Validation of FRIEND and ACSM Equations for Cardiorespiratory Fitness: Comparison to Direct Measurement in CAD Patients.

Won Young Jang,Seung-Young Roh,Yoonjee Park,Eung Ju Kim,Seung-Woon Rha,Jin Oh Na,Chang Gyu Park,Jah Yeon Choi,Dong Oh Kang,Jieun Lee,Se-Hyun Park,Cheol Ung Choi,Woohyeun Kim,Yuna Jang,Hong Seog Seo,Woo-Sub Kim

doi:10.3390/jcm9061889

Abstract

The regression equation of the American College of Sports Medicine (ACSM) was a preferred method for estimating maximal oxygen consumption (VO2max). Recently, a more precise equation from the fitness registry and the importance of exercise national database (FRIEND) for healthy people was developed. This study compared VO2max estimated by the ACSM and FRIEND equations to VO2max directly measured in coronary artery disease (CAD) patients. Overall, 293 CAD patients who participated in cardiac rehabilitation between June 2015 and December 2018 were analyzed. Directly measured VO2max values were compared to the ACSM and FRIEND equations. The directly measured VO2max was significantly different from the estimated VO2max by ACSM equation (24.16 vs. 28.7 mL/kg/min, p < 0.001), which was overestimated by 20% in men and 16% in women. However, there was no statistically significant difference between the directly measured VO2max and the estimated VO2max by the FRIEND equation. (24.16 vs. 24.15 mL/kg/min, p = 0.986). In CAD patients, the estimated VO2max from the ACSM equation was significantly higher than the directly measured VO2max. In addition, estimated cardiorespiratory fitness (CRF) by the FRIEND equation showed similar results with directly measured CRF. As a result, the FRIEND equation can predict CRF more accurately than the ACSM.

Highlights

Cardiorespiratory fitness (CRF) is defined as the circulatory and respiratory ability that supplies oxygen properly to the skeletal muscles during physical activity and the ability of the muscle to extract oxygen [1]
We analyzed 293 coronary artery disease (CAD) patients who underwent percutaneous coronary intervention (PCI) and who participated in cardiac rehabilitation
There was a significant difference in excellent effort among sexes; 51% was achieved by men and only 28% was achieved by women (Table 2)

Summary

Introduction

Cardiorespiratory fitness (CRF) is defined as the circulatory and respiratory ability that supplies oxygen properly to the skeletal muscles during physical activity and the ability of the muscle to extract oxygen [1]. Many studies have shown that a better CRF lowers the risk of development and recurrence of coronary artery disease (CAD) and all-cause mortality [2,3,4,5,6]. Performing exercise tests for CRF measurement is strongly recommended in CAD patients without any contraindications [7]. CRF is measured by maximal oxygen uptake (VO2max). This metabolic demand for a given work rate has been expressed in metabolic equivalents (METs). One MET is equivalent to the amount of oxygen consumed at rest (~3.5 mL O2/kg/min) [8,9]

Methods

Results

Conclusion