Winslow - I lift a fair bit and have done for almost thirty years now (OMG!).
I also run, swim, ride, have boxed and done BJJ and other martial arts for 30 years (competed for 27). You know, just the usual
They're good when you're crippled with DOMS and good when your legs are just "heavy" after a big ride or run. Having started a new strength block today with some new lower body work in it, my legs were actually cramping during my swim this afternoon and I've got them on right now to help that out overnight. I'll sleep in them tonight and then run in my socks tomorrow as my calves are still not yet really ready to cope with running on their own.
I really urge people to give compression gear a try. I was not a big believer until I got an employee discount at 2XU and bought a stack. Now I'm a total fan boy.
Becca - That makes sense. I've used actual compression bandage during heavy pressing blocks over winter when the long rests and heavy loads often lead to some elbow issues. The warmth seems to keep it at bay.