Common knowledge would say choosing two is the only way to get through without burning out. But I think that's the thought process because we hear of the burn outs in college more than the success.
I think you can choose three, but you will be watering down all of them. This isn't bad if you can acknowledge that from the beginning.
Athletics: If you want to be the best athlete, you would do none of the other options. Any other stress besides athletics is, in the long term, detrimental to 100% maximization. But that shouldn't matter too much because not many people will or should maximize their life time potential.
Academics: Work smart, not hard. Sometimes you will need to do the marathon sessions in the library, but it's more beneficial to section out your work and do things in manageable chunks throughout the semester. Many people have input on the best way to maximize grades in college, and were probably better than me, but I did get by with a 3.7 my freshman year.
Partying: I'm going to call this social life. Everything in moderation is key, I have found that getting trashed too often or without purpose leaves me burnt out. Not good for the soul. You will have to find out at which level of partying is acceptable for YOU and your running/academics. But my solution was two nights a week; one night of going 'harder' and one night of sipping. The harder was usually saturday, as races and long runs were done that day, and our off day was sunday. The sipping would be any other day, as i wouldn't get drunk. It was just watching a soccer game with friends or going to a small get together. Nothing out of control, and kept me from the grind.
Just my input, good luck