I'm curious about the counter movement. Any links?
Unfortunately no, it was during a late night of fitness blog surfing and I can't remember precisely where I saw it. I can remember it was one strength coach talking about how another respected coach had his athletes throwing what were essentially weighted softballs as part of their training and showing no detrimental effects. I think the point being made was that a little extra weight in certain movements could be beneficial, but overdoing it was still entirely possible. If I come across the article again I'll make sure to post it.
EDIT: Fear my Internet sleuthing skills!Overload-Underload Training for Baseball"Sparing the rest of the details I created and patented a training bat that met the requirements of what I felt I needed. The results exceeded my wildest expectations – the average swing increase was 14.1 mph. That equates to an extra 96 feet the ball will travel, 1 mph gain in bat speed equals 6 added feet in distance (1)."
"The most amazing part of these results is that these gains took place over the course of only 6 weeks....The throwing group also had outstanding results going up an average of 6 mph in only 6 weeks. One player in particular went up 34 mph in bat speed and I had two 17 year olds hit 90 mph in bat speed – a very impressive mark for any age or level! Players ranging from 12 – 17 years old took part in the program and the gains were pretty consistent for all age and ability levels."
There's a journal review from NSCA's Strength and Conditioning Journal but it's not available to the public, you'd have to buy it or subscribe.
Effects of Baseball Weighted Implement Training: A Brief ReviewGranted, all of this is baseball related but it's an interesting idea. As long as the overload/underload of weight wasn't too great, and the shape and mass distribution of the object was as even as a regulation one, improvements could be found.
