To reset your Fitbit Alta, you'll need to repeatedly press a button on your charger. But to wipe your data, you'll need to disconnect your account.

Fixes for drained battery, update issues, dirt, weak connections, and more Restart > clean connections > use a different charger > replace the cable > bring the phone closer. Check Bluetooth ...

If your Fitbit won't charge properly, there are a number of things you can try to get it working again, including cleaning ...