How to back up a User Profile Service application using SQL Server in SharePoint 2010 ?

• Open SQL Server Management Studio
• Connect to the database server.
• Expand Databases.
• Right-click the database that you want to back up, point to Tasks
• Then click Back Up.
• In the Back up Database dialog box,
• In the Source area, select the backup type that you want to perform
• User Profile Service application always requires a full backup, so select Full backup
• In the Backup component area, click Database.
• Provide the name to the backup
• We can set an expiration date to make this back up available till desired date.
• By default its 0, means no expiration date
• Provide the path where you want to store this back up under Destination
• That’s it we are done with user profile backup

A very good article available @ http://technet.microsoft.com/en-us/library/gg576965