Related Experiment Video
Updated: May 17, 2026

Dual Test Gas Pulmonary Diffusing Capacity Measurement During Exercise in Humans Using the Single-Breath Method
Published on: February 2, 2024
Longitudinal cardiorespiratory fitness algorithms for clinical settings
Andrew S Jackson1, Xuemei Sui, Daniel P O'Connor
1Department of Health and Human Performance, University of Houston, Houston, Texas 77204-6015, USA. udde@mac.com
New algorithms estimate cardiorespiratory fitness (CRF) using longitudinal health data. These non-exercise models accurately track CRF changes over time in men and women.
Area of Science:
- Cardiorespiratory fitness assessment
- Longitudinal data analysis
- Non-exercise algorithms
Background:
- Current non-exercise algorithms for cardiorespiratory fitness (CRF) estimation are limited by their cross-sectional data development.
- Cost-effective CRF estimation in healthcare settings is crucial.
Purpose of the Study:
- To develop novel non-exercise algorithms for estimating CRF in men and women.
- Utilize longitudinal data for improved accuracy and tracking of CRF changes.
Main Methods:
- Analysis of longitudinal data from 1325 women and 10,040 men (aged 20-86).
- Included two to 21 maximal treadmill tests per participant between 1977 and 2005.
- Independent variables: age, body composition (fat %, BMI), waist circumference, physical activity, resting heart rate, smoking behavior.
Main Results:
- All tested health indicators were independently associated with CRF.
- Positive correlation between physical activity and CRF.
- Higher body fat and BMI, elevated resting heart rate, and smoking were linked to lower CRF.
- Error estimates for percentage fat algorithms: women 1.41 METs, men 1.54 METs; BMI algorithms: women 1.51 METs, men 1.66 METs.
Conclusions:
- Easily obtainable health indicators can accurately estimate CRF in both men and women.
- Longitudinal non-exercise algorithms enable precise tracking of CRF changes with aging.
- Provides cost-effective tools for monitoring CRF in clinical settings.
Related Concept Videos
Respiratory Volumes and Capacities
Respiratory Volumes and Capacities I
Respiratory Capacities
One key metric is the Inspiratory Capacity (IC), which represents the maximum amount of air that can be inhaled with full effort. IC is calculated by summing the tidal volume and inspiratory reserve volume, typically ranging from 2.4 to 3.6 liters.
The Functional Residual Capacity (FRC) represents the air in the...
Assessment of Respiration
Subjective Assessment: Nurses interview the patient to gather information directly during the subjective assessment. It includes questions about the individual's medical history, medications, and symptoms, focusing on past respiratory conditions like asthma or COPD,...
Assessment of Ventilation II: Respiratory Depth and Rhythm
Respiratory depth measures the volume of air inhaled or exhaled during a breath. It can vary from shallow to deep and typically remains consistent when a person is at rest or asleep. Occasionally, individuals will automatically inhale deeply, known as sighing, which inflates the lungs with more air than normal breathing.
To assess respiratory depth, observe the degree of chest excursion or movement:
Respiratory Volumes
Tidal Volume (TV) Tidal volume (TV) is the air inhaled or exhaled in a...
