Any way to manually edit the LOAD on an activity?

I completed the following workout and it was a 17 hour total time run through the Grand Canyon. I needed to turn off wrist HR to keep the battery from dying on me, and now i'm getting nearly no effect for the workout. 

Can anyone point me in the direction of what's needed to get this to "count" as it's ruining a lot of my Garmin metrics to use load/effort this month for other workouts.