Runners love to tell you about their post-workout highs, but they rarely mention the mid-workout delirium that comes when muscles deprive your brain of blood, leading to doubts about how long you've been running, what your target heart rate should be, and indeed how to get home again. Garmin's updated Forerunner GPS watches actually can't help with that last one, but the larger touch bezel on the new and 410 (above) means oxygen-deprived cardio hounds can easily scroll through data describing things like pace and heart rate, even when it's raining -- or you're sweating exces
