Fitbit Zip Versa Manual page 4

When you're not exercising, wear your device a finger's width above your wrist bone. Fitbit's PurePulse
technology is designed to be most accurate when you wear your device on the top of your wrist.
For improved heart-rate accuracy, keep these tips in mind:
1. Experiment with wearing the device higher on your wrist during exercise for an improved fit and
more accurate heart-rate reading. Many exercises such as bike riding or weight lifting cause you
to bend your wrist frequently, which could interfere with the heart-rate signal if the watch is
lower on your wrist.
2. Make sure the device is in contact with your skin.
3. Do not wear your device too tight; a tight band restricts blood flow, potentially affecting the
heart-rate signal. That being said, the device should also be slightly tighter (snug but not
constricting) during exercise than during all-day wear.
4. With high-intensity interval training, boxing, or other activities where your wrist is moving
vigorously and non-rhythmically, the movement may prevent the sensor from finding an
accurate heart rate. Similarly, with exercises such as weight lifting or rowing, your wrist muscles
may flex in such a way that the band tightens and loosens during exercise. Try relaxing your
wrist and staying still briefly (about 10 seconds), after which you should see an accurate heart-