Rio 2016: Day 4 Preview - Medals up for grabs in the pool and on horseback.

There is plenty of Olympic action in the pool and an excellent chance of Australian gold in the equestrian.

Take a look at what is coming up on Day 4 of the Rio Olympics with our handy AEST guide.

• Top men’s sprinters hit the water and women’s medals up for grabs
  
• Australia on its high horse for equestrian finals
• Matildas try to rebound from rough start
• Aussie men’s rugby sevens team look to build on women’s gold
  

A photo posted by ~La vie en rose~ (@amysonggg) on Apr 13, 2016 at 5:29am PDT

Swimming

It is another big day in the pool with Aussie gold-medal hope Cameron McEvoy back in the water for the heats (from 2:02am) and semi-finals (from 11:03am) of the blue-riband event, the 100m freestyle. Eighteen-year-old sprint star Kyle Chalmers will also be there.

McEvoy will also line up in the 4x200m freestyle relay.

The semi-finals start at 3:17am, with the final the last race of the day, at 12:38pm on Wednesday.

Australia will have two representatives in the women’s 200m freestyle final at 11:19am, with Bronte Barratt and Emma McKeon making the cut. Also look for American Katie Ledecky as she tries to add to her gold and silver medals.

Not to beat the drum for the Americans too much, but you are running out of chances to see Michael Phelps swim, so watch for him go for gold medal number 20 in the 200m butterfly final at 11:28am.

Five-time Olympic medallist Alicia Coutts will contest the women's 200m individual medley final at 12:29pm.

Equestrian

Australia is sitting pretty in the three-day equestrian event and will go for gold on day four.

Chris Burton leads the individual rankings and Australia is on top of the teams event.

Burton completed a perfect cross-country phase aboard Santano II to keep his tight lead in the individual competition and give Australia a narrow advantage in the teams event.

The team jumping final starts at 11:00pm on Tuesday, with the individual jumping final from 3:00am Wednesday.

Football

It is safe to say the Matildas would be disappointed with their results in Rio thus far.

A first-up loss to Canada was a shock, and blowing a two-goal lead in a 2-2 draw with Germany was not an ideal response.

On day four, they have a great chance to get things on track when
they face Zimbabwe at 5:00am at Fonte Nova Arena.

Rugby sevens

Australia's women have their gold medal, now the pressure is on the men to back them up.

The men's team will kick off its campaign against France at midnight, before meeting Spain at 5:00am for their pool B clash.

Other highlights

• Basketball:
  Australia's women, the Opals, look to continue their unbeaten start to the Games when they meet group A rivals France at the Youth Arena from 1:15am.

• Artistic gymnastics:
  Australia does not have a horse in the race, but it would be worth your while to watch the women's team final from 5:00am to catch a glimpse of the unstoppable Americans, particularly gun Simone Biles

• Canoe slalom:
  Aussie Ian Borrows will go down the rapids in the men's canoe single semi-final at 2:30am, with the final scheduled for a 4:16am start.

• Hockey:
  After the disappointment of losing to Spain, Australia's men's team, the Kookaburras, line up against Belgium at 9:30am on Wednesday.

• Rowing: Rhys Grant lines up in the men's single sculls quarter-finals from 9:30pm Tuesday, before medal contender Kim Brennan will compete in the women's event from 10:10pm.

• Water polo: Australia's women, the Stingers, will take to the water on day four, clashing with Russia at the Maria Lenk Aquatics Centre from 2:00am.
  
  This post originally appeared on ABC News.

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