You can rebuild the heap and the nonclustered indexes, and update statistics, by creating and then dropping the clustered index, using the ALTER TABLE ... REBUILD or by changing the data compression. (when using the REBUILD on a heap, not all the options are available to you).

You need to determine when this is necessary by using sys.dm_db_index_physical_stats to check the level of fragmentation. I prefer ALTER TABLE ... REBUILD but creating and dropping the clustered index works as well.

I hope that helps