15 Most Important Olympic Storylines to Watch

Like a dark cloud over hovering over Rio de Janeiro, the threat of the Zika virus is overshadowing much of what's supposed to be a jovial time in the Olympic host city. From various athletes pulling out of the games (including the world's top golfer, Jason Day) to members of the media skipping out (like pregnant Today Show host Savannah Guthrie), Zika is such a threat that many have even called for the games to be postponed or outright canceled to prevent the spread of the virus. Whether or not Zika continues to be an increasing worry and grab headlines throughout the actual run of the games remains to be seen. 

Aside from Zika fears, the world is grappling with another important worry heading into the games: is Brazil even ready for them? According to reports from the country in recent weeks, the answer is: not really. While it seems every host city comes down to the wire in the lead-up and manages to pull through in the end, Rio is looking as if fears about preparedness aren't just hype. With half-built venues, crumbling infrastructure, and an athlete's village that’s apparently so shoddy it's been deemed "uninhabitable," it will be interesting to see if the city gets their shit together in time, or if the fact they’re so unprepared becomes a running theme. 

Like a cringe-worthy soap opera with plenty of twists and turns, the Russian doping scandal has cast a pall over the previous Olympic host country’s prospects in Rio. Thanks to leader Vladimir Putin's win-above-all attitude, the Russian team is missing more than 100 athletes after they were disqualified for breaking the Olympic committee's strict anti-doping rules. Cheer up, Russia! There's always Tokyo 2020.  

Okay, enough gloom and doom. After all, the Olympics are about the majesty of sport and for proof, look no further than the rising stars from Team USA's gymnastics contingent. Despite a disappointing start in trials, two-time gold medal winner Gabby Douglas, the star of the London games, makes her return and looks to snap up additional hardware while in Rio. Meanwhile, her 19 year-old teammate Simone Biles is on track to be a breakout star this year on her own.

The Olympic king is back. One of the greatest athletes in the history of the games is planning on making his final run for glory in Rio. Currently the proud owner of a record-breaking 18 gold medals, it will be exhilarating as always to watch if the famed swimmer can add more Olympic accolades to his already crowded mantle.

Speaking of all-time athletes, one of the world's greatest is headed down south to claim Olympic glory in both singles and doubles matches (partnered with sister Venus, of course). Thanks to 22nd Grand Slam win in June, 2016 has already been a banner year for the legendary player and she’s keen on continuing her incredible run in Rio de Janeiro. 

He's the fastest man on planet earth and one of the most incredible athletes of all time, and this Olympics Usain Bolt is looking to cement his incredible legacy. For the Jamaican hero, he'll be eyeing his third and final triple-gold haul after dominating in Beijing in 2008 and London in 2012. Whether or not Bolt will reign supreme once again is up for question considering it’s been eight full years since his Olympic debut, which is considered a lifetime for any athlete. (But who are we kidding, it's best to never doubt Mr. Bolt.)

As if June's NBA finals weren’t exciting enough, basketball fans will be treated to bonus action this summer thanks to a team chock full of NBA all-stars heading down to Rio, ranging from the likes of Carmelo Anthony and Kevin Durant, all under the watchful eye of legendary head coach Mike Krzyzewski. However, there are notable absences. Superstars including LeBron James, Steph Curry, and Blake Griffin have all bowed out of participating in the games. Nonetheless, if medal games are as fun as a recent exhibition match against China, we're in for a treat. 

Citing a knee injury, add Tennis great Roger Federer to the list of names who are skipping out on Rio this year. Without Federer’s star power, that means that Team USA’s men’s tennis contingent could have a breakout star in their ranks. Could it be a rising pro like 23 year-old Nebraska native Jack Sock who previously won the Men's Doubles competition at Wimbledon in 2014, or perhaps Steve Johnson who, while at USC, was ranked the number one player in college tennis?

Poor Rio. Not only are they grappling with Zika woes and are barely prepared for the games, water safety also seems to be a major concern for the host city with recent studies discovering strains of an ominously-dubbed "super bacteria." For a place known for its incredible beaches, that's not great news, especially considering the dozens of aquatic events the summer games feature. As if that weren't enough, there's even been reports of dismembered body parts washing up on the city's sandy shores. Though, not to worry; health experts in Brazil are calling for water-bound athletes to simply keep their "mouthes closed" while submerged. Ok, then!

At the risk of sounding like a neurotic parent, rampant crime is also a top issue of concern for those in Rio during the games. Just ask the city's police and firefighters, who are so fed up and exhausted they recently staged a protest at the Rio airport holding a sign that said, "Welcome to hell" in full display of incoming visitors. At issue is the fact the state-run military police force hasn't exactly been getting paid for their services. In a city where drug trafficking has always been a headache and roughly 42,000 people are killed by guns each year, it all adds up to a situation that, as they say in Rio, is "No bueno."

Thanks to fears stemming from the aforementioned Zika virus, numerous top golfers from the United States are skipping out on hitting the green at the games, including stars Jason Day, Jordan Spieth, and Dustin Johnson. Keep an eye on whether or not this hurts Team USA's chances on the green, or elevates those who are confirmed to go, which include Bubba Watson and Rickie Fowler.

Thanks to the upheaval across the world since the last Olympics, the Rio games will mark the first time a team solely made up of refugees displaced by domestic strife will be able to go for gold. While it's more of a symbolic gesture than a practical one (the team will be only made up of 10 members, many from Syria and the South Sudan), it's meant to shine a brighter spotlight on a budding worldwide refugee problem. 

Due to the sheer number of medal events, every Olympics sees the return of some sports and a farewell to others. This year, rugby makes a reentry to the games after last appearing all the way back in 1924. In both men's and women's tournaments, powerhouse countries including the US, Australia, and South Africa will go for gold during the contact sport's grand return. 

It goes without saying that no world event seems to be complete without the constant threat of terrorism these days, and the Rio Olympics are sadly no exception. With gruesome attacks orchestrated by ISIS popping up around the globe in recent months and the recent arrest by Brazilian authorities of 12 suspected terrorists who were eyeing to do something nefarious in Rio, terrorism remains a top worry for officials in Brazil and beyond.