This was a good long run because it looked calm, useful, and well paced for most of the session. After the opening kilometres, you settled into a long steady block mostly around 6:15 to 6:34 per kilometre, which gave the run real endurance value without making it feel like a grind.
What makes it more encouraging is the way the run finished. The late lift into the high 5:50s did not look chaotic or desperate; it looked like there was still room in the legs after more than 80 minutes of controlled work. That is a better signal than the watch's VO2 max estimate right now, because it shows usable strength and rhythm inside the session itself.
The caution is that the cost was still real. Heart rate climbed late and briefly touched a level that will always look dramatic on the watch, but the overall feel, pacing, and structure suggest this was more a steady long run with a purposeful finish than a run going off the rails. That means the next step can now be real quality, not another placeholder easy day.
Takeaway. Good endurance signal and good late strength. The body handled this long run well enough that the next move should be a controlled faster session to work economy and race rhythm, rather than another purely easy outing.
Next step. Interval Sessions. Make the next run a true interval session. Keep the fast blocks quick enough to matter, but smooth enough to repeat well.