According to a recent survey, one in every five people owns a smartwatch or fitness tracker. These wrist-worn monitors are a convenient way to track your daily steps, and they're likely more accurate than the tally on your smartphone, which you may not have with you at all times. Most wearable devices also provide a variety of other data, such as your heart rate, walking speed, and so on.
But does using one have an impact on how active people are? The answer is yes, according to the largest study on the subject to date (see "Fitness trackers and activity levels: What's the evidence?"). Regular physical activity is essential for a healthy heart, and the improvements seen in this study could potentially make a difference, according to Dr Megan Wasfy, a cardiologist at Harvard-affiliated Massachusetts General Hospital's Cardiovascular Performance Laboratory.
"The increase in moderate-to-vigorous physical activity was close to 50 minutes per week, which is one-third of the 150 minutes recommended by federal activity guidelines," Dr. Wasfy says. The extra 1,200 daily steps taken when people wore trackers were roughly the same as the number of steps linked to a longer life in several studies. 10,000 steps a day has been recommended as a daily goal for a long time, but research shows that 8,000 steps a day is almost as good for your health, especially in older people.
What is the evidence for fitness trackers and activity levels?
A group of Danish researchers looked at the evidence and analyzed it to find out how feedback from wearable fitness trackers affects how much people work out and do other things.
They found 121 different studies involving nearly 17,000 mostly healthy adults ages 18 to 65. The participants' median age was 47, and the majority were female. The study's intervention periods had a median duration of 12 weeks.
Researchers discovered that using physical activity monitors led to an extra 1,235 steps per day and 49 minutes of moderate-to-vigorous physical activity per week on average. They also stood for an additional 10 minutes per day, though this was insignificant. The study was published in The BMJ on January 26, 2022.
There is currently no long-term data.
The key, according to Dr. Wasfy, is to stay physically active throughout your life. Because many of the studies in the review lasted only a few months, it's impossible to know whether wearing a fitness tracker will result in long-term behavioral changes, she adds. To change your behavior with a fitness tracker, you need to do more than just move around. You also need to remember to keep the tracker charged, wear it regularly, and look at your data.
Dr. Wasfy points out that many people who might be motivated to use these devices are already regular exercisers. Instead of transitioning from sedentary to more active lifestyles, these people use them to ramp up their program or train for a race. However, if you fall into the latter category, a fitness tracker can be a useful tool, according to Dr. Wasfy. "For people who want to start exercising more, daily feedback on their progress can help keep them engaged," she says.
Tracker data
Sensors in activity monitors track your movement and other health parameters. A sensor that shines a light through the skin to detect blood flow, revealing your heart rate, is one basic feature. The accelerometer, for example, tracks movement and velocity and allows the device to count steps. A global positioning satellite (GPS) sensor provides a more accurate assessment of your speed, distance, and pace during a walk, run, or ride for people who want extra detail to help boost their performance.
According to Dr. Wasfy, being able to correlate how intensely you're exercising with your heart rate can be interesting for the average person, but it's certainly not required. If you don't want to use a fitness tracker, the old-fashioned "talk test" is a simple way to determine exercise intensity. You should be able to speak in full sentences but not sing during moderate-intensity exercise.
However, if you've recently recovered from a heart attack or heart surgery, or if you have other heart issues, you may need to monitor your exercise intensity more closely, and a fitness tracker's heart rate function provides an easy way to do so. "High-intensity exercise may carry some additional risk," she advises. "Ask your doctor about a heart rate goal that makes sense for you."
