Originally Posted by asgelle

Don' just make things up.

Using the defaults at analyticcycling.com, a 165 lb bike+rider would coast down a
5% grade at 33 mph so a rider would have to brake to go 29 or 31 mph. That said, The rider would have to brake 105W to go down hill at 29 mph and 61W for 31. You could say that's an increase of 44W to go from 29 to 31. On the other hand for our rider to climb at 8 mph takes 280W and 394W for 11 mph. An increase of 114W. It looks to me like 44 is a lot less than 114.

You might also choose your work more carefully. This has nothing to do with efficiency. The word is speed. "When it comes to speed, it takes ... ."