All the SAs are unique in their course load, military obligations and other items. At USNA, I never carried below 18 credit hours a semester. Not sure on USAFA and USMA, but guessing they have similar rules, that you cannot have below 15 hours/semester. That did not include PE which was 1-2 hours a week and didn't count towards my credit hours. There are also athletic requirements, some play a D1 sport or club level. Others play intramurals. These can vary in how much time they take, but D1 and club are alot. This is on top of staying shape to passing PT tests required each semester. Ultimate Frisbee intramural twice a week won't keep in the level of shape required, you will need get in long runs and other items. You also have military obligations that can vary from studying on weekly knowledge to character development seminars and lectures. There are also watch requirements at each school too. I don't think the academics are that much different than a top level engineering school elsewhere, it is very aggressive 4 year schedule and all the other obligations and requirements that come along with a SA.