Our lab has had a Primo Pad in his crate since he was a puppy. We've never used any other bedding.
Vinyl dog floor protection pads- Primo Pads
Are you crating him during the day when this happens, or is this at night? It might be that his need for exercise has gone up a bit. Another option is to use frozen Kongs. Archie usually gets two a day -- one in the morning while I shower, and one at night while we eat dinner. (I use part of his daily kibble, soaked with water, a little sweet potato, a little plain yogurt, sometimes other random treats, with a baby carrot shoved in the end. Freeze it, and voila. We own four Kongs so I can always have a couple frozen.)
Good luck!
-e