The workout music selection is limited to playlists (you can even download preselected Nike-branded workout playlists in iTunes, one of which should have come free with the kit), shuffle music, or none. We all know music is a motivator as you're cruising down Main Street, but the voice prompts do give you an intangible push. One should be able to program prompts like "You are one slow runner, dude." We'd love to see a system that adjusts the tempo for a song based on your pace--that would be cool, though you can activate PowerSong, a "motivational" song of your choosing, by holding down Select. My current PowerSong is "Push the Button." What's yours?
Once you've completed a session, you can connect your Nano to a computer and transfer the workout data to the Nike + Web site. The interface is intuitive with nice colors, comparative charts, and rollover data, and you get a sense that this data is really a reflection of you. Once you compile enough data, you can track your progress (or regression) and utilize data such as how many calories you burned in a week or the maximum distance traveled in a session, or even the point at which you engaged the PowerSong. Throw in the various goals, such as workout regimens, group challenges, and even trophies (personal bests), and the experience starts to feel like a video game. Though I personally run only once in a while (unlike CNET's own SF marathon-running Kent German), I did find the data useful. In a way, it made me want to run more often.
My last workout for this review was more realistic--I wore shorts and ran a 2-mile workout (see stats above). I'm going on a longer run to record the accuracy of the pedometer (will report later), but in general, the system seems accurate. The Sport Kit does not use GPS, unlike other fitness systems, and relies on "a sensitive piezoelectric accelerometer that monitors your footstrike when you walk or run and determines the amount of time your foot spent on the ground. This contact time is directly related to your pace." Check out Apple's FAQ. A calibration option allows the software to learn your typical walking and running gaits, though the manual notes, "Even after calibrating, the accuracy of the distance measurements may vary depending on gait, running surface, incline, or temperature." Pedometer-to-Nano latency is about three seconds. We'll also report on how the adapter affects the Nano's battery life.