Today was a beach run on Long Island, in pretty great sand, with a nice breeze. Overall a great run due to the great location! 
No bugs unlike my normal trail runs, too!
At run start, I activated a 0.10U/hr basal on Loop, and ate half a small banana. Unfortunately, I did not estimate pre-run carbs properly again today. I thought because it appeared that I was trending down to 78, I should eat. 1/2 banana was too much though. This is very odd because the last several runs, but not ALL, have had similar results - BG trending down, eat some carbs, then IMMEDIATELY spike on run start. I’m not sure why, maybe the G6 sensor (vs G5) is just quicker to respond??? YES, I’m using Dexcom G6 CGM for these BGs, not finger sticks since G6 (vs G5) seems to be remarkably accurate for me! I think for tomorrow’s run on the beach, I will not eat or eat only a small amount pre-run, and then just be ready with some carbs along the way.
One other note, at run end, I did NOT take a bolus immediately for the carbs. Not a good idea, and not something I usually do, but the graph shows the spike immediately after eating 10g! 
Here are the numbers, per Apple Health watch:
08:18 Run Start, Activate Running20% Override (Basal .10U/hr), BG 78, 1/2 Banana (10g)
08:39 BG 89, Deactivate Running20% Override and resume Schedule Basal of 0.50U/hr
09:00 BG 128, High for the run, but did not take a bolus; let Loop give 1U+ temp basals
10:16 Run end, BG 60
Run time: 1 hr 56 mins
Distance: 10.2 miles
Here is the Tidepool graph…
