Aaron H. Gouw1, Gary P. Van Guilder1, Arnar Larusson2, Gregory Laredo2, Ryan M. Weatherwax3, Bryant R. Byrd1, Lance C. Dalleck1. Ventilation can exclusively be used to predict ventilatory thresholds: a retrospective analysis. 1High Altitude Exercise Physiology Program, Western Colorado University, Gunnison, CO, USA. 2Tyme Wear Inc., Boston, MA, USA. 3Department of Health & Kinesiology, University of Utah, Salt Lake City, UT, USA.


Aim: We retrospectively analyzed a cohort of graded exercise tests (GXT) and compared ventilatory thresholds (VT1 and VT2) predicted from ventilation (PRED) to ventilatory thresholds derived from the gold-standard method using indirect calorimetry (TRUE). Methods: A cohort of 202 participants (132 women, 70 men; age range 18–69 years) completed GXT in the High Altitude Performance Laboratory at Western Colorado University between September 2014 and February 2020. Bland–Altman 95% limits-of-agreement were used to quantify the agreement between TRUE and PRED VT1 and VT2. Results: For VT1 time point detection, the mean differences between TRUE and PRED were -0.05 ± 1.28 min (95% CI, -2.56 to 2.46 min). For VT2 time point detection, the mean differences between TRUE and PRED were 0.10 ± 1.55 min (95% CI, -2.93 to 3.12 min). Conclusion: In this retrospective study, it was shown that modeling ventilation data elicited acceptably accurate estimates for VT1 and VT2 time point detection, workloads, and heart rates during both treadmill and cycle ergometer GXT. These novel findings are encouraging and provide critical preliminary data for the successful translation of the threshold-based training paradigm to a larger demographic of the population.