Reddick ended up with the fastest average lap speed (89.923 mph) in the 50-minute first session that included three spins by 2020 Cup champion Chase Elliott.
Chase Briscoe ended up second-fastest in single-lap speed (89.753 mph) and Kyle Busch was third (89.695 mph). Justin Haley and Kurt Busch rounded out the top-five.
Completing the top-10 in average speed were Ricky Stenhouse Jr., Ross Chastain, Todd Gilliland, Ty Dillon and Christopher Bell.
Among those drivers who ran at least 10 consecutive laps, Stenhouse had the best average lap speed (88.869 mph). He was followed by Kurt Busch, Reddick, Austin Dillon and Elliott in that category.
In the opening minutes of the practice Alex Bowman brought out the first caution with a spun off Turn 4.
About seven minutes in, Elliott spun and came to a stop on the frontstretch but his No. 9 Chevrolet did not appear to suffer any damage.
Roughly 18 minutes into the practice, a caution was displayed for debris in Turns 1 and 2 which appeared to the come from the No. 11 Toyota of Denny Hamlin after contact with the wall.
“I didn’t see the corner, the dust was so bad,” Hamlin said afterwards. His car did not appear to suffer serious damage.
Nearly 25 minutes in, Elliott spun a second time but quickly got going again.
With about 10 minutes remaining, Chastain spun to bring out a brief caution. Elliott spun a third time with eight minutes to go but continued on without an issue.
Logano, the winner of last year’s inaugural dirt race at Bristol, did a 360-degree spin on track in the final minutes of practice.