Better Living Through Big Data

How to make sense of your wearable fitness data


Modern wearable devices typically record a range of fitness data that includes steps taken, distance travelled, calories burned, stairs climbed and active minutes. Some use their built-in accelerometers to track your sleeping patterns, while newer devices incorporate heart rate monitors to give you even more data about your health and fitness.

But what does it all mean? What is a healthy heart rate? How many calories is too much? How many steps is a healthy number?

Many people have abandoned fitness devices because they often don’t tell you anything you don’t already know. They visualise the data in pretty graphs; they send you messages to encourage you (or shame you) into walking, running or cycling more. But they don’t tell you why the data matters.

Making sense of fitness data is a huge challenge that many devices (and their companion apps) haven’t truly mastered. They don’t give you enough context, leaving you to identify patterns in the daily and weekly numbers and to translate those patterns into meaningful actions that will benefit your long-term health. Having some guidelines can be useful.

Fitbit health dashboard
The Fitbit dashboard shows you a variety of metrics including steps and sleep. But you need to make sense of them.

For example, according to the NHS, “the average person walks between 3,000 and 4,000 steps per day, and 1,000 steps is the equivalent of around 10 minutes of brisk walking”. A figure of 10,000 steps per day is often bandied around as a healthy amount that goes beyond normal activity.

Steps aren’t always a good metric to track exercise. So fitness bands like the Fitbit Charge and the Jawbone UP24 also measure duration of activity. In this case, the NHS recommends 150 minutes (2 hours 30 minutes) of moderate-intensity aerobic activity per week, whether that’s jogging, fast walking, cycling or playing some sort of sport.

Fitness bands and smartwatches usually help you to guesstimate the number of calories that you’ve burned during periods of activity. But this data isn’t useful unless you know how many calories you have absorbed. Only then can you try to balance the two. Again, the NHS has some recommendations on this – 10,500kJ (2,500Kcal) per day for men, 8,400kJ (2,000Kcal) per day for women.

Not all fitness-orientated devices track sleep and their accuracy can vary. Besides, you know if you’ve had a bad night’s sleep, you don’t need curves of pastel data to tell you that fact. The key is knowing what to do about it so you sleep better the next night. BUPA suggests that “adults need between seven and eight hours of sleep. However, some people can function after sleeping for much less time.”

jawbone sleep tracking
The Jawbone UP3 can identify different stages of slumber, such as REM, Light and Deep Sleep. Try to get more Deep Sleep.

Actionable advice is something that health apps are still coming to grips with. The Jawbone UP3 combines accelerometer and heart rate data to identify the physical characteristics of the different stages of slumber – REM, Light and Deep Sleep. By tracking these metrics the UP3 acts as an automatic sleep diary, while its Smart Coach feature delivers “a range of bite-size, actionable recommendations for a better night of sleep” – cut down on caffeine, reduce screen time, go to bed earlier and let your brain wind down.

In 2015, we’ll start to see the newest fitness bands and smartwatches including heart rate monitors as standard. According to the Mayo Clinic, “a normal resting heart rate for adults ranges from 60 to 100 beats a minute.” In general, a slower resting heart rate is an measure of a stronger and healthier heart. A higher resting heart rate indicates that the heart is working harder to pump blood around the body, which may be caused by excess weight.

Another sensor we’ll be seeing more of is one that measures Galvanic Skin Response (GSR). GSR tracks the electrical conductance of the skin, which changes with the amount of moisture. Ultimately, this ‘sweat sensor’ could identify periods of strong exertion, high and low emotional states, stress and fatigue. So not only will your next health wearable be able to monitor your fitness more accurately, it might also be able to track your mood.

For advice on choosing the best fitness tracker, click here.


Share This Article

Related Topics


Read This Next

Read Full Story