VENTILATORY THRESHOLD

Ventilatory Threshold



Ventilatory Threshold

Introduction

Aerobic exercise is a decisively important component of any fitness program. However, establishing and maintaining ideal workout intensities for the most effective and safe workouts can prove to be a challenge for both exercisers and fitness professionals alike. In designing the cardiorespiratory exercise prescription, it is meaningful to consider that many people engage in aerobic exercise to control weight, improve their health status or reduce their disease risk. Knowing your client's goals and purposes for doing aerobic exercise helps to best determine the intensity, frequency, duration and progression of the exercise prescription.

Traditionally, aerobic exercise programs have been developed around accepted standards of percentages of maximum heart rate and oxygen consumption (VO2). For instance, the American College of Sports Medicine (ACSM) recommends between 55-90% of maximum heart rate or 40-85% of maximum oxygen uptake for most individuals (ACSM 1998). Although the success of these techniques has been consistently demonstrated, many fitness enthusiasts find the necessary objective monitoring, such as continuously checking heart rates, to be difficult and sometimes tedious.

Recent studies have helped validate an easier way to stay on track - the Talk Test. This method appears to be a simple way of maintaining recommended exercise intensities, while avoiding the problems of the more involved practices of heart rate and VO2 assessment (Persinger et al., 2004).

How the Talk Test Works

The Talk Test was developed to be an informal, subjective method of estimating appropriate cardiorespiratory exercise intensity. The method entails maintaining an intensity of exercise at which conversation is comfortable. When an exerciser reaches an intensity at which he or she can “just barely respond in conversation,” the intensity is considered to be safe and appropriate for cardiorespiratory endurance improvement. The newest research supports the usefulness of the Talk Test and highlights its ability to closely reflect actual heart rate and VO2 levels (Persinger et al., 2004).

The Purpose of the Study

This study examined the consistency and effectiveness of the Talk Test as a tool for exercise prescription on the treadmill and cycle ergometer, hypothesizing that the ability to vocalize correlates positively with aerobic exercise intensity on both of these modes of exercise. Thus the researchers were specifically interested in the consistency of the Talk Test for intensity monitoring on a treadmill and cycle ergometer.

The Subjects

Ten male and six female participants (average age = 24 yrs) volunteered to participate in this study. All subjects were considered to be healthy and moderately active. Participants were pre-screened for contraindications to exercise testing prior to the study.

The Testing

All participants performed four separate exercise tests, completing two assessments on a treadmill and two on an electronically braked cycle ergometer. These tests were performed on different days, at the same hour each day. The order of testing was randomized.

The exercise protocol was designed to best meet each participant's individual exercise capacity. To accomplish this, the treadmill speed was set at a pace that the subjects subjectively felt they could comfortably exercise “virtually indefinitely”, which was either walking or ...