David Beckham has revealed the reason why he retired from football, saying that he would have carried on until he "literally couldn't walk anymore" if he could have done.

The 48-year-old explained the reasoning in his newly-released four-part documentary on Netflix.

He rose to fame playing for Manchester United in the 1990s and early 2000s before he made the move to Real Madrid in Spain.

Following that Beckham played for LA Galaxy in the United States, AC Milan in Italy and finished up his career at Paris Saint-Germain in France.

After he began playing in 1992 he hung up his boots on May 18, 2013, after 21 years in the game.

His final match was for PSG against Brest where he was substituted in the 80th minute to receive a standing ovation from the fans.

Physical impact of playing football led to retirement

In his new documentary, Beckham explained that the physical after-effects of playing football were the main reason why he retired.

He said: "I never thought about retirement, I wanted to play until I literally couldn't walk anymore.

"I think I loved the game more than anyone has ever loved it. That's what I think. I know it's not true, but I think that I loved the game more than anyone.

"But I felt different. My body felt different. I was waking up after games, I felt beaten up.

"I felt every time that I was getting out of bed, I was aching, I was hurting. I'd roll out of bed in the mornings because I just was in so much pain. So coming to that decision, it was actually a really tough one."

Discussing how he felt coming off in his final match Beckham shared: "All of a sudden I couldn't breathe, and I couldn't control my emotions. When I finally come off, I completely lose it.

"But as much as it hurt me knowing I was never going to play football again, I knew I'd made the right decision."

Beckham is available to watch on Netflix right now.