The Suunto X3HR is 'the' training watch for the active outdoorsperson. It integrates an altimeter function with a heart rate monitor - to keep a pulse on you and your environment. This unique combo lets you get the most out of your outdoor workouts. The altimeter monitors terrain variations during running, triathlon training, hiking, and mountain or road biking. Weather functions allow you to predict weather changes and plan accordingly. The heart rate monitor gives comprehensive feedback on your performance. The smaller overall size is ideal for men and women who don't like oversized watches and/or have smaller wrists.