Fitbit Flex is the ideal way to track your activity without imposing on your lifestyle. Just strap it to your wrist and leave it there, through day and night and then sync it with your smartphone or computer to see how active you are.
Flex measures your sleep and will tell you how long you slept and how many times you woke up, giving you a sleep quality score. Flex can also wake you up in the morning with a silent alarm that won't bother your partner.
Discovered for you at John Lewis