Here is an app connected under desk exercise bike that doubles as a pedal smartphone charger. eveia comes with everything you need to generate power for your USB devices. It comes with apps to keep you motivated. This exercise bike has a portable design and 5 resistance levels. It works with iOS and Android devices.
You will need to pedal only for a couple of hours to generate enough energy to charge your AirPods or headphones. eveia is smart enough to connect to your Apple & Android Health apps. More information is available here.