (YG; n=22, 30....
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-0033-1351332
更新日期：2014-05-01 00:00:00
abstract：:Previous studies have demonstrated conflicting results on the effects of acute exercise on FMD. The aim of the study was to examine brachial artery FMD before and after 3 bouts of acute exercise performed at different intensities. 10 healthy males (mean±SD age: 22±1 years) completed 30 min of cycling at 50, 70 and 85%...
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：:The changes in selected muscle and blood metabolites - blood catecholamines, cyclic AMP, glucagon, growth hormone, insulin, and C-peptide--were measured in five male long-distance runners after moderate 90 min (4.3 min/km) and intense 45 min (3.3 min/km) of continuous running exercises. After the 45-min exercise, the ...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-2008-1025851
更新日期：1985-10-01 00:00:00
abstract：:Orthostatic tolerance is impaired following an acute bout of exercise. This study examined the effect of fluid ingestion following treadmill exercise in restoring the cardiovascular responses to an orthostatic stress. Five men (age, 29.6 +/- 3.4 yrs) were exposed to a graded lower body negative (LBNP) pressure protoco...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-2007-972615
更新日期：1997-04-01 00:00:00
abstract：:This study compared acute responses of systolic and diastolic blood pressure (SBP/DBP), cardiac output (Q), heart rate (HR), stroke volume (SV), total peripheral resistance (TPR) and rate of perceived exertion (RPE) during resistance exercise performed continuously and discontinuously. Hemodynamic responses and RPE we...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-0035-1549957
更新日期：2015-11-01 00:00:00
abstract：:Natural immunity, including that of the natural killer (NK) cells, is strongly influenced by physical exercise, but the physiological significance of the reported changes in NK cells after exercise training is as yet unclear. The exercise effect is likely mediated by interactions between the central nervous and endocr...
journal_title：International journal of sports medicine
pub_type： 杂志文章,评审
doi：10.1055/s-2000-1447
更新日期：2000-05-01 00:00:00
abstract：:Hemoglobin oxygen binding properties and acid-base status were investigated in Colombian athletes (A) and controls (C) from Cali (C-1000 m) and Bogotá (B-2600 m). [Hb] and Hct values were not influenced by altitude, but Hct was lower in the blood of athletes (in Cali 2.6%, in Bogotá 1.4%). Both training and altitude p...
journal_title：International journal of sports medicine
pub_type： 杂志文章,评审
doi：10.1055/s-2007-1024755
更新日期：1990-02-01 00:00:00
abstract：:Physiological characteristics of japanese female classical ballet dancers were investigated in comparison with sedentary women of similar age (non-dancers). Subjects were 20 professional female ballet dancers with a mean age of 26.5 +/- 4.4 years (mean +/- SD) and 66 sedentary women with a mean age of 23.7 +/- 3.6 yea...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-2007-972815
更新日期：1996-02-01 00:00:00
abstract：:Muscle biopsies from m. vastus lateralis of two world class shot putters (shot putter 1 and 2) and the untrained brother of shot putter 1 were analyzed for fiber type distribution with ATPase staining and in situ hybridization for the expression of alkali myosin light chain (MLC) isoforms. Shot putter 2 had a predomin...
journal_title：International journal of sports medicine
pub_type： 临床试验,杂志文章
doi：10.1055/s-2003-39092
更新日期：2003-04-01 00:00:00
abstract：UNLABELLED:Caffeine has many diverse physiological effects including central nervous system stimulation. Ventilatory threshold and a recently described heart rate variability threshold both have a relationship with autonomic control that could be altered by caffeine consumption. The purpose of this investigation was to...
journal_title：International journal of sports medicine
pub_type： 杂志文章,随机对照试验
doi：10.1055/s-0032-1301904
更新日期：2012-07-01 00:00:00
abstract：:Inhibition of adipose tissue lipolysis, leading to a reduced availability of non-esterified fatty acids for energy production in the active skeletal muscles, may be involved in the impairment of endurance exercise capacity after administration of a beta-adrenoceptor blocking agent. The effect of increasing the availab...
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-2007-1021137
更新日期：1993-01-01 00:00:00
abstract：:This study was undertaken to assess whether ventilatory anaerobic threshold (T vent) reflected endurance capacity (EC) in sports medical control. Fifteen subjects performed two cycle ergometer tests. The first was a maximal exercise test, which consisted of increasing the load 20 W/min until exhaustion. During this te...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-2008-1025654
更新日期：1987-06-01 00:00:00
abstract：:The oxygen uptake (VO2) attained during a constant speed 800-m pace trial on a treadmill is less than the maximal VO2 (VO2max) in male middle-distance runners with a high VO2max (i.e., > 65 ml x kg (-1) x min (-1)). We therefore investigated whether the VO2 attained was influenced by the pacing strategy adopted. Eight...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-2005-837468
更新日期：2006-01-01 00:00:00
abstract：:Little if any research has examined the variability in time to exhaustion (TTE) during submaximal treadmill running. This study investigated the test-retest reliability of submaximal treadmill TTE as a measure of endurance capacity. 16 endurance-trained males (n=14) and females (n=2) completed a run to exhaustion at 7...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-0035-1555928
更新日期：2016-03-01 00:00:00
abstract：:The relationships between perceived exertion and the physiological variables oxygen uptake (VO2), heart rate (HR) and blood lactate concentration (HLa) were studied in tethered swimming. Seven male and ten female subjects swam at five submaximal intensities. The degree of perceived exertion was measured both on the ca...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-2007-973025
更新日期：1995-08-01 00:00:00
abstract：:Chlorhexidine-containing mouthwash (STRONG), which disturbs oral microflora, has been shown to diminish the rise in plasma nitrite concentration ([NO2-]) and attenuate the reduction in resting blood pressure (BP) typically seen after acute nitrate (NO3-) ingestion. We aimed to determine whether STRONG and weaker antis...
journal_title：International journal of sports medicine
pub_type： 杂志文章,随机对照试验
doi：10.1055/s-0035-1554700
更新日期：2015-12-01 00:00:00
abstract：:We reported previously that a static handgrip exercise evoked regional differences in the facial blood flow. The present study examined whether regional differences in facial blood flow are also evoked during dynamic exercise. Facial blood flow was measured by laser speckle flowgraphy during 15 min of cycling exercise...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/a-1244-9870
更新日期：2020-09-18 00:00:00
abstract：:Prior research about the effects of the amount of exercised muscle mass upon cardiovascular responses (CVR) has neglected a potential bias related to total exercise and concentric/eccentric duration. Autonomic responses and perceived exertion (RPE) were compared in resistance exercises performed with larger and smalle...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-0043-116671
更新日期：2017-11-01 00:00:00
abstract：:This study examined muscular adaptations of knee extensors following short-term low-frequency downhill walking training. 22 young males (training group: TG, n=12; control group: CG, n=10) participated. TG conducted 40-min downhill treadmill walking (load: 10% of body mass, gradient: 28%, velocity: 5 km/h) 1 session/we...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-0034-1385885
更新日期：2015-02-01 00:00:00
abstract：:In the last decade the study of the human muscle mechanics and energetics in physiology and pathology underwent a radical change. Indeed, the use of biopsy is being progressively accompanied by non-invasive techniques which allow a more integrative assessment of muscle function in vivo. Magnetic resonance imaging (MRI...
journal_title：International journal of sports medicine
pub_type： 杂志文章,评审
doi：10.1055/s-2007-972724
更新日期：1997-10-01 00:00:00
abstract：:This study examined the influence of 28 days of dietary carbohydrate (CHO) supplementation on plasma cytokine responses to cycle ergometry. Sixteen highly trained male cyclists and triathletes (age: 30.6+/-5.6 y; VO2max: 64.8+/-4.7 mL x kg(-1) x min(-1); mean+/-SD) participated in the study. One group (n=8) consumed a...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-0029-1243645
更新日期：2010-03-01 00:00:00
abstract：:Decreased ability to perform activities of daily living (ADLs) associated with deterioration in physical capacity are key determinants of the poor quality of life and loss of independence of patients with Alzheimer's disease (AD). The purpose of this study was to determine the effects of a 12-week training program (in...
journal_title：International journal of sports medicine
pub_type： 杂志文章,随机对照试验
doi：10.1055/s-2008-1038432
更新日期：2008-10-01 00:00:00
abstract：:500 and 69 male former elite athletes and 319 male controls completed a health questionnaire in 1985 and in 1995. Register data on the subjects were also collected. Subjects were aged 65 years or less and had no history of hypertension in 1985, and they had been healthy at the age of 20 years. The athletes were groupe...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-2002-23176
更新日期：2002-04-01 00:00:00
abstract：:To examine torque variability in 2 antagonistic muscles 20 individuals performed maximal and submaximal (5, 10, 20, 50 and 75% of Maximal Voluntary Contraction, MVC) isometric wrist flexions and extensions (5 s) at 5 different angles (230, 210, 180, 150 and 130°). The EMG activity of Flexor Carpi Ulnaris (FCU) and Ext...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-0031-1280777
更新日期：2011-10-01 00:00:00
abstract：:Fitness, and specifically body composition of football referees requires attention in order to achieve the highest possible standards. The aim of the present study was to describe body composition of elite Spanish football referees over 11 years. Data from 2001 to 2012 pre-seasons were analyzed from a total of 470 ref...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-0034-1398582
更新日期：2015-06-01 00:00:00
abstract：:In major track and field competitions, the most risky discipline is the combined event. Therefore, we aimed to record and analyze the incidence and characteristics of sports injuries incurred during the Youth and National Combined Events Championships. During the French Athletics Combined Events Championships in 2010,...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-0031-1301332
更新日期：2012-10-01 00:00:00
abstract：:The study aimed to verify possible associations between game-play running performance and outcomes derived from fitness (running) tests in female futsal players. Sixteen women professional elite futsal players from a 1st division league team (19.2±2 years-old, 4.3±2.1 years of experience) participated. Firstly, a grad...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/a-1202-1496
更新日期：2021-01-01 00:00:00
abstract：:The effects of long distance running training (up to 40km/day) on the biomechanical properties of young canine articular cartilage were investigated using in situ indentation creep technique. The stiffness of articular cartilage was determined in the form of instantaneous and equilibrium shear moduli. The rate of cart...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-2007-1021056
更新日期：1994-07-01 00:00:00
abstract：PURPOSE:The modified Dmax method can accurately determine the second lactate threshold (LT2), which is valuable for predicting aerobic performance and prescribing exercise. The purpose of this study is to determine if the modified Dmax method can accurately find thresholds in VE (VT2), VCO2 (VCO2T), RER (RERT), and RR ...
journal_title：International journal of sports medicine
pub_type： 杂志文章
doi：10.1055/s-0043-125448
更新日期：2018-04-01 00:00:00
