Katherine and Katie going for Olympic gold in Rio showdowns

Katie Archibald begins her glory bid in Brazil today.

The 40-year-old rower will contest the double sculls final - her fifth Olympic final - with Victoria Thornley after they came through Tuesday’s semi-final.

And Milngavie cyclist Katie Archibald also begins her gold medal bid today when the ladies’ team pursuit competition gets under way at the velodrome.

Grainger and Thornley opened by finishing second to Lithuanian pair Donata Vistartaite and Milda Valciukaite in their opening heat on Saturday and were again second behind Poland’s Magdalena Fularczyk-Kozlowska and Natalia Madaj, again making sure they did enough to make it through.

Grainger is the defending champion, having won gold with Anna Watkins at London 2012 to claim her first Olympic title following silvers in the quadruple sculls in 2000 and 2008 and the coxless pairs in 2004.

In contrast Archibald is in her first Olympics but looking to add to a collection which already includes World, European and Commonwealth Games gongs.

She was part of the team pursuit squad which took gold at the 2014 World Championships and a silver last year and has also won the last three European titles.

Archibald also won individual gold in the 2014 and 2015 individual pursuit events at the Euros and completed a golds hat-trick at last year’s championships by also winning the elimination race.

The 22-year-old - who also won bronze for Scotland in the points race at the Commonwealth Games in Glasgow two years ago - had seen her participation at Rio placed in doubt after she was injured in a motorcycle crash earlier this year which forced her to miss the world championships.

However former Balfron High School pupil Ross Murdoch missed out in his bid to add an Olympic medal to his collection.

The 22-year-old made it safely through the heats of the 100 metres breaststroke in Rio, clocking 59.47 in third place behind team-mate Adam Peaty who smashed his own world record.

But in the semi-finals Murdoch could only finish in sixth place in his race in 1:00.05 which placed him 11th overall, not enough to qualify for the final which Peaty won with another new world record.

Murdoch is the reigning Commonwealth and European 200m champion but failed to make the Olympic team at his preferred distance, although he did win 100m silver at the European Championships earlier this year.