Abstract：
:Heavy whole-body exercise, requiring a 10- to 15-fold increase in minute ventilation, encroaches on the capacities of the respiratory muscle system to respond. Recently, using the technique of bilateral phrenic nerve stimulation, it has been shown that heavy endurance exercise (> 85% of VO2max) lasting > 8-10 min causes diaphragmatic fatigue (15-30% reduction in transdiaphragmatic pressures when electrically stimulated at low frequencies [1-20 Hz] supramaximally). The fatigue appears to be due to an interaction of diaphragmatic work (i.e., pressure production) combined with effects related to exercise intensity (i.e., increased blood flow competition with the locomotor muscles and increased production of metabolic by-products) and requires > 60 min for recovery. Fitness (i.e., as implied from VO2max) appears to allow greater diaphragmatic work for a similar degree of fatigue. Unloading the respiratory muscles (with helium/oxygen gas or using a pressure-assist device) during heavy exercise < 90-95% of VO2max does not appear to alter exercise time, VO2max, or minute ventilation, implying that respiratory muscle fatigue plays little role in altering human performance at these work intensities. However, unloading the respiratory system with helium at work intensities > 90-95% of VO2max has been shown to improve exercise time. This would imply that respiratory muscle fatigue may play a role in limiting human performance at the extremes of human performance or that other factors related to the respiratory system (i.e., alterations in the sensation of dyspnea or mechanical load) may play an important role.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
Johnson BD,Aaron EA,Babcock MA,Dempsey JAdoi
10.1097/00005768-199609000-00008subject
Has Abstractpub_date
1996-09-01 00:00:00pages
1129-37issue
9eissn
0195-9131issn
1530-0315journal_volume
28pub_type
杂志文章,评审abstract：:The close balance between the O2 requirement to perform exercise and the O2 supply was analyzed. A non-uniform capillary PO2 can result in anaerobic metabolism in some muscle fibers despite an apparently adequate mean capillary PO2. The pattern of lactate increase for constant work rates and incremental exercise is de...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/00005768-198606000-00017
更新日期：1986-06-01 00:00:00
abstract：:Cardiovascular responses were obtained during cycling with graded levels of lower-body positive pressure (LBPP) applied to the exercising limbs. Seven men performed four incremental work rate (25 W.min-1) exercise (IWREx) tests to their limit of tolerance while exposed to 0, 15, 30, or 45 Torr LBPP. They also performe...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/00005768-199406000-00008
更新日期：1994-06-01 00:00:00
abstract：:A 25-yr-old female triathlete presented with 4 d of increasing left calf pain that started 1 d after an elective termination of pregnancy during the eighth week of gestation. She had been training with running, bicycling, and swimming but did not recall any injury to the calf muscle. Deep venous thrombosis of the calf...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1992-01-01 00:00:00
abstract：:To compare the physiological response to a cocaine-exercise challenge in cocaine-conditioned animals with that of acute-cocaine animals, rats were injected i.p. with either cocaine (20 mg.kg-1) or saline, twice daily for 14 consecutive days. On the 15th day (test day) cocaine-conditioned rats received an i.v. injectio...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1995-01-01 00:00:00
abstract：PURPOSE:Compare three published methods of quantifying physical activity (total activity, peak strain, and bone-loading exposure (BLE) scores) and identify their associations with areal bone mineral density (aBMD), volumetric BMD (vBMD), and bone strength. METHODS:Postmenopausal women (N = 239; mean age: 53.8 yr) from...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章,多中心研究
doi：10.1249/mss.0b013e318155a7fe
更新日期：2007-12-01 00:00:00
abstract：PURPOSE:This study was designed to determine changes in metabolic and cardiovascular risk factors following normobaric hypoxic exercise training in healthy men. METHODS:Following a randomized baseline maximal exercise test in hypoxia and/or normoxia, 34 physically active subjects were randomly assigned to either a nor...
journal_title：Medicine and science in sports and exercise
pub_type： 临床试验,杂志文章
doi：10.1097/00005768-200006000-00004
更新日期：2000-06-01 00:00:00
abstract：PURPOSE:Stroke volume response to exercise depends on changes in cardiac filling, intrinsic myocardial contractility, and left ventricular afterload. The purpose of this study was to compare these responses during an upright cycle test performed until exhaustion in children and adults. METHODS:Stroke volume, cardiac o...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1097/00005768-200203000-00012
更新日期：2002-03-01 00:00:00
abstract：:The serum levels of testosterone, free testosterone, prolactin, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were measured at rest, during 45 min of exercise on a bicycle ergometer at 50% of the subjects' previously determined maximal oxygen uptake (VO2max), and during a 30-min recovery period. Ten...
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
abstract：PURPOSE:FRESH START is a randomized controlled trial that will test whether a personally tailored, distance-medicine-based program will increase exercise and fruit and vegetable consumption, and decrease fat intake of individuals recently diagnosed with breast or prostate cancer. METHODS:Early-stage breast and prostat...
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.0000053704.28156.0F
更新日期：2003-03-01 00:00:00
abstract：:A previous study has shown that subjects who entrain breathing during cycling exhibit a lower oxygen consumption (VO2) compared with random breathing. We sought to investigate the hypothesis that entrainment of breathing during rowing improved biomechanical economy (reduced VO2) compared with spontaneous breathing. A ...
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：1994-05-01 00:00:00
abstract：:Older adults have low rates meeting the physical activity (PA) guidelines and high sedentary time. Low PA and excessive sedentary time have been linked to adverse health outcomes. Less is known about whether exercise training influences sedentary time and PA in various intensities. PURPOSE:This study aimed to examine...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000002407
更新日期：2020-12-01 00:00:00
abstract：:The purpose of this study was to determine the feasibility of using a 6" digital caliper and a 20x viewing microscope to measure hematocrit (HCT) from microhematocrit tubes. The reliability and validity of the digital caliper technique (DC) was simultaneously compared with that of the conventional "turntable" style mi...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1994-05-01 00:00:00
abstract：PURPOSE:Exercise training restores innate immune system cell function in post-myocardial infarction (post-MI) rats. However, studies of the involvement of lymphocyte (Ly) in the setting of the congestive heart failure (CHF) are few. To address this issue, we investigated the function of Ly obtained from cervical lymph ...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0b013e31815ed6d2
更新日期：2008-03-01 00:00:00
abstract：PURPOSE:Lateral compartment osteoarthritis accompanied by abnormal knee biomechanics is frequently reported in individuals with knee osteoarthritis after anterior cruciate ligament reconstruction (ACLR). The aim of this study was to evaluate changes in knee biomechanics produced by an adjusted and unadjusted varus knee...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000001201
更新日期：2017-06-01 00:00:00
abstract：:The influence of body weight on the performance in cross-country skiing has been studied by: dimensional analysis of the ratio (R) between the factors of importance to power production (VO2max, acceleration of gravity) and the braking powers, e.g., friction and air resistance; measuring the energy cost of level skiing...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1987-08-01 00:00:00
abstract：PURPOSE:Temperature increase, oxidative stress, and inflammatory reactions after endurance exercise were expected to stimulate the synthesis of heat shock proteins (HSP) in peripheral blood leukocytes. Furthermore, it was of interest whether regular endurance training influences HSP expression. METHODS:The expression ...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1097/00005768-200003000-00007
更新日期：2000-03-01 00:00:00
abstract：PURPOSE:To study the effect of genetic factors, birth weight, early childhood growth, sport, hours of training, and pubertal status on the stature and body mass index (BMI) of children aged 9-13 participating in sports at a competitive level. METHODS:A total of 184 children (96 girls, 88 boys), competing in swimming, ...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1097/00005768-200010000-00006
更新日期：2000-10-01 00:00:00
abstract：:Sudden cardiac death is always a tragedy. Sudden death during sport is particularly poignant because people tend to associate sport with health and fitness. Both the public and the medical profession would like to prevent such events, and preparticipation medical screening is often promoted as one such method. When we...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章,评审
doi：10.1097/00005768-199810001-00002
更新日期：1998-10-01 00:00:00
abstract：PURPOSE:The aim of this study was to compare the biomechanical changes during natural heel-toe running with learned midfoot and Pose running. METHODS:Twenty heel-toe runners were instructed in midfoot running and a novel running style in which the acromium, greater trochanter, and lateral malleolus are aligned in stan...
journal_title：Medicine and science in sports and exercise
pub_type： 临床试验,杂志文章
doi：10.1249/01.MSS.0000113684.61351.B0
更新日期：2004-02-01 00:00:00
abstract：PURPOSE:To determine whether a low-cost, commercially available global positioning system (GPS) can be used to study outdoor walking of healthy subjects, allowing the detection of walking and resting (nonwalking) periods and the accurate estimation of speed and distance of each walking periods. METHODS:The same EGNOS-...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/mss.0b013e3180cc20c7
更新日期：2007-09-01 00:00:00
abstract：PURPOSE:For ultra-endurance athletes, whose energy expenditure is likely to be at the extremes of human tolerance for sustained periods of time, there is increased concern regarding meeting energy needs. Due to the lack of data outlining the energy requirements of such athletes, it is possible that those participating ...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1097/00005768-200101000-00022
更新日期：2001-01-01 00:00:00
abstract：PURPOSE:Obesity in adolescence increases the risk for early adult cardiovascular disease. We recently showed that 6 months of diet, exercise, and metformin resulted in reductions in adiposity and that diet/exercise alone reduced proinflammatory factors and intrahepatic fat in pubertal children with uncomplicated obesit...
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.0b013e31823cef5e
更新日期：2012-05-01 00:00:00
abstract：PURPOSE:The purpose of this study was to examine the exercise dose-response issue in a sample of 121 regular exercisers categorized as relatively low, moderate, or high dosage physical activity participants. METHODS:Male and female students, faculty, and staff of a midwestern university, currently engaging in various ...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1097/00005768-199907000-00021
更新日期：1999-07-01 00:00:00
abstract：PURPOSE:To evaluate the effects of intensity of exercise on insulin resistance and the expression of inflammatory proteins in the skeletal muscle of diet-induced obese (DIO) rats after a single bout of exercise. METHODS:In the first exercise protocol, the rats swam for two 3-h bouts, separated by a 45-min rest period ...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0b013e3181e45d08
更新日期：2010-12-01 00:00:00
abstract：UNLABELLED:Considerable evidence suggests regular physical activity can reduce chronic pain symptoms. The dysfunction of endogenous facilitatory and inhibitory systems has been implicated in multiple chronic pain conditions. However, few studies have investigated the relationship between levels of physical activity and...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0b013e3182a69cf1
更新日期：2014-03-01 00:00:00
abstract：PURPOSE:This study aimed to investigate longitudinal associations of objectively measured physical activity (PA) and sedentary behavior (SB) with body composition and physical fitness at a 12-month follow-up in healthy Swedish 4-yr-old children. METHODS:The data from the population-based MINISTOP trial were collected ...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000001313
更新日期：2017-10-01 00:00:00
abstract：BACKGROUND:Tendinopathies are painful overuse injuries observed in athletes participating in jumping sports. These injuries are heavily dependent on the resulting strain from the applied mechanical load. Therefore, mechanisms to reduce tendon strain may represent a primary prevention strategy to reduce the incidence of...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000002004
更新日期：2019-09-01 00:00:00
abstract：PURPOSE:The goal of this study was to explore the effect of lifelong aerobic exercise (i.e., chronic training) on skeletal muscle substrate stores (intramyocellular triglyceride [IMTG] and glycogen), skeletal muscle phenotypes, and oxidative capacity (ox), in older endurance-trained master athletes (OA) compared with n...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000000789
更新日期：2016-03-01 00:00:00
abstract：INTRODUCTION:Unilateral elbow pain results in sensorimotor dysfunction that is frequently bilateral, affects local and remote upper limb muscles, and persists beyond resolution of local tendon symptoms. These characteristics suggest supraspinal involvement. Here, we investigated 1) the excitability and organization of ...
journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：10.1249/MSS.0000000000000469
更新日期：2015-04-01 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
