As a start, i'll tell you about myself. I'm 16, 5'10, and hit the scales at a whopping 100 pounds. I'm very lean (don't know how, eat more than most people I know) and have a % body fat of around... 5%... probably closer to 4.5%.
Just recently I acquired my fathers old 1988 centurion road bike. The bike rides great, no wobble, new gear set, and is in great shape. When I was in 7th grade, I did Bike Virginia (2004 Shenandoah Odysee) on a good ol' recumbant (yeah, it sucked going up the hills I won't lie)
However, after that ride, I pretty much stopped cycling all together, and really let my self get out of shape (thanks video games?) and instead of seeing 10 miles as nothing more but a drop in the bucket, 10 miles now is actually pretty tough. I do 5 mile days now, and I can feel myself getting stronger, but I need a solid plan of attack to get ready for a 40-60 mile ride in a few months, and then i'll probably do Bike Virgina/BRAG next summer and keep chugging. I plan on picking up a trainer tomorrow to help with the rides, but i'm not quite sure what the best way is to mainly just increase my longevity. Sprints? 20 minute good effort rides? Hour long leisure rides? What should I do to train... on a trainer to increase longevity.. and possibly my breathing? Any help is greatly appreciated.
As a side note, where can I get some bike shorts that'd probably fit me. Being so lean (small waist!) but fairly tall presents some issues. The leather saddle on my bike hasn't quite fully been broken in and honestly, my tush gets sore after just 4-5 miles on the bike. (probably doesn't help i'm wearing just regular nylon gym shorts either... and I can almost feel it starting to chafe when I start sweating, thanks cotton boxers)