NFL combine - Day 2: Hall, Walker impress in 40-yard dash

Day 1 | Day 2 | Day 3 | Day 4

Breece Hall and Kenneth Walker both posted impressive 40-yard dash times Friday as running backs took to the field on Day 2 of the NFL Scouting Combine.

Hall, who's arguably the top running back prospect in the class, ran the 40 yards in 4.39 seconds. The Iowa State product had the sixth-fastest time but was only 0.02 seconds off the co-leaders. His top run was initially clocked at 4.44 seconds, but the NFL reduced it on his official time.

Hall also had the best vertical jump (40 inches) and tied for the third-best broad jump (10 feet and 6 inches) as he solidified his status as one of the top athletes in his position group.

Walker, a Heisman Trophy candidate who rushed for 1,636 yards and 18 touchdowns last season at Michigan State, was one of three running backs to clock a 4.38.

Top 40-yard dashes: RBs

Georgia's James Cook also had a nice day, standing out in receiving drills. The 22-year-old is the younger brother of Minnesota Vikings star Dalvin Cook.

Offensive linemen worked out on Day 2 as well, and Kentucky's Dare Rosenthal owned the top 40-yard time at 4.88 seconds. Ten others, including projected first-round pick Charles Cross from Mississippi State, ran the dash in under five seconds.

Boston College's Zion Johnson reigned supreme on the bench press with 32 reps of 225 pounds - and did all of them barefoot.

Defensive linemen and linebackers are due up Saturday as the combine moves to Day 3.