Ellie Kemper Is 'Rejuvenated By Strength And Grit Of NYC' After Running First Marathon

"Unbreakable Kimmy Schmidt" star Ellie Kemper is now a "retired marathoner" according to her Instagram bio. The actress ran in the NYC Marathon, her first-ever marathon, and finished the race in 5:17:39.

Kemper, 42, shared an appreciation post after she completed the race on Sunday. "Uh-oh….get ready for the emotional post!!!!!! Well I completed the @nycmarathon! And now for the gratitude," she began the caption of her carousel of marathon photos on Instagram. "Thank you to EVERY SINGLE PERSON out on the streets cheering, yelling, high-fiving, and handing out bananas. Thank you in particular to the parents and caregivers who brought out their adorable sweetie pie babies whose little angel faces literally carried me through the journey."

Her caption continued to thank all the volunteers and everyone at New York Road Runners who organized the marathon that consisted of 50K participants. She also thanked her partner Brotherhood Sister Sol, the nonprofit organization she fundraised for. "Yesterday was insane on every level and I am REJUVENATED by the strength and grit of NYC," she concluded her caption.

Many of her friends and fans ran to the comment section to cheer her on and send congratulatory messages filled with love and support. Some of Kemper's "Office" co-stars dropped into the comments to congratulate her big accomplishment. Angela Kinsey wrote, "Congratulations Ellie!!! So awesome!!" and Kate Flannery added, "You wear it well!!!!! ❤️ congratulations!" Actress Mariska Hargitay commented, "It was such a joy this is my favorite day in New York. The community, the love, the triumph of the human spirit!🔥❤️💥✨"

Kemper shared the news that she would be running in her first ever marathon on Instagram in early October with a photo of her dressed in her running attire ready to go. She captioned the post, "You knew it had to happen….I am running the @nycmarathon! This will be my first marathon ever and here I am in my cute new marathon running belt."

Her caption continued talking about the organization she was raising money for. "I am honored to be a part of Team #BroSisRuns, raising money for The Brotherhood Sister Sol. This is a nonprofit in NYC dedicated to educating young people and organizing for justice & equity," she wrote. "Please help me reach my fundraising goal if you can!! Any amount is appreciated! Link is in my bio. Guys, I’m just a major athlete now, I am Rocky Balboa, I am raising money for @brosis512, get used to it!!!"

"The Office" star's fans dropped into the comment section to wish her well, tell her about their first-time marathon stories, and encourage her. One of her "Unbreakable Kimmy Schmidt" fans reminded her to, "Take it ten seconds at a time," and one of her costars, Lauren Adams wrote, "Go Kemper go!!!!"

Other celebrities that ran the NYC Marathon this year included Lauren Ridloff, Tiki Barber, Chelsea Clinton, and Ashton Kutcher. Kutcher, 44, finished the marathon with a time of 3:54:01, and raised more than $1 million to help fight child sex abuse through his foundation Thorn. Kutcher partnered with Peloton to train for the 26.2 mile race through the five boroughs and to bring awareness to his charity.

Kutcher told PEOPLE that he does "genuinely enjoy running" and said he was motivated by one victim of child sex trafficking that Thorn has been searching for over the past two years. "I put that kid on the other side of the finish line," he said. "I know she's out there and I want her to know that somebody's coming for her."