Document Detail


Cardiopulmonary responses of middle-aged men without cardiopulmonary disease to steady-rate positive and negative work performed on a cycle ergometer.
MedLine Citation:
PMID:  10331751     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND AND PURPOSE: Understanding physiological responses to negative work allows therapists to be more knowledgeable when they prescribe this form of exercise. The physiological responses of 12 men without cardiopulmonary disease, aged 39 to 65 years (X=49.7, SD=9.3), to negative work (eccentric muscle contractions) and to positive work (concentric muscle contractions) were compared. SUBJECTS AND METHODS: Subjects performed the 2 types of work on a motorized cycle ergometer at pedaling frequencies of 35, 55, and 75 rpm with a constant power output of 60 W. Steady-rate values of oxygen consumption (VO2), heart rate (HR), minute ventilation (VE), tidal volume (VT), and breathing frequency (fb) were obtained during 6 test conditions (positive and negative work at each of the 3 pedaling frequencies). RESULTS: Values for all measures were greater during positive work than during negative work, except for fb. During positive work, values for all variables were greatest at 75 rpm, except for fb. During negative work, VO2 and HR were greater at 75 and 35 rpm than at 55 rpm, and VE and VT were greater at 75 rpm than at 55 rpm. Breathing frequency was not different among pedaling frequencies. CONCLUSION AND DISCUSSION: The results confirmed that negative work performed on a cycle ergometer is associated with low metabolic cost in older men without cardiopulmonary disease. Although VE was determined primarily by changes in VT during negative work, a comparable disproportionate increase in fb was observed at the start of negative work. Such changes in breathing patterns have implications for the prescription of negative work for patients with lung disease.
Authors:
F Chung; E Dean; J Ross
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Physical therapy     Volume:  79     ISSN:  0031-9023     ISO Abbreviation:  Phys Ther     Publication Date:  1999 May 
Date Detail:
Created Date:  1999-06-01     Completed Date:  1999-06-01     Revised Date:  2009-11-11    
Medline Journal Info:
Nlm Unique ID:  0022623     Medline TA:  Phys Ther     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  476-87     Citation Subset:  AIM; IM    
Affiliation:
Physiotherapy Department, Burnaby Hospital, British Columbia, Canada.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adult
Aged
Analysis of Variance
Cardiovascular Physiological Phenomena*
Energy Metabolism / physiology*
Exercise Test / methods*
Heart Rate / physiology
Humans
Lung / physiology*
Male
Middle Aged
Muscle Contraction / physiology*
Oxygen Consumption / physiology
Pulmonary Ventilation / physiology
Tidal Volume / physiology

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Effects of repetitive handgrip training on endurance, specificity, and cross-education.
Next Document:  Multiple system atrophy.