Health and fitness trackers are becoming more and more popular, with over 8.5 million sold last year. People are clearly interested in getting fitter, healthier, and improving their performance.
Fitness trackers do exactly what their name entails. They track fitness data ranging from steps to heart rate to location and distance. The downside of the huge variety of devices out there is that it can get confusing when it comes to selecting one. You want to get the functionality you need and want, but don’t want to spend extra money on capabilities you won’t necessarily be using.
Below are some of the metrics for the most popular fitness trackers, to help you determine exactly what you need and/or are likely to use. As a bonus, I’ll explain how you can utilize them to meet your fitness goals.
It may sound really basic (and it is, really), but measuring steps is great if you’re looking to increase your activity and incorporate healthy behavior changes into your lifestyle with minimal effort. Steps are easy to measure and easy to record. These devices usually are worn on the hip or wrist and track each step you take throughout the day.
To begin, you’ll want to determine the average number of steps you take in a day. Many tracker recording apps will do this for you, or you can just take your steps taken in a week and divide by number of days. Once you have your average steps per day the goal should be to increase your steps by 500 a day or set a goal of X number of steps per day. Or you can aim for a benchmark: 10,000 steps is a popular benchmark and the distance is equivalent to about five miles of walking a day. But keep in mind that this is just a starting point; hitting this benchmark may or may not be useful for you, depending on where you’re starting from. This feature is great for simply giving you a realistic picture of your overall activity level, and to improve your daily habits.
The ability of many watches, such as the Fitbit, to not only track and record this information but to share it socially means you can even work some competition into your step-counting, which can be helpful if you need that to get you motivated. Fitbit has a great online dashboard to upload your information where you can look for trends and compare results to those of your friends. Research has shown that people who get the most out of their fitness devices, and stick with using them, are those who use them in more social contexts.
Counting calories burned is important not only if you’re trying to lose weight, but also if you’re looking to maintain or gain weight, or want to make sure you’re refueling properly after an intense workout.
To begin working properly with calories you must know your Basal Metabolic Rate (BMR). This is the minimum fuel you need over a 24-hour period just to keep your body running (even if you’re doing nothing but lying in bed). The most popular equation is as follows:
For men: BMR = [10 x weight (kg)] + [6.25 x height (cm)] – [5 x age (years)] + 5
For women: BMR = [10 x weight (kg)] + [6.25 x height (cm)] – [5 x age (years)] – 161
Once you have determined your BRM you need to account for the calories you burn during the day. The general rule of thumb is you burn an additional 500 calories just moving around the house, getting to work, etc. This is where a sleek, low-profile activity/steps tracker designed to be worn all the time—like the basic models of the Fitbit, Mio Fuse, Garmin Vivosmart, or Timex Move X20—can be very useful, by giving you an accurate idea of this non-workout caloric expenditure and pointing the way towards increasing this figure. And finally, you’ll want to account for calories burned during a workout. This gives you your total calorie expenditure for any given day.
For example, say your BMR is 1500 and your daily activity calories (500) plus workout calories (400) add up to 900. This means your maintenance level of calories for that day would be 2400 calories. Obviously, if your goal is weight loss your caloric intake will need to be lower than this figure. On the other hand, if you are more concerned about making sure you’re taking in enough calories to perform at your best, you’ll want to maintain a neutral or positive caloric balance. Some of these above-mentioned trackers, and the mobile apps that come along with them, make it easy to track calorie intake so you can meet your goals.
I will describe in more detail how to use calories to determine how best to refuel under HR Zones because each zone determines the kind of fuel you burn.
I would have to say heart rate (HR) is the single most important piece of information a device can provide because it can be used for so many things—accurately gauging the intensity of your workout at any particular time, monitoring your readiness for a workout, and even helping decide how much food you should consume after a workout.
Many devices, primarily the fitness trackers listed above, take your heart rate through your wrist and not a chest strap. While the wrist models are overall more convenient and comfortable, the most accurate and reliable devices are those that measure your heart rate through a strap. If you’re going to be relying on monitoring your heart rate to design and track your workouts, you’ll want the precision of this method.
Just as you need to determine your basic metabolic rate to intelligently track calories, you will need to determine your maximum heart rate (MHR) in order to establish what your heart rate zones are. There are a lot of pretty complicated ways of measuring this, including a professionally administered stress test, but if you are looking for a rough estimate, you can use the following equation:
MHR = 208 − 0.7 × age
Heart rate zones are very important because of the depth of information they can provide. They determine physiological exertion levels (versus just perceived exertion), allow you to train at a certain intensity during certain workouts so you know if you’re working hard enough to see any fitness gains, and cues when you’ve backed off enough to allow for recovery.
For example, at Athletic Republic, during a treadmill sprint workout we wait for each athlete’s heart rate drop to under 120 beats per minute (bpm) between sprints. That way we know the body is physiologically ready for the next high-intensity interval, and will be able to maintain correct form.
For higher-level athletes who are looking for every advantage, information about heart rate zones you were in during workouts can help you refuel properly afterwards since you use different energy sources at different levels of intensity.
Zone 1 is 50-60% of MHR and considered easy intensity. Target this zone for recovery workouts and to increase recovery. Heart rate is increased which increases circulation, but energy expenditure is fairly negligible.
Zone 2 is 60-70% of MHR and considered moderate intensity. Target this zone to increase recovery and work on basic endurance. Energy expended here is a mix of oxygen and fat.
Zone 3 is 70-80% of MHR and considered hard intensity. Target this zone to increase aerobic fitness and endurance. Energy expended here is mix of oxygen and carbohydrates.
Zone 4 is 80-90% of MHR and considered very hard intensity. Target this zone to increase max performance and speed capacity. Energy expended here is mostly carbohydrates.
Zone 5 is 90-100% of MHR and considered maximal. Target this zone to increase maximum speed and neuromuscular performance. Energy expended here is almost entirely carbohydrates.
Every device measuring (and recording) heart rate should be able to give you a breakdown of the time you spent in each zone. Below is the screen shot from my Suunto Ambit3 data of a resistance-training workout I did recently:
As you can see, I spent almost 60% of my time of my time in zones 3-5, where I was burning primarily carbohydrates. For this particular workout it said I burned around 762 calories; when replacing those calories I will probably want to consume 60% of those 762 calories in carbohydrates to ensure a maximum recovery from this workout.
Overtraining is an issue that athletes, be they weekend warriors or professionals, may have to deal with. It can be caused by training too hard/often or when sufficient time is not taken between workouts for recovery. A heart rate monitor can be very helpful for keeping an eye on this, since two signs of overtraining are an inability to return to a lower heart rate after activity within a couple minutes and waking up with a heart rate that is above your normal resting rate.
By checking your heart rate in the morning, you can determine if you’ve recovered enough from your last workout to train hard again that day. You’ll want to start tracking your heart rate every morning when you wake up so you can develop a trend of heart rates. If you have a big workout planned and you notice your heart rate is much higher than normal on that morning, it means that your body is trying to compensate for lack of energy or to increase blood flow to aid in recovery. It might be worth waiting one more day so you can perform at a higher intensity in your next workout.
GPS functionality on a device significantly increases its cost; you therefore probably want to think through whether you’ll need or use this function. Having a GPS on your tracker can definitely be fun but not worth the extra expense if you are only looking for basic fitness metrics. However, since the distance indicators on non-GPS fitness trackers are estimates of steps (sometimes way off but can give you an idea), GPS functionality is great for telling you exactly how far you ran, hiked, biked, etc. and it will also track your vertical gain. If you’re interested, you can also track at big-picture data like many vertical feet you skied in a winter or climbed on a bike in the summer.
When using these metrics for fitness you can always see how your run times compare or use a social fitness platform like Strava to compare your times to your own personal bests or those of your friends. I love looking at the GPS routes from my adventures and seeing if I can find another route or to give me perspective on the location and scale of where I was.
Below is a screenshot from my trek back to the Egypt Trail head from Neon Canyon in the Glen Canyon area of southern Utah. Its cool to see this mapped out because it was a three-hour hike through open desert in an area I was not familiar with. The compass on my Suunto was also a huge help in ensuring we were tracking the right direction.
The above are probably the most important metrics, and ones shared by most fitness devices within the different categories. Beyond that, there are a number of other features that may or may not be important to you:
Many step trackers also help track sleep. They do this by looking at movement and patterns in heart rate. Duration of sleep can be important for recovery and it can be nice to look back and see that you have obtained at least 8 hours of sleep a night, but in my opinion it overall isn’t that important.
If you’re planning on using the device for swim workouts, you’ll obviously want to make sure your device is completely waterproof. Some are merely water-resistant.
If you can’t miss a call or a message while you’re working out, or just want to know at a glance whether you need to stop and pull out your phone, this function could be handy.
The alarm functions on fitness devices vary, but a lot of the newer fitness trackers feature gentle alarms that wake you with a silent vibration at the wrist.
Just remember, none of these devices do much for you if they don’t get a lot of use. Be sure to pick something that’s in line with your goals and isn’t more complex than you’re willing to deal with. Whether you’re just trying to boost your overall fitness, or are training hard towards a specific goal, a fitness device is sure to get you there faster and more efficiently.