He and Arab-Israeli Olympic swimming hopeful Jowan Qupty were high school roommates and best friends. He won a silver medal in the 200 meter freestyle, and a bronze medal in the 400 meter freestyle, at the 2007 European Junior Swimming Championships. He won a silver medal in the 100 meter freestyle at the 2009 Maccabiah Games.
Shapira Bar-Or represented Israel at the 2008 Summer Olympics in the 100 meter and 200 meter freestyle, and has qualified to represent Israel at the 2012 Summer Olympics.
Shapira Bar-Or is Jewish, and his hometown is Jerusalem, Israel. Although he played basketball for a top Israeli junior team, a knee injury that he suffered at 11 years of age led him to shift his focus to swimming.
Shapira Bar-Or and fellow Israeli swimmer Jowan Qupty, who is a Christian Israeli Arab, had known each other when they were children, and swum together for the Jerusalem United swim club in Israel. They attended The Bolles School, in Jacksonville, Florida, together. There they were roommates for two years, swim team teammates, and became best friends. Qupty's father, commenting on the friendship and teamwork between his Christian Arab Israeli son and his son's Jewish Israeli roommate/teammate, said: "Just to see them together after the race jumping and hugging each other; they were so happy. I was looking at them through my tears. Coming from our part of the world, you don't see that." The younger Qupty observed that "people were amazed all the time" that he – a Palestinian – and a Jew could coexist, and Shapira Bar-Or said: "It shows how simple the situation is. If I can live with a Palestinian guy, I'm sure in our country we can live with a couple millions of Palestinians and Israelis together."
In November 2006, he won the 200 yard freestyle (1:38.37) at the Florida State 1A Championships, and was runner-up in the 500 yard freestyle. He was named Times-Union 2006 Florida All-First Coast Swimmer of the Year.
After high school, Nimrod Shapira Bar-Or attended the University of Arizona, where he majors in Management Information and Systems in the Eller College of Management. In 2009, he was a silver medalist at the NCAA Championships at College Station, Texas as part of the Arizona Wildcats 800 free relay team (6:11.82), and in 2010, he was a bronze medalist in the same event in Columbus, Ohio. He was honored as a member of the Pac-10 All-Academic First Team. He was named the Counsilman-Hunsaker National Collegiate Swimmer-of-the-Week on November 17, 2010, and again honored in 2011 as a member of the Pac-10 All-Academic First Team. His fastest times in college competitions, through March 2011, were 19.92 in the 50 yard freestyle (2010), 42.37 in the 100 y freestyle (2011), 46.44 in the 100 y fly (2010), 1:33.50 in the 200 y freestyle (2010), 1:43.71 in the 200 y fly (2010), and 1:44.85 in the 200 y IM (2011).
In July 2007, he won a silver medal at the European Junior Swimming Championships in the 200 m freestyle (1.50.36), in Antwerp, Belgium. He finished behind Mikhail Polischuk of Russia. He also won a bronze medal in the 400 m freestyle (3:54.83).
In August 2007, he won a gold medal in the 400 m freestyle (3:55.23), and established the Israeli 18-and-under national record in the 200 m freestyle (1:50.06) at the Israeli Summer National Championships.
In March 2008, he swam on the team that set a new Israeli record in the 4×200 meter freestyle relay, at 7:20.87, at the 2008 European Championships in Eindhoven, Netherlands. In July 2008, he set a new Israeli record in the 200 meter freestyle, at 1:48.76 at the Croatian Open Championships in Dubrovnik, Croatia. He broke his own national record in the 200 meter freestyle the next month at the Olympics.
In July 2009, he set a new Israeli record in the 100 meter freestyle, at 48.93, at the World Championships in Rome, Italy. Also at the 2009 World Championships, he swam on the team that set a new Israeli record in the 4×100 meter medley relay, at 3:36.23.
In August 2009, he won gold medals in the 50 m (22.75; surpassing the 14-year-old former record of 22.79 established by Yoav Bruck), 100 m (49.49), 200 m (1:49.36), and 400 m freestyle races at the Israeli Summer National Championships at Wingate Institute in Netanya. In July 2010, he won gold medals in the 50 m, 100 m (49.89), 200 m, and 400 m freestyle races at the Israeli Long Course National Championships.
Shapira Bar-Or competed on behalf of Israel at the 2008 Summer Olympics in Beijing, China. In the 100 meter freestyle he swam a 49.10 (a national record) and came in 26th, and in the 200 meter freestyle he swam a 1:47.78 (also a national record) in the first heat, and a 1:48.16 in the semi-finals, coming in 15th. He was the first Israeli swimmer to compete in an Olympic semi-finals.
He competed on behalf of Israel at the 2012 Summer Olympics, in London.
He won a silver medal in the 100 m freestyle (49.02; behind Jason Lezak, and a new Israeli record) at the July 2009 Maccabiah Games.