TOKYO • Japan must act to tackle "rampant" abuse of youth athletes by sports coaches before it hosts the Tokyo 2020 Olympics next year, activists said on Wednesday.

The call comes after a new report warned that abusive behaviour by sports coaches remained common in the country.

Human Rights Watch "found that child abuse is still rampant in sports training throughout Japanese schools, federations and elite sports", the watchdog's national director Kanae Doi told reporters.

"While the topic of child abuse in sports is a global problem, we chose to focus on Japan for 2020 because the Olympics and Paralympics are coming to Japan," she said.

"Every Japanese knows unfortunately that corporal punishment has been prevalent in Japanese sports."

The group documented the experiences of more than 800 former child athletes, including Olympians, in 50 sports across the nation.

It found many had been punched, kicked or verbally abused, while others reported being ordered to eat excessively, train even when injured or were denied water.

"I was hit so many times I cannot count," one athlete told the group.

The issue is one that haunts Keiko Kobayashi, whose son was a talented 15-year-old judoka when his coach used a choking technique on him and threw him to the floor, causing severe brain injuries.

"I want to teach children that this is abuse," Kobayashi, 70, told AFP.

"I want to teach them to raise their voice."

The coach was not prosecuted because the injury occurred during practice, and he continues to work as a school teacher and judo instructor, Kobayashi said.

Her son, now 30, is still suffering the effects of his injury and requires close supervision by his family and medical professionals.

Abuse in Japanese sport has made headlines in recent years.

In 2018, a 13-year-old boy in a school badminton team killed himself. His parents accused the boy's coach of longstanding verbal insults and abuse.

Violence is also often reported in Japan's sumo stables and, in 2013, a national Olympic judo coach stepped down after elite judokas accused him of abuse and violence.

But activists say young athletes are often afraid to report abuse because Japan's culture emphasises respect for elders, leaving coaches to continue their harassment.

"I think a real problem here is that we have accepted this practice. And this is due to our culture and social norms," said Takuya Yamazaki, a sports lawyer who worked on the HRW report.

HRW wants to see tougher action from the government, specifically targeting the abuse of young athletes, including the establishment of an independent body that would decertify abusive coaches.

"When Tokyo 2020 starts, I wish Japan will be proud of its reform to protect its own children from abuse in sports and embrace this reform as an important and lasting legacy," Doi said.

Athlete abuse, however, is not an issue in Japan alone.

On Thursday, former Singapore national figure skater Yu Shuran revealed that she too had been abused while training in China.

The 19-year-old said that from the age of 11, she had been hit repeatedly by coaches, sometimes with skating blades that drew blood from her shins.

She added that she got through the abuse by "numbing it out".

The BBC also reported that dozens of Australia's former top gymnasts have spoken out about mental and physical abuse within the nation's elite programme.

In stories shared online, many argued that coaches had normalised a "toxic" environment.

Earlier this month, British Olympic gymnasts Becky and Ellie Downie also claimed abusive behaviour in gymnastics had become "completely normalised" and several athletes told the BBC of "a culture of fear" in the sport.

In South Korea, triathlete Choi Suk-hyeon, 22, took her own life earlier this month after years of physical and verbal abuse from coaches and having her complaints to sporting authorities allegedly ignored, according to reports.

AGENCE FRANCE-PRESSE, REUTERS