Activity trackers :: OK up to a point

A number of seemingly unrelated events have occurred recently. However they all have a bearing on each other and the development of the wearables market:

1. Fitbit announced it was seeking to raise $100m in an IPO

Fit bit Fitbit Flex

2. Apple updated the firmware for its Watch. One of the updates has been to modify the way the Apple Watch monitors the wearer’s heart rate. Apple Watch initially attempted to regularly monitor heartrates in the background. It will still attempt to check the heartrate every 10 minutes, but not if the wearer is moving. The Watch will attempt to monitor heart rate continuously in workout mode. The likely issue that Apple is addressing, although it has not said so publicly, is one of extending battery life. However we believe an additional reason will be accuracy related. To enable accurate readings the light-based monitoring system needs to pattern match blood capillaries below the skin’s surface. Movement of the Watch relative to the wrist will disrupt this contact and its ability to accurately monitor heart rates will be disrupted.

3. The World Health Organization (WHO) published a report this week on the, literally, growing epidemic of obesity. Europe’s growing obesity crisis will see almost three-quarters of men and two-thirds of women in the UK being overweight in 15 years. Projections by the World Health Organisation and UK-based researchers highlight a problem “of enormous proportions” facing many countries over the next decade and a half. The report provides statistics for 57 countries that are based on analysis of existing data for 2010 and projections which involved the UK Health Forum. The group warns that the data is inconsistent and incomplete. But even allowing for statistical irregularities anyone who walks around European and American cities can’t help but notice that people’s weight is becoming a serious cause for concern and more importantly for governments and public health services a potentially massive drain on public finances. The forecasts make for staggering reading. They suggest that in Ireland, 89% of men and 85% of women in the country will be overweight or obese by 2030. In the UK, the comparable figures will be 74% for men and 64% for women, up from 70% and 59% respectively in 2010.

WHO logo close-up_of_fat_stomach_bursting_through_shirt

Analysis

So the questions become ones of what can be done and how can technologies like Fitbit or Apple Watch help alleviate the obesity epidemic?

A person’s weight has broadly two key drivers that can be summarized as: energy consumed minus energy expended. The processes are highly complex but for most people most of the time if the equation is biased toward excess energy consumption it will lead to weight gain and if energy expenditure regularly exceeds energy consumed weight will be lost.

Activity tracking computing devices in the form of heart rate monitors, cycling computers etc have been available for many years. Most active sports enthusiasts have been through several models from companies including Garmin, Polar and Suunto. Athletes have long understood the need to monitor and quantify their performance as part of a formal training program or more spontaneous personal development.

More recently activity trackers such as those from Fitbit as well as Jawbone, Misfit and increasingly now in smart watches including Apple Watch, Android Wear and others based on proprietary OSs, have brought a more approachable and fun way to quantify a person’s level of activity. If these lead to people moving more it can only be a good thing. However increasing energy expenditure through moving more is only one part of the equation. And while important it is only a small part of the story. If I were to jump up from my desk and run 8km in 45 minutes — something I try to do a few times a week, my calorie expenditure will roughly equate to a couple of Mars bars, or a few apples (the healthier option). In other words it takes a lot of extra effort to move the needle significantly on energy expenditure. In a world where people are pressured at work and in their social lives, squeezing-in an hour’s walk, run or cycle is something that’s all too easily squeezed-out of their schedule.

This means there should be more focus on energy consumption — because for most people, most of the time, what they eat is the driver of body mass. It gets more complicated still, because not all calories are created equal; the human body’s response to 100 calories worth of sugar is very different to its response to 100 calories of fat. Science has yet to fully understand all the processes at work. The challenge is trying to conduct carefully controlled studies across a sufficiently significant cross section of the population and over a long enough period of time — many years. It’s more or less impossible. This leads to the conflicting reports that pepper the daily news flow and serve to confuse rather than enlighten.

myfitnesspal logo
MyFitnessPal App

The best we can do currently is to use applications for tracking food consumption such as MyFitnessPal. These have astonishingly comprehensive food databases, but even the best are cumbersome to use. Doing so on the go, in the ebb and flow of daily life, is a test of dedication that few are willing to undertake. And the nutrition tracker that’s included in the Fitbit application is no where near as good as MyFitnessPal. The issue with all nutrition trackers is that they require the user to manually input everything they eat. This requires knowing precise weights and measures of foods consumed. Just about okay if the food consumed is a packaged item — like a Mars bar, but a portion of, say, home-cooked vegetable curry is almost impossible to do with any precision.

As a result the best trackers, including the much vaunted Apple Watch, can only tell the user approximately how much walking, running, cycling or stair climbing has been done. And independent tests of their accuracy at tracking energy expended in the form of calories burned, are laughably inaccurate. So when it comes to assessing the ‘Energy Consumed minus Energy Expended’ equation, one side of the equation is barely addressed and the other grossly inaccurate.

So while it is a nascent market and early adopters are notoriously fickle, we shouldn’t be surprised that on current evidence many people start using trackers but a lot also give up using them after a short time.

Looking longer term we can see a number of segments of potential users of activity trackers:

1. Those that are dedicated fitness enthusiasts. Many will already use advanced fitness and activity tracking devices such as a Garmin Forerunner (image below). These people may also be adopters of simpler activity trackers to capture their non-sports related activity.

2. People who are moderately active and would like to understand their activity better and gain motivation to improve their level of activity.

3. People who are in poor shape but want to change and who really need help in getting on to a better path.

4. People who are in poor shape, but don’t care and are unlikely to be motivated to do anything unless forced to do so by medical practitioners and even then are unlikely to become long term users.

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Garmin Forerunner 920XT GPS-enabled watch

The WHO study suggests the numbers of people in groups 3 and 4 will grow rapidly over the next few years across developed markets and increasingly also in developing markets as the so-called diseases of affluence (diabetes, coronary heart disease etc) take hold.

Single function activity trackers such as Fitbit are application specific while devices like the Apple Watch are multi-purpose. Is there any reason to think that Apple Watch will enjoy more sustained usage?
There are many reasons why activity tracking adopters stop using them after a few weeks to a few months. The following are likely significant factors:

  • Synchronizing the tracker with smartphone apps can be a hit and miss affair, even with the best trackers. Without this link the devices rapidly become useless appendages that offer little incentive to continue their use.
  • People find the goals, for example 10,000 steps per day, to be beyond their reach. They feel defeated and stop using.
  • People have inflated expectations about how their fitness will change. When it doesn’t they become disillusioned and stop using them.

The net result is that people will tend to take up using activity trackers with good intentions, but sooner or later most have given up.

Smart watches that also track activity may fare better because the other functions they offer may be sufficient to warrant continued usage. The cost is also likely to be an incentive to continue using a smart watch. The cost-per-day for half a year’s use of an activity tracker that cost $100 is obviously much lower than for a smart watch costing many hundreds of dollars.

Apple Watch 2

So what does this all mean for makers of activity tracking technology and for people more broadly?

Our view is that anything that draws attention to how much (or how little) a person moves and provides a gentle nudge to do more must be a good thing. For the makers of activity trackers there will continue to be millions of people for whom activity tracking should be of greater focus. Smart watches that offer activity tracking among a range of other applications will likely achieve more sustained usage.

However the one area that can make the greatest difference to human health — tracking food consumption and encouraging health-oriented changes — remains an elusive goal.