Abstract des Autors

The VO2-power regression and O2 demand predicted for a supra-VO2peak intensity (i.e., 432 W) were determined in seven well-trained male cyclists, using five incremental exercise protocols. These protocols were either continuous (CON) or discontinuous (DISCON), and comprised five to eight work bouts ranging in intensity between 40% and 85% VO2peak; the work bouts differed in duration (4-15 min), and the VO2 was measured during the 4th minute (CON4, DISCON4), from min 4 to 6 (DISCON6), 8 to 10 (DISCON10), or 13 to 15 (DISCON15) of each work bout. The y-intercepts of the VO2-power regressions were not different, whereas the slope was higher when determined using DISCON10 (12.7+/-0.9 ml/min/W) and DISCON15 (12.5+/-0.9 ml/min/W) compared with DISCON6 (12.2+/-1.0 ml/min/W), DISCON4 (11.6+/-1.1 ml/min/W) or CON4 (11.9+/-0.7 ml/min/W). The O2 demand (at 432 W) was also higher for DISCON10 (6.05+/-0.29 l/min) and DISCON15 (6.05+/-0.28 l/min) compared with DISCON6 (5.88+/-0.31 l/min), DISCON4 (5.70+/-0.31 l/min) and CON4 (5.82+/-0.25 l/min). This demonstrates that the O2 demand predicted for high power outputs depends on the incremental protocol used. Verf.-Referat