Insights into Anaerobic Power Reserve On Relationships with Exercise Tolerance, Work Above Critical Power, and Accumulated Oxygen Deficit in Endurance-Trained Male Cyclists: A Pilot Study

The anaerobic power reserve (APR) model seeks to account for the heterogeneity in athletes' anaerobic characteristics. However, its relationship with exercise tolerance across various durations and with anaerobic markers remains unclear. Therefore, we investigate the relationship between APR, exercise tolerance, work above critical power (W'), and maximal accumulated oxygen deficit (MAOD) in male cyclists. We further analyzed this relationship replacing maximal aerobic power (MAP) with critical power (CP) as the lower boundary of the power reserve,, defining a so-called maximal power reserve (MPR). After preliminary tests, 19 endurance-trained male cyclists performed five trials to exhaustion (Tlim) at 130%, 115%, 100%, 85%, and 80% of maximal aerobic power (MAP) and Wingate test. APR and MPR correlated with all Tlim values (r> 0.493, p = 0.03), except at 80%MAP. After controlling CP or MAP, only correlations with supramaximal Tlim remained significant (r> 0.703, p< 0.002). When PPO was fixed, only MPR correlated with Tlim at 130% and 115%MAP (r> 0.508, p = 0.037). Both APR and MPR were associated with MAOD and W′ (r = 0.480–0.542, p = 0.045), but only MPR remained significantly related to MAOD after adjusting for lower boundary (r= 0.488, p= 0.040). Our findings showed that in endurance-trained male cyclists, both power reserves relate to exercise tolerance, however their influence decreases for longer efforts. MPR exhibited a stronger link to anaerobic capacity compared to APR. The association between exercise tolerance and APR/MPR appear largely driven by peak power output (PPO), rather than the choice of lower boundary.