This is indeed the energy required at a given velocity ,in a nice world without friction forces, nor any fluid drag. It gets much worse for us engines trying to power through wind. The power required to overcome the air drag of a particle moving at a given velocity is a cubed function of the velocity, not a squared function of velocity as with no air drag. So to answer the OPS question, if he were to ride a 5 miles course and wanted to burn the most energy, he should proceed to finish that course as quickly as possible. (ohh now we neglect the caloric loss due cold temps, good enough)