Fitness watches are all the rage these days, promising to keep tabs on everything, from your steps to your sleep. But how much can you actually trust this tech? How accurate are fitness watches and trackers? Depending on the brand and what you’re wanting to track, some of these watches could do the job – but they might not always be as accurate as you’re hoping.
Let’s look closer at the claims your watch might be making, and how realistic it is that they’re telling you the truth. Plus, we’ve pulled together some tech-free alternatives for tracking your fitness that could work just as well.
Since the days of plastic pedometers, step counting has been the bread and butter of fitness watches, and they generally do a decent job – as long as you’re walking in a straight line. On flat surfaces, the count is usually pretty accurate, but they can get a little confused on stairs or bumpy trails. And let’s be honest, we’ve all waved our arms around just to hit that daily step goal. So, while they’re mostly reliable, take those step counts with a grain of salt – they’ve been found to underestimate by about 9%, so give yourself some grace.
From hitting a daily move goal to immortalising run routes, when it comes to exercise tracking, fitness watches do their best to keep up. For running, cycling, or swimming, they’re decent companions – especially if they’ve got GPS. But take them into a busy city or dense forest, and they might have trouble finding their bearings. And for activities like weightlifting or yoga, they’re not really well versed in the metrics they need to measure. If it’s simply time-tracking you’re after, they’ll do the job – but so will your phone’s timer, so it’s up to you if it’s worth the extra cost.
Wrist-based heart rate monitors use light to track blood flow beneath the skin, and can be fairly accurate when you’re relaxing or doing steady cardio. One study even found they are accurate with an error rate of plus or minus 3%. However, during intense workouts or exercise using more strenuous and rapid arm movement, they tend to start guessing. If you’re after precision, chest straps that measure electrical signals are much more accurate. That said, if you’re after a convenient way to casually track your fitness, wrist-based monitors really aren’t too bad.
Sleep tracking is another popular feature, with devices estimating sleep stages using motion sensors and heart rate variability. While they’re decent at identifying general sleep patterns, they can struggle to distinguish between light sleep and periods of wakefulness. They also tend to overestimate or underestimate the time spent in deep or REM sleep. For more accurate analysis, clinical methods like polysomnography are still the go-to option if you’re wanting to track your sleep for medical reasons. On a side note, we’ve put together a guide to better sleep, so check this out afterwards too.
Fitness watches offer calorie burn estimates based on algorithms that consider your age, weight, gender, and activity level. However, these calculations don’t account for individual variations in metabolism, making them more of a ballpark figure than an exact measurement. While useful for general trends, they’re best viewed as approximations, and if you’re genuinely trying to track your calories down to the digit, the figures your watch shows you definitely won’t give you the full picture: the error margins were found to range from −21.27% to 14.76% in one study.
While there are certainly some ways that fitness trackers fall short, they all have one thing in common: simply wearing them makes people more active. They also seem to help people maintain good habits in the long run, so even if they’re not getting the data spot on, there is a net positive effect happening as a result of them, which we love. However, if you’re wanting medical-grade information on how your body works and stats on the activity you’re doing, these devices probably shouldn’t be your first port of call – that’s what your GP is there for.
Fitness watches aren’t the only way to track your progress. Instead, or as a supplementary way to dig into the data, there are alternatives you can use. Depending on what you’re wanting to measure, these options could be more cost-efficient, accurate or simply work better for you. Let’s dive into it:
Rate of Perceived Exertion (RPE): This is a simple method where you rate your effort level on a scale of 1 to 10 based on how hard you feel you’re working. This is a great way to tune into how your body feels during workouts, helping you adjust intensity without relying on devices.
Manual logs: In a workout journal, record details like exercises, sets, reps, durations, and how you felt afterward. Over time, this creates a clear picture of your progress and areas for improvement, and can be just as insightful as digital tracking.
Heart rate chest straps: If accuracy is key, chest straps are the way to go. They’re particularly useful for activities requiring precise heart rate monitoring, such as interval training or endurance events.
Professional assessments: Regular check-ins with a fitness professional, like a trainer or physiologist, will give you detailed feedback. These assessments often include strength, flexibility, and cardiovascular tests tailored to your goals.
Mindful observation: Simply paying attention to how you feel during and after workouts can be incredibly insightful. Notice patterns in your energy, recovery, and performance, and let that guide your adjustments.
Fitness watches are great tools for monitoring activity and staying motivated, but they’re not perfect by any means. Bear in mind that their accuracy can vary depending on the feature you’re measuring. However, by combining their data with other methods of measuring, you can build a pretty effective approach to tracking your health and fitness journey. Give a few a go!
How accurate are wearable fitness trackers? Less than you might think | The Conversation
How accurate are fitness trackers? | Live Science
Brickwood K, Watson G, O’Brien J, Williams A, ‘Consumer-Based Wearable Activity Trackers Increase Physical Activity Participation: Systematic Review and Meta-Analysis’, JMIR Mhealth Uhealth 2019.