I used to do quite a bit of "Adventure Travel". You really are asking two questions-- Sports/Active and Poor/3rd World.
First, understand if you will be in 3rd countries, you probably don't want anything shiny, or of significant value. Although I love Tissot, and Seiko as good choices, I would still reserve those for 2nd World and higher. Even a Sunnto is too BIG and draws a lot of attention. NO GOLD, even faux plating.
That said, your best bet, I hate to say, is Casio G, Timex Expedition, "Basic" Swiss Army/Military, or maybe something Russian.
Again, if you are talking real 3rd world, keep it low key. There are some areas where tourists on bus trips or in cars will have watches yanked off their wrists while your arm is perched on window ledge whilst stopped in traffic.
You may also be faced with a barter situation. So go to Costco and pick up a couple of Casio's and have a few extras in your pack.
Also, have 2 Wallets! A faux realistic looking wallet with and old expired ID, and expired Credit Cards, plus cash for all in the open cash transactions, and keep your real stuff squirreled away. Most "bad people" will take the faux and go. They may get some cash, and by the time they notice the Credit Cards are useless, you should be long gone.
Second, for Sports and Active stuff, non-3rd world. Good advice above. Sunnto, T-Touch, Seiko. I would however put Tissot on the more fragile side (read some reviews).