Do you do any excursions/trekking in woods or are you entirely a city guy? It's in woods and mountains where I do walking for fun. Nothing extreme, whole-day treks up to 40 km; in contrast some of my once and future companions regularly participated in 100-km/1000m+ elevation difference day-and-night contests. *Traitor*, n. A benighted individual who perceives an illusory distinction between serving his nation and abetting the criminals who govern it.
At any rate, it took me almost two months to get back to that speed after my bout of pneumonia -- just to prove to myself that I wasn't a total basket case -- but since then I've slacked off. Coincidentally, around about that time is when I became obsessed with New York trees -- we have almost 200 species! -- and I started carrying around New York City Trees: A Field Guide and nerdily notating whenever I hit on a new or interesting species. ("Treespotting," I call it.) Trying to make out buds, leaf shapes, etc. slows you down when you're walking, but I've decided it's worth it. What I may lose in physical fitness, I gain in mental stimulation!
I also love long treks in the woods (or fields -- Iowa, my home state, has incredible walking/bike paths) -- but unfortunately most of my travels outside New York these days are to South Florida, home of my Significant Other, and the only sane place to walk there is on the beaches.
A few years ago, I had a rather severe case of pneumonia, the sickest I've ever been in my life. Before that I had always pushed myself to do at least 5 mi an hour, which is really exhillarating. As you no doubt know, there's a certain speed where the body realizes it would be more economical in terms of calories, etc., just to break into a run, so, for me, when I get close to 5.5 miles, it's agony keeping myself walking, not running.
At that stage I usually start running. Actually if I have a reason to walk fast and no company I usually start running anyway just because it is a bit boring to walk.
