Predicting VO(2max) with an objectively measured physical activity in Japanese men

Area of Science:

• Exercise Physiology
• Biometrics
• Public Health

Background:

• Estimating maximal oxygen uptake (VO2max) is crucial for assessing cardiorespiratory fitness.
• Objective measures of physical activity (PA) are needed for accurate VO2max prediction.
• Previous studies have explored non-exercise models for VO2max estimation.

Purpose of the Study:

• To investigate the utility of accelerometer-derived physical activity variables for estimating VO2max in Japanese adult men.
• To develop and validate non-exercise models for predicting VO2max using objective PA data.
• To determine the optimal combination of PA variables for improving VO2max prediction accuracy.

Main Methods:

• Recruited 127 Japanese adult men (aged 20-69 years).
• Measured VO2max via bicycle ergometer maximal incremental test.
• Assessed daily step counts (SC) and moderate-to-vigorous (MVPA) and vigorous PA (VPA) using accelerometers for seven days.
• Developed and cross-validated non-exercise regression models using hierarchical linear regression.

Main Results:

• SC, MVPA, and VPA were significantly correlated with VO2max after adjusting for age (r=0.58, 0.42, 0.51, respectively).
• Models combining age, SC, and VPA with BMI or waist circumference achieved high predictive accuracy (R²=0.71-0.74, SEE=3.9-4.2 ml kg⁻¹ min⁻¹).
• Combining SC with VPA, not MVPA, enhanced VO2max prediction and explained more variance.

Conclusions:

• Accelerometer-derived physical activity variables, particularly step counts and vigorous PA, are valuable for estimating VO2max in Japanese adult men.
• Non-exercise models incorporating objective PA data offer a practical approach to assess cardiorespiratory fitness.
• The findings support the use of SC and VPA in regression models for accurate VO2max prediction.