Are wearable health trackers accurate?

Many people want to keep track of their health on the go. Wearable devices are intended to give you a snapshot of your overall health by tracking calories burned, steps walked, blood pressure level and other data.

However, the accuracy of the health readings has come into question. “You can use your wearable as a tool for tracking your health, but it shouldn’t be the only thing you rely on,” says Dr. Robert Gillespie, a cardiologist affiliated with Sharp Memorial Hospital.

What wearables might get wrong
Dr. Gillespie suggests you take the following into consideration when using wearables:

• People of color
  Most devices track heart rates using optical sensors that continuously monitor the volume of blood at your wrist. However, several popular brands rely on green-light sensors — a simple, cheaper light that has a shorter wavelength. Green light is more easily absorbed by melanin, the pigment that gives skin, hair and eyes their color.
  
  The more melanin in your skin, the harder it becomes to get accurate heart rate readings. Heart rate — the number of times your heart beats per minute — can be an important data point for doctors trying to identify heart problems. “It is important for companies that offer health monitoring devices to consider the population as a whole because there may be variations among race, age and gender,” Dr. Gillespie says.

• Focusing only on the numbers
  Wearables track your steps in a day and let you know when you’ve reached your daily goal. Reaching your goal can be rewarding, but can also offer a false sense of accomplishment if your device isn’t accurate. It can also be easy to focus only on the numbers, rather than the effort you put forth and how your body feels, which can lead to feelings of discouragement when you don’t reach your intended goals for the day.

• Calorie burn count is debatable
  Many wearables track how many calories you have burned in a day, but often the calories burned are estimates. The devices don’t take into account unique factors such as genetics, metabolism and body type.

• All wearables are not created equal
  Not all wearable devices measure the same things. Tracking devices without a GPS system may not be able to accurately measure your distance if you are going for a run, and many are unable to sufficiently track resistance or weight training.

A healthy lifestyle is most important
“What’s important is living a healthy lifestyle to help lower your risk of disease,” Dr. Gillespie says. He recommends four tips everyone should follow to stay on top of their health — with or without the aid of wearables:

1. Get regular exercise
   One of the best ways to manage your health is to exercise frequently during the week. According to the American Heart Association, adults should get 150 minutes per week of moderate activity, such as brisk walking, gardening and water aerobics, or 75 minutes per week of vigorous activity, such as running, swimming laps or aerobic dancing. A combination of moderate and vigorous activity spread throughout the week is OK too.
   
   According to Dr. Gillespie, an easy way to check the intensity of your exercise is the talk test. You know you are getting moderate activity if you can still talk, but it’s difficult to understand you. You are getting vigorous activity if you can only say a few words during exercise.

2. Check your heart rate manually
   You can ensure a more accurate heart rate reading if you do it yourself. To check your heart rate, place your index and middle fingers of one hand on the opposite wrist, just below the base of the thumb. Count the number of beats in 15 seconds and multiply by four to get your heart rate.
   
   If you choose to use heart rate to measure how hard you are working out, ensure your heart rate is within the target for your age, Gillespie says. Subtract your age from the number 220 and stay within 70 to 80% of that number during exercise.

3. Know your numbers
   According to Dr. Gillespie, tracking your blood pressure is the most effective way to lower your risk of heart disease. Normal blood pressure is an upper number (systolic pressure) less than 120, and a lower number (diastolic pressure) less than 80. However, there are other health factors that may determine appropriate blood pressure numbers. You should talk to your doctor to learn what numbers are best for you.
   
   Having high blood pressure, also known as hypertension, can increase your risk for heart disease and stroke. Heart-healthy habits, like following a balanced diet and getting regular exercise, can help you manage your blood pressure.

4. Eat a healthy diet
   A healthy lifestyle involves many choices, including what you consume on a daily basis. You can eat smart, but still enjoy your food and manage your weight. A diet full of whole grains, green leafy vegetables, low-sugar fruits, low-fat dairy and lean meats may help decrease your risk of heart attack and stroke, and lower your blood pressure.

Talk to your doctor if you have concerns about your health or fitness level before beginning a new fitness routine. Together, you can develop a plan that improves your lifestyle and leads to better overall health and wellness.