l Make sure the tracker is in contact with your skin.
l Don't wear your tracker too tight; a tight band restricts blood flow, potentially
affecting the heart-rate signal. However, the tracker should be slightly tighter
(snug but not constricting)during exercise than during all-day wear.
l With high-intensity interval training or other activities where your wrist is
moving vigorously and non-rhythmically, the movement may limit the
sensor's ability to provide a heart-rate reading. If your tracker doesn't show a
heart-rate reading, try relaxing your wrist and staying still briefly.
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