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Updated: Mar 19, 2026
Author Spotlight: Integrating Alveolar-Capillary Reserve Measurements in Exercise Adaptation and Therapeutic Strategies
Published on: February 2, 2024
Assessment of double anaerobic threshold in trained subjects
Alessio Pellegrino1, Mauro Contini2, Edoardo Falconi1
1Department of Experimental and Clinical Medicine, University of Florence, Florence 50134, Italy; Sport Medicine Unit, Careggi University Hospital, Florence 50134, Italy.
Background:
Regular training increases Anaerobic Threshold (AT) and improves ventilatory efficiency during exercise. A presence of a Double AT (DT), a delayed ventilatory response to CO2 increase during exercise, was described in some healthy subjects, and may represent a favorable adaptation mechanism for trained subjects. The aim was to investigate the prevalence of DT in trained individuals and the relationship between training and ventilatory efficiency.
Methods:
Maximal CardioPulmonary Exercise Test (CPET) of trained subjects were analysed for assessment of AT with the metabolic (V-slope analysis, MetAT) and the ventilatory methods (end-tidal and ventilatory equivalent methods, VentAT). Trained subjects were assigned to groups DT+ or DT- based on the presence/absence of DT, respectively. Trained subjects were also classified by type of sport practiced. Determinants of ventilatory efficiency were assessed at adjusted multivariate regression analysis.
Results:
DT was identified in 52 cases out of 205 enrolled (25.4%). No differences by age, sex, body mass index and peak CPET parameters were observed between groups. DT+ subjects had a longer duration and greater ΔVO2 values of isocapnic buffering period. Ventilatory efficiency was negatively associated (better values) with the presence of a DT (p = 0.017). Type of sport practiced did not influence the prevalence of DT nor the ventilatory efficiency response.
Conclusion:
DT was found in 25.4% of trained people. The presence of DT is not influenced by the type of training and is not related to maximal aerobic capacity; however, subjects with a DT have a greater isocapnic buffering period and a better ventilatory efficiency.
