Brailsford spent some of his early career working as an export sales manager at Planet X Bikes. He was first employed by British Cycling as a consultant in 1998, after Lottery funding began the previous year. Brailsford became programmes director before becoming performance director in 2003 following the departure of Peter Keen.
'Marginal gains' philosophy
At British Cycling, Brailsford was noted for his innovativeconcept of 'marginal gains': Brailsford's approach involved the constant measuring and monitoring of key statistics such as cyclists' power output, and training interventions targeting specific weaknesses, for example the relative weakness of Bradley Wiggins in mountain racing. As well as looking at traditional components of success such as physical fitness and tactics, it also entailed a more holistic strategy, embracing technological developments, athlete psychology, and everyday life: Peaking in the mid-2010s at the height of Brailsford's reputation, 'marginal gains' philosophy was discussed beyond cycling in the UK mainstream media. Brailsford's '1% Factor' was also discussed in business circles in the UK and internationally. In UK education policy, the Social Mobility Commission argued in 2014 that improvements in the academic performance of disadvantaged students in British schools could be compared to "the success of British cycling team: the aggregation of marginal gains". Latterly, the philosophy has been criticised and ridiculed, including by Wiggins.
At the 2004 Olympic Games Great Britain won two cycling gold medals, their best performance since 1908. Under Brailsford's leadership, the cycling team continued to improve, winning multiple world championships in road, track, BMX and mountain bike racing. Great Britain led the cycling medal table at the 2008 and 2012 Olympic Games, winning eight golds at both, while British cyclists won 59 World Championships across different disciplines from 2003 to 2013.
In 2010, Brailsford also became the manager of the new British-based professional team, Team Sky. In this role he oversaw Bradley Wiggins', Chris Froome's and Geraint Thomas' victories in the 2012, 2013, 2015, 2016, 2017 and 2018Tours de France. In April 2014, Brailsford resigned as performance director at British Cycling to concentrate on his Team Sky responsibilities.
Team Sky became Team Ineos in May 2019, due to a change of sponsor. Brailsford remained as team principal after the changeover.
Doping controversy
In March 2018 the Commons Digital, Culture, Media and Sport Committee published the report . Chapter 2 of the report, "British Cycling and Team Sky", focused on Therapeutic Use Exemptions gained by both organisations for the use of drugs on the WADAProhibited List, citing the defence used by Wiggins and Shane Sutton that TUEs were used to "find gains" and put oneself "back on a level playing field" with rivals. The report alleged in particular that the drug triamcinolone had been "used to prepare" Wiggins "and possibly other riders supporting him" for the 2012 Tour de France, "not to treat medical need, but to improve his power to weight ratio ahead of the race". It concluded that Team Sky had crossed an "ethical line" by exploiting this loophole "to enhance the performance of riders". Following the publication of the report, Brailsford was defended by Chris Froome.
In December 2008 the 14 medals, including eight golds, achieved by British Cycling at the Olympics won him the BBC Sports Personality of the Year's Coach Award.