Thats one thing i like about bluegrass. Theres alot of good songs without lyrics, and when i listen to flatt and scruggs foggy mountain breakdown i feel like i just chugged a whole pot of coffee, but maybe thats just me
This is why I almost exclusively listen to heavy metal with unintelligible singing- has the energy to get me going, but no distracting human-parts to the song. Then again, I am a big weirdo, and like very very very high energy music. Perhaps electronic type stuff would be an option as well, I wouldn't know as I absolutely can't stand electronica in any form. I even find the vocals from bluegrass to be distracting, much less anything with any sort of "hook".
Though I really like bluegrass.
And, just for giggles, here is an example of bluegrass metal:
Bluegrass cover of the Amon Amarth song Twilight of the Thunder God