Triathlon - training for Duathlon

I've been toying with the idea of registering for a local duathlon sprint in Sept (3.1 mi run/16.5 bike/3.1 run).

My story? I was woefully out of shape a little over a year ago and through diet, cycling, running and weight training I have dropped 90 pounds. I've completed a metric century cycling and have plans for a century later this summer and a 5k in early fall. My times aren't great (8:40 miles generally) but I'm a much stronger cyclist (18-19mph avg. on typical C. Mass rides...ie w/ hills).

This morning I decide to try two legs and rode 20 miles and then ran 3. I didn't cook through the transition and my time was slowish. 64min on the ride and about 28:30 on the run.

Funny, I felt like I came out of the gates too fast on the run and was worried about gassing so I slowed myself up (maybe too much).

I guess my question is what should I be doing to enhance my training? I'm not looking to win anything (I'm not deluded) I'm just looking to finish someplace other than last.

I've heard some use the ride as a time to conserve energy (I must admit I pushed a bit today), is that the case even with sprint length events?

I'd like to try a triathlon at some point but I really need to get some training in swimming. I had issues with ear infections as a kid and as a result never got to be that strong a swimmer. I won't drown but a couple laps in a 25m pool and I need a rest...

I've found that track workouts help my bike-run transition. I do 1200, 800, and 400 repeats, as well as occasionally fast miles and that's helped overall with my run but also with acceleration off the bike in particular. If you do try out any track/speed work, be careful and begin gradually to avoid injury. I've heard there's lots of good info. in Friel's Training Bible for Triathletes.

On you training runs, work up to, I'd say, at least 12 miles. A good rule of thumb seems to be double your race mileage as a base.

I did 8 miles the other day without too much trouble...can't imagine running 12, I'll give it a go though. People really do 52 mile runs training for a marathon?

Congratulations on the weight loss and goal to race!

Various training methods are often discussed to increase race pace. Intervals and fartlek sessions are a great way to improve leg speed. Regular Brick sessions as you have already done (Ride then run in the one session) helps the legs get used to the transition from ride to run muscles.

What pace you race at depends on you fitness and pace you can sustain. Sprint distances now for me are just that! Flat out from start to finish. Heart rate hits mid 170bpm immediately and stays there for the duration...

Marathon training is different for the stress it places on the musculature. Training sessions usually don't go past 32-34km for the longest run prior to the race...