Analyzing peak power

I wish to analyze peak power for 10 second / 30second / 60 second bands across an entire ride for individual time trial performances (i.e. outdoor races). I want to understand how well or not I stayed within my planned range. Over sustained efforts straying too far outside the planned range for too long impacts performance where effort is being expended unnecessarily (e.g. burning matches out of corners) to the overall detriment of the race performance. I record my power using a Garmin head unit and have been digging through Garmin Connect, Strava and TR apps trying to find this information and can’t seem to be able to find this kind of analysis. I appreciate any info on where and how to obtain this information.

Sounds like you want rolling mean power over 10/30/60 second intervals? Don’t any of these apps “smooth” the data over windows of settable width?

That said, constant power is fastest only when race conditions are constant.