Totally true. I walk quite a bit (3 km a day or more) and last weekend I walked probably about twice that, in the snow, and my glutes were quite sore the next day.
That's also why just walking for one minute makes such a big difference while running: it changes the load on your muscles and gives the running muscles a chance to rest... before starting to run again, of course. (If you walk for too long, your running muscles just cool down and don't want to run anymore, though!)