Abi was born in Westminster, London to Nigerian parents. Her name "Adesola" means "crowned with wealth" in Yoruba. She attended Bentley Wood High School. She represents Shaftesbury Barnet Harriersathletics club. Her first outing to a major athletics came at the 1998 World Junior Athletics Championships, where she finished fourth as part of the British 4 x 100 m relay team. She continued to perform well at the junior level, but her progress was interrupted in 2000 by an injury. She managed to bounce back the following year, with her comeback including a silver medal at the European under-23 Championships. She was again part of the 4 x 100 m relay squad at the 2001 World Championships. Although the squad came away empty handed, they set the second fastest time ever by a British squad. She went on to take gold at the World Student Games that same year. 2002 saw Abi make the final of the Commonwealth Games 100 m and improve on this in the relay by taking silver behind an Australian team. She also made the final of the European Athletics Championships, where Ekaterini Thanou took the gold. She continued to improve and in 2003 broke her 200 m personal best in taking her first national senior title. 2004 saw Abi step up to hold her own with the best in the world. At a meeting in Kalamata, Greece, in May she won the 100 m, then beat the reigning European Champion Muriel Hurtis in the 200 m.
At the 2004 Summer Olympics Abi was unfortunate in not making the 100 m final. Running in the faster of the two semi-finals, she finished fifth in her heat with a time of 11.18 s, that equalled LaTasha Colander's fourth placed time that saw her through in the second semi. Despite not making that final, her good form gave her confidence for her preferred event the 200 m where she set a personal best in the first round, then comfortably progressed through round two and the semi-final, finishing second in both to Allyson Felix. She was passed early on in the final by eventual winner Veronica Campbell and eventually finished joint 7th, but happy with her overall performance. Her appearance in the 200 m final was the first women's Olympic sprint final to feature a Brit since Kathy Smallwood-Cook at the Los Angeles Olympics twenty years previously. She was also the only Briton to reach the sprint finals, all of the men failing for the first time in twenty-eight years, despite later going on to win the 4 × 100 m relay.
After 2004
Following the Olympics, a stress fracture injury caused her to miss the 2005 athletics season. She returned to the track in 2006, but the injury continued to limit her performances. In 2010, she returned to take silver in the 200 m and a gold in the 4 x 100 m relay at the Commonwealth Games in Delhi.
In 2012, Abi came 2nd in the Oslo leg of the Diamond League 200 m Women in 22.71s. She then qualified for 2012 Olympics in London, where she competed in the 100 m and 200 m, making the semi-finals in both events. In 2014, she announced her retirement.
