Now that headphone jacks are being killed off, there's no choice but to look at Bluetooth alternatives. There are tons of form factors out there, but the most fashionable right now is the truly wireless earbud, which is difficult to get right and usually quite expensive. The Jabra Elite Sport is a decent option, and it's currently going for $100 less than its original MSRP.
At $249 there are potentially other options out there that make more sense, but for just $149 the Elite Sport is well worth your time. The compact earbuds are designed for active use. They're light, IP67 rated, and come with a variety of wings and tips to ensure a secure fit. You can get up to 4.5 hours from a single charge, plus an additional 9 with the included charging case.
You also get access to the Jabra Sport Life app, with which you can monitor your heart rate and get workout guidance. I've just started using the Elite Sport myself, and I've been pretty impressed with them so far. Several retailers are offering them for the discounted price of $149, including:
It's unclear how long these offers will last, so snap them up while you still can.