Amy faces cold water and fear during her first open-water swim

There's three weeks left before the U.S. Women's Sprint Triathlon in Naperville, and I'm dealing with a few lingering anxieties and doubts.

For one, my right thigh continues to bother me at times. There's a very real possibility this won't be completely healed by the time I do this triathlon. That's unnerving.

But despite this, I still have managed to reach my physical peak, and the injury is not bugging me during workouts. So I feel OK that I'm not doing further damage; it's just a slow healing process.

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The other anxiety-inducing factor this week is my first open-water swim, which I do on Saturday.

Now, I wasn't expecting to suddenly turn into Amanda Beard in the pool or anything, but I have to admit I also didn't think it'd be quite this hard.

I swim in the deep end of Naperville's Centennial Beach, where the swimming portion of the triathlon actually will take place.

And the water's freezing! It's a bit of a shock when I first dive in, and I swim furiously off the start, completely forgetting about pacing. Consequently, I'm exhausted halfway out to the rope that separates the deep and shallow ends. (It's probably only the distance of a few pool laps!)

At the rope, I try to calm down and catch my breath. Then I head back, going at a slower pace. But I'm a little shaky and dizzy as I leave the water.

To be honest, it's kind of scary swimming in open water. I can't just put my feet down and stand up. Out here, I could actually drown. (I'm really not trying to scare myself, though people have drowned here before - but not in a long time.) Also hard is that unlike the pool, there's no clear blue line marking your path. A few times, I have to stop mid-stroke to look up and get my bearings. I have no idea where the heck I'm swimming. I also am not wearing a swim cap, and hair flying everywhere doesn't help.

This initial swim is, if anything, a good reality check. I was in the pool for maybe 10 minutes, and I'm exhausted! But it's motivation - I clearly still have work to do, and I'll be back next weekend.

On Sunday, I do my third (and final) 5K, this one at Lincoln Park Zoo. It's a good run, with some longer uphill stretches. But there's also quite a few narrow sections that force me to walk because of the crowds. I clock in around 31:30, about the same time as my first race. My performance is neither particularly impressing or depressing - but I suppose any day you're able to run 3.1 miles near the lake can't be all that bad a day. At this point, improving my 5K time isn't a huge deal. I've got other things - beach swimming and combined bike-and-run workouts - to focus on now.