A return to a regular routine, like Scott’s traveling to a “Monday Night” location or grappling in an M.M.A. gym, is a significant marker in a cancer survivor’s life. So are the nights he co-anchors “SportsCenter.” But the effort can sap his strength. Soon after returning from his last operation, Scott frequently needed to lean back in his chair and relax during commercial breaks, often not hearing much of what his producer said.

Steele said that for years, Scott had masked his pain when the cameras came on.

“I’ve visited while he’s been getting chemo; it shook me up,” she said. “But then I’d put the TV on at 11 that night, and he’s still Stuart Scott.”

Restoring Energy

Thin but muscular, Scott uses mixed martial arts and high-intensity cross-training workouts to restore the energy that chemotherapy saps from him.

Dressed all in black for a recent workout, he popped in a mouthpiece inscribed with the initials of his daughters, Sydni, 14, and Taelor, 19, and then walked onto the blue and gray padded floor to face Darin Reisler, the sculptured owner of the gym. For 90 minutes, they battled and sparred.

Despite his weakened condition, Scott is skillful, quick and graceful. His breathing grew labored as the workout progressed, but he was happy to be back. He needs the physical contact, he said, the jolt of competitiveness.

“Jab! Cross! Hook! Jab!” Reisler shouted. Scott’s punches shot out in quick combinations that smacked off Reisler’s hand pads, echoing in the nearly empty gym.

Image Hired in 1993, Scott soon became one of the signature anchors on “SportsCenter” and on the network’s N.F.L. and N.B.A. programming. Credit... Phelan M. Ebenhack/Associated Press

The kicks came next — three in rapid succession. Then Scott leapt and delivered a flying kick at Reisler. “You kick like an ox,” he told Scott.