Introduction: Anaerobic capacity, defined as the maximum amount of anaerobic energy release during exercise, is generally calculated according to the maximal accumulated oxygen deficit (MAOD) method, gross efficiency (GE) method or the concept of critical power. All of these methods assume a constant GE during exercise. However, recent literature showed that gross efficiency (GE) declines during exercise and therefore influences the estimated expenditure of anaerobic and aerobic resources [1]. Therefore, the purpose of the current study was to compare the calculated anaerobic work (AnW) produced during cycling time trials of different length, with and without a GE correction for a decline in GE. Methods: AnW was calculated in eighteen trained competitive cyclists during four different time trials (500-m, 1000-m, 2000-m, and 4000-m). GE was estimated at the start and finish [1] of the time trial. To give insight in the rate of decline of GE during the time trial, two time trials were reproduced (1000-m and 4000-m) and stopped at 50% of the corresponding `full` time trial, which provided an estimate of GE at 50% of the corresponding `full` time trial. Results: AnW during time trial exercise corrected for a decline in GE was 30% (confidence interval [25, 36%]) higher (p < 0.001) compared to AnW without a GE correction. A significant interaction effect between calculation method (constant GE, declining GE) and distance (500-m, 1000-m, 2000-m, 4000-mp) was found (p < 0.001). Further analysis revealed that the calculated AnW with GE correction was different from AnW without GE correction for all time trial distances. AnW calculated without GE correction did not result in equal values for AnW calculated over different time trail distances (p <0.001), which is in contradiction with the concept of a constant anaerobic capacity. However, AnW with correction for a declining GE did result in a constant value for anaerobically attributable work (p = 0.18). Conclusion: AnW calculated during short time trials (< 4000-m) with a correction for a declining GE is 30% [25, 36%] higher compared to anaerobic capacity calculated assuming a constant GE. The concept of a constant anaerobic capacity was only supported when AnW during time trials was calculated with a correction for a decline in GE during the race. Therefore, AnW calculated corrected for a decline in GE may represent anaerobic energy contributions during high intensity exercise better than calculating AnW assuming a constant GE.
© Copyright 2014 19th Annual Congress of the European College of Sport Science (ECSS), Amsterdam, 2. - 5. July 2014. Veröffentlicht von VU University Amsterdam. Alle Rechte vorbehalten.