"I know I'm in good form. And my goal is to run a new personal best," said Hahner of the upcoming Berlin Marathon. "It's important that the first 30 kilometres go smoothly. If I still have some fight after that, then you can still turn it up from the back."
In April, Hahner ran to the top spot of German long-distance runners with a surprise win at the Vienna Marathon. With a time of 2:28:59, she found her place at the top of the podium. "The victory brought me to a new level. It was an incredible feeling , to win a marathon in a woman versus woman duel. More than anything, it was a huge step forward in my mentality," she said.
But after her win, Hahner faced harsh criticism by turning down the opportunity to represent Germany at the European Championships in Zurich this summer.
Her decision was met with disappointment and anger from the German Athletics Association (DLV), but Hahner was determined to stay true to her self-set limits of two marathon races a year. She also competes in 10 kilometre and half marathon-distance races.
She said that her decision was difficult and that the DLV's offer had left her in a quandary.
"It wasn't that I didn't want to race in the European Championships. Running for your own country is brilliant," she said, adding that as amateur athletes, she funds most of her races herself and the finances of running in Zurich didn't make sense for her.
She's expecting a top 10 finish in Berlin, but her real goal for the race is to beat her personal best of 2:27:55, which she set in Frankfurt in 2013.
A late start
Hahner's passion for running is a relatively new one for the 24 year-old. When she was 17, she and her fraternal twin Lisa were inspired by an interview they saw with musician and endurance athlete Joey Kelly, who is known for running Ultramarathons, Ironman Triathlons and Tough-Guy-Races.
"We were so fascinated by the way he spoke about running and the strength its given him and how he accomplished things that didn't seem likely. That was - bang - the starting gun."
Thankfully, they never followed the unsportsman-like footsteps of Kelly, who was disqualified from the Hawaiian Ultraman for kicking a volunteer in the head a year after the Hahner twins were inspired by his interview.
The twins grew up on a farm in the Black Forest region of Baden-Württemberg with three other siblings.
Anna and Lisa also played table tennis and reached the brown belt level in Jujutsu before taking off down the track.
In 2013, Anna finished her degree in education from the University of Mainz, all while running races across Europe.
Through her team Run2Sky, of which the twins make up two-thirds, she counts Gerolsteiner and Adidas as her sponsors. They're both fans of Borussia Dortmund and have their sights set on competing in 2016 Summer Olympics in Rio.
"That's the highest goal. All the plans are made with that in mind," she said. "We're going to be at the start line together, my twin sister Lisa and I."
Germany's line up for Rio has yet to be determined, but one thing is already sure: Anna will be at the start line with her sister Lisa in Berlin along with 46,000 other runners, inline skaters and wheelchair users on Sunday.