A typical marathon-training schedule involves several months of increasing mileage. But the physical gains you earn from all of those runs are only part of the equation that can make or break your race.

“As a coach, I always emphasize the importance of preparing for more than just the distance,” says Gab Reznik , NASM-certified personal trainer, run coach, and head coach at Tone House, a fitness studio in New York City. “ Marathon training isn’t simply about building the fitness to cover 26.2 miles. It’s about developing the confidence, adaptability, and mental resilience to handle whatever challenges arise along the way.” Because if there’s one guarantee in the marathon, it’s that something unexpected will come your way.

To help you prepare for any scenario that pops up during your 26.2, we tapped three run coaches for their insights about what marathoners tend to report back to them postrace—the things that surprised them, the mindsets that helped them when the miles got grueling, and what they wish…