I've been doing quite a bit of swimming of late; I had been somewhat overweight, and the place to which I go to exercise has an outstanding aquatic center.
I'm not really very good at swimming at all though. In fact, how do they say? I suck at it. I never had a lesson, except whatever my parents might have taught me in the backyard suburban pool of yore. But that's not the point.
The thing about swimming is, once you can keep yourself from sinking, it's pretty much a situation of building up endurance, and I had at least enough of backyard suburban pool experience to not sink. And, to suck at swimming merely means that one is swimming highly inefficiently. But...
Whether one swims well or badly, it can be like aquatic Tai Chi. There is - by necessity, 'cause you might drown otherwise! - a cultivation and honing of awareness that is, in my experience, that is more intense than other forms of exercise (with the exception of the martial arts, of course), though such cultivation is present in any exercise, I'll grant.
There is a certain elegance and sublime quality to swimming - it's due to the fog streaming off the pool at 5:30 in the morning; it's due to the viscosity of the water itself, it's due to the fluid motions that are essential to moving in the fluid.
Moreover, there's a certain degree of accomplishment to such exercise as well, though of course such thoughts - them ol' gaining ideas, you know - are pretty much poisonous if you're in the water doing that kind of thinking. But, once out of the water, to know, that in at least some not-too turbulent bodies of water such as lakes, that one could swim 100 or 200 meters to shore if necessary engenders an appreciation for the everything associated with the activity that one just doesn't get working on an elliptical trainer or treadmill.
Anyway, I would recommend some kind of athletic practice into your practice, however little you can do; I would not recommend that as a teacher of course, but as a guy who sucks at practicing what he preaches.