Will Laura Trott become Britain's most successful female Olympian?
Laura Trott could be about to make Olympic history if she wins gold in the women's omnium later.
The cyclist will become the first female athlete from Britain to ever win four Olympic gold medals.
If successful, she will overtake Charlotte Dujardin who equaled her record with a sensational performance in the freestyle dressage event on Monday.
Trott goes into the final round at the Rio velodrome with an eight-point lead over Belgium's Jolien D'Hoore, with American Sarah Hammer 10 points behind in third.
The 24-year-old from Manchester came second in the scratch race before winning both the individual pursuit and elimination events earlier this week.
Her Olympic gold medal record is:
London 2012: Team Pursuit gold medal
London 2012: Omnium gold medal
Rio 2016: Team Pursuit gold medal
She has also won:
Team GB set a target of 47 medals for Rio 2016, and are currently on course for their best ever away Games since Beijing in 2008 with 41 medals (16 gold, 17 silver and eight bronze).
Who else is competing on Tuesday?
Jason Kenny takes part in the men's keirin
Nicola Adams defends her London 2012 boxing gold medal
Alex Scott will be crowned Olympic champion in sailing's Finn class
Chris Langridge and Marcus Ellis take on China in the badminton semi-final