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. McGavock, Jeffrey L Hastings, Peter G. Snell, Darren K McGuire, Eric L. Pacini, Benjamin D Levine, Jere H Mitchell

Research output: Contribution to journalArticle

22 Citations (Scopus)

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 VO 2max (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).

Original languageEnglish (US)
Pages (from-to)293-298
Number of pages6
JournalJournals of Gerontology - Series A Biological Sciences and Medical Sciences
Volume64
Issue number2
DOIs
StatePublished - Feb 2009

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Bed Rest
Exercise
Cardiac Output
Oxygen
Acetylene
Cardiovascular System
Stroke Volume
Ventilation
Comorbidity
Gases

Keywords

  • Arteriovenous oxygen difference
  • Cardiac output
  • Longitudinal
  • Maximal oxygen uptake

ASJC Scopus subject areas

  • Aging
  • Geriatrics and Gerontology
  • Medicine(all)

Cite this

@article{ca7bbe3b5d9c4f66ade9c6137b7ee424,
title = "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",
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 VO 2max (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 = "Arteriovenous oxygen difference, Cardiac output, Longitudinal, Maximal oxygen uptake",
author = "McGavock, {Jonathan M.} and Hastings, {Jeffrey L} and Snell, {Peter G.} and McGuire, {Darren K} and Pacini, {Eric L.} and Levine, {Benjamin D} and Mitchell, {Jere H}",
year = "2009",
month = "2",
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language = "English (US)",
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journal = "Journals of Gerontology - Series A Biological Sciences and Medical Sciences",
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T1 - A forty-year follow-up of the Dallas Bed Rest and Training Study

T2 - The effect of age on the cardiovascular response to exercise in men

AU - McGavock, Jonathan M.

AU - Hastings, Jeffrey L

AU - Snell, Peter G.

AU - McGuire, Darren K

AU - Pacini, Eric L.

AU - Levine, Benjamin D

AU - Mitchell, Jere H

PY - 2009/2

Y1 - 2009/2

N2 - 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 VO 2max (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).

AB - 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 VO 2max (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).

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KW - Longitudinal

KW - Maximal oxygen uptake

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