Kirk, 52, who has been largely out of sight since he was stricken in January, said in a written statement he was walking and working out on a stair climbing , machine to build up his endurance and mobility.
"I walked an average of 3,677 steps per day, a total of 14.79 miles over ground and on the treadmill, and up 145 flights of stairs," Kirk calculated.
The rigorous program is part of a trial on the benefits of walking under way at the Rehabilitation Institute of Chicago, the Chicago Tribune said Saturday.
The newspaper noted Kirk, a naval reserve intelligence officer, made no predictions on when he might resume his Senate duties.
Kirk met face-to-face Thursday with Rep. Judy Biggert, R-Ill., at his home in Highland Park. Biggert told the Tribune her colleague looked good. "He's doing well," she said. "I think he's eager to get back, but I imagine that he will return (to Washington) whenever the doctors tell him he can."