Ventilatory Threshold Related to VO₂reserve, 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% VO2reserve (VO2R) 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 VO2peak, VO2R, HRR, and RPE across the full spectrum of very low to very high VO2peak values. Methods Eight hundred and sixty-three records of exercise tests were retrospectively examined. Data were stratified for VO2peak, activity level, age, test modality, and sex. Results When stratified for VO2peak, VO2 at VT (VO2vt) had a lower mean value of ∼14 mL·kg-1·min-1 in the lowest fit, rose gradually until median VO2peak, and rose steeply thereafter. When graphed relative to VO2peak, VO2vt as a percentage of VO2R (VT%VO2R) resembled a U-shaped curve, with a nadir ∼43% VO2R at VO2peak ∼40 mL·kg-1·min-1. Average VT%VO2R increased to ∼75% in groups with the lowest or highest VO2peak. There was a large variance in the value of VT at all VO2peak levels. Mean RPE at VT was 12.5 ± 0.93, regardless of VO2peak. 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 VO2peak values.