165 votesWayne Mack commented
Let me provide an opposing viewpoint, as I find that these types of sessions may actually be detrimental.
I have seen teams implement regularly scheduled "Backlog Grooming" sessions that mask an extended analysis/design phase prior to the start of the sprint. Some of the smells that arise include very large Product Backlogs, stories fully defined and decomposed prior to sprint planning, and short, low-value sprint planning meetings.
Instead of having a pre-sprint grooming session, I usually encourage teams to have a full sprint planning session and to continue to have discussions of story details within the sprint.