Ventilatory Threshold Related to (V)over dotO₂reserve, Heart Rate Reserve, and Rating of Perceived Exertion in a Large Varied Sample

Purpose: ACSM guidelines state that aerobic exercise intensity should be 30%/40% to 89% (V)over dotO(2)reserve ((V)over dotO(2)R) 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 (V)over dotO(2peak), (V)over dotO(2)R, HRR, and RPE across the full spectrum of very low to very high (V)over dotO(2peak) values. Methods: Eight hundred and sixty-three records of exercise tests were retrospectively examined. Data were stratified for (V)over dotO(2peak), activity level, age, test modality, and sex. Results: When stratified for (V)over dotO(2peak), (V)over dotO(2) at VT ((V)over dotO(2)vt) had a lower mean value of similar to 14mL.kg(-1).min(-1) in the lowest fit, rose gradually until median (V)over dotO(2peak), and rose steeply thereafter. When graphed relative to (V)over dotO(2peak), (V)over dotO(2)vt as a percentage of (V)over dotO(2)R (VT%(V)over dotO(2)R) resembled a U-shaped curve, with a nadir similar to 43% (V)over dotO(2)R at (V)over dotO(2peak) similar to 40mL.kg(-1).min(-1). Average VT% (V)over dotO(2)R increased to similar to 75% in groups with the lowest or highest (V)over dotO(2peak). There was a large variance in the value of VT at all (V)over dotO(2peak) levels. Mean RPE at VT was 12.5 +/- 0.93, regardless of (V)over dotO(2peak). Conclusions: Given the relationship of VT as the transition from moderate- to higher-intensity exercise, these data may help the understanding of aerobic exercise prescription in persons across the spectrum of (V)over dotO(2peak) values.