u/dearlordnonono

What do you guys use as a mouth protector from flies?

I'm bored of running and the next second it feels like I've been hit by a sick stick as a fly dives down my throat and the result is instant retching and watery eyes.

I get a blocked nose when I run so am quite a mouth breather I'm sorry to say.

Is there anything I can use that stops the flies but still allows airflow?