Last spring break, in a last-minute decision, mechanical engineering senior Steve Guillen packed a backpack, grabbed his helmet and biked 738 miles east to Destin, Fla. He had no plans and no set accommodations, just the will to challenge himself.

After getting kicked off highways and even enduring an upper respiratory infection, Guillen completed his journey in eight days.

Now, more than a year later, he has decided to up the ante. While most other college students will spend their Saturdays on the couch, Guillen will spend his attempting to run the 50-mile Hells Hills Endurance Trail Run in Smithville.

Guillen will complete his new “unthinkable challenge,” as he puts it, with no training, His only motivation is the desire to question and challenge his own perceived limits.

“Most of the time there is nothing real stopping people from doing what they want to do,” Guillen said. “It’s perceived. They make up all these excuses. For me, I always wanted to run one of these ultramarathons, so I asked myself, ‘Why am I not doing it?’ There’s not going to be a better time to do it. The time is now.”

While he has juggled the idea in his mind for quite some time, Guillen didn’t decide to participate in the run until a week ago. It was another last-minute decision, but this time he is doing it for charity and as an experiment.

Guillen is attempting to raise 50 bitcoins for the Texas Alliance for Minorities in Engineering. He said the greatest gift his parents ever gave him was an education, and now he wants to help give back.

He chose to donate in bitcoins for the same reason he signed up for the race. Bitcoin, which is a relatively new virtual currency, is still in the stages of the unknown. Many aren’t sure if it will succeed or fail, which is the same question many are asking about Guillen’s run.

Guillen is trying to challenge normal conventions. He said he wants to step away from the fear of failure and stop it from preventing his aspirations, while using his mental strength to succeed.

“I don’t want this to be a test of physical strength,” Guillen said. “That’s not the point of this unthinkable challenge. There’s an emphasis on thinking, on the power of one’s own mind and the ability [to] push themselves through barriers. I wanted this to be a mental test of whether I can succeed or fail.”

Many people train a year for the race, with some contestants spending up to 18 months in preparation for Saturday.

“At first my family thought I was going crazy and were actually concerned for my health,” Guillen said. “They asked, ‘Is this guy nuts?’ And I may be, but I like to think I’m at least a little sane.”

After he explained the reasoning behind his adventures and the goal he is striving to achieve, Guillen gained the full support of his family and friends.

“Steve has always been obviously a little bit different,” said Michael Guillen, Steve Guillen’s older brother. “He does his own thing and sets his own goals. But we’re definitely supportive of him doing it. The family is always behind him.”

The 50-mile race, which has a 15-hour time limit, will consist of 117 contestants, mostly from Texas and a few from Mexico. Guillen will travel to Smithville on Friday night and will start his race Saturday morning at 5 a.m. The course is a 16.7-mile loop that the runners will circle three times. Food stations will be posted along the way, but Guillen will also take a fanny pack with him, filled with replenishing food so he can refuel while he runs.

Guillen has had no official training for the race. While he tries to go to the gym regularly, he said it can sometimes be difficult with his tough course load. He has used this week to prepare his body mentally and metabolically, thinking about the race and changing some of his eating habits to consume about 250 calories per hour, which is his goal during the race.

“One thing I haven’t done a lot of this week is sleep,” Guillen said. “I’ve just tried to do some schoolwork and prepare mentally for the race, asking myself a lot of questions. I’ve been going to my friends and my family getting advice, but that’s pretty much it.”

Guillen has accepted the fact that he might not make it the full 50 miles. He has even accepted the risks, such as injury, that come with the race. But, despite these doubts, the simple purple and gold sign on the door of Guillen’s bedroom perfectly explains his thought process as he attempts his “unthinkable challenge.”

“Attitude + Ambition = Achievement.”