To clear a few things up regarding Plebe Summer... Only Falls sports will have impact upon Plebe Summer. Football tends to miss more than the others. Soccer players, water polo, volleyball and the others do miss parts of the Plebe Summer, but it is very little. It is like the week prior to Parents Weekend. At least during my summer, they missed parts of Parents Weekend too for practice. So as you can see, just like all varsity sports its a trade off. During the academic year plebes who are varsity athletes still have to pass all professional knowledge tests, have come arounds, etc. Sometimes schedules don't match up, but its part of time management to schedule these things and complete the requirements.
Just because Navy doesn't have traditional athletic scholarships, doesn't make them any easier to walk on to. Yes most teams will hold a "try out," but to be honest don't get your hopes up. Some teams like sprint football, crew, etc are easier. That is simply because sprint football doesn't really exist in high school and crew is such a small sport at the high school level. Also remember Navy brings in full recruiting classes from NAPS and direct each year. So at football try outs there could be 60+ plebes. Baseball could have 20+, basketball 10+ players. Varsity sports are hard, time consuming, physically demanding. They are a blast and worth it, if its something you truly want to do.
The football team determines based upon height and weight, position, etc who runs or rides the bike. Each player knows. If they do not pass the PRT prior to the start of camp, no practice. A few years ago one of their starters missed the Ireland trip because he didn't pass the PRT. They all do pass the test before graduation. Its amazing to watch some of these guys go from 280+ to 225 in a matter of months. The team doesn't abandon them to do this on their own, but helps they slim down and builds a cardio plan. My next door neighbor passed his PRT the week of commissioning. He worked so hard. our entire company was out there cheering him on. He went from 295 to 220 in 4 months.