It takes the Forerunner 610 on average 60 meters to recognize a change in speed from 8-minute miles to 7-minute pace. This rapid reaction time is a standout quality that is especially useful during interval workouts done off a track. Plus, the surprisingly intuitive—although not iPhone easy—touchscreen interface and ability to quickly locate satellites make the 610 easier to use than its predecessors. These features, combined with its size and battery life, make the 610 the best running training tool we have tested. It is not, however, a true multisport watch. Its bike functions are limited and swim functions are nonexistent.