The chart to the left is from the same athlete who I gave a hard time to last week for doing a hill reps workout with positive splits on each work interval and a positive trend for the entire hill reps portion. In other words, she was starting out at too high of an effort on each work interval and then fading as each progressed. And she was fading as the workout progressed. This is the way most athletes train and race in steady state events such as time trials, triathlons and running races.
You'll recall that I made the point that you should make the first part of the workout and race feel much easier than the second half by holding back a bit at the start. In a flat race with no wind the first half of the race would be completed in about 51% of the total race time, the second half in about 49%. The above chart is from a workout one week following the workout for which I gave her so much criticism. You can see here that she completed the workout exactly as it should be done. The work intervals trend upward to the right slightly and increase in intensity as the session progressed. Very well done.