Effectiveness of wearable activity trackers to increase physical activity

Anecdata point: I was very active before I got an Apple Watch, but having the watch has increased my activity in two ways. First, it scratches the part of my brain that loves routines; meeting a daily goal provides a dopamine hit beyond that from the activity itself. Second, it provides an extra nudge on days when I might otherwise have said “ah, I’m feeling lazy/tired/unmotivated etc., I’m going to skip today.” I didn’t initially think I would care about the rings, but I think they’ve contributed to my health overall.

Its studies like this and my own experience that makes me so annoyed that Google seems to be intentionally killing the FitBit brand.

They first removed all of the social features, which was a massive encouragement for large swathes of my friends and family. You have one family member that is training regularly for 5ks, half-marathons, marathons, etc and its always nice to just be able to get anywhere close to their steps for the week. Have a friend that you usually can beat, all of a sudden you're encouraged to hop on the treadmill and get an extra 1000 steps in that day. Theres a poor alternative called Stridekick, that seems to check all the boxes as a replacement, but just somehow is just poorly designed enough to be an app no one actually wants to use.

Now they've issued an update that is bricking Fitbit devices and are just sending out coupons to buy a new one.

Whats frustrating is that the market seems completely devoid of anything currently to replace them. All the halfway decent options are all huge clunky smartwatches. If you have no interest in apps on your wrist, because you already own a phone, it seems like the only option is the ugliest Garmin I've ever seen or Chinese ones of unknown quality that do not connect to any of the fitness ecosystem. When my FitBit seemingly got hit with a bug that killed it, (worked fine one day, then suddenly battery only lasted an hour after just over a year of owning it), I desperately looked for an alternative and ended up stuck getting the cheapest FitBit. It really wasn't an option to forgo not having a device as my insurance pays me up to 90 bucks a month for hitting my step goals.

Surprisingly positive. Personally thought activity trackers might have a fairly short term interest effect, with boredom or laziness after several months.

https://www.thelancet.com/action/showPdf?pii=S2589-7500%2822...

"wearable activity trackers increased step counts on average by around 1800 steps per day, walking time by approximately 40 min per day, and moderate-to-vigorous physical activity (MVPA) by around 6 min per day."

"effects were in favourable directions (ie, negative effects suggesting improvement in BMI, blood pressure, cholesterol, glycosylated haemoglobin, and waist circumference and bodyweight, and positive effects suggesting improvement in aerobic capacity)"

"strong effects on step counts at 4–6 months (increase of 1127 [95% CI 710–1543] steps per day), [...smaller effect on] step counts up to 4 years (an increase of 494 [251–738] steps per day), [...another found] small but non-significant beneficial effects up to 1–2 years (BMI –0·21 kg/m², 95% CI –1·06 to 0·65).

My personal experience is just one data point, but an activity tracker has been an important part over the last 4 years of improving my health dramatically. 4 years ago I was sedentary, and was experiencing some pretty nasty hip pain that was really starting to get in the way of even my sedentary life (standing or walking for an hour or two became amazingly painful for days).

This week, according to my watch, I have 870 "Activity Minutes", I use my treadmill basically every day, and I never would have imagined I would say this, but I enjoy jogging. My hip pain has much more manageable.

Part of that is definitely the encouragement from the fitness tracker. Part of it is also using the data from the fitness tracker to adjust my activity and sleep. Part of it is my health insurance has a gamification where I earn money for activity, and also get to low key compete with others. I think it pays me nearly a grand a year for activity, all told.

Honestly, I feel 20 years younger.

Meta study,

> Taken together, the meta-analyses suggested activity trackers improved physical activity (standardised mean difference [SMD] 0·3–0·6), body composition (SMD 0·7–2·0), and fitness (SMD 0·3), equating to approximately 1800 extra steps per day, 40 min per day more walking, and reductions of approximately 1 kg in bodyweight. Effects for other physiological (blood pressure, cholesterol, and glycosylated haemoglobin) and psychosocial (quality of life and pain) outcomes were typically small and often non-significant.

So not nothing but a very small intervention.

I'll add to the anecdotes here: I lost 90 lbs and got fit over the past five years, and my Fitbit played an important role in that.

Initially, it was helpful for me to be aware of my overall physical activity. Weight loss is mostly diet, but I didn't have a clue about my average steps or my heart rate during exercise.

I got to watch my resting heart rate drop from the 70s down to the 40s as I picked up cycling, hiking, and regular walks.

When I began weightlifting and other more strenuous training, I then understood my heart rate zones and could track my progress.

Gaining a deeper understanding of my body and seeing progress over time was very motivating. Definitely a big positive for me.

This is a permutation of the Hawthorne Effect, which is individuals' modification of behavior in response to being observed.

https://en.wikipedia.org/wiki/Hawthorne_effect

Most effective if you are being observed by strangers, rather than your future self.

Has ramifications for diet (food logs a very effective intervention, maybe more than any particular regime), and it strikes me that it's also part of surveillance states' playbook.

Peter Attia cites the Hawthorne Effect here and in his podcast episode on good v bad science:

https://peterattiamd.com/what-i-actually-eat-part-ii-ifik-2/

Impressive results, but I think it is important to keep in mind that most of the examined studies in this meta-analysis combined wearable activity trackers with an intervention. The effect of only using a wearable is probably much smaller and the duration of the effect is unclear.

From the limitations section of the discussion:

“Although this umbrella review provides strong assurance of the efficacy of wearable activity trackers in increasing physical activity, few of the systematic reviews and meta-analyses examined the effectiveness of wearable activity trackers alone. […] the multifaceted interventions yielded effects around 50% larger than those using wearable activity trackers alone.”

After an ios update where my phone started tracking a move ring (I was lazy and accepted some new defaults) I was definitely more motivated to close it every day. I noticed I was walking more so a few weeks ago when my old watch died I bought an apple watch so that I can also “count” my active workouts like lifting weights too.

It’s not a huge effect but it’s definitely helpful.

It’s great that the otherwise annoying “attention hacking” from my devices feels like they’re actually helping me.

And whoever came up with the ring design deserves a lot of credit, they look and feel really good. The default notification settings are a bit too chatty though.

Got one on sale after New Years when Garmin was clearancing out the old Instincts to make way for v2 of the same. My intention was just to be more aware of my activity level and at least make informed choices.

The imaginary internet points have proven remarkably effective at keeping my step count up since then. I hate admitting as much, but I guess in this case it's a force for good?

I can tell you from wearing a fit bit for a few years, in my personal experience all it did was increase my anxiety.

So the study says it increases activity. But it also says: “Effects for other physiological (blood pressure, cholesterol, and glycosylated haemoglobin) and psychosocial (quality of life and pain) outcomes were typically small and often non-significant.” so what’s the point of the extra activity?

> In total, 39 systematic reviews and meta-analyses were identified, reporting results from 163 992 participants spanning all age groups, from both healthy and clinical populations. Taken together, the meta-analyses suggested activity trackers improved physical activity (standardised mean difference [SMD] 0·3–0·6), body composition (SMD 0·7–2·0), and fitness (SMD 0·3), equating to approximately 1800 extra steps per day, 40 min per day more walking, and reductions of approximately 1 kg in bodyweight. Effects for other physiological (blood pressure, cholesterol, and glycosylated haemoglobin) and psychosocial (quality of life and pain) outcomes were typically small and often non-significant. Activity trackers appear to be effective at increasing physical activity in a variety of age groups and clinical and non-clinical populations. The benefit is clinically important and is sustained over time. Based on the studies evaluated, there is sufficient evidence to recommend the use of activity trackers.

That seems remarkably effective. It’s in line with my personal experience as well. Unfortunately, it also occupied a part of my daily headspace. I was exercising more with the tracker, but without the tracker I enjoy exercise more as it feels less goal-oriented.

Seeing my estimated VO2 max number rise and my resting heart rate going down is super motivating on my Apple Watch. I thought it would feel like a boat anchor being tracked all the time, but I really enjoy seeing all the heart metrics.

My Apple Watch isn’t perfect but it’s pretty accurate in measuring exercise nowadays. It was much rougher in the first year or two though, they have certainly improved the hardware and software.

Guess I’m one of those weird ones who returned my Fitbit and never use my Apple Watch. I liked them to establish baselines for new activities or trails but anything else was a hindrance. But even then what’s the point. Maybe I don’t think of exercise as something to maximize. Just has to be good enough.

It many cases hindrance came from comparing walks. When it’s much better for me to just pick the walk that suits my mood, not the most strenuous.

Nobody is asking: Are these step counters accurate?

It can be very enlightening to wear two of them (one on each wrist) for a few weeks.

I find one is often going to read 50% more than the other one.

For me it was increasing physical activity that made me want to get the tracker, so I could see how I was progressing when I started swimming. But perhaps it has helped me keep at it!

I do about an hour of swimming twice a week now - started at half an hour once a week, then gradually increased the time, then started going more than once, it's made a big difference! I also wanted to improve my diet (and cut sugary drinks like soft drinks and juices), and then after a year or two found that I was losing weight to the point where I was a bit lighter than I wanted to be, so I had to increase how much I was eating a bit to make up for the deficit. That had definitely never happened before, I'd been gradually increasing my weight prior to that.

> 40 min per day more walking [...] psychosocial (quality of life and pain) outcomes were typically small and often non-significant

Interesting if 40 more minutes a day walking didn't have much if any effect on happiness.

A study of measuring the effectiveness of selling your car to increase physical activity would be very interesting. But in our present economical logic who would profit from such a study and finance it?

To add my own anecdote. I am easily drawn in by the numbers game and, as a result, I started to walk even in conditions that would keep me at home several years ago. Freezing weather, rains, serious heat.

My immunity has improved a lot, and I think it comes from the relentless exposure to all kinds of Central European weather. I no longer experience bouts of cold etc., and except for Covid, I didn't have anything flu-like even in winter, when there was an obvious wave of respiratory diseases all around.

I feel this is a no-brainer and it's nice to have a meta study confirm it. I won't be surprised if we start seeing health insurance plans offer rebates or discounts to people who use them.

Doesn’t do anything for me, it may serve as a clutch but you always fall back to average without any solid habit/life/situation changes

With regards to the worth of the gadget... Is it better to be slightly more physically healthy but have less privacy, or retain privacy but miss the potential benefit? This is a question for present age.

You'd think that knowing the amount of steps you do etc in a day would certainly be your information for one's own eyes only, but no - corporations are heavily involved.

> [...] equating to approximately 1800 extra steps per day, 40 min per day more walking, and reductions of approximately 1 kg in bodyweight.

My morning walk is about 40 min per day and about 4km (distance varies but I'm pretty reliably 6km per hour) and that works out to about 4500 steps. So 1800 steps in 40 min more walking seems to be a REALLY slow walk, less than 3km per hour.

I used mine for the past month or two to track my activity and plan my weight loss - it's been surprisingly accurate. Being able to log calories right from my wrist instantly is great to prevent me from forgetting, and the total caloric expenditure estimation has been surprisingly accurate as compared to results on the scale.

As a longtime P90X (video workout series) devotee, I’ve enjoyed a similar effect before the trackers. As Tony Horton says, “keep showing up, keep pressing play.” Routine creates healthy habits.

Can these trackers be used to encourage other activities? Like do more math exercises?

How about a mental activity tracker to increase mental activity ? Too much physical activity makes me dumber. Playing bullet or blitz chess might consume as many calories as walking per unit time.