If the first thing you do upon waking up is slip off your Jawbone UP health monitoring bracelet and plug it into your iPhone to see how you’ve slept, followed by checking how many steps you took yesterday on your Fitbit, then monitoring your heart rate, checking your mood, and manually entering what you eat and drink into various self-trackers and apps, welcome to the age of quantified self.

With an estimated $800 million in sales of wearable monitoring devices last year, this sensor-happy gluttony of self-tracking is shaping up to be a biological metric of the future.

“I remember when I was learning to drive, my dad taught me to check all the dipsticks and the tires, and now my car just knows what it needs," says John deSouza, CEO of MedHelp.org, the world’s largest online health community, which serves more than 130 million patients annually and houses the largest repository of self-reported medical data. “[The car's computer] tells me when it needs to be serviced, and they plug it in and tell me exactly what is misfiring and which tire is low on air.”

Similarly, our bodies already have the health information we need; we’re just now learning how to download and read it.

But is all this self-tracking necessary?

Well, if you’ve ever used a scale or kept a checkbook, you’ve self-monitored. But does self-monitoring help your health and/or change your habits, or is it all an exercise in time-wasting technology, like a round of Words with Friends?

Dr. Robert Epstein, senior research psychologist at the American Institute for Behavioral Research and Technology and the author of "Self-Help Without the Hype," says the explosion of new self-monitoring tools is a positive step.

“Research shows clearly that heightening awareness of one's performance virtually always improves that performance — smarter eating, higher productivity, superior performance in sports, and so on.”

Using Nike’s FuelBand, for example, lets you compare yourself to others in your age group, which is highly motivating, and the exercisers' algorithms can be used to analyze data to make recommendations for improvement.

“There is a plus side to sharing data, and I think it’s been shown in a number of contexts, in terms of weight control or exercise, it can be highly motivating to have friends or people close to you sharing your information and trying to achieve the goal together,” says Dr. Jack Smith, professor of microbial and molecular pathogenesis in the Texas A&M Health Science Center College of Medicine.

What data can do

DeSouza recounts occasionally feeling completely out of breath while running. His doctor told him he was pushing himself too hard. With the help of a Garmin wristband device, DeSouza noticed that in cold weather he would become breathless when he pushed his heart rate over 180 beats per minute. When he returned to his doctor and shared that information, the doctor diagnosed him with exercise-induced asthma in cold weather.

“It’s incredible that data can give you all these insights to yourself.”

It seems that self-tracking allows you to learn interesting correlations that you may not see otherwise. “It allows you to personalize what’s happening to you and give you a normative baseline on your health before you are sick. That’s extremely valuable,” says deSouza.

The information also allows you to compare your data to other people. The number one question of users of tracking devices is “Am I normal and how does my data stack up against other people like me?”

A lot of health information we have is based on the 35-kilogram-man model, and if you don’t fall into that norm, the data doesn’t often fit you. Imagine being able to go to the doctor with a chart of health data you’ve tracked. You’d get a much better conversation about your health.

From a financial perspective, in a matter of seconds automated systems can look at financial transactions and decide if it was you who made that transaction based on past data. “I think it takes them about 100 milliseconds to decide if a transaction is yours,” says deSouza.

What if the doctor could just look at your data and be alerted to a diagnosis?

What about privacy?

Most of the health-related apps that provide advice or information have more upside than risk. But if personal data like your glucose levels were disclosed to a third party, that might have social, personal or financial implications that are negative, Smith explains. But the history of calories eaten or steps taken — not so much. You want to be careful that only people who have a right to access your data can do so.

Consumers need to be aware of the privacy and security agreements on trackers and review their changes over time. Buyer beware also when it comes to what type of self-monitoring app or device you purchase, as some — like mood trackers — may have sketchy technology. “It’s a bit like using an app that tells you two people are compatible for each other. It may work; it may not work,” says deSouza.

“We're still at the infancy of self-tracking so it’s still more manual then we’d like; it doesn’t do everything for you, but within a couple years I think we will see where the data is being monitored automatically and you’ll learn directly from it — and I think we’ll get there fairly quickly.”

Related health and fitness stories on MNN:

The quantified self: Are we tracking ourselves too much?
The wearable device trend is taking off, recording everything from how well you sleep to how quickly you eat. So can it improve your life?