So, I must do "run" checks every so often. Israel runs four times his land speed (20 feet into 80 feet), for X times his Constitution Score (X being 16), so after 16 rounds Israel would've ran 1,280 feet (or 380 meters). So after he ran his 1,280 feet, he must successfuly do its Constitution checks to continue running afterwards. Israel knows this is quite the task, but he won't cast any spell, instead, he'll just run.
After his 1,280 feet, here are the constitution checks (spoilered inside the spoiler].
Spoiler
Show
DC 10 [roll0] Up to 1,360 ft.
DC 11 [roll1] Up to 1,440 ft.
DC 12 [roll2] Up to 1,520 ft. < Stops Here.
DC 13 [roll3] Up to 1,600 ft.
DC 14 [roll4] Up to 1,680 ft.
DC 15 [roll5] Up to 1,760 ft.
DC 16 [roll6] Up to 1,840 ft.
DC 17 [roll7] Up to 1,920 ft.
DC 18 [roll8] Up to 2,000 ft.
DC 19 [roll9] Up to 2,080 ft.
DC 20 [roll10] Up to 2,160 ft.
DC 21 [roll11] Up to 2,240 ft.
DC 22 [roll12] Up to 2,320 ft.
DC 23 [roll13] Up to 2,400 ft. < Maximum posible.
After that, Israel rests for a minute (if necesary, cause I don't know the total distance for fifty laps in X court. And continues running.
Spoiler
Show
DC 10 [roll14] Up to +1,360 ft.
DC 11 [roll15] +Up to 1,440 ft.
DC 12 [roll16] +Up to 1,520 ft. < Stops Here.
DC 13 [roll17] +Up to 1,600 ft.
DC 14 [roll18] +Up to 1,680 ft.
DC 15 [roll19] +Up to 1,760 ft.
DC 16 [roll20] +Up to 1,840 ft.
DC 17 [roll21] +Up to 1,920 ft.
DC 18 [roll22] +Up to 2,000 ft.
DC 19 [roll23] +Up to 2,080 ft.
DC 20 [roll24] +Up to 2,160 ft.
DC 21 [roll25] +Up to 2,240 ft.
DC 22 [roll26] +Up to 2,320 ft.
DC 23 [roll27] +Up to 2,400 ft. < Maximum posible.