Sports Shorts: Five-time Olympic champion Franklin retires at 23

Summary of sports events and persons who made news on Thursday

Missy Franklin, the 2012 World Swimmer of the Year, announced her retirement on Wednesday at age 23, citing intense pain from shoulder injuries that have dogged her for nearly three years.

Franklin was a 17-year-old when she won the 100 and 200 metres backstroke events at the 2012 London Olympics, the latter in a world-record time that still stands more than six years later.

She also made the final in two other individual events in London, and was part of two victorious US relay teams.

Franklin picked up six golds at the 2013 Barcelona World Championships, but never improved her personal best times from London.

She struggled to replicate her teenage performances after first experiencing bad shoulder pain in early 2016.

She still made the U.S. team for the Rio Olympics, however, where she picked up another relay gold after swimming in the heats, before having surgery on both shoulders last year.

"This was perhaps the hardest letter I’ve ever had to write ... Today, I announce my retirement from competitive swimming," Franklin wrote on Twitter.

She explained her reasons for retiring in an article for ESPN.com.

"I've been in too much pain, for too long, to go through another surgery with a longer recovery time and no guarantee it would even help," she wrote.

"It took me a long time to say the words, 'I am retiring.' A long, long time. But now I'm ready."

Top US rhythmic gymnast Zeng handed six-month doping ban

Laura Zeng, the United States top-ranked rhythmic gymnast and winner of five Pan Am Games gold medals, was handed a six-month ban on Wednesday by the United States Anti-Doping Agency (USADA).

Zeng, who also represented the United States at the 2016 Rio de Janeiro Olympics, tested positive for the banned diuretic and masking agent acetazolamide in an out-of-competition test on Oct. 18, USADA said in a statement.

Zeng provided evidence to a USADA investigation that the prohibited substance was from an altitude sickness medication, which was prescribed to her parent and given to her in response to an illness.

USADA said the 19-year-old believed she was being given ibuprofen and therefore did not have to apply for a Therapeutic Use Exemption, which is required to authorise the use of a prohibited substance in sport.

Along with her five gold medals from the 2015 Toronto Pan Am Games, Zeng also dominated the Pan American Championships staged in Lima, Peru in September, sweeping six gold medals, including the all-around title.

Zeng's ban began on October 18, the date her positive sample was collected.

'Tennis has serious integrity problem'

Scrapping official live scoring data at the lowest level of professional tennis and taking a harder line on "tanking" are among the recommendations made by an International Review Panel in a report published on Wednesday.

The panel was formed in 2016 by the sport's four main professional governing bodies to address betting-related and other integrity issues.

"Today, tennis faces a serious integrity problem," the panel said.

"There are several reasons for this: The nature of the game lends itself to manipulation for betting purposes.

"There are many contingencies. There is only one player who must act. Detection is difficult, not least because at many lower level matches there are no spectators and inadequate facilities to protect players from potential corrupters.

"Moreover, under-performance is often attributed to ‘tanking’, which too often has been tolerated."

The panel said there was no simple solution to the problem with a package of measures required, including banning tournaments from accepting sponsorship by the betting industry and reorganising the Tennis Integrity Unit with independent oversight.

The panel said players in the lowest tiers were susceptible to being corrupted because of the difficulty of making a living, with only 250-350 players earning enough money to break even.

"The player incentive structure creates a fertile breeding ground for breaches of integrity," the panel said.

The sport's major bodies released a joint statement saying they would work jointly to implement the panel's recommendations.