Whether it's a Fitbit, Garmin Vivofit, Jawbone or a fitness tracking app on a smartphone, you've likely discovered that fitness trackers are the gift that keeps on giving — and giving and giving — you copious amounts of data.
So what to do with all those reports you're receiving on your heart rate, steps taken and calories burned?
The answer depends on your personal interests and fitness goals.
Why we like feedback
Quantity is an inherent part of athletics. People, particularly the competitive ones, strive to run the fastest, hit the hardest, swim the farthest. We know we've come closer to beating records or meeting our personal bests by tracking time, speed and distance. Fitness tracking devices make keeping track of what we're doing and how well we're doing it as easy as pushing a button and strapping a band onto our wrist.
This practice has come widely into vogue in recent years and has been redefined as a concept and movement called the "quantified self," which one California-based company, Quantified Self Labs, summarizes as "self-knowledge through numbers."
Online media outlet LiveScience now devotes an entire section to the subject, noting that, "Wearable devices such as activity trackers, along with apps that let us log our every step, snack and snooze could bring us a better understanding of ourselves, our nature and may even benefit our health."
While some insurance companies and private health care providers have taken an interest in individual fitness data, it's still seems best designed for personal use.
According to an article posted in the Brigham and Women's Hospital Bulletin, clinicians are not inclined to comb through weeks' worth of someone's data. "We need real clinical trials to validate that these sensors measure what they say they are measuring, and we need to determine if they are of value in a clinical setting. That will require FDA approval and time," said Dr. Adam Landman, BWHC chief medical information officer for Health Information, Innovation & Integration.
Tuan Nguyen, a fitness director and personal trainer for Berkshire West Athletic Club in Pittsfield, Mass., said the major appeal with fitness trackers is their ability to equip a user real-time feedback and a sense of accountability.
"It's all about personalized information rather than generalized info," he said.
So, instead of guessing that an hour of running or Zumba could burn 600 to 800 calories, people can actually see what they're getting out of a workout at their own rigor and pace, and use that information to modify their activity to alter the outcomes.
What you see and what you get
Just as people vary, so do their fitness goals, and so it's important to use a device that works best with your lifestyle and needs.
For many device owners, using a fitness tracker is simply an investment in personal motivation.
"It's like having a cheerleader with you at all times," said Mary Makuc of Monterey, Mass.
Makuc, who has a spinal cord injury that's left her left side partly paralyzed from her leg to her chest, found that her Samsung smartphone fitness app wasn't sensitive to her movements beyond steps.
"But my arms are fine," said Makuc, who can swim, do chair yoga and every day calorie-burning activities like washing dishes. After browsing online forums of people with limited mobility, she found that the Nike+ Fuel Band could track her upper body movements, too.
"For me, it's not just about steps it's about activity. [The feedback is] very encouraging. It actually says, 'Go, Mary!' on it. And that's really helping me to be more active every day," said Makuc, who noted she's also been able to reduce her body mass index by a point since she started using the device at the start of this year.
A basic device will give basic data for someone who is curious about how much they move through the day, while advanced and intermediate devices can provide the data and tools to more seriously track a person's health as it applies to fitness, activity and other health targets.
Fitness data can also be synced with other online fitness and nutrition tracking apps, like the popular MyFitnessPal, to further customize health and wellness goals.
Fitbit, which is now a household name in digital fitness tracking devices, has a web page designed to help its customers find a device that works with a person's fitness goals and interests.
The "everyday" devices track the basics: steps, distance and calories burned and minutes of activity. The "active" devices add on features, like floors climbed, sleep tracking and continuous heart rate. And the "performance" devices pack in all of these tools plus additional features, like music, GPS and caller ID.
Getting the data is one thing, but understanding how to use it effectively is another, fitness experts say.
Nguyen said one key activity to track is your heart rate and the number of heart beats that occur per minute of activity.
The American Heart Association says people should calculate their resting heart rate, the beats per minute when not doing any intentional activity, and then their target heart rate, the number of beats per minute that occur while exercising. "You want to stay between 50 percent to 85 percent of your maximum heart rate," the AHA writes. Maximum heart rate is typically calculated by taking the number 220 and subtracting your age.
"Each person's target heart rate determines their fitness level, and whether you're over-training or under-training affects the level of workout," said Nguyen.
Under-training occurs when you're not meeting your target heart rate. So, it's great if you're walking thousands of steps each day, because any movement is good movement. But, Nguyen warned, you may not see your weight loss or endurance goals if you're not meeting your target heart rate.
"If you're under-training, you're not getting much of workout and not burning enough calories to meet your fitness goals," he said.
"Over-training can be just as dangerous," Nguyen added. "If a person exceeds their target heart rate this could lead to injury, dehydration, dizziness or, if done consistently, chronic pain."
When trying to find out the best and safest workouts for you, a device is no replacement for a physician or certified fitness professional, but the data you get from a device can still be a motivating and helpful tool to guide you toward the best plan of action.
"Using a fitness device gives us an understanding where our heart rate is and where we should be. It gives people the mindset of knowing that what we're doing is correct, right on their wrist," Nguyen said.