I went from doing 2 sprints last year to a few sprints and a quarter (sort of like olympic) this season. I am training for a HIM in November and there just seems to be more involved than just adding distace training. Now there is the nutrition aspect, which seems to be very important when you (I) want to go for 6-8 hrs...

Also my first year to tri, but I jumped right into a HIM (yeah, i was feally pretty bold too). Problem was I didn't know how to swim and my bike riding experience was best described as recreational (30 mile ride was the longest I had done). 2 months out from my race I struggled (+60 min.) to swim 1.2 miles in a pool and that was with taking short breaks. I had the same doubts you are having but just stuck to my training plan and got my butt back in the pool. Going into the swim on race day I didn't worry about my time (good thing too b/c damn I'm slow). I was the last wave in the water and the cutoff time started with the last wave, meaning I had the shortest cutoff time to work with (other AG had 45 min on me). I just had it stuck in my head that one way or another I was dragging my scrawny ass out of the water before the cutoff, and I did. Yes I was waaaayyy behind everyone, but none the less I made it. And I honestly remember thinking to myself at mile 30 of the bike, "this is it? this is the big bad HIM I worried about for 8 months." If you train properly, race day should be your easiest workout b/c you've nailed your nutrition plan and have tapered correctly. The hardest part about jumping to a longer distance is not the race but the training leading up to it.

If your goal is to finish the race, as was my goal, stick to it and train accordingly. Since its your first at that distance you'll finish with a PR and a new boost of determination to get faster before your next race.

I don't think going up to Olympic should be that much of a problem.
It will be more challenging than a sprint but I think you can handle it.

See the beginner olympic training plan
http://www.trifuel.com/training/triathlon-training/olympic-triathlon-tra...
You can do this on 4 hours a week.

From Jan 1st of this year until now, I've averaged 6.3 hours/week. In my last olympic distance race, I was pure MOP (5of10 I think in M30-34) with a time of just over 2:30. Like you, I'm new to the sport.

If you stick to a training plan for a given distance, you'll be fine. For us MOP athletes, the formula is very simple. If you do the work, you'll get the reward. Easy stuff.

I'd say it kind of depends on your outlook...if you want it to be a major part of your everyday life, like I tend to at this point, then it will take up chunks of your time and effect your entire lifestyle...but I am also just out of college, soon to be married (this Saturday) with no kids and few other commitments. This will change in the future.

In general though...I feel like, especially once you have a solid aerobic base, you put into it what you'd like to get out. You can probably complete olys on 3-4 training days a week once your fit and still be MOP to BOP. For HIM and IM you would have to devote more time minimum (4-5 days for HIM and 5 or so toIM minimum I'd think) to maintain the same level of competitiveness.

If you are working out 6-7 days a week for an olympic (like I am currently), the returns from each workout are diminished to a degree and so it's more about personal preference. I could easily cut back on my workload and still be ready for my next oly, but I am very competitive (w/ myself mostly) and am working to make speed gains, if I cared more about finishing than my time, I'd probably only workout 3-4 times a week.

So, in conclusion, you can do longer distance races with less training than what you see in plans if you are in shape and have the confidence in your abilities.

Same here jsk85! Congrats! I got married right out of college. 17 yrs and going strong. My husband will be there to cheer me on during my tri this Sunday. Best wishes to you this Saturday!