Take the guesswork out of heart rate training—one of the best ways to get fit fast—with Pear ($249; pearsports.com), an innovative device that puts the expertise of world-class coaches at your fingertips. Once you identify your goal (anything from weight loss to completing your first 5K), Pear’s free web-based program will create a custom training plan that syncs up with its Square One device. During your workouts, the device constantly monitors your level of exertion via the included heart rate monitor and foot pod. Slack off and a coach will interrupt your music to tell you to pick it up. Work too hard and they’ll ask you to slow down. With the push of a button, you can also get stats, such as pace, distance and time, on demand without breaking stride. Using Pear, it’s so easy to succeed, it almost feels like cheating.