He started swimming at the instigation of his grandfather, who was a swimming teacher, at the age of two years. He tried
judo at 10 years old, but left due to his mother. His first club was the
Canto do Rio in
Niterói. At age 13, he moved to
Fluminense. Three years later, he moved to
Vasco, where he stayed until 2000. He participated at the
1999 Pan American Games in Winnipeg, where he finished 11th in the
100-metre butterfly, and 11th in the
200-metre individual medley. He was at the
2003 World Aquatics Championships in Barcelona, where he finished 37th in the
100-metre butterfly. Prior to the 2004 Olympics, he came to the United States, where he was trained by the Olympic champion
Anthony Nesty. and in the
50-metre backstroke, where he came in at 16th place. He was at the
2006 FINA World Swimming Championships (25 m) in Shanghai, where he finished 19th in the 100-metre butterfly, 20th in the 50-metre backstroke and 9th in the 4×100-metre medley. He swam at the
2006 Pan Pacific Swimming Championships, where he finished 5th in the
100-metre butterfly and 7th in the
4×100-metre medley. Mangabeira also qualified to compete in the
2007 World Aquatics Championships in the
100-metre butterfly and
50-metre backstroke, but did not make it past the initial heats. He ranked 17th in the 100-metre butterfly and 9th in the
4×100-metre medley, helping the Brazilian relay to qualify for the 2008 Olympics. At the
2007 Pan American Games in Rio de Janeiro, he won the silver medal in the
100-metre butterfly, and also helped the Brazilian
4×100-metre medley relay in heats, winning the silver medal in the event. He was at the
2010 Pan Pacific Swimming Championships in
Irvine, where he finished 4th in the
4×100-metre medley, 15th in the
100-metre butterfly, and 15th in the
100-metre backstroke. At the
2011 Pan American Games in Guadalajara, Mangabeira won gold in the
4×100-metre medley and in the
4×100-metre freestyle. == Post-career ==