[6] He was a time trial specialist, and in 2015, he broke track cycling's world hour record by 446 metres (1,463 feet), with a distance of 52.937 kilometres (32.894 miles).

Later in September, Dowsett competed at the UCI World Road Race Championships in all three men's elite events, with a best placing of eighth in the individual time trial.

On 30 October 2012, Dowsett signed with the Spanish Movistar Team for the 2013 season hoping to gain a ride at a Grand Tour.

[12] After competing in the Classics season for Movistar Team, Dowsett was selected to ride the Giro d'Italia, his first Grand Tour appearance.

[16] After a long breakaway, Dowsett took the lead of the Tour of Britain on the sixth stage[17] but lost it before the end of the race to Dylan van Baarle and finished eighth overall.

[19] In December 2014, Dowsett announced he would attempt to break the UCI Hour Record at the Lee Valley VeloPark on 27 February 2015.

[3][9] Following the last minute break up of the team in 2019,[27] he initially thought he would rest from professional cycling in 2020 and return to his local Maldon club, to focus on the Olympics and regaining the hour record.

[30] Following this, Dowsett contested the Giro d'Italia and won the eighth stage from a six-rider breakaway, soloing to victory from 18 kilometres (11 miles) remaining.

[8] As a result, he has a special exemption from the Union Cycliste Internationale's no needles policy, introduced in 2011,[37] to inject himself with the clotting protein Factor VIII every 48 hours.

[8] Dowsett started the charitable foundation Little Bleeders to raise awareness of haemophilia and to encourage and support young haemophiliacs to engage with sport.