What came first for you - swim, bike or run?

Bike.  After HS I got a Peugeot race bike. It was slick! Rode it everywhere, but sold it when I needed a few bucks.  Running after that, and someday I hope to be able to swim.

i started with running in HS, but cycling got me off the couch again after college and got me ultimately into triathlon.  i rode a bike every day growing up and was taught how to swim at a young age, but never did any sort of competitive swimming.

Running.  Sprinter first (100, 200, 400), then distance running starting mid teens and off and on (mostly on) ever since.

I was around water a lot as a kid.  We had a pool, and I was a diver in high school and a lifeguard in college, but I never swam on a team. I got a road bike when I was 14 and a mountain bike in college, and did some fairly regular rec riding and commuting, but no real training of any kind in either S/B until a couple of years ago.

Swim since I was a kid.  I didn't ride (other than riding around a bit as a kid) or run until my 30s.

I grew up a runner. Was doing races before I can even remember. Took up cycling in my mid-20safter one of my knee surgeries, when they told me I should cut back on the mileage. Took up swimming not long after.

Runner since end of HS and all through college. Marathoner until some of my training buddies talked me into buying a bike. Swimming? Not really!

So, summary would be 32 years running, 5 cycling, 3 of not drowning

General athlete. Biking and running came out of that. Swimming didn't come until triathlon.

Honestly, if you had the genetics to go reasonably fast in your HS years, you still have the genetics to go fast (relative to your AG at least) whatever age you are assuming you're not injured or have other health issues. Genetics don't disappear - they're in there, waiting to come out given the chance. 

Swim.  Started swimming for the summer team at age 4 and started on a club team at age 6.  Also played soccer from age 5-15 though, so running was also came first in  away.

Actually riding a bike a lot didn't start until I decided to do my first triathlon a couple years ago at age 15.

Biking for me, had to do something to keep the weight off after college. Just casual riding mostly. Then I ran into a college friend and met her roommate who had just finished IMCDA. She was also a swim coach so that left me with no excuses. That was all in 08, finally getting around to that first IM this summer. Depending on how this goes I might consider moving to bike full time. I have recently hooked up with a good group of riders, so might focus on the bike and do some racing this fall and next year.