Ventilatory Threshold Related to V̇O2reserve, Heart Rate Reserve and Rating of Perceived Exertion in a Large Varied Sample.

Abstract

ACSM guidelines state that aerobic exercise intensity should be 30/40-89% V̇O2reserve (V̇O2R) or heart rate reserve (HRR). Determining the proper intensity within this range is the "art" of exercise prescription, often relying on rating of perceived exertion (RPE) as the adjunctive intensity modulator. Current guidelines do not consider the use of ventilatory threshold (VT) due to the need for specialized equipment and methodological issues. The purpose of this investigation was to evaluate VT related to V̇O2peak, V̇O2R, HRR and RPE across the full spectrum of very low to very high V̇O2peak values. 863 records of exercise tests were retrospectively examined. Data were stratified for V̇O2peak, activity level, age, test modality and sex. When stratified for V̇O2peak, V̇O2 at VT (V̇O2vt) had a lower mean value of ~14 ml•kg-1•min-1 in the lowest fit, rose gradually until median V̇O2peak, and rose steeply thereafter. When graphed relative to V̇O2peak; V̇O2 at VT as a % of V̇O2R (VT%V̇O2R) resembled a U-shaped curve, with a nadir ~43% V̇O2R, at V̇O2peak ~ 40 ml•kg-1•min-1. Average VT%V̇O2R increased to ~75% in groups with the lowest or highest V̇O2peak. There was a large variance in the value of VT at all V̇O2peak levels. Mean RPE at VT was 12.5 ± 0.93, regardless of V̇O2peak. Given the relationship of VT as the transition from moderate- to higher-intensity exercise, these data may help the undertanding of aerobic exercise prescription in persons across the spectrum of V̇O2peak values.