Gal began his equestrian career as a jumper at age 14, beginning with ponies and graduating to larger horses at age 20. However, when he discovered his horse did not like jumping, he switched to dressage. While enjoying solid success in national and international competition, he did not become a truly dominant rider until he began competing with Totilas in 2008. Gal would later say that he and his team understood that Toto was a special horse after their first Grand Prix competition.
Since then, Gal has replaced his countrywoman Anky van Grunsven as the dominant rider on the world dressage circuit. In July 2009, he and Toto broke van Grunsven's world record score in Grand Prix Freestyle with an 89.50% mark at Hickstead, England, and shortly thereafter followed it up with another record score of 90.75% in the same discipline at that year's European Championships. In December 2009, at the fourth leg of the 2009–10 FEI World Cup Dressage series at Olympia in London, they extended their record in GP Freestyle to 92.30%, more than 10 points above the second-place finisher. While not setting a world record, they easily won that season's FEI World Cup final in GP Freestyle at home in the Netherlands, winning by more than 7 points with a score better than their first world record. The pair also have a world-record score in the Grand Prix Special discipline to their credit, having recorded 86.460% at Aachen in July 2010.
Gal and Totilas were installed as the overwhelming favorites in the 2010 FEI World Games in Lexington, Kentucky, USA, their first competition outside Europe. Klaus Röser, head of the German dressage team that has long dominated the discipline, said about Gal, "That we can beat Edward; I don't think so, I don't believe so. We have to be realistic." Röser's assessment proved correct, with Gal and Toto first leading the Dutch team to gold in the team competition, and then easily winning gold in Grand Prix Special and Grand Prix Freestyle.
In a piece in The Courier-Journal of Louisville, Kentucky that ran before the 2010 Games, dressage trainer Susan Posner pointed out that Toto was only in his second year in dressage despite being 10 years old, and said that his success illustrated how capable Gal was as a rider.