Donald Trump has a bone to pick with the pollsters; Ben Carson has piles of mail; and Marco Rubio has some trades to make.
Like athletes, Republican candidates spend the final, few hours before presidential debates getting ready in their own, unique ways. And for many of them, on Wednesday, the stakes were higher than ever, thanks to a shake-up in national polling showing Carson at the top of the race -- albeit within the margin of error -- over Trump.
So, who's studying and who's taking a nap ahead of Wednesday's showdown? Find out below.
Trump tweeted. The real estate mogul spent the morning complaining about the fairness of the debate before it had even begun.
Carson's lead is clearly under Trump's skin. Trump has complained about the credibility of the polling and pointed reporters to an online poll that shows Trump with a strong lead, even though the poll is conducted online and such polls are historically less reliable.
Carson got a haircut. The newly minted front-runner spent time on Tuesday in his West Palm Beach home before heading to Boulder on Wednesday morning.
“I’m going to relax today and go through all of these piles of mail that I haven’t been able to get through,” Carson told The Hill on Tuesday. “And I’ll probably get a haircut.”
On Wednesday morning, a spokesman said Carson would largely be "reading and relaxing" as well as "going over a few last-minute thoughts about questions." He'll spend the final few hours before the debate with his wife, Candy.
Sen. Marco Rubio sized up his team. Rubio released a video of himself getting a phone update on "Cruz, Bush, and Carson," -- you know, his fantasy football players, Victor Cruz, Reggie Bush, and Carson Palmer.
In addition to the cheeky video, he spent the morning at church, before heading to the debate site to do a walk-through.
Sen. Rand Paul went back to school. Paul skipped the walk-through, sending a staffer to do it Tuesday, instead opting to host a small meet-and-greet with students at the University of Colorado dining hall and chatting with the press briefly.
Hours after vowing to filibuster the debt deal, Paul stressed that his decision sets him apart from the rest of the candidates, and said he hopes he can let Americans know that the debt ceiling should be used to control spending during the debates.
The rest of his time will be spent with family and a little last-minute debate prep.
Gov. Jeb Bush worked out. The former Florida governor burned some calories this week, preparing for the debate with a Tuesday hike with campaign aides and military veterans. (One source tells MSNBC he beat everyone to the top of the trail.) Wednesday, he snuck in another workout before a formal walk-through of the debate site. Bush also attended Mass Wednesday morning and had lunch with wife Columba and son Jeb Jr.
He'll spend the rest of the afternoon preparing for the debate.
Sen. Ted Cruz celebrated. The Texas Republican spent Tuesday night celebrating his daughter's fifth birthday in Boulder, hours before the debate.
Additional reporting by NBC News and MSNBC staff.