Skip Navigation



The Journals of Gerontology Series A: Biological Sciences and Medical Sciences Advance Access published online on February 5, 2009
The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, doi:10.1093/gerona/gln025
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
64A/2/293    most recent
gln025v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by McGavock, J. M.
Right arrow Articles by Mitchell, J. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by McGavock, J. M.
Right arrow Articles by Mitchell, J. H.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2009. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oxfordjournals.org.

A Forty-Year Follow-Up of the Dallas Bed Rest and Training Study: The Effect of Age on the Cardiovascular Response to Exercise in Men

Jonathan M. McGavock1,2, Jeffrey L. Hastings2, Peter G. Snell1, Darren K. McGuire1, Eric L. Pacini2, Benjamin D. Levine1,2 and Jere H. Mitchell1

1 Pauline and Adolph Weinberger Laboratory for Cardiopulmonary Research, Internal Medicine and the Donald W. Reynolds Cardiovascular Research Center, University of Texas Southwestern Medical Center, Dallas
2 Institute for Exercise and Environmental Medicine, Presbyterian Hospital, Dallas, Texas

Address correspondence to Benjamin D. Levine, MD, Institute for Exercise and Environmental Medicine, Presbyterian Hospital, 7232 Greenville Ave, Dallas, TX 75231. Email: benjaminlevine{at}texashealth.org


  Abstract

Background: In 1966, five 20-year-old men underwent a comprehensive physiological evaluation of the capacity for adaptation of the cardiovascular system in response to 3 weeks of bed rest and 8 weeks of heavy endurance training; these same participants were reevaluated before and after training at the age of 50. The aim of the present study was to reexamine these same men 40 years following the original assessments.

Methods and Results: In all three studies, minute ventilation and expired gases were analyzed during exercise testing with Douglas bag collection. Cardiac output (CO) was determined using the acetylene rebreathing technique. Compared with the original 30-year interval, the decline in maximal oxygen uptake (VO2max) (–11% vs –25%), maximal CO (+6% vs –11%), and maximal stroke volume (+10% vs –10%) were greater between 50 and 60 years of age. The annualized decline in VO2max (55 mL/min/y) between ages 50 and 60 was approximately fourfold higher than the decline between 20 and 50 years (12 mL/min/y).

Conclusions: In the original five participants of the Dallas Bed Rest and Training Study, VO2max declined after 40 years of living due to a balanced decrease in central and peripheral determinants of oxygen uptake. The rate of decline in VO2max and its components accelerated after the age of 50 years secondary to age and clinical comorbidities. The net proportional decline in VO2max for a period of 40 years of life was comparable with that experienced after 3 weeks of strict bed rest at the age of 20 (27% vs 26%, respectively).

Keywords Maximal oxygen uptake; Cardiac output; Arteriovenous oxygen difference; Longitudinal

Received: March 12, 2008; Accepted: July 27, 2008

Decision Editor: Luigi Ferrucci, MD, PhD


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.