New fitness monitors handy, dandy

Awake or asleep, working out or chowing down, keep tabs on your training progress with a new generation of fitness monitors. Thinkstockphotos.com

You've certainly seen them -- bright rubber bracelets adorning the wrists of women and men on the street, in the gym and in your office. They are not souvenirs from a concert you missed; they're a new generation of fitness monitors designed to track daily activity, sleep and energy expenditure.

While heart-rate monitors and GPS-enabled gadgets measure intensity and performance while you exercise, fitness monitors let you see what happens in between workouts. By tracking multiple data points, they help you understand how active you are overall and how daily decisions may affect how you feel, eat, sleep and perform athletically.

The monitors let you set customizable goals so that you are tracking progress in a way that's relevant to you. For example, celebrity trainer Harley Pasternak has clients use the Fitbit to understand their activity patterns, so they know if they are being active enough but can make sure they're not overtraining.

But which monitor is right for you? Here's a closer look at four devices:

The motivator

The Fitbit Flex ($99.95) tracks daily steps, distance, calories and sleep. It syncs your data wirelessly with a Web-based dashboard and mobile app and presents the information in easy-to-understand graphs and charts. You can enter additional information such as weight, meals (log your food by picture, keyword or barcode scanning), mood and additional non-step-based activities, such as yoga or weightlifting, so you can gather a full picture of your health and wellness.

The Flex uses a number of tools to keep you motivated, like LED lights on the wristband that show progress toward your daily goal. It also boasts an active online community, allowing you to compete with or support your friends and family, and awards badges for daily, weekly and lifetime achievements.

The data hound

Worn by tennis champ Victoria Azarenka, UP by Jawbone ($129.99) offers the most sophisticated data tools of the bunch. It tracks the same data as the Fitbit Flex but does more with it. Not only can you view your data historically, but you can also plot it against other factors to see how, for example, exercise affects your sleep patterns. UP can also send you reminders to move when you've been idle for too long.

But that's not all. While the Fitbit Flex will act as a silent alarm, UP offers "smart" alarm features customized to you. For example, its alarm will gently wake you during a state of light sleep so that you wake up feeling less groggy. Want a power nap? UP will analyze your sleep patterns, determine the optimal nap duration (between 25 and 45 minutes) and wake you. The one downside is that UP doesn't automatically sync to its app. You have to manually plug the wristband in to your smartphone.

The calorie counter

If you want to track your calorie burn as accurately as possible, the Body Media Fit Link ($149) is for you. That's why contestants on "The Biggest Loser" depend on the device. In addition to an accelerometer -- which measures the acceleration of your body, based on movement and gravity, and converts that data into information on steps taken, distance and calories burned -- the Link uses body sensors to measure heat flux, skin temperature and sweat to capture more than 5,000 data points every minute.

The sensors make it more accurate measuring calorie expenditure than other fitness monitors, especially for non-step-based activities. However, you wear the Link around your upper arm instead of your wrist, a major difference between the Link and other monitors.

The Link tracks activity, steps and sleep and syncs with an online activity manager (available by subscription only). You can log your meals to get a clearer picture of calories in/calories out and the nutritional profile of your meals. You can also check your calorie burn for a specific time period or activity, a feature that the other monitors don't offer with as much precision.

The goal achiever

The Nike+ FuelBand ($149) keeps activity tracking to the basics -- counting steps -- and monitors your progress toward reaching a daily goal. Rather than just measuring calories burned, the FuelBand also calculates how much "NikeFuel" you've generated. NikeFuel measures activity levels in a standardized way so that everyone earns the same amount of fuel for the same activity, regardless of body type. The FuelBand's large display lets you view time, steps, calories and fuel on the wristband itself so you don't always have to check your smartphone or computer. The LED display lights up from red to green to show your progress during the day. It also integrates with the Nike+ online community and smartphone application.

The FuelBand is more expensive than its counterparts UP and the Fitbit Flex and does not track sleep. However, if you are primarily concerned with measuring activity levels, don't need the other bells and whistles and want to connect to the Nike+ community, the FuelBand is for you.