Anaerobic work capacity in cycling: the effect of computational method

Abstract

Purpose To compare the anaerobic work capacity (AnWC, i.e., attributable anaerobic mechanical work) assessed using four diferent approaches/models applied to time-trial (TT) cycle-ergometry exercise.<p> <p>Methods Fifteen male cyclists completed a 7×4-min submaximal protocol and a 3-min all-out TT (TT_AO). Linear relationships between power output (PO) and submaximal metabolic rate were constructed to estimate TT-specifc gross efciency (GE) and AnWC, using either a measured resting metabolic rate as a Y-intercept (7+ Y_LIN) or no measured Y-intercept (7-Y_LIN). In addition, GE of the last submaximal bout (GELAST) was used to estimate AnWC, and critical power (CP) from TT_AO (CP_3´AO) was used to estimate mechanical work above CP (W’, i.e., “AnWC”). <p>Results Average PO during TT_AO was 5.43±0.30 and CP was 4.48±0.23 W∙kg⁻¹. The TT-associated GE values were~22.0% for both 7+ Y_LIN and 7-Y_LIN and~21.1% for GE_LAST (both P<0.001). The AnWC were 269±60, 272±55, 299±61, and 196±52 J∙kg⁻¹ for the 7+ Y_LIN, 7-Y_LIN, GE_LAST, and CP_3´AO models, respectively (7+ Y_LIN and 7-Y_LIN versus GE_LAST, both P<0.001; 7+ Y_LIN, 7-Y_LIN, and GE_LAST versus CP_3´AO, all P<0.01). For the three pair-wise comparisons between 7+ Y_LIN, 7-Y_LIN, and GE_LAST, typical errors in AnWC values ranged from 7 to 11 J∙kg⁻¹, whereas 7+ Y_LIN, 7-Y_LIN, and GE_LAST versus CP_3´AO revealed typical errors of 55–59 J∙kg⁻¹. <p>Conclusion These fndings demonstrate a substantial disagreement in AnWC between CP_3´AO and the other models. The 7+ Y_LIN and 7-Y_LIN generated 10% lower AnWC values than the GE_LAST< model, whereas 7+ Y_LIN and 7-Y_LIN generated similar values of AnWC.