The apps are one thing but devices such as the Apple Watch offer a much deeper level of analysis. So how do they actually get you fitter? Over the past few months I put the self-tracking concept to the test, trialling the top gadgets available. I've been surprised at how effective they can be.
It all started with a Fitbit Flex, an accelerometer you wear on a discreet wristband that measures motion patterns to track how many steps you take per day, then vibrates or lights up when you've hit a target. As a desk-bound office worker who uses public transport all the way to and from my office, I felt my activity levels were something I should possibly worry about. The average person walks about 3500 steps a day, but research shows that hitting 10,000 will much improve your health.
So with the help of my Fitbit (fitbit.com), I started counting. Conscious of the target, I began walking part of the way home to rack up extra points, or even just going to the bathroom furthest from my desk. The vibration was like a daily pat on the back and once I became aware of what 10,000 steps felt like I started increasing my daily target, competing with myself.
This was my introduction to the motivational power of the personal tracker, and I was hooked. I now knew how much I was walking, but could I make my more strenuous bouts of exercise more efficient too?
I decided to try the new-for-2014 TomTom Multi Sport Cardio watch, which boasts a GPS position tracker and an "extremely accurate" heart rate monitor (it works by shining a light through the skin of the wrist and monitoring changes in the blood flow). This means it can provide real-time information on pace, heart rate, calories burned and distance travelled when I am running, swimming or cycling. Even more impressively, the watch records and pools all this information into a single graphic, so I could compare my performances. Racing myself started to become strangely addictive.
Heart rate monitoring, I learned, is the single most accurate way of understanding how your body is responding to exercise. Depending on what your goals are - an easy workout, fat burning or improving endurance - the watch sets you an optimal heart rate to stick to and displays it as your exercise, so you can ensure you hit the right intensity.
Suddenly I saw the real point of life logging. "When used properly, this data can be more motivational than any personal trainer," says technology writer Richard J. Anderson in an online essay he wrote in July titled "Spying on Myself".
"The point of the Quantified Self movement is that once you have data on yourself you can identify patterns and then things to change to improve. Then, you check your new data and, if the change is working, keep at it. It's about self-awareness, and then self-improvement."
I decided to get even more scientific, in the hope of becoming even more exercise-efficient. Enter Tinke, a slim device about 4cm high that is being hailed as revolutionary in the fitness tracker scene. It is made by a company based in Singapore, but can be shipped free worldwide (shop.zensorium.com). To use it, you simply download an app on to your smartphone and register, then plug the Tinke into the phone and touch the pad of your thumb to a sensor on the top. Using light reflective technology, Tinke measures and communicates to your phone not only your heart rate, but your breathing rate and blood oxygen level as well, all combined into one overall "Vita score", which is a great indication of general fitness. A low resting heart rate, low respiratory rate and high blood-oxygen level, I discovered, equal a good Vita score and good fitness, and vice versa.
As someone who is easily discouraged from exercise when I don't notice visible changes, I found that Tinke was brilliant. I may not have changed on the outside, but knowing essential differences were happening inside was hugely motivational.
Before gadgets like these it wasn't possible to do this kind of deep analysis unless you were in a lab, says Blaine Price, Open University computer science academic. "The difference that 21st-century technologies have brought is the ability of ordinary people to record automatically and relatively effortlessly a wider range of data about one's life with a precision previously available only to elite athletes, scientists and medical staff."
Sensors are getting ever smaller and more accurate and just about everyone carries a powerful analytical computer in the form of a smartphone with them at all times. It's possible to become a better version of yourself just by assessing and acting on the data you collect. So don't be surprised if you get hooked on life-logging before the Apple Watch hits the shelves - it is no longer the preserve of the super geek.
Photo / Thinkstock
Five other things to track for everyday benefits
1. Sleep: wrist-worn trackers such as the Fitbit Flex calculate sleep efficiency based on your movements, allowing you to make connections between pre-bed habits and sleep quality. Alternatively there are smartphone apps such as Sleep Cycle, that are cheaper but still insightful.
2. Spending: various smartphone apps track your financial habits - good examples are Spendometer (iPhone) or Expense Manager (Android). Enter every penny you spend, use categories for tracking, and you'll start to really understand where your money goes.
3. Alcohol: work out exactly how much you're drinking, and how this is racking up in costs and calories, with smartphone apps like DrinkControl.
4. Mood: Emotion Sense (Android) invisibly monitors data such as calling and texting patterns, movement and sound levels, combined with brief questionnaires, to track your mood and help you to become more self-aware. MyMoodTracker (iOS) keeps track of a range of factors, including sleep, medication, exercise, stress and menstrual cycle, to record how they may influence moods.
5. Time and productivity: Chronos runs in the background of your smartphone or desktop browser, compiling data to show you exactly where your hours are spent. RescueTime helps you understand your habits so you can be more productive.
