Packers running back Aaron Jones feels he’s added lower body strength without sacrificing his burst after his off-season workouts. He showed flashes of great ability during his rookie N-F-L season in Green Bay, but was sidelined by injuries more than once. Jones decided he needed to develop the lower part of his body to withstand the punishment of a 16-game pro season. Spending hours in the team’s weight room, the second-year back says he is bigger so he can hold his ground without getting hurt as much. At the same time, Jones and his coaches are hoping he retains the explosive ability which let him average five-and-a-half yards-a-carry during his rookie season.