# Improving exercise capacity in chronic obstructive pulmonary disease patients through uphill walking

> **NIH VA I21** · OMAHA VA  MEDICAL CENTER · 2021 · —

## Abstract

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality and presents an
important healthcare problem, especially for Veterans. Prevalence of COPD in the Veteran population ranges
from 33%-43%, a higher prevalence than among the general population of the United States. COPD patients
experience diminished exercise capacity. A significant portion of this limitation in exercise capacity is due to
dynamic hyperinflation and dyspnea. Humans demonstrate a coupled relationship between walking and
breathing. Our preliminary data indicates that patients with COPD demonstrate an abnormal coupling pattern
compared to those without COPD, using one stride for one breath, even at speeds outside of their self-selected
walking pace. Current pulmonary rehabilitation relies on increasing intensity of exercise through accelerated
walking. Based on coupling patterns in patients with COPD, increasing speed leads to an increase in
respiratory rate, dynamic hyperinflation, and dyspnea, thus limiting exercise time. The goal of this proposed
project is to investigate, in Veteran COPD patients, the effect of walking faster vs. walking on a slope
on dynamic hyperinflation and dyspnea, oxygen uptake and dead space, and walking and breathing
coupling. We hypothesize that walking on a slope will alter breathing and walking coupling, lower
respiratory rates, and reduce dynamic hyperinflation and associated dyspnea. We predict that walking
on a slope will permit an increase in oxygen uptake and a decrease in dead space in patients with
COPD as compared to accelerated walking speeds. These hypotheses will be tested through three aims: 1)
Identify differences in dynamic hyperinflation and dyspnea; 2) Compare differences in respiratory rate, oxygen
uptake, and lung dead space; 3) Determine the complexity of walking and breathing coupling ratios. In this
cross-sectional study, Veterans with COPD will be recruited and screened using a cardiopulmonary exercise
test. A total of 25 eligible Veterans will be enrolled through stratified sampling of disease severity. The time
course of work rate will be calculated from the cardiopulmonary exercise test. The speed and slope that
corresponds to 70%-80% of peak work rate will be used. An additional constant work rate test will be given
using increases in speed with a level treadmill to determine the speed that elicits oxygen uptake comparable to
the sloped walking test. Subjects will be asked to perform two experimental trials (walking faster vs. walking on
a slope) at 70%-80% peak work rate. Measures of dynamic hyperinflation, dyspnea, oxygen uptake, dead
space, and coupling will be recorded during all walking trials. Possible covariates will also be collected. We
anticipate that dynamic hyperinflation and dyspnea will be reduced in patients with COPD due to slower
walking and slower respiratory rates during sloped walking as compared to faster level walking. It is expected
that this will be influenced by the...

## Key facts

- **NIH application ID:** 10060752
- **Project number:** 5I21RX003294-02
- **Recipient organization:** OMAHA VA  MEDICAL CENTER
- **Principal Investigator:** DEBRA J ROMBERGER
- **Activity code:** I21 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2021
- **Award amount:** —
- **Award type:** 5
- **Project period:** 2020-01-01 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10060752

## Citation

> US National Institutes of Health, RePORTER application 10060752, Improving exercise capacity in chronic obstructive pulmonary disease patients through uphill walking (5I21RX003294-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10060752. Licensed CC0.

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