What can my activity tracker do for me?
Activity trackers become more and more popular. These devices are easy to wear and can also function as beautiful accessories as bracelets (e.g. Fitbit), fitness watches (e.g. Apple watch), or belt attachments (e.g., pedometers). You can also get an activity tracker application simply on your mobile phone. They surely look great but how useful are they really?
Some producers claim that activity trackers improve physical activity levels, stimulate weight loss, reverse diabetes, reduce anxiety and stress levels. The question is: Is this all true? And if so, how big the effect really is?
In other words, do these claims have any scientific evidence?
Are the activity trackers good for physical activity?
Physical activity is very important for good health and a high quality of life in general. There is no question about that. But let’s face it, in our daily lives it is hard to get enough activity without making particular efforts towards that.
The truth is that current lifestyle involves a lot of sitting. We sit at work, in the car, and then when relaxing we sit some more while for example watching TV. This sedentary behaviour undoubtedly adds to the epidemic of chronic metabolic diseases which plague developed countries nowadays.
Conscious effort to increase activity levels therefore is the only chance to improve the situation. Technological advances, including activity trackers, might play a major role.
Researchers have tested the usefulness of activity trackers in increasing physical activity in children, adolescents, adults, elderly, and people with medical conditions (References at the bottom). So how do activity trackers influence our health?
There are different ways to measure how much we move. We can have a look for example how many steps per day we do.
Can activity trackers increase the number of steps we take per day?
An analysis of 11 studies has shown that adults (aged between 18 and 75 years) who have started using various activity trackers increased their daily step count by 600 steps. This change was achieved by using only the wearable device.
If on the other hand, the intervention combined wearable devices with other components, the step count per day increased even more, by around 700 steps per day (Brickwood et al, 2019). This indicates the efficacy of activity trackers in increasing the number of steps walked by a person every day.
Activity trackers were even more useful in older adults.
The analysis of 24 studies has shown that the physical activity improved by 1558 steps per day (Oliveira et al, 2019). Moreover, this change was sustained even after 6 months. It did not matter whether the participants had any additional health conditions or were generally healthy older adults (Oliveira et al, 2019), they all benefited. This means that activity trackers were very effective in increasing the number of daily steps performed by older adults.
How about people with painful rheumatic conditions?
These conditions are usually complex to manage and involve a constant battle with chronic pain. Exercises can be useful in managing pain, so increasing physical activity may have beneficial outcomes for these patients.
The effects of activity trackers on physical activity in people with rheumatic conditions were tested in 7 studies (Davergne et al, 2019). The difference was 1520 steps per day (Davergne et al, 2019), so the trackers were very effective also in this group.
To sum up, activity trackers improve step count per day in adults, older adults and people with rheumatic conditions.
However, step count is not the only way to measure physical activity. Counting steps tells us nothing about how intensive a person was moving. We know from research that the amount of activity we do daily matters, but so does the intensity of this activity.
How activity trackers influence the intensity of physical activity?
To know how activity trackers influence the intensity of training, we use a different measure than counting steps. For this purpose, we use time spent in performing moderate and vigorous.
The influence of activity trackers was tested on moderate and vigorous physical activity levels in 12 studies (Brickwood et al, 2019). For healthy adults, the changes in intensity observed after applying activity trackers were non-significant.
In people with rheumatic conditions (7 studies) however, the difference of 16 minutes in moderate-to-vigorous physical activity per day was found (Davergne et al, 2019). People with rheumatic conditions spend more time exercising more intensely.
Let’s sum up now how activity trackers influence physical activity:
In general, people using activity trackers were moving more. But the intensity did not change in healthy adults but increased if the person had a chronic condition.
This outcome is important as people with chronic pain often suffer fatigue which prevents them from moving at high intensity. Being tired and in pain does not help in achieving healthy levels of physical activity.
The use of activity trackers motivated these participants to crank up the intensity of their movement. It may, therefore, be a viable strategy to improve quality of life and health specifically in these participants.
How activity trackers influence sitting?
It’s not only about increasing the amount or intensity of our movement. The amount we sit directly influences our health too.
We don’t think about it, but if we sit too much, it can be a reason we get sick. Also, excessive sitting was linked to dying earlier. Therefore, if we can reduce the amount of time we spent sitting, it will likely have a positive effect on our health.
Can activity trackers help with reducing sitting?
The results of seven studies (Brickwood et al, 2019) conducted on sedentary behavior in adults showed that adults do not sit less when they use activity trackers. Also, in people with rheumatic conditions, the amount of sitting did not change after introducing activity trackers.
Activity trackers on physical activity and sitting summary
Activity trackers increase how much people move. They also improve the intensity of physical activity in people with rheumatic conditions. However, activity trackers did not reduce the amount of sitting.
Let’s switch gears now.
Will this increase in movement translate to the weight loss though?
Are the activity trackers good for weight loss?
We understand that a precise balance between intake and expenditure of energy is crucial for achieving a sustainable weight loss (or weight gain for that matter).
When the researchers explored weekly energy expenditure, the analysis of 5 studies has shown that the use of activity trackers could provoke the additional expenditure of 300 kcal per week (Brickwood et al, 2019).
Activity trackers than worked for increasing caloric expenditure. However, I feel that we need some context here.
Firstly, how this caloric expenditure was achieved?
The use of physical activity trackers could have increased the amount or level of participants’ activity. More activity used more energy by burning more calories.
Secondly, is 300 kcals a little or a lot?
The amount of the additional calories participants spent per week (300 kcal), roughly equals a doughnut. This means that by adding an activity tracker to your life, you could possibly earn a “doughnut” of energy per week.
How does it relate to loosing weight?
Hypothetically, let’s say you buy yourself and activity tracker today. Let’s also say that you are an average person, exactly the same as the average person was from the studies I have mentioned before.
How much this purchase will influence your weight a year from now?
300 kcal per week * 52 weeks of the year = 15,600 kcal per year
Almost 16,000 additional calories burned in a year because you have started using your activity tracker. This is about 2 kg of weight loss.
In fact, the analysis of 5 studies has shown that wearable devices did not evoke significant weight loss (Jo et al, 2019).
If you were thinking about buying an activity tracker to help you lose weight, you may be disappointed that the average effect found was only worth a doughnut a week of energy.
You have to remember however that the most important influence on weight loss has your diet. If you are consistently in a calory deficit (neither too big nor too small calory deficit) and eating healthy mostly unprocessed diet, you will eventually lose weight. Even if you will not change anything else in your lifestyle.
So, the activity trackers were effective in slight increase in caloric expenditure but did not cause significant weight loss.
Again, please do not get discouraged. Weight loss is dependent on many variables and the amount of physical activity is only one of them. But if you can increase your activity levels you will have an easier time controlling your weight. Exercising has many more benefits to health than merely the use of calories.
How about the influence of activity trackers on other physiological markers?
Are the activity trackers good for blood glucose levels?
Only one study (Lim et al, 2016) looked at the use of activity trackers on blood glucose levels. In this study, hundred older participants who have been diagnosed with diabetes were randomized to either use glucometer and an activity tracker providing them with feedback or only use glucometer.
The participants who used glucometer and activity tracker with feedback saw on an average decrease in their glucose levels and improved their hemoglobin A1c levels.
Activity trackers have shown a promising effect on lowering blood glucose levels, but the results are based on only one study.
Are the activity trackers good for blood pressure?
We have discussed more broadly the relationship between physical activity and blood pressure in one of our previous posts titled Exercise can control your blood pressure by Suranga Dassanayake. In a nutshell, being physically active can positively influence your blood pressure levels, especially in people with elevated blood pressure.
There are a few studies exploring the influence of wearable devices on blood pressure (Jo et al, 2019). Two studies have shown decrease of 3-7 mm Hg systolic blood pressure and 23 mm Hg in diastolic blood pressure (Jo et al, 2019). One study showed no effect. What does it mean?
The drop of 20 mm Hg on the diastolic reading is substantial. Physical activity is a non-invasive method of lowering blood pressure, therefore, always worth trying and encouraged. If the activity trackers may support this outcome, they may be worth considering as part of the management strategy in some people.
To sum up, activity trackers showed some improvement in diastolic blood pressure, but the studies in this area are scarce.
Are the activity trackers good for cholesterol levels?
Two studies tested the effect of activity trackers in cholesterol management (Jo et al, 2019). The results showed no significant difference in high-density lipoprotein cholesterol and low-density lipoprotein cholesterol (Jo et al, 2019). Therefore, the use of activity trackers cannot be recommended as a sole management method for cholesterol levels at the moment.
However, people who have high cholesterol tend to also have problems with their cardiovascular system, including the heart. Therefore, physical activity and a proper diet are important elements of the management plan. If activity trackers can support physical activity, they may be worth considering as a supporting element in the treatment plan.
Are the activity trackers good for mental health?
Activity trackers seem to have an effect in improving some of physiological parameters of health. How do they influence the mental state of the user?
In one study (Ryan et al, 2019), the authors explored just that. They investigated how owners feel about wearing their activity trackers, but also how they reacted to taking the devices away from them.
Wearing activity trackers had some positive outcomes on the owners’ mental status.
As devices provided feedback to the owner, they elicited perceptions of the prevention of chronic diseases. They also motivated the owner and engaged them in the pursuit of health.
However, if participants were prevented from wearing their device, they could feel anxiety or frustration. These feelings can be a sign of dependence on the device to provide feedback and reinforce the behaviour.
Activity trackers, or rather their lack of, could, therefore, also cause some negative feelings of anxiety or frustration.
This is something to look for and avoid.
Activity trackers can improve physical activity and therefore promote healthy lifestyle and prevent lifestyle-related diseases.
The main effect of activity trackers is increased physical activity levels by more steps and more minutes spent on the moderate-to-vigorous activities.
No effects of activity trackers were found when they were used as the only intervention for weight loss (a cumulated result of 5 studies), blood glucose levels (1 study), blood pressure (a cumulated result of 3 studies), and cholesterol levels (a cumulated result of 2 studies).
Are you using any activity trackers at the moment? Are these enough benefits for you to use an activity tracker? Would you consider buying one for yourself or your loved one?
Please let us know in the comments below.
Böhm B, Karwiese SD, Böhm H, Oberhoffer R. Effects of Mobile Health Including Wearable Activity Trackers to Increase Physical Activity Outcomes Among Healthy Children and Adolescents: Systematic Review. JMIR mHealth and uHealth. 2019;7(4):e8298.
Brickwood, K. J., Watson, G., O’Brien, J., & Williams, A. D. (2019). Consumer-based wearable activity trackers increase physical activity participation: systematic review and meta-analysis. JMIR mHealth and uHealth, 7(4), e11819.
Davergne, T., Pallot, A., Dechartres, A., Fautrel, B., & Gossec, L. (2019). Use of Wearable Activity Trackers to Improve Physical Activity Behavior in Patients With Rheumatic and Musculoskeletal Diseases: A Systematic Review and Meta‐Analysis. Arthritis care & research, 71(6), 758-767.
Jo, A., Coronel, B. D., Coakes, C. E., & Mainous III, A. G. (2019). Is there a benefit to patients using wearable devices such as Fitbit or Health Apps on Mobiles?: A systematic review. The American journal of medicine.
Lim S, Kang SM, Kim KM, Moon JH, Choi SH, Hwang H, Jung HS, Park KS, Ryu JO, Jang HC. Multifactorial intervention in diabetes care using real-time monitoring and tailored feedback in type 2 diabetes. Acta diabetologica. 2016 Apr 1;53(2):189-98.
Oliveira, J. S., Sherrington, C., Zheng, E. R., Franco, M. R., & Tiedemann, A. (2019). Effect of interventions using physical activity trackers on physical activity in people aged 60 years and over: a systematic review and meta-analysis. British journal of sports medicine, bjsports-2018.
Ryan, J., Edney, S., & Maher, C. (2019). Anxious or empowered? A cross-sectional study exploring how wearable activity trackers make their owners feel. BMC psychology, 7(1), 42.