After Things not to do with lvm and crypto I want to be careful when resizing a luks partition: here's a note with the right procedure.
As explained in this bug report, the way to resize a luks partition is:
# lvresize -L+100M /dev/vg00/test
Extending logical volume test to 400.00 MB
Logical volume test successfully resized
# cryptsetup resize test1
# resize2fs /dev/mapper/test1