Abstract：
:The purpose of this study was to determine whether the magnitude of the activation force, defined as the force that must be applied to the load cell in order to activate the resistance arm of an isokinetic dynamometer, affected knee extensor torques. Twenty-four healthy female subjects performed resisted knee extension through the range of 95 degrees to 5 degrees knee flexion, with a 5-s rest between concentric and eccentric muscle actions. Six exercise sets, composed of the combinations of activation force (20,50, and 100 N) and angular velocity (45 and 135 degrees.s-1), were randomly assigned on each of two occasions, completed within a 10-d period. Although peak torques were not affected by the activation force, average torques, eccentric torques at mid-range (50 degrees knee flexion), and torques during the initial portion of each muscle action (80 degrees knee flexion during concentric muscle actions and 20 degrees flexion during eccentric actions) increased as the activation force increased. The effect of the activation force tended to be more pronounced during eccentric than during concentric muscle actions, and at the faster angular velocity. Comparisons of torques should be based on similar test protocols, including activation force.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
Kramer JF,Vaz MD,Hakansson Dsubject
Has Abstractpub_date
1991-02-01 00:00:00pages
231-7issue
2eissn
0195-9131issn
1530-0315journal_volume
23pub_type
临床试验,杂志文章,随机对照试验abstract：:Natural killer (NK) cells are highly influenced by physical exercise. The possible important mechanisms behind exercise-induced changes in NK cell function are cytokines, hyperthermia, and stress hormones, including catecholamines, growth hormone, cortisol, and beta-endorphins. Infusion studies mimicking stress hormon...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章,评审
doi：10.1249/00005768-199402000-00003
更新日期：1994-02-01 00:00:00
abstract：PURPOSE:To quantify the relationship between total training load and running performance during the most important competitions of the season (national cross-country championships, 4.175- and 10.130-km races). METHODS:Eight well-trained, subelite endurance runners (age (mean+/-SD): 23+/-2 yr; VO2max: 70.0+/-7.3 mL.kg....
journal_title：Medicine and science in sports and exercise
pub_type： 临床试验,杂志文章
doi：10.1249/01.mss.0000155393.78744.86
更新日期：2005-03-01 00:00:00
abstract：PURPOSE:Power training plays an essential part in many sport disciplines. The importance of eccentric power training remains a matter of controversial discussion. The objective of this study was therefore to investigate the difference in metabolic reaction between eccentric and concentric stress in comparable work. ME...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1097/00005768-200105000-00018
更新日期：2001-05-01 00:00:00
abstract：PURPOSE:The objective of this study is to test the feasibility and impact of a 10-wk after-school exercise program for children with attention deficit hyperactivity disorder and/or disruptive behavior disorders living in an urban poor community. METHODS:Children were randomized to an exercise program (n = 19) or a com...
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.0000000000000891
更新日期：2016-07-01 00:00:00
abstract：:The present study was designed to assess the effects of acute exercise and short-term intensive training on catechol-O-methyltransferase (COMT) activity. COMT inactivates catecholamines and converts primary catecholestrogens (CE) into their O-methylated form yielding the 2- (2-MeOE) and 4-methoxyestrogens (4-MeOE). Bl...
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
abstract：:Acute bouts of aerobic exercise have been consistently associated with significant reductions in anxiety, but explanations for this effect remain elusive. The cerebral lateralization hypothesis predicts that anxiety reductions would be caused by a postexercise decrease in anterior right, relative to left, hemisphere a...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1994-08-01 00:00:00
abstract：:Nine male and five female college students were tested on four occasions to determine the effects of various exhaustive weightlifting stimuli on forearm blood flow as measured by strain-gauge plethysmography. Maximum voluntary dynamic wrist curl strength was determined in the first session, which was followed by rando...
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:This is the first study to use the quiet eye (QE) as an objective measure of visuomotor control underpinning proficiency differences in children's motor coordination. METHODS:Fifty-seven, year 5 primary school children (9-10 yr old) completed the Movement Assessment Battery for Children, Second Edition (MABC-2...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0b013e31828288f1
更新日期：2013-06-01 00:00:00
abstract：PURPOSE:This study aimed to determine whether competitive intermittent exercise in the heat affects recovery, aggravates markers of muscle fiber damage, and delays the recovery of performance and muscle glycogen stores. METHODS:Plasma creatine kinase, serum myoglobin, muscle glycogen, and performance parameters (sprin...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0b013e31827ded04
更新日期：2013-05-01 00:00:00
abstract：INTRODUCTION:Common life events, such as getting married or gaining employment, may be opportunities to intervene on health behaviors like physical activity. The purpose of this study was to determine the changes in moderate-to-vigorous physical activity (MVPA) associated with several common life events from adolescenc...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000001839
更新日期：2019-04-01 00:00:00
abstract：PURPOSE:To investigate the use of Tritrac accelerometers to measure energy expenditure (EE) of various activities for women in the field setting, as compared with portable indirect calorimetry. METHODS:Twenty women (age 20-29) performed a choreographed routine of six activities (walking, jogging, stair climbing, walki...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1097/00005768-200210000-00020
更新日期：2002-10-01 00:00:00
abstract：PURPOSE:This study aimed 1) to define the principal components of physical function assessed by 10 common lower extremity physical performance tests and 2) to derive a reduced-item set of physical performance tests that efficiently and accurately measures raw performance and limb symmetry on each underlying component i...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000002422
更新日期：2020-12-01 00:00:00
abstract：:Perceptual and physiological congruity was examined during recovery from high-intensity dynamic exercise. Nine males (24.8 +/- 0.6 yr; VO2max; 52.3 +/- 1.5 ml.kg-1.min-1) undertook in random order four maximal treadmill protocols. Treadmill speed was held constant (5.3 km.h-1) while grade was incremented by 2, 4, 6, o...
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：
更新日期：1992-03-01 00:00:00
abstract：PURPOSE:The frequency of interruptions in sedentary time (sedentary breaks) is an aspect of sedentary behaviors that may be associated with metabolic health outcomes. The aim of this study was to describe the change in the frequency of sedentary breaks during a 10-yr period from ages 5 to 15 yr. METHODS:The longitudin...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0b013e318245ca20
更新日期：2012-06-01 00:00:00
abstract：:The AMP-activated protein kinase (AMPK) has been referred to as an "energy sensor" because it binds to and is regulated by both AMP and ATP. The binding of AMP to AMPK allows it to be phosphorylated by upstream kinases, resulting in its activation. In contrast, the binding of ATP prevents its activation. AMPK regulate...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章,评审
doi：10.1249/01.mss.0000233796.16411.13
更新日期：2006-11-01 00:00:00
abstract：PURPOSE:The asthmatic airway responds to exercise by bronchodilation (BD) during and bronchoconstriction (BC) after exercise. A refractory period induced by an initial exercise challenge that provides protection against BC during a subsequent exercise bout has also been observed. However, no studies examining during-ex...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1097/00005768-200301000-00004
更新日期：2003-01-01 00:00:00
abstract：PURPOSE:This study established the published prediction equations for the energy expenditure of walking and running compared with the measured values. To make this comparison we first determined whether differences exist in energy expenditure for 1600 m of walking versus running, and whether energy expenditure differen...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/01.mss.0000147584.87788.0e
更新日期：2004-12-01 00:00:00
abstract：:The purpose of this study was to describe the body composition of adolescent and young adult ballet dancers using total body electrical conductivity (TOBEC). We studied 112 female and 33 male dancers. The mean ages were 15.0 +/- 2.0 and 18.7 +/- 3.1 yr for females and males, respectively. The mean percent body fat (PB...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1991-05-01 00:00:00
abstract：PURPOSE:Cardiopulmonary exercise testing (CPX) provides valuable clinical information, including peak ventilation (V˙Epeak), which has been shown to have diagnostic and prognostic value in the assessment of patients with underlying pulmonary disease. This report provides reference standards for V˙Epeak derived from CPX...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000001740
更新日期：2018-12-01 00:00:00
abstract：:We investigated the breath-by-breath pattern of ventilatory response to bicycle exercise in seven elite male cyclists (VO2max = 71.7 ml X min-1 X kg-1) and ten sedentary males (VO2max = 47.3 ml X min-1 X kg-1) to analyze differences in breathing patterns between individuals with normal and high exercise ventilations (...
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：:We used an algebraic model of resting heart rate (HRr), HRr-mn (HRo), to compare resting parasympathetic (n) and sympathetic (m) influence, intrinsic heart rate (HRo), and resting autonomic balance (Abal) in ten endurance-trained (ET) and ten nontrained (NT) men. The values of m, n, and Abal were determined by selecti...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/00005768-198902000-00008
更新日期：1989-02-01 00:00:00
abstract：:The purpose of the study was to evaluate selected parameters describing performance characteristics of a free-weight and isokinetic bench press. A secondary purpose was an attempt to clarify the technique requirements essential for a successful lift. Parameters describing the free-weight condition were generated from ...
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：UNLABELLED:It is often reported that females lose less body weight than males do in response to exercise. These differences are suggested to be a result of females exhibiting a stronger defense of body fat and a greater compensatory appetite response to exercise than males do. PURPOSE:This study aimed to compare the e...
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.0b013e31826ced79
更新日期：2013-02-01 00:00:00
abstract：PURPOSE:The purpose of this study is to examine whether performance supercompensation during taper is maximized in endurance athletes after experiencing overreaching during an overload training (OT) period. METHODS:Thirty-three trained male triathletes were assigned to either OT (n = 23) or normal training groups (n =...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000000301
更新日期：2014-09-01 00:00:00
abstract：PURPOSE AND METHODS:The isovolumic contractile responsiveness of left ventricular (LV) myocardium to altered extracellular [Ca2+], [Na+], and pacing frequency was examined using perfused hearts (37 degrees C) isolated from sedentary (SED) and treadmill-trained (TR) adult female rats. RESULTS:The suppressive effect of ...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1097/00005768-199810000-00006
更新日期：1998-10-01 00:00:00
abstract：PURPOSE:Increasing step rate has been shown to elicit changes in joint kinematics and kinetics during running, and it has been suggested as a possible rehabilitation strategy for runners with patellofemoral pain. The purpose of this study was to determine how altering step rate affects internal muscle forces and patell...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0b013e3182a78c3a
更新日期：2014-03-01 00:00:00
abstract：PURPOSE:Splanchnic hypoperfusion is a physiological phenomenon during strenuous exercise. It has been associated with gastrointestinal symptoms and intestinal injury and may hamper athletic performance. We hypothesized that L-citrulline supplementation improves splanchnic perfusion and decreases intestinal injury by en...
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.0000000000000332
更新日期：2014-11-01 00:00:00
abstract：PURPOSE:Lateral knee osteoarthritis (OA) is common after anterior cruciate ligament reconstruction (ACLR), yet gait characteristics associated with lateral knee OA after ACLR are not well understood. This cross-sectional study aimed to compare knee, trunk, pelvis, hip, and ankle kinematics and moments between people wi...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000000671
更新日期：2015-11-01 00:00:00
abstract：:We sought to determine how a stationary activity such as playing a stringed instrument may affect energy expenditure (EE) in adolescents. Using automated indirect calorimetry, we measured EE in eight adolescents (1 male, 7 females, 14.2 +/- 2.1 yr) while they each performed the following activities: watching televisio...
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
abstract：PURPOSE:To date, no study has examined the synergistic effects of a nutrition and combination of aerobic and strength training (CAST) on both adiposity and metabolic parameters in overweight Latina adolescent females. The goal was to assess if a 16-wk nutrition plus CAST pilot study had stronger effects on reducing adi...
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.0b013e31819b6aea
更新日期：2009-07-01 00:00:00
