I'm glad Coach Izzy jumped in here, as I set this one aside until I could think of a good way to answer. To be honest, I thought this was a troll, like something I might write, with all I've done in cycling, to get a rise out of someone. I mean, for someone who knows what "RHR" means, how to calculate BMI, has had his body composition measured, and even knows his blood pressure at 20 years old, it sure seems like you did suspiciously little research into physically preparing for your bike tour.
Since Coach has spent the time to answer, I'll go out on a limb and hope I can talk you out of what only a 20 year old who calls himself "OutdoorStud" would think to do. <g> To sum up everything that will follow, whatever you were smoking when you signed on to pull this stunt, bring along as much as you can pack. You're going to need it.
First off, I second Coach's advice to check with your doctor about your plans. 120/70 is "normal" BP, and being a relatively inactive 20yo with 27% body fat suggests that you should ease into exercise, not freefall from 30,000ft.
Now, having considerable saddle time myself, I can tell you that you will probably be able to somehow pedal your way through the first day. It will be much harder than you are thinking right now, but you will be able to do it. You will be glad when the ride is done, but you probably won't give up before finishing.
You will be hating life when you wake up the second day, and you will be calling for a taxi the second you sit your sore *** back on the saddle. 50-80 miles per day for two weeks is something that most experienced cyclists would probably train especially for, and it sounds like you're doing this more or less with no real training at all.
Things that I will tell you so you change your mind about this:
1. Your butt is going to really, really, really hurt. No joke. It will hurt so bad that you probably will have to ride standing up by day 3. There is no pair of cycling shorts good enough to let anyone skip the conditioning new cyclists undergo just so they can sit in the saddle for the 4-7 hours of riding you plan to do every day. Most only get one ride in a week that long.
2. You will not be able to sleep because your legs will be cramping constantly. Lack of conditioning, leading to intense muscle fatigue, is the primary contributor to exercise associated muscle cramping. Hell hath no fury like a hamstring scorned.
3. Your butt is going to be so sore that I want to know where you are riding so I can video you getting back on your bike on day 4.
4. By day 5, if you make it that far, you will be ordering the entire second page of the IHOP menu just so you can ride until lunch. This tour will cure you of your aversion to pre-exercise eating. In fact, training your stomach is just as important as training the rest of your body when preparing for events longer than about 3 hours. Yes, your body has plenty of calories stored in fat, but for some reason, your body doesn't like to use too many of them at one time. You need to eat before your ride, during your ride, and after your ride to prepare your muscles for the next day. If you don't eat, you will bonk. Then you will know why Gatorade, Powerbar, and Gu did so well even before they became "healthy" soda and candy replacements for non-athletes. Oh, and, digestion actually *increases* with increased activity up to well beyond the intensity you will be riding, so you just have to get over the initial discomfort. It's all in your head, really.
5. If you will not tell me where you are riding, please have *someone* ready with a video camera when you are trying to sit on your bike on day 5. Please. I have a PayPal account and a healthy limit on my credit card.
6. If you make it to day 6, then it probably won't get any worse the rest of the tour. By then, you will either be too exhausted to care anymore, or you might actually begin to see a conditioning effect, believe it or not.
Dude. In all seriousness, I will never tell someone that they will fail, but I will tell you that this is exactly the kind of trip you will be talking about the rest of your life, one way or another.
Cameron
P.S. Thanks, Izzy, for the plug! <g>