Abstract:
:Energy expenditure during bicycling on flat terrain depends predominantly on air resistance, which is a function of total frontal area (bicycle and rider), coefficient of drag, and air speed. Body position on the bicycle may affect energy expenditure by altering either frontal area or coefficient of drag. In this study, oxygen uptake (VO2) was measured for each of four body positions in 10 cyclists (8 males, 2 females, 24 +/- 2 yr, 67.7 +/- 3.3 kg, VO2max = 65.8 +/- 1.5 ml.kg-1.min-1) while each bicycled up a 4% incline on a motor-driven treadmill (19.3 km.h-1), thereby eliminating air resistance. Positions studied included: 1) seated, hands on brake hoods, cadence 80 rev.min-1; 2) seated, hands on dropped bar (drops), 80 rev.min-1; 3) standing, hands on brake hoods, 60 rev.min-1; and 4) seated, hands on brake hoods, 60 rev.min-1. Subjects rode their own bicycles, which were equipped with a common set of racing wheels. Energy expenditure, expressed as VO2 per unit combined weight, was not significantly different between drops and hoods positioning (30.2 +/- 0.6 vs 29.9 +/- 0.9 ml.kg-1.min-1) but was significantly greater for standing compared with seated cycling (31.7 +/- 0.4 vs 28.3 +/- 0.7 ml.kg-1.min.-1, P less than 0.01). These results indicate that body posture can affect energy expenditure during uphill bicycling through factors unrelated to air resistance.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
Ryschon TW,Stray-Gundersen Jsubject
Has Abstractpub_date
1991-08-01 00:00:00pages
949-53issue
8eissn
0195-9131issn
1530-0315journal_volume
23pub_type
杂志文章abstract::Potential physiological, anthropometric, and training determinants of running economy (RE) were studied in a heterogeneous group of habitual distance runners (N = 188, 119 males, 69 females). RE was measured as VO2 (ml.kg-1.min-1) during level treadmill running at 161 m.min-1 (6 mph) (VO2-6). Examined as potential det...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1992-10-01 00:00:00
abstract:INTRODUCTION:The GENEA shows high accuracy for classification of sedentary, household, walking, and running activities when sampling at 80 Hz on three axes. It is not known whether it is possible to decrease this sampling frequency and/or the number of axes without detriment to classification accuracy. The purpose of t...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e31825e19fd
更新日期:2012-11-01 00:00:00
abstract:PURPOSE:A combination of endurance and strength training is generally used to seek further health benefits or enhanced physical performance in older adults compared with either of the training modes alone. The mean change within a training group, however, may conceal a wide range of individual differences in the respon...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3181f1bf0d
更新日期:2011-03-01 00:00:00
abstract::Running technique and economy (VO2submax) were examined before and after a 6-wk period of running training. Fifteen males were filmed and performed 10-min economy runs at 3.36 m.s-1 on a treadmill. An incremental treadmill test was used to record running performance and maximal oxygen consumption (VO2max). Subjects we...
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:10.1097/00005768-199607000-00013
更新日期:1996-07-01 00:00:00
abstract:PURPOSE:Similar to musician's focal dystonia, a task-specific phenomenon known as yips, has also been reported in professional athletes. Yips is usually described as focal dystonia, or choking under pressure, or as lying on a continuum between both. Based on the common occupational conditions across musicians and athle...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000001696
更新日期:2018-11-01 00:00:00
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::The purpose of this study was to determine the validity and evaluate the accuracy of a portable telemetric oxygen uptake analyzer (K2). Two experiments were carried out: a) using a mechanical lung, the accuracy of the K2 to measure oxygen fractions and minute ventilation following 10 and 60 min of warm-up was determin...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1994-01-01 00:00:00
abstract:PURPOSE:The purpose of this study is to compare the time-frequency characteristic, using nonlinearly scaled wavelets, of the EMG signal as well as the three-dimensional (3D) knee kinematics of female and male elite soccer players performing an unanticipated cutting maneuver. METHODS:Fifteen female and 15 male elite so...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e31817b8e9e
更新日期:2008-10-01 00:00:00
abstract:PURPOSE:The purpose of the current study was to investigate the associations between the GNB3 C825T polymorphism, body fatness and fitness, and blood pressure in a sample of young Korean men. METHODS:A total of 282 apparently healthy Korean men (nonobese N = 152, obese N = 130) aged 19-33 yr participated in the study....
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000170096.96662.05
更新日期:2005-07-01 00:00:00
abstract::A 23-yr-old female body builder injured her right wrist while training. A correct diagnosis of pure distal radio-ulnar dislocation, ulnar volar, was made, and reduction was successfully carried out. After removal of plaster, the patient complained of wrist pain and clicking. Surgical exploration revealed a ruptured tr...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1990-04-01 00:00:00
abstract:PURPOSE:The chronic exposure at high altitude (HA) represents an ideal model for evaluating the in vivo effects of hypobaric hypoxia. Taking advantage of the EV-K2-CNR Pyramid, this study was designed to evaluate whether acute and chronic hypoxia differently modulates the in vivo immune responses. METHODS:The study in...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000162688.54089.ce
更新日期:2005-05-01 00:00:00
abstract:PURPOSE:The purposes of this study were 1) to add layers and features to a previously published fully automated algorithm designed to identify children's nocturnal sleep and to exclude episodes of nighttime nonwear/wakefulness and potentially misclassified daytime sleep episodes and 2) to validate this refined sleep al...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000000486
更新日期:2015-05-01 00:00:00
abstract::Sixteen untrained males, age 46 +/- 11 yr (mean +/- SD), were studied to determine the effects of 20 wk of strength training on lipoprotein-lipid profiles and post-heparin lipase activities. All subjects had abnormal lipoprotein-lipid profiles and at least two other risk factors for coronary heart disease (CHD). To co...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1991-10-01 00:00:00
abstract:PURPOSE:This study investigated the combined effects of exercise and smoking cessation on serum lipids. METHODS:Eighteen female smokers quit smoking using standard behavioral methods combined with exercise (N = 9) or with a nonexercise contact time control (N = 9). The smoking cessation program for both groups consist...
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:10.1097/00005768-199809000-00010
更新日期:1998-09-01 00:00:00
abstract:PURPOSE:To describe the level of usage of protective devices and equipment in a cohort of New Zealand rugby players. METHODS:Male and female players (N = 327) from a range of competitive grades were followed over the course of the season. Participants were interviewed weekly about their participation in rugby and use ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-200112000-00024
更新日期:2001-12-01 00:00:00
abstract::The availability of choline, the precurser of the neurotransmitter, acetylcholine, in the diet is sufficient to provide the body's requirements under normal conditions. However, preliminary evidence indicates that depletion of choline may limit performance, while oral supplementation may delay fatigue during prolonged...
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:1995-05-01 00:00:00
abstract:PURPOSE:Walking is likely to contribute substantially to nonexercise activity thermogenesis. The Tracmor triaxial accelerometer system (Maastricht, The Netherlands) is the most widely validated system for detecting body movement in free-living subjects. The aim of this study was to validate the Tracmor triaxial acceler...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-200109000-00024
更新日期:2001-09-01 00:00:00
abstract:PURPOSE:This study was conducted to test the hypothesis of autonomic imbalance in overtrained athletes during sleep and after awakening with analyses of heart rate variability (HRV) and nocturnal urine stress hormones. METHODS:We examined 12 athletes diagnosed to be severely overtrained (OA, 6 men and 6 women, mean ag...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000184631.27641.b5
更新日期:2006-02-01 00:00:00
abstract:OBJECTIVE:To evaluate the effect of chronic moderate-intensity exercise upon the alterations of immune system cell function induced by energy restriction. METHODS:Forty male Wistar rats were randomly assigned to the following groups: sedentary animals fed ad libitum (SF, N = 10) or submitted to energy restriction (SER...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000147626.32295.38
更新日期:2004-12-01 00:00:00
abstract:PURPOSE:To examine serum creatine kinase (CK) activity after resistance exercise bouts with different rest intervals between sets and exercises in high responding (HR) and normal responding (NR) subjects. METHODS:During each resistance exercise bout, three sets with 10-repetition maximum (10RM) loads were completed fo...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3181ca7e16
更新日期:2010-07-01 00:00:00
abstract:PURPOSE:During and following exercise there are a number of changes in pulmonary function, among which is a decrease in forced vital capacity (FVC). Several potential mechanisms may explain this decreased FVC, including an exercise-induced increase in thoracic blood volume. METHODS:We tested the hypothesis that altere...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199807000-00003
更新日期:1998-07-01 00:00:00
abstract:INTRODUCTION:Oral beta2-agonist administration improves muscle function in persons without asthma. We performed a double-blind, randomized, controlled crossover study to assess whether acute inhaled salbutamol administration improves muscle strength and fatigability in healthy moderately trained subjects. METHODS:Quad...
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.0b013e31816b87aa
更新日期:2008-07-01 00:00:00
abstract:UNLABELLED:Cell-derived procoagulant microparticles (MP) might be able to contribute to exercise-induced changes in blood hemostasis. PURPOSES:This study aimed to examine (i) the concentration and procoagulant activity of cell-derived MP after a moderate endurance exercise and (ii) the differences in the release, clea...
journal_title:Medicine and science in sports and exercise
pub_type: 临床试验,杂志文章
doi:10.1249/MSS.0b013e3182068645
更新日期:2011-07-01 00:00:00
abstract::Due to the invasiveness of direct techniques and problems that constrain the use of popular indirect techniques during very heavy (non-steady-state) exercise, measurements of maximal cardiac output are seldom included in studies of exercise. The acetylene-rebreathing technique is well-suited for maximal exercise; howe...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/00005768-198410000-00016
更新日期:1984-10-01 00:00:00
abstract:PURPOSE:Exercise is associated with altered gut microbial composition, but studies have not investigated whether the gut microbiota and associated metabolites are modulated by exercise training in humans. We explored the impact of 6 wk of endurance exercise on the composition, functional capacity, and metabolic output ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000001495
更新日期:2018-04-01 00:00:00
abstract:PURPOSE:To investigate the maximal physiological responses between aquatic and land-based graded exercise tests in overweight women. METHODS:Twenty healthy, overweight (body mass index (BMI) > or = 25 kg.m(-2)), Caucasian women (mean +/- SD; age 48 +/- 7 yr, BMI 30 +/- 4 kg.m(-2)) completed a deep water running (DWR) ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e318164d0e0
更新日期:2008-05-01 00:00:00
abstract:BACKGROUND:Recent work has identified deficits in dual-task gait balance control for up to 2 months after adolescent concussion; however, how resumption of preinjury physical activities affects recovery is unknown. PURPOSE:The objective of this study is to examine how return to activity (RTA) affects recovery from con...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000000462
更新日期:2015-04-01 00:00:00
abstract::Previous research on catecholamine (CA) response to exercise has linked heightened adiposity to a hypostress syndrome. In the present study a cognitive/psychomotor stressor was employed to determine whether this association exists during less metabolically challenging tasks. Moreover, because stress is manifested in a...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1995-03-01 00:00:00
abstract:PURPOSE:The objective of this study is to determine whether childhood muscular fitness phenotypes (strength, endurance, and power) are independently associated with adult metabolic syndrome (MetS). METHODS:We conducted a longitudinal study including 737 participants who had muscular fitness measures in 1985 when age 9...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000000955
更新日期:2016-09-01 00:00:00
abstract:PURPOSE:High internal stress is considered to be a possible cause of heel-pad problems. External biomechanical measurements are used to attempt to understand the causes of heel pain. However, internal stress cannot be measured experimentally. Therefore, the purpose of this study was to quantify the relationship between...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:2005-06-01 00:00:00