How much energy does it really take to toast a slice of bread

Take a slice of bread and put it in the toaster. As soon as it is ready and well buttered, watch the video of Robert Förstemann, a German Olympic medalist cyclist, who uses an exercise bike to provide the toaster with enough energy to toast a slice. He pushes on the pedals with all his strength for about sixty seconds, then collapses. The toast comes out passably toasted.