Canada at the Summer Olympics became the first Canadian Summer Olympian to win a medal in four straight Olympics. After George Hodgson won two gold medals in the 1912 Stockholm games, it would be 72 years before Alex Baumann became the second Canadian swimmer to win Olympic gold, when he won both individual medley events in world record time in the 1984 Los Angeles games. Victor Davis (1984), Anne Ottenbrite (1984), Mark Tewksbury (1992) and Penny Oleksiak (2016) are the only other Canadian swimmers to win gold medals. In 2004, Canada failed to win a medal of any colour in swimming for the first time
Rebecca Adlington would not compete in Rio. Adlington set a new British, Commonwealth, European and Olympic record of 8:18.06 in the preliminary heats of the women's 800-metre freestyle on 14 August 2008. She went on to win the Olympic 800-metre freestyle final on 16 August 2008 in a world record time of 8:14.10, her second gold of the tournament, a full six seconds ahead of the silver medalist, and two seconds ahead of the former world record which had been set by Janet Evans when Adlington was 6 months old. At the time, this was swimming's longest standing world record. The Sherwood