For first-time marathon runners, the countdown to race day might seem daunting, especially because so many unknowns can loom before, during and after the event.

However, of all the factors that could potentially influence your race performance — such as bad weather, race delays and other aspects you can't control — there are so many things you can manage when preparing to run a marathon, starting with conditioning and preparation in the weeks and months leading up to the big day.

But how do you know the best ways to prepare if it's your first time wearing a marathon bib? Ask the experts! Consult runners who've been there and can share their lessons learned.

Abbott’s Mike Sheehy has more than 80 endurance events under his belt. We asked him for his best tips on how to run a marathon and what he wishes he had known before his very first 26.2. His four pieces of advice, to no surprise, all convey one thing: prepare, prepare, prepare.

1. Give Yourself Enough Pre-Race Rest

Indeed, your body needs training, but in the days leading up to the race, it also needs rest — and an uninterrupted amount of it.

"There's a balance, because as runners, our bodies need to rest and recover," said Sheehy, a director of program management at Abbott and an established ultra-marathoner, who last year ran all six Abbott World Marathon Majors competitions. "I follow a standard week schedule of six days running and one day of rest, and the key to the right balance is that rest day."

But what exactly does "rest" mean? Surely, if you're visiting somewhere new for the marathon, it includes some light sightseeing the days before, right? Well, maybe not. If you're in the midst of that all-too-critical taper time, during which you rest your body up to three weeks before race day, you might want to reconsider the tours, said Sheehy.

"Rest means rest," he added. "The cities of the Abbott World Marathon Majors are all amazing and fun towns. When you get there, you'll want to explore and see everything. Just be mindful, because taper week is all about the taper and the rest. So be smart and rest your body."

2. Stay In the (Mind) Game at Every Mile

Physical preparation can only take you so far. You've got to get your mind right, too. That means mental motivation, mile for mile. Runners may find that their motivation peaks in the first half of the race, and as the finish line nears, their energy wanes. Don't let it, Sheehy said.

"From 13.1 to 20 miles, you need to mentally stay in the game," he said. "This is where everyone starts to let that little mean voice of doubt creep into [his or her] head. You have to fight it. Get to 20!"

Find tricks to keep your mind engaged and committed to finishing — anything from listening to the event's onsite music to repeating an internal monologue of "I can do this" motivation.

"Before each run, I talk to my mom," Sheehy said. "She passed away a few years ago and was a huge fan of my running. So, I just say something to her to let her know the plan. Then at each mile marker or during a race-timing pad, I talk to my oldest brother, Steve. He watches all my races online. So, I know he is monitoring me, and when I hit that timing pad, I tell him what is going on with the race. I know he can't hear me, but I hope he can sense what I'm doing."

3. Adapt in the Moment When Necessary

What do endurance athletes do when their well-crafted plan goes awry? They stay calm, adapt and keep moving — and then pursue their backup goal.

"Race goals are important," Sheehy said. "I always go in with a [two-goal] race plan. The first is my target goal time, the one I train for and I want. The one I am hungry to achieve. The second is the 'I am not going to go past this time' target. This allows me to have a goal if something goes wrong and forces me not to mentally quit on myself."

4. Recover Like a Champ

You've prepared. You've endured. And you've just crossed the finish line. But are you done?

"Not so fast," Sheehy said. Post-race recovery matters just as much as pre-race training, so make time to fuel your body after those grueling 26.2 miles, from getting proper hydration and nutrition to stretching those muscles that worked so hard the past few hours and during all your marathon training.

"Recovery starts as soon as I cross the line and start getting the right fuel into my system," Sheehy said. "I try to find a quiet spot to stretch out and foam roll. And good or bad, I like to talk about my races. Sometime that evening, [my brother] and I will go over each part of the race and talk about what was good and where we need a little work."

Ready, Set, Go!

Whether you're already marathon training or just considering an endurance race someday, know the human body can do spectacular things. With proper conditioning, motivation and fuel, the countdown to your first big race might not seem so daunting but rather enjoyable. Just ask the pros.

"The one thing I tell first-time marathoners is, 'You are not likely going to win, so enjoy it,'" Sheehy said. "Enjoy the entire experience, from packet pickup to the expo, carb loading, start-line chaos, the course, the finish and the joy of celebrating this epic accomplishment."