Ears clogged during workouts...

Hi guys, how are you? I hope well. I wanted to ask if you experience something similar to me and if you have any strategies to deal with it.

To get to the point, my ears get the feeling of being clogged during longer training sessions. In fact, it happens during my martial arts training, but rarely - maybe once or twice - during my FB workouts. It's annoying in class because I have to communicate with my sparring partner and I can't tell how loudly I'm speaking. My quick online search said it usually happens during strength training and with inocrrect brething. But during martial arts we mostly do cardio and I definitely make sure to breath correctly.

I've tried all the regular methods like yawning, drinking water and 'sneezing' with a plugged nose which are usually used on planes in cases of ear plugging.

So does anything like this happen to you? Do you have any methods which have helped prevent it or resolve the problem?

Thanks for taking the tims to read this! Any tips would be appreciated :)