My 2c on how I use my fitness tracker watch to its full capability
Fitness trackers have come a LONG way in the last few years, and plenty of features have popped up along the way.
But what ones are actually helpful? How do you save from drowning in all this data? I’m all about the big ticket items and keeping things as simple as possible, so in this blog I’m going to run you through the key metrics that I look at the most, and the metrics you can ignore to help keep your data driving you better.
What watches measure well: Metrics I use all the time
Lets kick off with what our fitness watches are most helpful for (outside of telling the time)
Fitness trackers have come a LONG way in the last few years, and plenty of features have popped up along the way.
But what ones are actually helpful? How do you save from drowning in all this data? I’m all about the big ticket items and keeping things as simple as possible, so in this blog I’m going to run you through the key metrics that I look at the most, and the metrics you can ignore to help keep your data driving you better.
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Lets kick off with what our fitness watches are most helpful for (outside of telling the time)
1️⃣ Heart Rate
My word they’ve come a long way – Heart rate measurements through fitness tracker and smart watches have become surprisingly accurate in the last few years – so much so that if a client has a fitness tracker watch, I tend to use it for my in clinic assessments over our heart rate monitors as a) I generally trust they are giving a very close to reliable result, b) it helps my clients understand how to measure it themselves, and c) the ultra scientific heart rate monitors are usually annoying to use (with the most accurate one being one you strap around your chest – warranted in some cases, but not in most!).
They’re not quite laboratory accurate, but for a consumable easy tool to monitor your day to day heart rate during rest, activities and exercise they work very well! Compared to a sternum monitor or an ECG machine (the gold standards for HR monitoring), most watches differ by less than 10% (read more about that in the following study.
The heart rate readings they give are great for your fitness tracking and awareness, and can be a great indicator of goal ranges during your exercise. And what’s more, they’re a reasonably easy one to understand and learn to help get a good idea of how much exercise you’re getting – which takes us to my second favourite measure!
2️⃣ Weekly activity minutes
As an exercise physiologist, I LOVE this number. Why? Because the Australian guidelines to activity state specifically to aim for 150-300 minutes of activity per week, with vigorous activity being worth double minutes. A super easy metric to understand, quantify and follow.
The beauty of the watch measuring this?
It does the maths automatically for you, and adds minutes as per your heart rate and individual specific heart rate zones (which we already know it measures pretty accurately!), and it even does the 2x calculation when you’ve reached your adjusted heart rate range for ‘vigorous’. How easy is that!
Another great metric for you number lovers out there to add to your watch settings, and one I would prescribe for all my clients if I could.
3️⃣ Steps
This wonderful metric is one that has been very popular in the last decade especially, and for good reason. Those who walk more have up to a ~65% reduction in mortality compared to those who don’t.
The above study also notes the sweet spot to be around 6-8,000 steps per day, with results still increasing but plateauing as you add more steps.
And the good news for us? Watches are pretty good at measuring them.
Step goals can be a great way to help your overall health, and most watches allow you to set goals around how many to aim for. This is a great one to track if you love numbers and results over time.
4️⃣ Stress levels/Heart rate variability
This one isn’t quite as accurate as some of the other measures, and it’s probably not measuring exactly what you think it is, but used in the right context (and not in isolation), it can be incredibly helpful.
When your watch reports ‘stress levels’, it’s usually pulling that number from a metric called Heart Rate Variability (HRV). HRV holds a special place in my heart – I actually did a uni pilot study on it (and that bias might be why it hasn’t made it into the ‘Metrics I Tend to Ignore’ category of this blog). In short, HRV gives us an insight into how your nervous system is functioning, and in turn, how much stress your body is under – whether that stress is physical, psychological, illness-related, or otherwise.
I’ve found HRV especially useful in measuring your general wellbeing over a given period or in recovery from illness, high stress, intense exercise etc. It’s even been used to predict overtraining in athletes and flare-ups in conditions like rheumatoid arthritis.
It’s also a measure I personally leaned on it a lot during marathon training – it became my go-to way of checking whether I’d properly recovered after a hard session (sometimes it took hours of couch time to get back to baseline!). It even tipped me off to my first COVID infection – my stress score spiked before I had any symptoms, prompting me to test.
So while it’s a bit more nuanced and less precise, HRV-based stress tracking can be a valuable tool in helping balance stress, recovery, and activity when taken with a grain of salt.
What metrics I tend to ignore
Now you know what I like and use, here are the measures I tend to ignore.
1️⃣ Active Calories
This one has been known for a while now – active calories are off by up to 73% when taken by a watch fitness tracker and NO device or brand is considered to accurately reflect calories burned.
There is nuance, however, and active calories can be used to compare your personal activity to another personal activity of yours as a measure of intensity (for example, one exercise session was 400 calories and the other was 600 calories, meaning overall the 2nd session worked you harder) but I wouldn’t use if or much else than this inter-session personalised general guide for how hard a session was.
And to add 1 more reason to why I don’t like tracking active calories, I’m overall not a fan of weight-centric treatment to our overall health, and talking calories when we have so many other more empowering measures to use instead (such as exercise minutes described above), it makes me want to leave this usually pretty inaccurate measure behind.
2️⃣ Sleep
The evidence for fitness trackers and accurately measuring sleep is OK, and they are able to pretty closely guess sleep and wake times, but the general measurement of sleep stages, restfulness etc is not particularly accurate and can vary quite a bit between brands.
But more than this, and as a personal bias for me, measuring sleep using a tracker for most people tends to lead to more anxiety and overall reduced sleep as a result (not to mention having a light up screen on your wrist for when you’re in bed trying to sleep).
Overall, if you’re a numbers person and like knowing the hours you sleep, watches can be helpful, but always remember to take their sleep measures with a grain of salt. My preferred method is to focus on more stable sleep and wake times as a best guess for your sleep time, and if you’re concerned about your sleep, reach out to your GP for a better, more calculated measure and approach.
3️⃣ Phone notifications
Yuck, get them off, the computer and phone are already buzzing!
Have this watch as a sanctuary for fitness and health (and… telling the time)
Very much a me thing, but I always leave them silent.
4️⃣ Complex exercise data
The last one on the list is the complex exercise metrics these watches pump out for exercise (such as power rankings, training impulse etc) are all pretty large extrapolations of data that for some might be helpful, but will likely never be as accurate as knowing your general splits, heart rate data, total steps and cadence etc. The GPS sensor, heart rate monitor and pedometer readings are usually more than enough.
Not to say they don’t have a role, but for most people I’d advise focussing on the basics of your activities (split times for running and walking, speed, splits and Watts for cycling, overall session time and heart rate for HIIT classes etc). There are simpler and more reliable ways to measure what you want to measure. No need to add to the confusion!
Conclusion
So there we have it! My slightly bias, somewhat science informed and overall general way I tend to use fitness trackers for myself and my clients for the best, most effective and simple use.
