Back in the day, exercise goals were measured in general terms
like laps around a track or miles biked. But today's athletes are as tech-obsessed as those of us who spend our days
slumped in front of a computer exercising our minds instead of our bodies. The New York Times has a good rundown
of some of the more popular gadgets, including old standbys like heart-rate monitors and pedometers, along with newer
tools like GPS systems for runners (like the Garmin Forerunner 301, pictured) and power meters for cyclists. As much as
we love gadgets, we don't need any of these to tell us whether we've exercised enough. We rely, instead, on a proven
method that's served us well over the years: we know we've had enough when we collapse in a heap.