Effect of a Previous Sprint on the Parameters of the Work-Time to Exhaustion Relationship in High Intensity Cycling

The relationships between both metabolic (E) and mechanical (W) energy expended and exhaustion time (t e ), was determined for 11 well-trained subjects during constant load cycloergometric exercises at 95, 100, 110, 115% maximal aerobic power performed both from rest and, without interruption, after an all-out sprint of 7 s. These relationships were well described by straight lines: y = a + bt e , where b was taken as the critical power (metabolic and mechanical) that can be sustained for long periods of time. b was unaffected by the exercise conditions and amounted to 82-94% of maximal aerobic metabolic and mechanical power. The constant a was taken as the anaerobic stores capacity in excess of the O 2 deficit. When the test was preceded by the sprint, a (metabolic and mechanical) was reduced to about 60-70% of control values. This reduction was essentially equal to the corresponding E and W output during the sprint. These data support the view that the slope of linear regressions of E and W on t e is indeed a measure of the critical power, whereas the y intercept of these same regressions is a measure of the anaerobic capacity.