Christian McCaffrey understands that staying ready for an NFL season takes more than repeating the same workout every week.

The San Francisco 49ers running back has built his career on speed, strength and versatility, but he refuses to describe his preparation as one fixed routine. Each season brings different physical demands, forcing him to adjust his training while remaining consistent with the fundamentals that support his performance.

“I would love to say that this is the routine, it’s the perfect routine, it gets the job done, and you’ll be great if you just do this,” McCaffrey tells Men’s Journal. “But I think that’s part of the challenge: constantly coming up with ways to reinvent yourself, working on your weaknesses and capitalizing on your strengths.”

His workouts combine speed training, conditioning, mobility, and exercises that test him physically and mentally.…