I'M NOT MUCH of a swimmer. I can swim, but I have a catlike aversion to putting my head underwater, and my most comfortable "stroke" is the doggy paddle. Early experiences attending splashy pool parties with extremely nearsighted and chlorine-sensitive eyes led to one too many unplanned encounters with the cement sides of the pool, and the hot tub scene started to look even better.
So instead of becoming a swimmer, I opted for more joint-imperiling pursuits, which occasionally put me out of commission. Yoga and Pilates are there for you in these times, sure, but the best thing for it, they say, is the water. If you're the type who's already content swimming solitary laps, more power to you. But if that sounds boring and/or frightening, you might consider what I did and give aqua aerobics a whirl.
The reputation is that aqua aerobics is... how to put this... for old ladies. And it is popular with this demographic, but that's because they're on to something! Unlike boring (fine, meditative) laps, there's music (the class I attended featured a Fleetwood Mac soundtrack), camaraderie, and the thrilling awareness that you are not drowning despite having spent the last hour flailing around in the deep end. (You could do shallow aerobics, I guess, but why don't you live a little?)
If you're already relatively fit, opt for ankle flotation rather than a flotation belt. You'll get a better workout, since it takes a degree of core strength just to keep your back straight and your legs underneath you. And like the best group workouts, intensity is dependent on your own capabilities; when instructed to "power up" your movements, your own fitness level dictates how hard or fast that may mean.
That said—it's not going to be as challenging as the CrossFit class you can't go to anymore because you lunged your quadriceps halfway off the bone. But it's a damn sight peppier than your average yoga class; there is literally no way to hurt your knees; and classes like the one at the (absolutely delightful) Mount Scott Community Center are exactly between free and the price of half a class at barre3.
Aqua Power (Deep), Mount Scott Community Center, 5530 SE 72nd, $5.50 drop-in, portlandoregon.gov/parks/60409 for complete schedule