# Bug in graph

Maybe there’s something I’m missing but I don’t think this line can go back up.

It could be correct.  As a simple example, consider you rode for the following sequence 1 min at 300 W, 5 minutes at 100 W, 1 min at 300 W, 5 minutes at 100 W, and so on.

Your best 5 minute power average is (1 min * 300W + 4 min * 100 W)/5 minutes = 700 W / 5 min = 140 W.

Your best 7 minute power average is (1 min * 300W + 4 min * 100 W + 1 min * 300 W)/7 minutes = 1000 W / 7 min = 143 W.

It takes a very special case but it can be correct.

It’s too early in the morning (I made a cut and paste error).  The best 7 minute power average is (1 min * 300 W + 5 min * 100 W + 1 min * 300 W) = 1100 W / 7 min = 157 W.

Thanks for your reply. It works using the formula you’ve outlined. But from a critical power perspective, it doesn’t seem to make any sense that one is able to output higher wattage over a longer duration that over a shorter one. In your example, I think it would make sense to make the 5 minutes value match the 7 minutes value so that it’s a downward or flat graph.

When I first saw a curve like this I also thought it made no sense.  After thinking about it, I’ve accepted this as fine because it’s what you actually did (based on how they compute it).  Since it’s been this way for a long time, I’m not in favor of them changing it.

In terms of what you are _ capable of _, I agree, longer time will always be strictly less than or equal to a shorter time.

Hmmm, I guess we’ll have to disagree on this one. To me, it goes against the core concept of critical power. That being said, it is an edge case.

In theory, Kevins example works on a very short ride with precise power changes to the hypothesized levels.  In reality, on a 1 hour and 45 minute ride, it is not very likely to occur.  There must be a problem in graphing calculations.

Pascal PT,

You’ll see dips like this frequently in CP charts, have you tried using anything else to analyse your rides /workouts like GoldenCheetah  or Trainingpeaks ?

http://www.goldencheetah.org/#section-tutorials