Abstract:
UNLABELLED:Migrating birds have been able to sustain an energy expenditure (EE) that is five times their basal metabolic rate. Although humans can readily reach these levels, it is not yet clear what levels can be sustained for several days. PURPOSE:The study's purposes were 1) to determine the upper limits of human EE and whether or not those levels can be sustained without inducing catabolism of body tissues and 2) to determine whether initial body weight is related to the levels that can be sustained. METHODS:We compiled data on documented EE as measured by doubly labeled water during high levels of physical activity (minimum of five consecutive days). We calculated the physical activity level (PAL) of each individual studied (PAL = total EE / basal metabolic rate) from the published data. Correlations were run to examine the relationship between initial body weight and body weight lost with both total EE and PAL. RESULTS:The uppermost limit of EE was a peak PAL of 6.94 that was sustained for 10 consecutive days of a 95-d race. Only two studies reported PALs above 5.0; however, significant decreases in body mass were found in each study (0.45-1.39 kg·wk(-1) of weight loss). To test whether initial weight affects the ability to sustain high PALs, we found a significant positive correlation between TEE and initial body weight (r = 0.46, P < 0.05) but no correlation between PAL and body weight (r = 0.27, not statistically significant). CONCLUSIONS:Some elite humans are able to sustain PALs above 5.0 for a minimum of 10 d. Although significant decreases in body weight occur at this level, catabolism of body tissue may be preventable in situations with proper energy intake. Further, initial body weight does not seem to affect the sustainability of PALs.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
Cooper JA,Nguyen DD,Ruby BC,Schoeller DAdoi
10.1249/MSS.0b013e31822430edsubject
Has Abstractpub_date
2011-12-01 00:00:00pages
2359-67issue
12eissn
0195-9131issn
1530-0315journal_volume
43pub_type
杂志文章,meta分析,评审abstract:PURPOSE:Patellar tendon abnormality (PTA) on diagnostic imaging is part of the diagnostic criteria for patellar tendinopathy. PTA and altered landing strategies are primary risk factors that increase the likelihood of asymptomatic athletes developing patellar tendinopathy. Therefore, the aim of this study was to examin...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e318275e0f2
更新日期:2013-03-01 00:00:00
abstract:PURPOSE:This study determined the effects of a single session of heavy-resistance exercise on myosin heavy-chain (MHC) mRNA expression, along with the expression of the transcription factors Myo-D, myogenin, and Id-1. METHODS:Four male subjects participated in a control group (CON) and seven in a resistance-exercise g...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-200208000-00006
更新日期:2002-08-01 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:Past investigations indicate that training-related injuries are associated with certain performance-oriented measures of physical fitness and certain lifestyle characteristics. This study examined associations between injuries, direct (physiological) measures of physical fitness, and lifestyle characteristics. ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-200106000-00014
更新日期:2001-06-01 00:00:00
abstract:PURPOSE:Few epidemiological studies have been conducted among middle-aged women on long-term total and specific physical activity (PA) trends. We studied in a cross-sectional setting the relationship of self-reported total daily PA with age and calendar time. METHODS:In a population-based cohort of 38,988 women aged 4...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000185086.19220.b3
更新日期:2006-02-01 00:00:00
abstract:PURPOSE:To determine whether females with chronic ankle instability (CAI) demonstrated decreased dynamic postural stability compared with controls in the anterior, lateral, and medial jump directions. METHODS:Individuals with CAI (n = 24) reported a history of moderate to severe ankle sprain, two or more episodes of g...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3181e40108
更新日期:2010-12-01 00:00:00
abstract:INTRODUCTION:Acute stress can increase fatigability and decrease steadiness of sustained low-force contractions that are required for functional tasks in upper limb muscles. Whether motor performance is more impaired in people with a chronic stress disorder is not known. PURPOSE:This study compared the fatigability an...
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.0000000000000244
更新日期:2014-07-01 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:The cold pain sensitivity in fighter pilots was studied by using a cold pressor test. METHODS:The pilots were divided into two groups: one group consisting of eight pilots (N = 8) who had experienced several acute in-flight neck pain attacks, and the control group (N = 8) who had not experienced these pain con...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199804000-00016
更新日期:1998-04-01 00:00:00
abstract:PURPOSE:This investigation assessed the effects of a 9-wk regimen of creatine monohydrate (Cr x H2O) supplementation coupled with resistance training on body composition and neuromuscular performance in NCAA Division I football athletes. METHODS:Twenty-five subjects were randomly assigned in a double-blind, randomized...
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:10.1097/00005768-200110000-00009
更新日期:2001-10-01 00:00:00
abstract:PURPOSE:The purpose of the study was to determine the effect of a home-based cycling program for women with a recent diagnosis of gestational diabetes mellitus (GDM) on aerobic fitness, weight gain, self-reported mobility, attitude, and intentions toward maternal exercise, and obstetric and neonatal outcomes. METHODS:...
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.0000000000000587
更新日期:2015-08-01 00:00:00
abstract:PURPOSE:This study aimed to evaluate the effect of an exercise program of two different intensities, with nutritional control, on gestational weight gain (GWG), infant birth weight, and maternal weight retention at 2 months postpartum (2 mopp). METHODS:Pregnant women (prepregnancy body mass index = 18.5-24.9 kg·m) wer...
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.0b013e31825365f1
更新日期:2012-08-01 00:00:00
abstract:PURPOSE:Increased serum testosterone (TST) occurs in response to resistance exercise and is associated with increased muscle mass. However, the effects of elevated TST and sequential resistance exercise bouts on androgen receptor (AR) expression in humans are not well known. This study examined three sequential bouts 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:10.1249/01.mss.0000139795.83030.d1
更新日期:2004-09-01 00:00:00
abstract:PURPOSE:This study aimed to quantify the repeated oxygen deficits attained during intermittent endurance exercise by measuring oxygen consumption (V˙O2) and oxygen demand (V˙O2) throughout a simulated roller ski race. METHODS:Eight male elite cross-country skiers (V˙O2peak, 77.4 ± 4.4 mL·kg⋅min) raced a 13.5-km roller...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000002209
更新日期:2020-04-01 00:00:00
abstract:PURPOSES:To validate the energy expenditure estimated from The Minnesota Leisure Time Physical Activity Questionnaire (MLTPAQ) with total energy expenditure (TEE) measured by doubly labeled water (DLW), and to present and examine the validity of an extended version of the MLTPAQ with additional questions about inactivi...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.MSS.0000093608.95629.85
更新日期:2003-11-01 00:00:00
abstract::To determine whether a 13C-bicarbonate, isotope dilution technique could be used to estimate relative changes in energy expenditure of leisure activities of short duration, we studied eight adolescents who performed the following activities: watching television (120 min); playing a stringed instrument (60 min plus 60 ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199709000-00021
更新日期:1997-09-01 00:00:00
abstract:PURPOSE:A potential confounding factor in the interpretation of left ventricular (LV) structural and functional data in female subjects could be menstrual phase or contraceptive use upon assessment. To date no study has addressed this issue. METHODS:Seventeen eumenorrheic (EU; mean +/- SD age = 21 +/- 3 yr) and 14 com...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-200002000-00008
更新日期:2000-02-01 00:00:00
abstract:PURPOSE:Sitting time (ST) is a serious global health issue and positively associated with cardiometabolic disease. The present study investigated associations between objectively measured ST, sedentary patterns, and cardiometabolic biomarkers in physically active young males. METHODS:Cross-sectional analysis was compl...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000002528
更新日期:2020-10-01 00:00:00
abstract::Vertical loading rates are typically found to be lower in forefoot compared to rearfoot strikers, promoting the idea that forefoot striking is desirable and may reduce running injury risk. However, prior work using linear models has shown that foot inclination angle (FIA) at initial contact is a poor predictor of vert...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000002023
更新日期:2019-10-01 00:00:00
abstract:PURPOSE:The effects of chronic exercise training on the expression of heat shock protein (HSP) in skeletal muscle of senescent animals are unknown. Therefore, the purpose of this study was to investigate the effects of chronic exercise training on skeletal muscle HSP expression in both young and old rats. METHODS:Youn...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-200105000-00008
更新日期:2001-05-01 00:00:00
abstract:PURPOSE:Reducing ice friction was one of the motives for developing the klapskate. However, the magnitude of power dissipation that occurs with conventional skates when a skater plantar flexes his ankle and the tip of the blade is pressed into the ice has not been quantified previously. In this study, we examine how ic...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-200103000-00025
更新日期:2001-03-01 00:00:00
abstract:PURPOSE:We evaluated the impact of anthracyclines on left ventricular function and myocardial tissue characteristics using cardiovascular magnetic resonance (CMR) imaging to determine their relationship with V˙O2peak. METHODS:Women with breast cancer who had not yet received treatment (No-AT, n = 16) and had received ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000002469
更新日期:2021-02-01 00:00:00
abstract:PURPOSE:To examine whether knowledge of the 1995 Centers for Disease Control and Prevention (CDC) and the American College of Sports Medicine (ACSM) national physical activity recommendations varies by sociodemographic, behavioral, and communication-related factors. METHODS:Cross-sectional analyses of 2381 participant...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3181a52100
更新日期:2009-10-01 00:00:00
abstract::In many interventions that are based on an exercise program intended to induce weight loss, the mean weight loss observed is modest and sometimes far less than what the individual expected. The individual responses are also widely variable, with some individuals losing a substantial amount of weight, others maintainin...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,评审
doi:10.1249/MSS.0b013e31828ba942
更新日期:2013-08-01 00:00:00
abstract:PURPOSE:This study was conducted to determine the effect of high pedaling cadences on maximal cycling power output (W(max)). METHODS:Nine well-trained cyclists performed a continuous, incremental cycle-ergometer test to exhaustion (25 W increases every 3 min) either at 80, 100, or 120 rpm on three different occasions....
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000218139.46166.ec
更新日期:2006-05-01 00:00:00
abstract::The association of physical activity to the initiation of health risk behaviors was examined in a 3-yr prospective study of a population-based cohort of 1245 adolescents aged 12-16 yr. Four hundred thirty-seven students (35% of the cohort) were identified at baseline via self-report survey as never having smoked cigar...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1995-12-01 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: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:PURPOSE:The best sprint performances are usually reached between the ages of 20 and 30 yr; however, even in well-trained individuals, performance continues to decrease with age. Although this inevitable decrease in performance has been related to reductions in muscular force, velocity, and power capabilities, these mea...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000001039
更新日期:2016-12-01 00:00:00
abstract::The objective of this study was to investigate the effects of shoes and foot orthotics on running economy and selected frontal plane knee kinematics during the support phase of running. Twenty-one male runners who had been fitted with orthotics served as subjects. Subjects participated in three submaximal runs on a tr...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1985-02-01 00:00:00