If you go to your typical outfitters or sporting gear store, you may find a lot of stuff that's geared for outdoory people. Performance fleeces, polyester base layers and shirts, cargo pants, etc. Much of this will be in your hiking and/or hunting section (if the latter, it will probably come in Mossy Oak and RealTree camo patterns) but you'll soon notice that if you look carefully, there's not necessarily a lot of difference between running and workout clothes and hiking clothes.
This shouldn't be surprising; runners will face many of the same challenges as hikers: namely, moisture management from both sweat and rain or other precipitation, and lightweight warmth that can be layered for comfort both when you're working hard and when you're cooling down and taking it easier. Of course, they also face some different challenges, but that mostly comes to play in terms of footwear, and maybe pants, if you're worried about your legs having to go through a lot of brush or other rough terrain. So, you can vastly expand your repertoire of available clothing; especially shirts, by looking at running shirts, running gloves, and maybe even track pants (although I'd personally be concerned that track pants wouldn't protect my legs from getting scratched up by rocks or bushes in a hiking environment; I'd rather wear something a bit more durable.)
I grew up thinking long sleeves equated to keeping warm, but long-sleeved, often mesh or mesh-paneled, polyester running shirts are pretty commin, and they have the advantage of being so light-weight that you barely feel them on, yet you aren't actually shirtless, and you keep the sun from beating down on your bare skin. Long-sleeved running shirts, therefore, seem like the ideal hiking shirts to me.
Of course, if you look at your sporting goods store, you'll probably see options by UnderArmour, or Nike Pro Combat or something like that. If you look at some place like Old Navy or Target or Meijer, you can get clothes that are exactly the same except half the price (and lacking the prominent display of expensive brand icons.) You can get a good hiking shirt for less than $20, and potentially quite a bit less than that, if you do your homework and shop around. Sadly, this isn't really true for pants. True, you don't need to spend over $100 a pair for RailRider Weatherpants or anything like that, but any "real" hiking pants are going to be more like $60-80 points. And its certainly not true for boots--you can go get some hiking boots at Target or Wal-Mart for $40 or so, but it's clearly questionable that they will perform like a highly engineered pair of boots. A "good" pair of boots is--again, sadly--probably about $200 (give or take about $50.) Can you hike in cheaper boots, or even shoes? Sure, but your feet and ankles are the most important component of your biological chassis when hiking. I'd rather spend a bit more to get some boots that are not only going to be durable, waterproof, and comfortable, which won't give me blisters or cause any other kind of foot or ankle injuries that will stop my hiking endeavors cold. And that means expending more resources in my boots. Because of this, I'm actually quite glad that many of my other items can get by with something cheaper.
Then, with some Sawyer Permethrin applications, you can make this all bugproof for months