I know in the Navy they'll test you the first day at boot camp not just in MEPS. I've seen recruits booted out 2 weeks into training just cuz they're results came back positive. It's not worth to suffer for the 1st 2 weeks and then get kicked out. And by the way, it's more mental than physical. They'll get you through the physical part, making your rack 5 times in a row has nothing to do with strength.