this is a ridiculous suggestion price wise, but check out custom IEMs. They are expensive as hell, but I have no issue spending money on something I use for HOURS every single day.

Sound quality is often much much better too.

Shure SE215s. Not all that expensive, but for the price they're an amazing IEM. You can also get a cable that has a mic/remote in it.

Those are regular IEMs. By custom parent comment means ones with a casing made specifically to fit inside your ear. Random example: http://vaiopocket.up.seesaa.net/image/sleek5.jpg, these can cost 3-4x more than a regular pair.

Have you ever had an earplug that fell out after 5 minutes?

The main reason earphones fall out of your ears is the wires. Most existing wireless earphones have some sort of wire attached to them. They're called "wireless" but that's technically not true because they do have wires, and these wires are what pulls the earphones out of your ear. It's physics.

Significant head movement without any wire pulling can also cause problems. I could easily see these falling out when I'm running.

I have the exact same problem. Check out 'earhoox' -- they solve the problem perfectly.

(They're silicone EarPod covers with little hooks that keep them perfectly placed in your ears.)