I get the question as to what I am doing when I am wearing headphones while exercising.
I am listening to music, of course.
I use an old iPod Touch deivce, which is an ancestor of the present-day iPad.
I bought it on eBay for $15 for its memory in which I could store and stream about 1500 items. The old iPod Touch 2 was battered from long years (10) of use but still working perfectly.
Any iPad or iPod touch or smartphone will do the same.
It works by activating Bluetooth wireless in settings and ”pairing” a Bluetooth headset. I picked up a Billboard headset for less than $20 at Staples
It is also possible to listen to audiobooks in addition to music.
If you don't have any music to install, you can stream almost anything from Spotify for $10 a month. Just install the Spotify app into your device. On Amazon you can buy huge collections of music for $0.99 each. Amazon also has in alternative to Spotify.
If you don't know what music you like, then you can use the Pandora app to find music for you.
If you have a large library of CDs, these can be converted to digital form. Tap or click to find out how.
Old LPs can be converted using a player which converts the music to digital form. About $50.
If you want to be able to stream your original collection of music, it can be uploaded to Amazon music so that it will be accessible to you anywhere. Just install Amazon music on your device or computer.
What do I listen to? Anything from the Brahms Liebeslieder to the Firehouse Five and everything in between.