Denmark's double Olympic badminton champion Viktor Axelsen announced his retirement at 32 on Wednesday, saying back problems meant he could no longer "compete and train at the highest level".

Viktor Axelsen of Denmark greets fans after the victory ceremony of badminton men's singles at the Paris 2024 Olympic Games in Paris, France, on Aug. 5, 2024. (Photo: Xinhua)

Axelsen, who won gold at the Tokyo Games in 2021 and again in Paris in 2024, had back surgery in April last year and said he had not managed to overcome his physical issues.

"Accepting this situation has been incredibly difficult," he said in a statement.

"But I have now reached a point where my body won't allow me to continue."

Axelsen retires as one of the most decorated players in history, having also won two world titles and a bronze medal at the 2016 Rio Olympics.

He spent more than 100 consecutive weeks at the top of the men's singles world rankings, an achievement surpassed only by Malaysian great Lee Chong-wei.

Standing 194cm (six foot four inches) and making full use of his giant wingspan, Axelsen redefined what a player could do on the court.

He said he had "accomplished everything I once dreamed of, and more".

"What makes it hardest to say goodbye is not the competition itself, but everything around it, the journey, the daily grind, the people," he said.

Axelsen speaks Mandarin and is a popular figure in China.

He regularly posts about his professional and family life on online Chinese platforms.

News of his retirement sparked a wave of reaction in the country, and was among the most discussed on the social media platform Weibo on Wednesday afternoon.

"A true legend of badminton bids farewell," wrote one user.

"He was not only a king on the court, but also won countless hearts with his humble and friendly attitude."

Axelsen won Olympic gold at the pandemic-delayed Tokyo Games in 2021 without dropping a single game all tournament.

He beat China's Chen Long in the final, becoming the first non-Asian to claim the title since 1996.

He sobbed in disbelief after Chen hit his final shot long, then regained his composure to take a courtside phone call from Denmark's Crown Prince Frederik.

He followed that up by defending his title at the Paris Games, emulating his hero Lin Dan by winning back-to-back Olympic golds.

He then began to struggle with injuries and spent prolonged periods off the court.

"I have given everything to this sport," he said.

"It has never been just a career to me. It has been my life and I have left no stone unturned."

Axelsen retires as only the second non-Asian player after countryman Thomas Lund to win the world title twice, which he achieved in 2017 and 2022.

He won the season-ending BWF World Tour Finals three times in a row from 2021 to 2023.