People ask me all the time for advice about what’s the best fitness tracker to buy. I love activity trackers and think they can do a real service to help people better understand their fitness level, weight-management issues, and sleep. They can be great motivators to change, too. But I also respect their limits.
Fitness trackers, heart rate monitors, sleep trackers, and Wi-Fi connected bathroom scales don’t solve health issues on their own. What they can do is clarify and organize information about your body so you can make some sense of it.
Does Accuracy Matter?
I’ve read the same studies as everyone else about whether fitness trackers and the optical heart rate monitors on some of them are accurate.
To a degree, accuracy isn’t all that important. Fitness trackers aren’t perfect, but they don’t need to be for you to get what you need out of them.
Have you ever gone to a doctor’s office and had a nurse weigh you with (gasp!) your clothes still on? Unless you’re severely underweight or have a specific medical condition that requires you to track your weight closely, the doctor doesn’t care if you weigh 150 pounds or 152 pounds, so the weight of your clothing doesn’t change the doctor’s picture of your overall health. Similarly, it doesn’t really matter if you take 12,000 steps a day or 12,300. Either way, you’re still in the same ballpark.
With step-counting, what matters is figuring out your baseline and deciding whether to maintain it or increase it over time (or possibly decrease it, though I reckon that’s a slim minority of people). It doesn’t matter if I got 9,852 steps today. But it does matter that on average, I get 10,000, and if my goal is to sit less and move more over time, I’d want that average to increase by, say, at least 2,000. It needs to increase by a good amount.
Some fitness trackers actually emphasis some sort of made-up “points” system instead of steps, and I think it’s an attempt to prevent people from getting distracted by the idea of “steps.” Instead, points coax you to think about overall movement and activity. Misfit’s app, for example, lets you see step counts if you want, but it puts points front and center. The now-retired Nike FuelBand line of trackers did the same thing.
I’ve criticized the points system before for being meaningless, but it does drive home the fact that “steps” don’t matter that much at all. It’s more about whether you’re increasing your overall movement measurably from your baseline.
Resting heart rate accuracy is similar—again with the exception being if you have a specific medical condition that requires you keep a close and accurate eye on your resting heart rate. For the rest of us, though, a ballpark figure or zone is good enough for the purpose of getting a sense of your overall fitness level.
If my resting heart rate is 58 beats per minute one morning and 62 the next, that’s fine. It’s not going to be the same every day. If one device tells me my resting heart rate is 61 and another says 64, it doesn’t really matter which one is “right” or more accurate because they’re both reasonably in the ballpark. However, if I take my own heart rate using my fingers and estimate it at 60bpm, and then I use a device that says my heart rate is 85bpm, that’s too far off. One of my measurements is probably wrong.
Within a range, the accuracy of personal health-tracking devices such as fitness trackers and heart rate monitors—which are not regulated by the FDA—doesn’t matter all that much. You just have to develop a reasonable sense of what it means for numbers to be within the same range. Sometimes you can guess by looking at the options fitness trackers provide for goals you can set.
Do You Need a Heart Rate Monitor?
Whether resting heart rate is something you need to track at all is another question entirely. Many people who ask me about fitness trackers say they want one with a heart rate monitor. “Okay. What will you do with your heart rate?” I ask them.
The fact is, you don’t need an optical heart rate monitor on a fitness tracker to record resting heart rate. There are free mobile apps that measure resting heart rate and log the data over time to give you a baseline average. Two examples are Runtastic Heart Rate Monitor (Android, iOS) and Instant Heart Rate by Azumio (Android, iOS, Windows Phone).
Using heart rate data during exercise or for training is another story entirely. When you’re active, heart rate information becomes really valuable. People who are just starting a fitness plan, for example, might need to check whether they are getting their heart rate high enough for the exercise to benefit them. Others might need to be careful to not strain their heart too much if they are new to working out. Runners and bicyclists increase their endurance through workouts that may not come close to their maximum safe heart rate but that make the muscle work at a moderate rate for long periods of time. There are a lot of ways to use heart rate data while working out, but if that’s not how you plan to use a heart rate monitor, you should question whether you need to buy a more expensive fitness tracker that has one in the first place.
What’s the Difference Between Steps and Activity?
I already alluded to the difference between step counting and activity, but there’s more to say about it.
If you’re just trying to get off the couch more, step-counting is fine. But if you actually have plans to get your heart rate up and workout, you need to start tracking activities.
Activity, in fitness tracker parlance, comprises exercise and physical activity that you do for an amount of time. An activity might be a session on an elliptical machine or playing basketball for fun. It can be going for a brisk walk during your lunch hour, but walking periodically from your desk to the bathroom doesn’t count.
The most useful activity trackers differentiate between activities and step-counting. Some of them automatically recognize when you start and end an activity, such as the Fitbit Alta and Misfit Ray. These devices notice when you jiggle and jostle your body more than normal.
Other trackers let you manually record an activity by pressing a button, which is better if you want fine control over your start and stop times, the way many runners do. The Garmin Vivoactive uses this method, as does pretty much every other device that’s a hybrid runner’s watch and fitness tracker. The Fitbit Charge HR also has a start/stop timer for activities, even though it doesn’t double as a runner’s watch.
You can track activities without a fitness tracking device if you use a good fitness tracking app. One of my favorites is Strava, and it has a special feature for Premium members called Strava Suffer Score. When you record an activity with Strava and wear a compatible heart rate monitor (it also works with bike power meters), the app calculates a score that tells you not only how long you worked out but how hard. The score is based on which heart rate zones you reached and how long you stayed in them. That’s a smart way to actually use heart rate data and activities to track and improve your fitness. In short, it’s a whole lot smarter than checking daily step counts.
Why Are You Tracking Your Sleep?
Why are you tracking your sleep? Maybe it’s because you’re curious how much you sleep, or maybe it’s because you sleep poorly and want to figure out why.
Those two reasons are radically different from one another. Any old sleep tracker will meet your needs if all you want to know is how many hours and minutes you sleep each night. But if you’re trying to figure out what’s wrong with your sleep, you need more information.
Whether you’re using a fitness tracker to measure sleep or a more elaborate bed-based device, like the Sleepace RestOn or Misfit Beddit, you need to start looking at how sleep data correlates with other factors in your life. If you are waking up needlessly throughout the night, you should also look at your sleep phases or sleep cycles to pinpoint how you’re sleeping before you’re disturbed. Being woken from a dead slumber and being stirred out of light sleep could have different causes.
Look at your sleep data in relationship to the other data you’re recording, such as daily activity and food intake. Are there any correlations? Do you sleep poorly after a day of low activity, or do you toss and turn from pain in your legs after a long run? I don’t know of any apps that do this well, but you might also want to independently track alcohol and caffeine intake when looking for factors that could be having an effect on your sleep.
What Else Should You Use?
If you’re serious about getting a better, clearer picture of your health and fitness, there are a few products I recommend adding to your home health kit.
Calorie counter. For losing weight in particular, counting calories makes a huge difference. MyFitnessPal is the best calorie-counting app and website there is, and it works with most activity trackers to balance calories consumed against calories burned through activities. Use it daily and religiously for best results.
Smart scale. The best bathroom scales now come equipped with Wi-Fi and Bluetooth, which lets them send your weigh-ins directly to an app so you can track them easily. If used in conjunction with a fitness tracker and calorie-counting app, you’ll be able to see correlations over time between how much exercise you get, how much you eat, and how much you weigh. The Withings Smart Body Analyzer (WS-50) (shown), one of our Editors’ Choices, takes your resting heart rate through your feet, too, so you get an extra data point out of that one.
Another Editors’ Choice, the QardioBase, has a pregnancy mode that disables all bioelectrical impedance features (bad for both babies and pacemakers) and replaces the number on the scale with a happy face. That’s an amazing feature for women who want to track their weight during their pregnancy to share with a health care providers, but don’t want to get caught up looking at numbers every day.
Smart thermometer. A smart thermometer isn’t necessary for daily tracking, but when someone gets sick, particularly infants and children, it’s great to have one in your home. Smart thermometers usually come in the form of an adhesive bandage that keeps an eye on body temperature and alerts a caretaker to changes via a connected smartphone.
An example is the TempTraq. It’s a disposable bandage with a thermometer inside and battery that lasts 24 hours. You put apply it to a sick child’s body near the armpit. If the child’s temperature reaches a certain mark, which you can set, the app notifies you. I also like that it saves the history of the child’s temperature, so if you end up having to see a doctor, you have a clear record, including timestamps, that’s easy to share.
Again, you don’t need a smart thermometer all the time, but when a baby gets sick, it’s wonderful to have one on hand.
Get It Together
As you add more devices to track your health, you might find that you’re stuck with a few different apps rather than one centralized place for looking at your health data. That can make it tough to spot correlations between different metrics.
It does help to use devices from the same manufacturer. For example, the Polar Balance smart scale is just okay on its own, but when paired with a Polar fitness tracker and heart rate monitor, it provides a lot of meaningful advice about how to change your lifestyle to reach your fitness goals. Plus, you can see your weight, daily activity, sleep, and workouts all in one interface.
You can pull disparate data together with some third-party apps, such as Apple Health and Microsoft Healthvault. Both let you input additional data, too, such as blood test results from a doctor.
When you think about tracking for the long term, it makes sense to use technology where it’s possible, rather than just tracking in your head or in a notebook. Technology helps us reduce errors from manual recording and spot trends over time. It can alert us when we slip and give us personalized suggestions for how to get back on track.