The Science Journal of the American Association for Respiratory Care

2008 OPEN FORUM Abstracts

COMPARING PREDICTIONS OF MAXIMUM AEROBIC CAPACITY USING SUBMAXIMAL EXERCISE PROCEDURES IN A SMALL SAMPLE OF UNIVERSITY STUDENTS

Jennifer Chism1, Kelly Hargrave1, Angela Hill1, William S. Chism1, Destiny Sharp1



Background: Maximum aerobic capacity (VO2 max) reflects how well oxygen is supplied to and used by skeletal muscle during mechanical work. As a global indicator of a person's pulmonary, cardiac, vascular and neuromuscular function, VO2 max is useful to grade baseline physical disability and an individual's progress during cardiopulmonary rehabilitation. However, to measure it directly requires exercising to exhaustion. This degree of effort is often not advisable in older or physiologically compromised patients. To address this limitation, several methods to estimate VO2 max require only moderate physical exertion. The purpose of this preliminary study was to examine if 3 of these produce similar results.

Methods:
In a convenience sample of five healthy university students, maximum aerobic capacity was predicted by: 1. Track Walk, based on elapsed time and heart rate after a brisk one-mile walk; 2. Treadmill Walk, based on submaximal heart rate and indirect calorimetry VO2 measurements made while walking on a treadmill using a Balke protocol; and 3. Nomogram Prediction, derived from a standardized gender, age, weight and height-based regression equation. The data were analyzed for significant mean differences with one-way analysis of variance, ANOVA.

Results:
There were no significant differences in predicted VO2max among the methods examined (F=0.704, df 2/14, p=.514). VO2 max predictions were: Mean (SEM) Track Walk 2.63 (.33) L/min; Treadmill Walk 2.60 (.36) L/min; and Nomogram 2.16 (.24) L/min, n=5.

Conclusion:
There is internal agreement among the methods chosen to estimate VO2 max in this small sample of young, healthy subjects. Treadmill or track walking procedures where individual performance is assessed may be acceptable for diagnostic purposes and structuring individualized rehabilitation programs in the absence of a direct measure of maximum aerobic capacity. Further study is needed in a larger, older sample to determine how well these methods perform.