Sydney McLaughlin-Levrone's training partner, Athing Mu, has reportedly split up with her coach, Bobby Kersee. The latter has been training the American since November 2022 in Los Angeles.Mu had a difficult 2025 season, as she ran only three races in this season. She opened the year by competing in the 800m at the Prefontaine Classic on July 5, where she ended up in the last position. She then ran at the Ed Murphey Track Classic in July, where she again missed the podium, placing sixth. In addition to this, she also missed her spot at the 2025 World Championships.The 23-year-old was eliminated in the 800m semifinals of the US Track and Field Championships. Currently she is in her off-season, and amid this, according to reports, she has parted ways with her coach, Kersee.Citius Mag shared the news on their Instagram handle, revealing that Mu has moved to Dallas with her husband. They added the details in the post's caption that read:"Tokyo Olympic 800m champion Athing Mu-Nikolayev has parted ways with coach Bobby Kersee, according to a report by LetsRun’s Jonathan Gault. She had been coached by Kersee in Los Angeles since November 2022. Kersee told LetsRun that Mu-Nikolayev has moved to Dallas with her husband. Kersee added that it was “a blessing” to coach Mu. Mu-Nikolayev has yet to announce a new coach." View this post on Instagram Instagram PostWhile Mu's 2025 did not pan out as expected, Sydney McLaughlin-Levrone had an impressive season, as she delivered multiple wins. She also won the World Athlete of the Year award on November 30.Athing Mu drops a loving reaction to Sydney McLaughlin-Levrone recreating her Olympic look in the GST photoshoot In October last year, Sydney McLaughlin-Levrone engaged in a photoshoot for Michael Johnson's Grand Slam Track League. The event officials shared a video that featured glimpses of the American's shoot. The 26-year-old was seen donning her New Balance athletic outfits. The post's caption read:"Grammy's red carpet or GST red track?"The post caught the attention of McLaughlin-Levrone's training partner, Athing Mu. The latter gushed over the world record holder's looks and penned a two-word reaction in the comment section that read:"Curls: ✨poppin✨"This isn't the first time Mu supported the 400m hurdles champion on social media. In May 2025, Sydney McLaughlin-Levrone shared her thoughts about competing in multiple events. She spoke about competing in the 200m, 400m, and 400m hurdles.The interview garnered the attention of Mu, who dropped a wholesome four-word reaction, showcasing her bond with the Olympic champion.