Importing mountainbike rides (with no power data) from Strava. Should I?

My riding is split between trainer rides, recently with Sufferfest and will now be trying out Xert workouts, and good ol’ fashion dirt rides. I have a smart trainer and a heart monitor so that data is good. For most of my off historical mtb rides, I have no heart rate data and surely no power data.

Going forward, lets say my trainer rides are done with Xert, if I go out and do a hard mountainbike ride without Xert being aware of it, is it going to jack with the analysis and predictions?

Thanks!

Have a peek at a couple of FAQs: 1 - How to choose your Athlete Type 2. How to add rides where you didn’t have a power meter.
These both help get an understanding of how to keep your data up-to-date.