Ventilatory thresholds differences according to aerobic fitness level in 1450 males and 241 females on cycle-ergometer: a cross-sectional study

The aim of the study was to analyze the influence of an aerobic fitness level on the percentage of maximum oxygen con-sumption, heart rate, and power output (%VO2max, %HRmax, and %Wmax) at which ventilatory thresholds 1 (VT1) and 2 (VT2)occur during a ramp incremental cycle‐ergometer test in males and females considering age. 1450 males and 241 femalesperformed a ramp incremental exercise test until exhaustion to determine VT1, VT2, and VO2max. Combining the oxygenconsumption at VT1, VT2, and VO2max by clustering analysis, males were classified as a low, medium, or high aerobic fitnesslevel and females were classified as a low or high aerobic fitness level. Results showed VO2max was very poorly correlated withthe %VO2max at which VT1 and VT2 occur (r ≤ 0.115), whereas oxygen consumption at VT1 and VT2 showed a stronger positiveassociation with the %VO2max at which VT1 and VT2 occur, respectively (r = 0.357–0.604). Furthermore, the %VO2max at whichVT1 and VT2 occur were greater the higher the aerobic fitness level (all p ≤ 0.002), observing a high heterogeneity in the%VO2max at which VT1 and VT2 occur even stratifying the sample by sex and aerobic fitness levels. In conclusion, the per-centage of maximum at which VT1 and VT2 occur are better related to oxygen consumption at VT1 and VT2, respectively, thanto VO2max. Moreover, the common strategy consisting of establishing exercise intensity as a fixed percentage of maximum mightnot be effective to match intensity across individuals even if sex and aerobic fitness levels is considered.