Former NFL running back Herschel Walker was always a physical specimen, and judging by a recent photo spread, he hasn’t missed a beat.

Walker, whose relatively simple workout regimen has been well-documented over the years, recently posed nude for ESPN the Magazine’s “Body Issue.”

The 48-year-old Walker has kept himself in tremendous shape as evidenced by the photo, but continues to do so with simple, yet tenacious workouts.

Walker wakes up every morning, skips breakfast and precedes to do in the neighborhood of 1,000 sit-ups and 2,000 push-ups. From there, Walker dives into mixed martial arts training. Walker now dabbles in the professional MMA scene as well.

Jeff Pearlman‘s book Boys Will Be Boys, which chronicled the Dallas Cowboys dynasty of the ’90s, also showed the craziness of Walker’s workouts and eating habits.

Former Cowboys running back Todd Fowler remembers.

“Herschel only ate one meal a day,” Fowler told Pearlman. “At breakfast and lunch, he’d drink juice and stuff. After we’d get out of meetings, he and I would go to Carl’s Jr. He’d get a double burger and fries. That’s all he’d eat the entire day. Plus, he only slept four hours per night. You’d get up [to go to the bathroom] at 2 a.m., and Herschel would be in the living room reading his Bible or doing push-ups or sit-ups.”

In the video below, Walker talks about his MMA preparation.