/Everything you need to know about activity trackers (wearables)

Everything you need to know about activity trackers (wearables)

Activity trackers (wearables) to measure sports and exercise behavior are popular. They measure how active we are in a day, how many calories we burn, what our sleep patterns are and sometimes our heartbeats. Professionals often have questions about activity trackers such as ‘how well do activity trackers measure (reliability and validity)?’, ‘What effects do they have on sports and exercise behavior of people?’ In this article, you will find the answers to these questions from various studies.

Research from the Mulier Institute shows that 4 million people between the ages of 16 and 79 have used electronic aids in sports and exercise in the last twelve months. Of them, 9% use a smartwatch and 11% use an activity tracker. These users exercise more often and are more often younger and better educated. Men in the 45 to 65 age group, in particular, appear to be “early adopters” of activity trackers.

There are different types of wearables: devices that you can wear on your body. Activity trackers, smartwatches and apps on the phone can, for example, keep track of your daily (sports) activities. The big difference between activity trackers and smartwatches is that activity trackers are purely focused on fitness and health, while the smartwatch is an extension of your smartphone and therefore contains functions that are not concerned with health. An app on your phone can register similar to an activity tracker, only you have to carry your phone on your body for this.

How are activity trackers used?

Activity trackers are mainly used for individual health goals, or from an interest in new techniques. There are many factors that influence the use of activity trackers. For example, a good appearance, an attractive display of results and the feeling that wearing an activity tracker is fun for more acceptance and use. In addition, ease of use plays an important role in both the purchase and the long-term use: too large, too bulky and not easily perceived as being a hindrance. Good synchronization with other apps is also important here. More research into gender differences around the assessment of aesthetics and comfort is needed. Technical factors, such as the battery life and the perceived reliability of the measurements, also influence usage.

The ability to compare one’s own results with those of others (often peers) encourages long-term use. Depending on personal preference, this can be competitive or cooperative. The opinion of the environment about the use of an activity tracker can also influence (long-term) use. Exceptionally high expectations of an activity tracker (cycling is not measured, while the user does cycle a lot) often leads to poorer experiences and therefore less sustainable use. Honesty and clarity about the possibilities, usefulness, and accuracy are therefore necessary for (long-term) use.

External and functional aspects, therefore, play a major role in both the first use and the sustainable use of activity trackers. In addition, learning new habits and retaining them is a key factor for the sustainable use of activity trackers. For example, a new habit is to put on the activity tracker every day. It would be nice if the activity tracker and accompanying app encouraged you to wear the tracker every day.

How well do activity trackers measure?

The commercially available activity trackers are reasonably reliable and valid in counting steps. Reliable as in every repeated measurement must measure the same. This makes a trend over time clearly visible. If a measurement measures what it has to measure. this is called a valid measurement. Read more about the definition of reliability and validity here. However, in terms of energy consumption and kilometers traveled, they score worse and more varied than activity trackers that are suitable for conducting research. Measuring the sleep pattern with the activity trackers can also be greatly improved. For people over 65, activity trackers are on average less reliable. This is because, on average, activity trackers are less able to reliably measure the slower pace (3.5 km / h) for walking and other activities.

What effects do activity trackers have?

The literature shows that activity trackers show a predominantly positive influence on exercise behavior. People become more physically active by wearing an activity tracker. However, it is not yet proven that an activity tracker can help with weight loss. Current trackers cannot measure this well enough. In addition, research has shown that the results may become more effective if activity trackers are used that also use behavioral change techniques such as social support, goal-setting, self-monitoring (feedback and rewards) and virtual coaching. The majority of the activity trackers are not yet combined with behavioral change techniques such as barrier identification, action planning, restructuring of negative attitudes and environmental restructuring. These techniques are actually more effective and especially suitable for people who are not motivated to move. Finally, support for the environment in becoming familiar with an activity tracker can also have a stimulating effect.

Sporty woman using activity tracker

Behavioral change techniques

  • barrier identification: mapping of barriers
  • action planning: targeted planning of actions
  • restructuring of negative attitudes: reordering of negative beliefs
  • restructuring of the environment: reorganizing the environment for favorable behavior

How are activity trackers used by professionals in practice?

Activity trackers can be of added value in the supervision of athletes and in healthcare. The exercise behavior can be seen 24/7, provided that it is linked to software and visible to professionals and users. In addition to personal contact, the user can also be guided from a distance. Activity trackers in healthcare are rarely used because healthcare providers do not always have the time to do something extra (assisting patients remotely via an app). Moreover, they do not always feel competent enough to realize this. It is not known how many activity trackers are used in the care and personal supervision of athletes.

Preliminary results from a study by the Power of Sport research group show what requirements a mobile application (whether or not in combination with an activity tracker) must meet.

According to the personal trainers, coaches, lifestyle professionals and physical therapists interviewed, apps should have the ability to:

  • set personalized goals to see progress, motivation and to slow down people when needed;
  • provide social and mental support through notifications and personal contact. Group assignments in an app can also serve as social support and/or motivation for some;
  • giving the trainer’s tools (through behavioral change techniques) to guide someone.


Reasons for non-use of apps by professionals:

  • Too many apps to choose from
  • The target group cannot always handle it (for example the elderly)
  • Too general information in existing apps
  • Fear deploying apps
  • Offer not complete

In short:

Comfort, an attractive display of the results, battery life, clarity about the possibilities and good synchronization with other apps are important for long-term use of the activity tracker.
An activity tracker is reliable and valid enough to keep track of the daily exercise pattern; sure to keep track of changes from week to week. Of the measured energy consumption, kilometers traveled and sleep pattern, the data turned out not to be reliable and valid enough on average.
Inform yourself about which activity trackers are the most reliable and valid, also for the older target group. View this selection tool for suitable activity trackers (also at low speeds) excel file.
Activity trackers can potentially become more effective when reliability and validity improve and they are better combined with behavioral change techniques, such as social support.

There are many possibilities for professionals to use activity trackers. In addition, it is important that the activity trackers meet quality criteria, which enable professionals to properly guide clients.