AP

Lawrence Okoye, the British Olympic discus thrower who decided to try American football and signed with the 49ers as an undrafted free agent, admits he didn’t know what he was getting himself into.

Okoye told England’s Shortlist magazine that the 49ers’ Organized Team Activities showed him just how tough American football is.

“It’s the hardest thing I’ve ever done,” Okoye said.

The 21-year-old Okoye is a great all-around athlete. In addition to reaching the Olympics in the discus, he has run 100 meters in less than 11 seconds, ridiculously fast for a man who weighs more than 300 pounds. And Shortlist reported that “He once scored a try at Twickenham,” whatever that means. But he says the training for the NFL is challenging him in a way he hadn’t been challenged before.

“The two things are worlds apart,” he said. “But there is crossover in terms of the work I do in the weights room where – for the past couple of years in particular – the objective has been to build size, strength and, most importantly, explosive power. Right now, my training time is spent between specific position drills, conditioning and weight training. It’s different each day, but the circuit stuff designed to improve my anaerobic fitness is the real killer.”

We’ll see in the next couple months if all that hard work will result in Okoye remaining a 49er, at least as a member of the practice squad, when the season starts.