9 x 15 sec. hill sprints at the end, walking down for recovery. Gave the effort an 8 because of the hill sprints. The 5 miles before that were easy & I kept my HR down! You can see, after the HR data settled in, that the hill sprints definitely brought it up. Whoop says my recovery is normal with HRV at 57 & it gave this run a 14.1 Strain Score.