My "high school 1 mile PR" was in the 12:30 range. That's the mandatory mile that I had to run as part of P.E. class, probably when I was 5' tall and 130 lbs at 14 years old. I guess that's "slightly overweight," but with a 14 year old metabolism, that's still pretty high. I ballooned to 210 lbs by 19 years old at 5'8", which is definitely in the obese range. At that point, I found the stairmaster and coupled it giving up meat for lent. (No, not my traditional Catholic conception of meat, but went vegetarian.) By doing an honest vegetarian diet, I dropped to 158 lbs. However, over time, fried chicken and rib eye steak became too tempting. Then I got married, and peaked out at 230 lbs by the beginning of 2006. I bought a cheap Timex GPS on woot.com and started walking--up to 25 miles in one week. By June I ran my first continuous mile ever--12 minutes! I also started using the treadmills at work more often. On my 30th birthday, I ran my first race--5km in 34 minutes. 60 lbs later, I'm pushing toward the possibility of breaking the 4 hour mark in a marathon, and having PRs in the sub-8 minute range for 5k, 10k and 10 mile races.

I've never understood how swimmers do it. Running is hard, but the coordination is at least easy. Swimming is your whole body, plus all the breathing timing... I get exhausted standing in water, even now.