Yes, you’re right! Research sprints are an essential part of successful design sprints. While the team sprints, I work in parallel to plan, recruit and prepare for the Friday interviews.
You’re also right about the importance of conducting UX research prior to design sprints. Our most successful design sprints build on research done BEFORE sprint week. I usually present those findings to the team on Monday (Day 1) of the design sprint. It would actually be pretty unusual for us to do a design sprint without first doing some kind of UX research to lay the groundwork — especially when working on tough problems or complex domains. You can read about the 5 types of UX studies startups need most here: Field Guide to UX Research for Startups.
