I ran my first 5k earlier this month. Usually when I first tell people they seem impressed but it's only ~3.1 miles. I decided to participate about two weeks before the race but didn't really start "training" until the week before. The first time I threw in some weights and overdid it a bit given that I hadn't been to the gym for about 6 months. By the time I finished running I was gasping for air. Fortunately, I was able to fit in another workout or two before the actual race.

My goal was to make it under 30 minutes, a little less than 10 minutes per mile. They gave us a chip to strap around our ankle to track our personal times. This was a nice touch because depending on where you lined up, you might not hit the start line for say twenty seconds. With the chip, your time only started after you first crossed. I made my goal, finishing in 29:01.

I had read that interval training produces better results than jogging at a constant pace so I alternated between walking and running during my workouts. Unfortunately, I think these better results were in reference to overall health gains and not for winning races. I ran the race the same way, alternating between running and walking as I hadn't built up the endurance to jog or run the whole length.

I wore a pair of socks I had bought that were supposedly made specifically for the Nike Shox running shoes which I have. This was a mistake because the socks slid halfway under my feet while I was running. My advice is to use the same gear you practice with. 

This was a fun experience and something I'd like to do again. I'm not interested in marathons or triathlons as I don't think our bodies are built for that degree of damage and stress but 3.1 miles is definitely manageable. The best part about 5ks is that there's usually a worthy cause for the event. So in addition to the running to improve your health there's an opportunity to give back as well.