Speed exercise

A friend from Brussels gave me this idea and I've been trying it out for a week now. I bought myself 1/2kg (1 lb) weights for wrists. While my friend says it helps to increase speed and sound strength (which I lost in the 6 months), I've noticed it helps to maintain balance and makes you play with more ease - less tension and twitching. Well, no progress in speed so far:) but let's wait and see...