At least as important as physical conditioning, is mental conditioning. Be prepared to be put under stress, to be tired constantly, and to be asked to do more things than you have time to do. You will be pushed. As long as you know that going in, you can take whatever they throw at you. Just maintain your perspective, and remember the goal--to complete the training. We all had a reason to undergo Basic--whether patriotic reasons, for the education, the job skill, the adventure, need of a job, etc. Whatever your reason, just keep it in mind and stay focused on doing a good job. Finally, help your buddies. If you find yourself idle, there will probably be one of your buddies who could use some help straightening out his stuff, shining his boots, doing a detail, etc. There will come a time when you will need his help, so invest some of your time when you have it.