Abstract:
PURPOSE:The magnitude of atrophy and strength loss induced by partial or complete disuse of skeletal muscles varies greatly among individuals. Factors predisposing some individuals to more extreme responses have not been identified. The purpose of this investigation was to determine whether 1) level of activity before disuse or 2) sex differences influence the magnitude of atrophy and changes in muscle strength, endurance, and sense of muscular effort in response to 21 d of arm suspension. METHODS:Thirty-one individuals (18 women, 13 men) completed either 8 wk of resistance training (TRAINED group) or no training (UNTRAINED group) before 21 d of elbow muscle arm suspension achieved by having one arm in a sling tethered to the body by a swathe. Muscle volume was measured using serial magnetic resonance imaging (MRI) cross-sectional images. Functional measurements included maximal isometric force (MIF) for elbow flexion, one-repetition maximum (1RM) for biceps curl, number of repetitions to fatigue at 50% of 1RM, and sense of muscular effort measured using a force-matching task. RESULTS:Flexor muscle volume decreased (P < 0.001) by -7.7 +/- 7.3% across all subjects. The decrease (P < 0.001) in flexor muscle volume was significant in men but not women. Arm suspension induced decreases (P < 0.001) in MIF and 1RM that did not differ across sex or training groups. The number of repetitions to fatigue decreased (P < 0.05) in the UNTRAINED but not TRAINED groups. No changes in sense of muscular effort were measured. CONCLUSION:The smaller initial muscle size or sex-specific factors attenuated muscle loss but not strength or endurance losses in females during disuse. Resistance training before disuse may attenuate the loss in muscular endurance.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
Miles MP,Heil DP,Larson KR,Conant SB,Schneider SMdoi
10.1249/01.mss.0000176302.99185.besubject
Has Abstractpub_date
2005-11-01 00:00:00pages
1983-9issue
11eissn
0195-9131issn
1530-0315pii
00005768-200511000-00022journal_volume
37pub_type
临床试验,杂志文章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::The effects of aerobic fitness on resistance to psychosocial stressors are reviewed. To unravel the inconsistent results in studies examining the relationship between aerobic fitness and psychosocial stress response, a meta-analysis was conducted. The results of 34 studies having 92 effect size estimates from 1,449 su...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,评审
doi:
更新日期:1987-10-01 00:00:00
abstract:PURPOSE:Physically active women have a reduced risk of breast cancer, but the dose of activity necessary and the role of energy balance and other potential mechanisms have not been fully explored in animal models. We examined treadmill and wheel running effects on mammary tumorigenesis and biomarkers in p53-deficient (...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e31819f1f05
更新日期:2009-08-01 00:00:00
abstract::Acute aerobic exercise improves mood and activates the endocannabinoid (eCB) system in physically active individuals; however, both mood and eCB responses to exercise may vary based on habitual levels of physical activity. PURPOSE:This study aimed to examine eCB and mood responses to prescribed and preferred exercise...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000001276
更新日期:2017-08-01 00:00:00
abstract::The individual anaerobic threshold (IAT) is the highest metabolic rate at which blood lactate (LA) concentrations are maintained at a steady state during prolonged exercise. The purpose of this study was to compare the effects of active and passive recovery on the determination of the IAT before and after an endurance...
journal_title:Medicine and science in sports and exercise
pub_type: 临床试验,杂志文章
doi:
更新日期:1989-10-01 00:00:00
abstract::To determine the relation of plasma volume change to intensity of weight lifting, blood samples were obtained from 15 males [mean (+/- SD) age = 22.3 +/- 3.2 yr; height = 176.3 +/- 6.9 cm; weight = 73.0 +/- 11.7 kg] before and over a 60-min period following weight lifting at four different intensities [40, 50, 60, and...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1989-04-01 00:00:00
abstract::In a variety of experimental models, hypoxia causes a shift in substrate use to favor increased dependence on glucose. One explanation for this phenomenon is a selective advantage derived from the increased metabolic economy (more ATP derived per unit oxygen consumed) that results when glucose is oxidized rather than ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3181729dd3
更新日期:2008-08-01 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:INTRODUCTION:Exercise with limb blood flow restriction (BFR) is a very popular exercise modality in Japan and is spreading widely to the rest of the world. The underlying principle of this training modality is that under the conditions of restricted blood flow, even low-intensity exercise can provide significant muscle...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3181bdb454
更新日期:2010-04-01 00:00:00
abstract:PURPOSE:The purpose of this study was to determine whether muscle power, activation time, and neuromuscular stimulation are related to physical activity patterns in older women. METHODS:Forty women (65-84 yr) were assigned to high-active (HA) and low-active (LA) groups on the basis of a historical activity questionnai...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/mss.0b013e318074ccd9
更新日期:2007-09-01 00:00:00
abstract::It has been suggested that television watching and physical activity are related to obesity. This association, however, has been investigated mainly in children. This study provided the opportunity to examine the relationship between television watching, physical activity, and body mass index in adult Pima Indians, a ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199707000-00010
更新日期:1997-07-01 00:00:00
abstract::Over the course of 2 yr, we prospectively studied the effect on resting metabolic rate (RMR) of multiple cycles of weight loss followed by regain in six weight cycling collegiate wrestlers (WC) (mean age = 19.0 yr) compared with 12 weight stable, physically active, nonwrestling controls (C) (mean age = 20.9 yr), whose...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1993-05-01 00:00:00
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:In large epidemiologic studies, physical activity (PA) is often assessed using PA questionnaires (PAQ). Because available PAQ may not capture the full range of PA in which urban Chinese adults engage, a PAQ was developed for this purpose. We examined the validity of this PAQ and the 1-yr stability of PA in 545 ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3181e1fcd5
更新日期:2010-12-01 00:00:00
abstract:PURPOSE:To examine change in physical fitness and body composition after a military deployment to Afghanistan. METHODS:One hundred and ten infantry soldiers were measured before and after a 9-month deployment to Afghanistan for Operation Enduring Freedom. Measurements included treadmill peak oxygen uptake (peak VO2), ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e318176b978
更新日期:2008-09-01 00:00:00
abstract::This randomized study compared the fibrinolytic circadian rhythm of healthy older men and older women (average age 66 +/- 5), before and after 6 months of endurance training versus stretching controls. Compared with men, women at baseline had similar rhythms for tissue plasminogen activator (t-PA) activity and plasmin...
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:10.1097/00005768-199606000-00001
更新日期:1996-06-01 00:00:00
abstract:INTRODUCTION:A nonlinear dynamic systems model has previously been proposed to explain pacing strategies employed during exercise. PURPOSE:This study was conducted to examine the pacing strategies used under varying conditions during the cycle phase of an Ironman triathlon. METHODS:The bicycles of six well-trained ma...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000210202.33070.55
更新日期:2006-04-01 00:00:00
abstract:PURPOSE:To provide evidence that lower-extremity muscle activity during running is tuned in response to the loading rate of the impact forces at heel-strike. METHODS:Six runners ran two 30-min trials per week for 4 wk. The trials tested two shoes which differed only in the material hardness of the midsole. The shoes w...
journal_title:Medicine and science in sports and exercise
pub_type: 临床试验,杂志文章
doi:10.1097/00005768-200209000-00021
更新日期:2002-09-01 00:00:00
abstract:PURPOSE:Exercise improves the diagnostic performance of ankle-to-brachial index (ABI) in the detection of exercise-induced arterial endofibrosis (EIAE). Pressure values for all four limbs are required to calculate ABI, but rapid systemic pressure changes occur during the recovery period from exercise. We checked whethe...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000232021.21361.9c
更新日期:2006-11-01 00:00:00
abstract:PURPOSE:The purpose of this study was to determine whether similar patterns of quadriceps dysfunction are observed when people with anterior cruciate ligament (ACL) deficiency perform static and dynamic tasks. METHODS:EMG data were collected from 15 subjects with an ACL deficient knee and 15 uninjured subjects as they...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000131959.20666.11
更新日期:2004-07-01 00:00:00
abstract:PURPOSE:The purpose of this study was to examine the ability of the YMCA submaximal exercise test protocol using a total body recumbent stepper to predict V˙O(2peak). METHODS:Of 112 individuals initially screened, 110 individuals with low to moderate cardiovascular disease risk met the inclusion criteria for participa...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e31824f5be4
更新日期:2012-08-01 00:00:00
abstract:INTRODUCTION:Poor muscle quality and sedentary behavior are risk factors for metabolic dysfunction in children and adolescents. However, because longitudinal data are scarce, relatively little is known about how changes in muscle quality and physical activity influence bone development. PURPOSE:In a 2-yr longitudinal ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e31829c32fe
更新日期:2013-12-01 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:PURPOSE:The present longitudinal study assessed cardiorespiratory capacity and running economy of Olympic athletes over several decades to measure changes in fitness in an elite group during aging. METHODS:Twenty-six male runners training for the 1968 Olympics were recruited. HR, V˙O2max, ventilation, and running econ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000001407
更新日期:2018-01-01 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.0000000000000532
更新日期:2015-06-01 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/mss.0b013e318043a235
更新日期:2007-06-01 00:00:00
abstract::Facial cooling (FC) elicits a marked bradycardia at rest that appears to be reduced during exercise. This study was done to delineate the effects of exercise mediated central command from those of muscle afferent feedback and sympathetic stimulation on the attenuation of the bradycardic effect of FC during the onset o...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199703000-00006
更新日期:1997-03-01 00:00:00
abstract::This study investigated in rather specific wheelchair tests the relationships among estimates of isometric upper-body strength (Fiso), sprint power (P30), aerobic power (VO2peak), and maximal power output (POaer) in a group of 44 men (age 34 +/- 12 yr) with longstanding spinal cord injuries ranging from C4/C5 to L5. F...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/00005768-199307000-00016
更新日期:1993-07-01 00:00:00
abstract:PURPOSE:The prevalences of diabetes, hypertension, and high cholesterol all decrease with increased levels of physical activity and cardiorespiratory fitness. Whether these reductions extend beyond contemporary guideline activity levels and whether fitness affects medication use independent of activity, remains unclear...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/mss.0b013e318145b337
更新日期:2007-11-01 00:00:00
abstract::Eight older (52 to 62 yr old) post-menopausal and 8 younger (20 to 30 yr old) women were matched with respect to body size, fatness, and maximal oxygen consumption, heat-acclimated, and then exercised at 35 to 40% maximal oxygen consumption in a warm-humid (37 degrees C, 60% relative humidity) environment. Results wer...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/00005768-198820020-00009
更新日期:1988-04-01 00:00:00