It's a bit random, but: if you're not already in good shape (and many of us hacker types aren't coming out of high school), find where the gym is and learn what to do there, and go three times a week.
College is one of the first chances where you A) generally have free access to a decent gym, B) have enough control over your own time to set a workout schedule, and C) you're generally old enough that working out will actually do something for you.
Getting in good shape will have a positive impact on your energy level, but more importantly it does wonders for your self-confidence and self-image.
I didn't do this in college and I regret it. Thankfully I am now on a schedule, controlling my diet, etc, and I feel far better than I have ever in my life. I've always been overweight, and you have no idea how good it feels to know that your health trajectory is improving as opposed to the opposite.
I have never been more glad that practically my entire wardrobe needs to be replaced. My BMI is now on the low end of "overweight", and I cannot fucking wait for the day when I finally drop back into the "normal" range - something that I haven't been since primary school.
I strongly agree with this. It's never too late to start hitting the gym either. I, like many others, gained the 'freshman 15'. Then I started hitting the gym and lost the weight and got myself into the good habits that helped me for the rest of my life.
An understated portion of college life is that it is independence with training wheels. You have the ability and chances to make wonderful mistakes and learn the reflexive life-lessons from them, but without suffering the odious penalties that one would incur as a fully self reliant adult. Learn to do laundry, to cook, maintain a healthy diet, balance your finances, to meet people who haven't known you since kindergarten, to act ways that the 'rents wouldn't approve. Find out who you are and shape it.
Excellent advice. It has hidden bonuses as well - if you schedule your workouts for the mornings it might bias you towards getting a little more sleep at least 3 times a week.
Never underestimate the effects of being fit and well rested on your ability to think clearly.
Also, check out other campus recreation opportunities. College is a great time to pick a life-long sport that you can use to stay in shape and blow off stress. Swimming, golf, tennis, running, hiking, cycling, etc. are all good. There are also lots of social clubs around campus, usually funded by your fees, that let you try otherwise fairy expensive activities like sailing, kayaking, backpacking, etc.
College is one of the first chances where you A) generally have free access to a decent gym, B) have enough control over your own time to set a workout schedule, and C) you're generally old enough that working out will actually do something for you.
Getting in good shape will have a positive impact on your energy level, but more importantly it does wonders for your self-confidence and self-image.