I have the Aftershox Trex Air and love them for outdoors but in anyplace noisy they are terrible. I have used them on the treadmill and airplane with ear plugs, but the sounds quality is not good and I find I have to crank the volume pretty high which actually makes it uncomfortable for me as I can feel the vibration on my jaw bone when it is that loud.
Personally, they are the headphones I always use outdoors but for the gym and airplane I use my AirPod Pros.
My usage: listening podcasts on trains (also quite noisy ones), while walking and cycling (not racing) and I like them a lot.
I suggest you try them yourself in an environment similar in loudness as where you want to use them. I also heard people for whom they didn't work that well.
The Aftershokz bone conduction headphones design is intended to allow you to hear environmental noise. It’s great for situational awareness in traffic. Terrible for noisy environments.
In noisy environments, you probably want something that does active noise cancellation like AirPods Pro.
Not exercise related but in fact I have used my Trekz Airs for working with loud power tools. Ear plugs block the external sound but I can listen through the bone conduction.
I just got a pair to use mountain biking, and I love them. Good sound, and I can hear people coming up behind me.
Earbuds never seem to stay in place for me, so these are a big improvement in that regard. They also don't blank out the sound when you swallow, if you have that issue (which I do).
I would think they would be fine for the gym or an airplane, if you don't mind the ambient noise. And you can wear earplugs too.
You would need to add ear plugs for the plane. I love the Aeropex for running. For the plane, Its probably best to use another pair. The Gym would be good because you can be aware of what's around you. That would not be true if you want to turn it up loud and become focused on just you and the music.
