Related Experiment Video
Updated: Aug 10, 2026
Assessment of Physical Activity Intensity with Accelerometers and Oxygen Consumption
Published on: June 20, 2025
Nonexercise models for estimating VO2max with waist girth, percent fat, or BMI
Larry T Wier1, Andrew S Jackson, Greta W Ayers
1Kelsey-Seybold Clinic, NASA/Johnson Space Center, Houston, TX, USA. larry.t.wier1@nasa.jsc.gov
Unlabelled:
Previously published nonexercise models using either percent fat or body mass index (BMI) as body composition measures provided valid estimates of VO2max.
Purpose:
This study was conducted to investigate the use of waist girth (WG) as a body composition surrogate in the nonexercise models and to compare the accuracy of nonexercise models that include WG, %fat, or BMI.
Methods:
A total of 2417 men and 384 women were measured for VO2max by indirect calorimetry (RER > 1.1); age (yr); gender by M = 1, W = 0; self-report activity habit by the 11-point (0-10) NASA physical activity status scale (PASS); WG at the apex of the umbilicus; %fat by skinfolds; and BMI by weight (kg) divided by height squared (m).
Results:
Three models were developed by multiple regression to estimate VO2max from age, gender, PASS, and either WG (R = 0.81, standard error of estimate (SEE) = 4.80 mL.kg.min), %fat (R = 0.82, SEE = 4.72 mL x kg(-1) x min(-1)), or BMI (R = 0.80, SEE = 4.90 mL x kg(-1) x min(-1)). Cross-validation by the PRESS technique confirmed these statistics. Accuracy of the models for predicting VO2max of subsamples was supported by constant errors (CE) < 1 mL.kg.min for subgroups of gender, age, PASS, and VO2max between 30 and 50 mL x kg(-1) x min(-1) (70% of the sample). CE were > 1 mL x kg(-1) x min(-1) for VO2max < 30 and > 50 mL x kg(-1) x min(-1).
Conclusions:
Waist girth is an acceptable surrogate for body composition in the nonexercise models. All models were similar in accuracy and valid for estimating VO2max of most adults, but with reduced accuracy at the extremes of fitness (VO2max < 30 and >50 mL x kg(-1) x min(-1)).
