In cycling, improved efficiency means that for a given wattage output, oxygen consumption (VO2) should decrease, or for a given VO2, power output should increase.

“the more he trained the less efficient he got meaning that yeah he could he could deliver more oxygen to his muscles he could he could deliver more aerobic energy but he he used more aerobic energy in order to maintain a given pace”

“for a given output how much oxygen how much input do you need to get this output and an athlete over time should get better and better for a fixed wattage you want to see what's called pvo2 come down”

“for a given output how much oxygen how much input do you need to get this output and an athlete over time should get better and better for a fixed wattage you want to see what's called pvo2 come down so power at a given vo2 should actually come down as you get better and running this would be the vvo2 you want to get faster as oh as so for a given oxygen consumption you want velocity to go up”

“if you look at the efficiency you get a much more interesting story which is that he started out at his most efficient when he was untrained and the more he trained the less efficient he got meaning that yeah he could he could deliver more oxygen or to his muscles he could he could deliver more aerobic energy but he he used more aerobic energy in order to maintain a given pace”