The cycling epic takes riders across Europe in a 3,924km journey that takes the elite around 15 days.
There's no route, just four checkpoints, and one stage, so self-sufficiency, route planning, and endurance are all tested.
Jahnke's groundwork was solid: she entered the 400km Maurice Brocco race as preparation, and won it.
She was aware that the Transcontinental was 10 times this distance, and explains that planning took up the eight months prior to the race.
Part of this was a 'Breakfast 100' that she trained with her cycling partner Marion, who was to attempt the Transcontinental with her.
"We would meet at 6am and ride 10km before breakfast," says Jahnke. "The night before we had done an intensive interval session to empty our carbohydrate stores, so we would really train our fat metabolism the next morning."
The race itself took Jahnke through some landscapes she had been looking forward to.
"Riding through Croatia, Bosnia, Montenegro and Albania will definitely stick in my memory," she said after the event.
"Riding 414km during the night from Geraardsbergen and the 321km on our last day (with plenty of climbing) is something I don’t usually do. It's unbelievable what your body is capable of."
The determined ride saw the athlete and her partner complete the course in time for a finishers party. They were the only female pair in the party and the first females to have ever completed the event in time for the party.
Fuel for the epic crossing was focused on carbohydrates, with simple and complex carbs being used depending on the profile of the stage. High-calorie foods including nuts biscuits and fruit juice were popular.
Much of Jahnke's food was bought during the trip at supermarkets and petrol stations, often filling up on fruit during the day then carb loading with pasta and pizza later in the day.
"TCR is really a life-changing experience," Janke told Great Vegan Athletes. "And a lot of people didn't think it would be possible on a vegan diet. I actually think it was part of the key to success."