Lindsey grew up in Reedsburg, Wisconsin. Her parents are Kurt and Kerri Lentz, and older brother Tyler was a successful swimmer for the University of Iowa Hawkeyes.
Swimming for Sauk Prairie High School, Lentz was a four time letter winner. Placed 14th at the WIAA state meet in the 200-yard freestyle. Earned all-state honors in the 400-freestyle relay freshman and sophomore years while earning most valuable player honors junior and senior year.
Had a successful rookie season swimming mainly mid distance freestyle and butterfly for the Minnesota State University, Mankato mavericks. Lentz finished in the top 16 in the 200 freestyle and 100 butterfly at the Rochester mid season invitational.
Lentz came into her element in the 200 butterfly in her sophomore season. At the conference championship meet, Lentz went best times in her 200 fly and 400 IM. She also finished top 16 in her 200 fly, 200 and 400 IM events.