Here's Ray Rice ... continuing to train for a possible NFL comeback -- and busting his ass on the treadmill at 22 MILES PER HOUR!!!!
Yeah, that's fast.
It all went down at BlueStreak Sports Training in Stamford, CT -- where Ray and his wife, Janay, have been putting in work for years.
Our Rice sources tell us the running back feels he's in the best shape of his life -- and still believes he can make a real impact on an NFL team ... if he gets a chance.
Lions, Packers, Vikings ... thoughts?