Ratings of perceived exertion at anaerobic threshold in patients with coronary artery disease

Meire Forti,Tarcísio Augusto Gonçalves Nery,Antonio Roberto Zamunér,Ester Da Silva,Mariana Rodrigues Salviati,Vandeni Clarice Kunz

doi:10.1590/1809-2950/37321022014

Abstract

The study aimed to identify and compare the ratings of perceived exertion (RPE) at the ventilatory anaerobic threshold (VAT) in healthy subjects and patients with coronary artery disease (CAD). A total of 30 male subjects took part in the study and were divided into three groups: a control group (CG) composed of 10 healthy participants; a group composed of 10 participants diagnosed with CAD beta-blocker user (G-DACb); and a group composed of 10 participants with CAD non-beta-blocker user (G-DAC). The participants performed a cardiopulmonary exercise test (CPET) with continuous type ramp protocol to determine the VAT, through the visual graphical analysis (loss of parallelism between the oxygen uptake and the carbon dioxide output). During CPET, before the end of each one-minute period, the subjects were asked to rate dyspnea (RPE-D) and leg fatigue (RPE-L) on the Borg CR-10 scale. After the VAT was determined, the score that the participants gave on the Borg CR10 scale was verified. CG participants showed higher workload, oxygen uptake, carbon dioxide output, ventilation and heart rate at the VAT compared to the G-DAC and G-DACb (p<0.05). However, regarding the RPE-L and the RPE-D, no significant difference between the groups were observed (p<0.05). Values between five and six on Borg CR-10 scale matched the VAT in the subjects studied. However, other parameters must be concomitantly used for prescribing exercise intensity in physical training protocols, at levels close to the VAT for patients with CAD.

Highlights

A sedentary lifestyle has been considered the main modifiable risk factor for coronary artery disease (CAD)[1]
We verified that the body mass index was lower in the control group (CG) compared to the CAD-G, while heart rate (HR) was lower in the CADb-G group compared to the CAD-G
Our purpose was to identify and compare the values of ratings of perceived exertion (RPE)-L and RPE-D obtained at the ventilatory anaerobic threshold (VAT) moment in healthy individuals and patients with CAD who used and did not use beta-blocker medication, as well as to verify the relation of the ventilatory and metabolic variables and power with RPE

Summary

Introduction

A sedentary lifestyle has been considered the main modifiable risk factor for coronary artery disease (CAD)[1]. Regular physical exercise can reduce cardiac mortality from 20 to 30% along with lifestyle changes[2]. The dropout rate in physical conditioning programs and cardiac rehabilitation is approximately 45%3. One of the main problems related to adhering to physical exercise programs is the difficulty to achieve and maintain the intensity prescribed for training[4]. Some authors[5] report that intensities close to the ventilatory anaerobic threshold (VAT), the level of physical exercise at which the production of energy by the aerobic metabolism is supplemented by the anaerobic metabolism[6], are an indispensable parameter for effective training and are safe in regards to potential cardiovascular events

Methods

Results

Conclusion