Digifit Connect 2

Photo: Courtesy of Digifit

The Digifit Connect 2, a transceiver you stick into your Apple device, collects data from a suite of wireless sensors—including ones for your bike and sneakers—so you can adjust your exertion level to reach your fitness goal.

$50 for the device, $10 for the app; DigiFit.com
The Gruve

Photo: Robert Gauthier

Calorie-Burning Power
The Gruve uses your body's vibrations to measure how many calories you're burning during everyday physical activities (like wrestling with laundry). Bonus: If you sit still for too long, it vibrates to remind you to get moving.

$179 (includes a one-year subscription); Gruve.com
Withings' Smart Blood Pressure Monitor

Photo: Courtesy of Withings

Blood Pressure
With Withings' Smart Blood Pressure Monitor, you can upload your readings to an iPhone, iPad, or iPod touch and graph trends over the course of a day or a month or a year. The device makes it simple to share your data with your doctor via e-mail.

$129; Withings.com

Photo: Courtesy of Zeo

Morning Energy
My favorite feature of the Zeo (the sleep-tracking device) was its alarm: Whereas a traditional alarm sometimes jolts you from a deep sleep (which can leave you groggy), the Zeo beeps at a "natural awakening point" when you're transitioning in or out of REM.

$150; MyZeo.com

Next: What happens when you start recording every little detail of your health?