Why are my Paceline Minutes different from my actual Workout duration?

I wore my device and exercised for more minutes than what displays in the Paceline app. What happend?

Paceline minutes are equal to the amount of time you maintained an elevated heart rate, so it is expected that the total duration of your workout may be different than the amount of Paceline Minutes you received. 

This is because during a workout, there are times where you’re doing activities that do not generate elevated heart rate (eHR) minutes -- such as stretching, resting, or pausing for a drink of water.