Comparison between a 30-s all-out test and a time-work test on a cycle ergometer

Summary

The relationship between the amount of work (W _lim) performed at the end of constantpower exhausting exercise and exhaustion time (t _lim) has been studied for supramaximal exercise [105%, 120%, 135% and 150% of the individual maximal aerobic power, (MAP)] performed on a Monark cycle ergometer in nine men. TheW _lim -t _lim realtionship was described by a linear relationship (W _lim =a+b·t _lim). Intercepta was roughly equivalent to the work produced during a 1-min exercise performed at MAP. Slopeb was equal to 79% of MAP. Intercepta has been correlated with the total amount of work (AW) performed during a 30-s all-out test supposed to assess anaerobic capacity. Intercepta was significantly (p<0.05) correlated with AW. The anaerobic capacity was not depleted at the end of the all-out test, as the mechanical power at the 30th s of this test was approximately equal to twice MAP. However, AW was significantly higher than intercepta. It was likely that the value of intercepta was an underestimation of the maximal anaerobic capacity because of the inertia of the aerobic metabolism. Indeed, an exponential model of theW _lim-t_lim relationship, which takes the inertia of the aerobic metabolism into account, shows that a linear approximation of theW _lim-t _lim relationship yields a systematic underestimation of the anaerobic capacity. Consequently, intercepta of theW _lim-t _lim relationship is not a more accurate estimation of the anaerobic capacity than the AW performed during a 30-s allout test. The inertia of the aerobic metabolism could also explain: (i) that slopeb of theW _lim-t _lim relationship was lower than MAP, and (ii) that a significant correlation between the anaerobic threshold and slopeb of theW _lim-t _lim relationship has been found previously.