Abstract:
:Estimates of muscular efficiency in competitive and recreational cyclists at similar work intensities and cycling frequencies were examined. Twelve healthy college-age male nonsmoker volunteers were grouped as either competitive (CC; N = 6) or recreational (RC; N = 6) cyclists based upon previous cycling experience. Subjects were studied at pedaling frequencies of 50 and 80 rpm during bouts of graded and submaximal endurance (75% VO2peak) exercise. Between rest and 250 W, we observed no intergroup differences in VO2 (energy input) at either 50 or 80 rpm. Estimates of whole body (gross) muscular efficiency ranged from 15% to 24% in competitive and 13% to 22% in recreational cyclists at 50 rpm but were not different. Delta (delta) efficiencies ranged from 20% to 34% in competitive and from 21% to 28% in recreational cyclists. Delta efficiency decrease from 27% to 21% in competitive cyclists, from 25% to 21% in recreational cyclists as a function of pedaling frequency, and was not different between groups. Competitive cyclists rode longer at both 50 rmp (27 +/- 5 min vs 14 +/- 2 min; P < 0.05) and 80 rpm (35 +/- 4 min vs 20 +/- 4 min; P < 0.05). At 50 rpm (3.08 +/- 0.02 l.min-1 vs 2.78 +/- 0.05 l.min-1; P < 0.01) and 80 rpm (3.14 +/- 0.01 l.min-1 vs 2.7 +/- 0.04 l.min-1; P < 0.001), the mean VO2 was also greater in competitive cyclists. Although both groups showed superior endurance at 80 compared with 50 rpm and total work was approximately double competitive cyclists at each pedaling frequency, we observed no differences in whole body muscular efficiency during sustained exercise at 75% VO2peak. Our results suggested that previous cycling experience was of minor importance when comparing cycle ergometer efficiency between these two groups. The increased endurance at higher pedaling frequencies during submaximal exercise is not explained by altered muscular efficiency.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
Nickleberry BL Jr,Brooks GAdoi
10.1097/00005768-199611000-00008subject
Has Abstractpub_date
1996-11-01 00:00:00pages
1396-401issue
11eissn
0195-9131issn
1530-0315journal_volume
28pub_type
临床试验,杂志文章abstract:PURPOSE:In order to investigate overtraining-related adaptations in the autonomic nervous system, cardiac autonomic activity was examined in a junior cross-country skier who presented with reduced performance in competitions, early breathlessness during training sessions, and accumulated central fatigue. METHODS:Power...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-200009000-00001
更新日期:2000-09-01 00:00:00
abstract:PURPOSE:The purpose of this investigation was to determine whether whole body composition could be estimated in tall individuals using summed measures from two partial DXA scans. METHODS:Using a pencil-beam DXA, a convenience sample of young individuals (N = 19) were scanned three times. Two partial scans of the upper...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000170077.87301.65
更新日期:2005-07-01 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:BACKGROUND:For optimal health benefits, moderate- to vigorous-intensity physical activity (MVPA) is recommended in sustained bouts lasting ≥10 min. However, short spurts of MVPA lasting <10 min are more common in everyday life. It is unclear whether short spurts of MVPA further protect against the development of hypert...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000000662
更新日期:2015-11-01 00:00:00
abstract:PURPOSE:The study purpose was to determine the relationship: 1) of muscle metabolism to exercise performance and 2) of exercise performance to rate of weight gain. METHODS:Eighty-three black and white premenopausal women were evaluated for maximum oxygen uptake (VO2max ), isometric quadriceps and triceps surae strengt...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.MSS.0000048641.47125.1C
更新日期:2003-02-01 00:00:00
abstract::Sprint-trained athletes demonstrate a remarkable ability to perform exercise which results in fatigue quickly. However, the mechanisms for these enhanced performance capabilities have not been fully elucidated. Elevation in glycolytic enzymes and increased fast-twitch fiber compositions which would result in an enhanc...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,评审
doi:
更新日期:1984-08-01 00:00:00
abstract::Data obtained from 16-mm film of world caliber Olympic weight lifters performing at major competitions were analyzed to study energy changes during body segment and barbell movements, energy transfer to the barbell, and energy transfer between segments during the lifting movements contested. Determination of barbell a...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1982-01-01 00:00:00
abstract:PURPOSE:This study investigated the changes in running mechanics and spring-mass behavior over a 24-h treadmill run (24TR). METHODS:Kinematics, kinetics, and spring-mass characteristics of the running step were assessed in 10 experienced ultralong-distance runners before, every 2 h, and after a 24TR using an instrumen...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3181fec518
更新日期:2011-05-01 00:00:00
abstract::It is commonly believed that exposure to cold environmental temperatures depresses immune function and increases the risk for infection. This review paper will 1) present an overview of human physiological responses to cold exposure, 2) present the human studies examining the effects of cold exposure on immune respons...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,评审
doi:10.1097/00005768-200212000-00023
更新日期:2002-12-01 00:00:00
abstract:PURPOSE:sarcopenia plays a principal role in the pathogenesis of frailty and functional impairment that occur with aging. There are few published accounts that examine the overall benefit of resistance exercise (RE) for lean body mass (LBM) while considering a continuum of dosage schemes and/or age ranges. Therefore, t...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,meta分析,评审
doi:10.1249/MSS.0b013e3181eb6265
更新日期:2011-02-01 00:00:00
abstract:PURPOSE:The purpose of this study was to determine the accuracy and reliability of the following electronic pedometers for measuring steps: Freestyle Pacer Pro (FR), Kenz Lifecorder (KZ), New Lifestyles NL-2000 (NL), Omron HJ-105 (OM), Oregon Scientific PE316CA (OR), Sportline 330 (SL330) and 345 (SL345), Walk4Life LS ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.MSS.0000089342.96098.C4
更新日期:2003-10-01 00:00:00
abstract:PURPOSE:To compare the historical evolution of performance for males and females in anaerobically dominated sprint events in three different sports: running, swimming, and speed skating. METHODS:Times of the top six finishers in a total of 283 men's and women's Olympic and world championship finals held between 1952 a...
journal_title:Medicine and science in sports and exercise
pub_type: 历史文章,杂志文章
doi:10.1249/01.mss.0000247005.17342.2b
更新日期:2007-03-01 00:00:00
abstract:PURPOSES:To compare the claudication distances between men and women patients with peripheral arterial disease (PAD), and to determine whether sex differences in claudication pain persisted after controlling for potential confounders such as demographic, functional, and physiological measures. METHODS:A total of 488 m...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-200211000-00001
更新日期:2002-11-01 00:00:00
abstract:PURPOSE:To compare pacing and performance of schoolchildren between running tasks where the end point was defined in units of either distance or time. METHODS:Thirty-eight schoolchildren (age = 12.6 ± 0.5 yr, mass = 46.2 ± 7.5 kg, stature = 150 ± 7 cm) first performed a best-effort 750-m running task on a 150-m runnin...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e318271edfb
更新日期:2013-02-01 00:00:00
abstract::To investigate the possible role of elastic potentiation on mechanical efficiency, three male marathon runners were filmed while running on a treadmill at various steady-state speeds ranging from 7.0-22.0 km X h-1. Kinematic and mechanical energy analyses were performed from the film. Expired air was collected for ene...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/00005768-198315040-00009
更新日期:1983-01-01 00:00:00
abstract:PURPOSE:The aim was to determine the feasibility of a 6-wk speed-based exercise program that could be used to initiate new exercise behaviors and to improve rapid movement in older adults approaching frailty. METHODS:The intervention group included 14 older adults (3 males and 11 females; mean ± SD, age = 70 ± 7.6 yr,...
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.0000000000001069
更新日期:2017-01-01 00:00:00
abstract::This article focuses on sports related spinal cord and nerve injuries, ranging from mild "stinger" syndrome to complete quadriplegia. Particular emphasis is placed on recommendations for return to competition after such injuries. Cervical spinal cord symptoms after a spine injury from contact sports require a more pre...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199707001-00005
更新日期:1997-07-01 00:00:00
abstract:PURPOSE:Existing studies have failed to provide evidence of a positive effect on exercise performance by wearing compression short tights covering only both thighs. This could be due to an inadequate pressure intensity that otherwise has a significant effect if applied on the crucial point in the thigh. This study aime...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000000330
更新日期:2014-11-01 00:00:00
abstract:PURPOSE:Light-intensity physical activity (LIPA) accounts for much of adults' waking hours (≈40%) and substantially contributes to overall daily energy expenditure. Encompassing activity behaviors of low intensity (standing with little movement) to those of higher intensity (slow walking), LIPA is ubiquitous, yet littl...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000000631
更新日期:2015-10-01 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::Two studies were conducted to test the validity of an all-out procedure for the assessment of the maximal accumulated oxygen deficit (AOD). Subjects in study 1 (N = 9; VO2max = 57 +/- 3 ml.kg-1.min-1 [+/- SEM]) completed three supramaximal efforts on a cycle ergometer. Exhaustive exercise during an all-out isokinetic ...
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:1995-02-01 00:00:00
abstract:PURPOSE:Prolonged sitting time (ST) is associated with higher mortality. However, previous studies used only a single measure of ST at baseline, so they could not directly assess the effect of continued exposure to high ST, or of changes in ST, on mortality. We prospectively assessed the association of continued sedent...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3182897e87
更新日期:2013-08-01 00:00:00
abstract::The 1-mile run/walk test is the field test of choice for evaluating maximal aerobic power (VO2max) in school-aged children. The objective of this study was to determine the relative importance of selected metabolic determinants of mile run/walk performance in children 6-14 yr of age. Mile run/walk time (MRWT), VO2max,...
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: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::By placing the muscles of the take-off leg in faster eccentric or slower concentric conditions, a high jumper can increase the ground reaction force and the height of the jump. Film analysis of seven high jumpers showed that the radial velocity of the center of mass with respect to the supporting foot was more negativ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/00005768-198806000-00014
更新日期:1988-06-01 00:00:00
abstract:UNLABELLED:Environmental heat stress degrades aerobic performance; however, little research has focused on performance when the selected task elicits modest elevations in core body temperature (<38.5 degrees C). PURPOSE:To determine the effect of environmental heat stress, with modest hyperthermia, on aerobic performa...
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.0b013e3181adb9fb
更新日期:2010-01-01 00:00:00
abstract:PURPOSE:Type 2 diabetes is associated with increased risk of cardiovascular disease and elevated C-reactive protein (CRP) levels. Aerobic exercise training has been shown to improve CRP; however, there are limited data evaluating the effect of other exercise training modalities (aerobic, resistance, or combination trai...
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.0b013e31824526cc
更新日期:2012-06-01 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::Vigorous exercise is associated with a sensation of well-being, and this subjective state has been objectively quantified with psychometric, cardiovascular, and neurophysiological data. Reductions in state anxiety have been demonstrated to follow acute physical activity, and this response persists for 2-5 h. Chronic p...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,评审
doi:
更新日期:1985-02-01 00:00:00
abstract:PURPOSE:Recent literature suggests that subconcussive impacts may influence cognitive functioning across the life span. These effects are suggested to manifest as functional and possibly structural changes. Head impact biomechanics during American football have been characterized from the high school to professional le...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3182798758
更新日期:2013-04-01 00:00:00