I've been thinking for a while now about getting a weight vest around 50lbs. This would be a great way to become faster and stronger. Kinda like knocking 2 birds out with 1 stone. Cuz after a while, if you got fast in the weight vest, you would be really fast without it. Just some food for thought
Weight vests are excellent! We used them at my fencing club for conditioning, really gets your movement speed and agility to the next level.
On a similar topic - wrist weights. Throw a couple of those on, pop in a heavy grade blade, and practice some cuts... you'll feel it! MAV and I do this for training, against his heavy bag (except we use a rather heavy suburi bokken instead of a saber).